Organic matter is known to be the precursor of numerous chlorination by-products. Organic matter in the secondary effluent from the Wenchang Wastewater Treatment Plant (Harbin, China) was physically separated into t...Organic matter is known to be the precursor of numerous chlorination by-products. Organic matter in the secondary effluent from the Wenchang Wastewater Treatment Plant (Harbin, China) was physically separated into the following fractions: particulate organic carbon (1.2-0.45 μm), colloidal organic carbon (0.45-0.1 μm), fine colloidal organic carbon (0.1-0.025 μm), and dissolved organic carbon (DOC) (〈 0.025 μm). Moreover, 〈 0.45 μm fraction was chemically separated into hydrophobic acid (HPO-A), hydrophobic neutral (HPO-N), transphilic acid (TPI-A), transphilic neutral (TPI-N), and hydrophllic fraction (HPI). The chlorine reactivity of these organic fractions obtained from both size and XAD fractionations were evaluated. The structural and chemical compositions of the HPO-A, HPO-N, TPI-A, and TPI-N isolates were characterized using elemental analysis (C, H, O, and N), Fourier transform infrared spectroscopy (FT-IR), and proton nuclear magnetic resonance spectroscopy (1H-NMR). Results showed that DOC was dominant in terms of total concentration and trihalomethane formation potential (THMFP), and there was no statistical difference in both specific THMFP (STHMFP) and specific ultraviolet light absorbance among the 0.45, 0.1, and 0.025 ixm filtrates. HPO-A had the highest STHMFP compared to other chemical fractions. HPO-A, HPO-N, TPI-A, and TPI-N contained 3.02%-3.52% of nitrogen. The molar ratio of H/C increased in the order of HPO-A 〈 HPO-N 〈 TPI-A 〈 TPI-N. The O/C ratio was relatively high for TPI-N as compared to those for the other fractions. ^1H-NMR analysis of the four fractions indicated that the relative content of aromatic protons in HPO-A was significantly higher than those in the others. The ratio of aliphatic to aromatic protons increased in the order of HPO-A 〈 HPO-N 〈 TPI-A 〈 TPI-N. FT-IR analysis of the four fractions showed that HPO-A had greater aromatic C=C content whereas HPO-N, TPI-A, and TPI-N had greater aliphatic C-H content. TPI-N contained more oxygen-containing functional groups than the other fractions.展开更多
With increase in shale gas exploration, inorganic and organic geochemical investigations of shale have become extremely important. Here, we explore the six argillaceous (shale) intervals (Arangi, Koldaha, Rampur, Bija...With increase in shale gas exploration, inorganic and organic geochemical investigations of shale have become extremely important. Here, we explore the six argillaceous (shale) intervals (Arangi, Koldaha, Rampur, Bijaygarh, Rewa and Sirbu shale) from Son valley sector, Vindhyan Basin with an aim to understand provenance conditions, palaeoclimate, tectonic setting and hydrocarbon generation potential. Whole rock geochemistry indicates Vindhyan sediments derived from felsic source(s) except for Sirbu shale that indicates additional influx of mafic rocks with differentiated felsic source. A comparative study of Vindhyan shale rare earth elements (REEs) points to Mahakoshals and Chhotanagpur gneissic complex (CGC) as probable sediment provenance for Vindhyan sediments. CIA analysis, after necessary corrections for K-metasomatism, suggests evolution in weathering and palaeoclimate indicating a transformation from moderate weathering conditions with warm and humid climate during lower Vindhyan deposition to intense weathering conditions with hot and humid climate during upper Vindhyan deposition. Trace (La/Y vs. Sc/Cr) and REE analysis indicates passive margin setting for Vindhyan sediments whereas a wide range spanning passive to active continental margin setting is also inferred using (Th-Sc-Zr/10) and (Th–La-Sc) ternary diagrams. However, these tectonic discriminant diagrams lack in explaining rift- or sag-related origin of any intracratonic basin such as the Vindhyan Basin. The total organic carbon (TOC) content in Vindhyan shales ranges from 0.29% to 8.44%. The thermally liberated hydrocarbon (S1) values range from 0.01 to 0.18 mg HC/g rock (milligram hydrocarbon per gram of rock sample), whereas hydrocarbon from cracking of the kerogen (S2) shows values ranging from 0.04 to 0.47 mg HC/g rock. Based on modified Van Krevelen correlation (HI vs. Tmax) diagram, organic matter from Arangi and Bijaygarh shales is characterized as thermally mature, Type III kerogen of gas prone character indicating good to very good gas generation potential.展开更多
The Bozhong Sag is the largest petroliferous sag in the Bohai Bay Basin,and the source rocks of Paleogene Dongying and Shahejie Formations were buried deeply.Most of the drillings were located at the structural high,a...The Bozhong Sag is the largest petroliferous sag in the Bohai Bay Basin,and the source rocks of Paleogene Dongying and Shahejie Formations were buried deeply.Most of the drillings were located at the structural high,and there were few wells that met good quality source rocks,so it is difficult to evaluate the source rocks in the study area precisely by geochemical analysis only.Based on the Rock-Eval pyrolysis,total organic carbon(TOC)testing,the organic matter(OM)abundance of Paleogene source rocks in the southwestern Bozhong Sag were evaluated,including the lower of second member of Dongying Formation(E_(3)d2L),the third member of Dongying Formation(E_(3)d_(3)),the first and second members of Shahejie Formation(E_(2)s_(1+2)),the third member of Shahejie Formation(E_(2)s_(3)).The results indicate that the E_(2)s_(1+2)and E_(2)s_(3)have better hydrocarbon generative potentials with the highest OM abundance,the E_(3)d_(3)are of the second good quality,and the E_(3)d2L have poor to fair hydrocarbon generative potential.Furthermore,the well logs were applied to predict TOC and residual hydrocarbon generation potential(S_(2))based on the sedimentary facies classification,usingΔlogR,generalizedΔlogR,logging multiple linear regression and BP neural network methods.The various methods were compared,and the BP neural network method have relatively better prediction accuracy.Based on the pre-stack simultaneous inversion(P-wave impedance,P-wave velocity and density inversion results)and the post-stack seismic attributes,the three-dimensional(3D)seismic prediction of TOC and S_(2)was carried out.The results show that the seismic near well prediction results of TOC and S_(2)based on seismic multi-attributes analysis correspond well with the results of well logging methods,and the plane prediction results are identical with the sedimentary facies map in the study area.The TOC and S_(2)values of E_(2)s_(1+2)and E_(2)s_(3)are higher than those in E_(3)d_(3)and E_(3)d_(2)L,basically consistent with the geochemical analysis results.This method makes up the deficiency of geochemical methods,establishing the connection between geophysical information and geochemical data,and it is helpful to the 3D quantitative prediction and the evaluation of high-quality source rocks in the areas where the drillings are limited.展开更多
From the outcrops in the Yaomoshan and Hongyanchi sections,oil shales,deep dark mudstones or black mudstones with better organic richness were found.Through the analysis of the samples in the organic petrology method,...From the outcrops in the Yaomoshan and Hongyanchi sections,oil shales,deep dark mudstones or black mudstones with better organic richness were found.Through the analysis of the samples in the organic petrology method,the microscope features of the sedimentary organic matter were studied.The results indicate that three types of kerogens present in the measured samples.Kerogen type Ⅰ consists of the laminate algainite,abundant sporinite and only little content of cutinite,which can mainly generate oil.The generation hydrocarbon components of the type Ⅱ kerogen are dominated by the sporinite,cutinite and little the exinite debris.The type Ⅲ kerogen is comprised of the sporinite and debris of the exinite with some components of gas generation.Through the analysis of the experiments,the organic kerogen of the Lucaogou formation is mostly comprised of the type Ⅰ,partially type Ⅱ,and particularly type Ⅲ.In Hongyanchi formation,the organic type is mixed by the types Ⅱ and Ⅲ.The plot of the (S1 +S2) or TOC value and the content of exinite show two trends.From the evolution of burial and the Permian source rocks in Changji Depression,the Permian formation source rock has ended the generation of hydrocarbon.A significant difference in constituents of the organic macerals among three kerogens in these samples leads to the distinction of the potential hydrocarbon generation.The Lucaogou formation for kerogen type Ⅰ has better potential hydrocarbon generation.It can reach the oil peak with Ro ratio of 0.9%.For the kerogen Ⅱ,the oil peak of the source rocks comes late with the Ro ratio of 1.0% with less quantity of the generation hydrocarbon than the kerogen Ⅰ.For type Ⅲ,it can mainly generate gas and reach the gas peak with the Ro ratio of 1.3%.In a word,the Lucaogou formation and Hongyanchi formation source rocks with high organic richness in Permian source rocks have well exploration prospects.展开更多
The paper presented an assessment of the resource potentials of composting organic waste materials arising from the municipal solid waste stream from cities in Nigeria. Through a review of quantitative data, the compo...The paper presented an assessment of the resource potentials of composting organic waste materials arising from the municipal solid waste stream from cities in Nigeria. Through a review of quantitative data, the composition of municipal solid waste arising within cities in Nigeria was examined in order to identify the potentials for composting organic materials from the waste stream composition. The data showed that the average majority of the waste stream was organic materials which implied high potentials for composting organic waste materials from Nigerian cities. The review also identified further potentials for composting was associated with the large population and the majority of them engaged in agriculture, as a high potential market for compost manure in Nigeria. There were more potentials derivable from the current policies of importing and supplying chemical fertilizer with huge subsidies for domestic agriculture in the country. The need to substitute these policies of chemical fertilizer with the use of compost manure implied high potentials for composting in the country. The paper also identified numerous benefits of composting in general and with particular reference to the Nigerian situation which includes, among others a reduction of the vast quantity of solid waste for final disposal, reducing air pollution and ground water leachate and also employment generation and increased income. Therefore, the paper recommended a deliberate government policy to promote composting of organic solid wastes material and marketing of compost manure to substitute the current policies of importing chemical fertilizer with subsidy for domestic agriculture as a strategy to achieve sustainable waste management in Nigeria.展开更多
Located between terrestrial and marine ecosystems,mangrove forests are sensitive to changes in climate.The responses of mangrove ecosystems to climate change in the future can be understood by reconstructing past mang...Located between terrestrial and marine ecosystems,mangrove forests are sensitive to changes in climate.The responses of mangrove ecosystems to climate change in the future can be understood by reconstructing past mangrove dynamics using proxies preserved in the intertidal sediments.Considering the complexity of the proxies commonly used,it is necessary to develop a relatively simple,inexpensive proxy.In this study,available chemical tracers(δ13Corg and C:N)of the four cores(YLW02,YLW03,O18,and Q37)from the intertidal zone of the northern Beibu Gulf(NBG)and a three-end-member(mangrove,sea grass,and suspended particulate matter)model was utilized to determine the contribution of mangrove-derived organic matter(CMOM)in carbonate-free sediments.Compared with the summed concentration of mangrove pollen(SCMP),a significant positive correlation between CMOM and SCMP is displayed.The calculated CMOM for an additional 210Pb-dated sediment core from the Yingluo Bay,NBG(YLW01)clearly indicates a mangrove development going through degradation,flourishing,relative degradation,and relative flourishing,which are separately in correspondence with the lowest,highest,lower,and higher air temperature and rainfall in the time intervals of 1890–1918 AD,1919–1956 AD,1957–1990 AD,and 1991–2010 AD.This suggests that CMOM preserved in intertidal sediments has a potential to reconstruct historical mangrove development in high resolution,at the very least,along the coasts of the NBG.展开更多
This paper intends to clarify the needs serendipity in creating new business. The authors will show that serendipity is capability method of finding potential needs and/or new markets. In economic society, potential n...This paper intends to clarify the needs serendipity in creating new business. The authors will show that serendipity is capability method of finding potential needs and/or new markets. In economic society, potential needs and/or new markets are only partially exposed, such as an iceberg. Serendipity is a capability that can expose the potential hidden part through accidental opportunity. Something more concrete can be formed from the exposed parts. The authors describe cases that demonstrate the usefulness of serendipity. In one case, a high-tech start-up had intended to use medical electronic equipment and/or industrial electronic equipment as the first application of their core technology. In these markets, they were competing with established major companies, so this start-up had difficulty entering these markets. However, a specific distributor found potential needs that were met by the start-up's products, and has created a new market by combining their core technology with social needs. The authors define serendipity capability by analyzing this case example and argue that serendipity can contribute to finding opportunities and solving social issues.展开更多
Soil potentially hazardous metal(PHM)is continually attracting public attention worldwide,due to its highly toxic properties and potentially huge damage to human being through food chain.Phytoremediation is an effecti...Soil potentially hazardous metal(PHM)is continually attracting public attention worldwide,due to its highly toxic properties and potentially huge damage to human being through food chain.Phytoremediation is an effective and eco-friendly way in remediation technology.A pot experiment was carried out to investigate the effect of different organic materials(biogas residue(BR),mushroom residue(MR),and bamboo-shoot shell(BS))application on phytoremediation of two PHM-contaminated soils(Fuyang soil as‘heavily-polluted soil’and Wenzhou soil as‘moderately-polluted soil’,respectively)by Sedum alfrecdii Hance.The results indicated:1)for moderately-polluted soil,the 5%BR treatment had the strongest activation to Cu and Zn,for heavily-polluted soil,1%BS treatment had the highest activation effect for Cu,Zn,Pb and Cd.2)the above-ground biomass of Sedum alfredii Hance increased with the addition rate of organic materials.3)for Cd uptake of Sedum alfredii Hance in moderately-polluted soil,only 1%BS treatment had a better accumulation effect,compared to the control,for Zn element,MR treatments were weaker than the control,while other treatments were better than the control,of which 5%BR,1%BS and 5%BS accumulated more Zn element by 39.6%,32.6%and 23.8%,respectively;in heavily-polluted soil,the treatments of 5%BS,1%BR and 5%BR accumulated more Cd than the control by 12.9%,12.8%and 6.2%,respectively,the treatments with organic materials addition promoted Zn accumulation in shoots of Sedum alfredii Hance,and the best treatment was 5%BS.Therefore,an appropriate application rate of BS and BR could improve the remediation efficiency for Zn/Cd contaminated soils by Sedum alfredii Hance.展开更多
Azerbaijan is a country with a huge range of different soil types, which is due to its geographical location. The country is located in two climatic thermal zones, subboreal and subtropical, characterized by a peculia...Azerbaijan is a country with a huge range of different soil types, which is due to its geographical location. The country is located in two climatic thermal zones, subboreal and subtropical, characterized by a peculiar hydrothermal regime, diverse vegetation and soil fauna. For proper zoning of the soil cover of bioclimatic landscape zones and the development of effective organization of management systems, assessment of assimilation potential is of great importance, i.e. self-cleaning potential. The purpose of our research was to assess the actual assimilation capacity and self-cleaning ability of alpine and subalpine meadow soils and meadow steppes in case of their contamination with organic pollutants based on a comprehensive system analysis of biogenic and abiogenic factors. The collected material was comprehensively analyzed from the standpoint of the biogenicity and self-purification capacity of soils of various bioclimatic landscape zones from the standpoint of the danger of soil contamination with organic matter, based on the natural features of the soil and biogenic and abiogenic factors, and appropriately grouped according to the landscape feature. The analysis of the obtained data allows us to position the soils of the Alpine and subalpine meadows and meadow steppes on the growth of the assimilation potential in relation to organic pollutants in the following sequence: Mountain-meadow chernozem-like> Mountain-forest meadow> Mountain- meadow steppe> Mountain-meadow sod.展开更多
The Red Soil Hilly Region in South China, where there is a high capacity of carbon(C), and the land use and vegetation cover change greatly, is an important ecological area in the world, and has an important impact on...The Red Soil Hilly Region in South China, where there is a high capacity of carbon(C), and the land use and vegetation cover change greatly, is an important ecological area in the world, and has an important impact on the global carbon cycle and the seasonal fluctuation of atmospheric CO_2. To better evaluate the effects of reclamation systems in orchards converted from grasslands on soil carbon sequestration, we investigated soil organic carbon(SOC) content and stable C isotope(δ^(13)C)composition in three nectarine orchards at Yuchi Experimental Station in South China. Compared with the sloping clean tillage orchard and terraced clean tillage orchard, SOC content in the terraced orchard with grass cover was increased by 14.90% to 38.49%, and 7.40% to 15.33%, respectively. During the 14 years after orchard establishment, the soil organic matter sources influenced both δ^(13)C distribution with depth and carbon replacement. SOC turnover of the upper soil layer in the terraced orchard with grass cover(a mean 63.05% of replacement in the 20 cm after 14 years) was 1.59 and 1.41 times larger than that of the sloping clean tillage orchard and terraced clean tillage orchard under subtropical conditions, respectively. The equilibrium value of soil organic carbon in the three treatments ranged from 16.067 to 25.608 g/kg under the experimental conditions. The equilibrium value of soil organic carbon in the surface layer under grass cover was 54.801 t/hm^2, and the carbon sequestration potential was 24.695 1 t/hm^2.展开更多
An analytical procedure involving Rock-Eval pyrolysis of whole-rocks was adopted on fresh outcrop samples covering the three lithostratigraphic units in the Afikpo Basin of the Lower Benue Trough. Three petroleum syst...An analytical procedure involving Rock-Eval pyrolysis of whole-rocks was adopted on fresh outcrop samples covering the three lithostratigraphic units in the Afikpo Basin of the Lower Benue Trough. Three petroleum systems are present in the Cretaceous delta frame: the Asu-River Group, the Eze-Aku Group and proto-Niger Delta sequences. The Afikpo Basin has been correlated to three petroleum systems in the Lower Congo Basin, Niger Delta and the Anambra Basin. The organic geochemistry of the shales, carbonaceous mudstones and coal beds show relatively moderate to high total organic carbon contents. The best potential hydrocarbon source rocks are the Eze-Aku Group and proto-Niger Delta shales, carbonaceous mudstones and coal beds where maturation was attained. The high total organic contents, thermal maturity and terrigenous characters of the Asu-River Group, Eze-Aku Group and proto-Niger Delta sediments, suggest the presence of a large amount of natural gas with a small quantity of oil accumulation. Variations in source rock facies were observed from one lithostratigraphic unit to another, and initial HI values as a function of TOC were proposed for each lithostratigraphic unit. The results also show that TOC, HI, OI, S2 and Tmax vary from older to younger rocks. The Tmax values discriminate the rocks into immature and mature source rocks. Source rocks with high Tmax suggest high geothermal gradient/or recycled organic matter. Also high Tmax and S2 yield indicate late and post maturity. Recycled organic matter is characterized by low Tmax. The principal source rocks for gas in the Afikpo Basin are the Eze-Aku Group and proto-Niger Delta beds deltaic systems, consisting mainly of III to IV kerogens with a subordinate amount of type II organic matter. Based on the obtained results, it is concluded that the Cretaceous shales, carbonaceous mudstones and coals in the Afikpo Basin of the Lower Benue Trough are capable of generating and expelling hydrocarbons in the case of sufficient maturity.展开更多
Persulfate is considered a convenient and efficient remediation agent for organic contaminated soil.However,the potential risk of sulfur into the soil remediation by persulfate remains ignored.In this study,glass bott...Persulfate is considered a convenient and efficient remediation agent for organic contaminated soil.However,the potential risk of sulfur into the soil remediation by persulfate remains ignored.In this study,glass bottles with different persulfate dosages and groundwater tables were set up to simulate persulfate remediation of organic pollutants(aniline).The results found sulfate to be the main end-product(83.0%–99.5%)of persulfate remediation after10 days.Moreover,H_(2)S accounted for 93.4%–99.4%of sulfur reduction end-products,suggesting that H_(2)S was the final fate of sulfur.H_(2)S was released rapidly after one to three days at a maximum concentration of 33.0 ppm,which is sufficient to make a person uncomfortable.According to the fitted curve results,H_(2)S concentration decreased to a safe concentration(0.15 ppm)after 20–85 days.Meanwhile,the maximum concentration of methanethiol reached 0.6 ppm.These results indicated that secondary pollution from persulfate remediation could release harmful gases over a long time.Therefore,persulfate should be used more carefully as a remediation agent for soil contamination.展开更多
The aim of this research work was to report a facies analysis of the N’Kappa formation, identified the clay minerals present in those facies and evaluate their oil potential. For that to be done, Lithostratigraphic d...The aim of this research work was to report a facies analysis of the N’Kappa formation, identified the clay minerals present in those facies and evaluate their oil potential. For that to be done, Lithostratigraphic descriptions were performed on three natural outcrops chosen in three different localities of the northern border of Douala sedimentary basin. Ten shaly samples were then collected on those outcrops and submit to X ray diffraction and Rock-Eval pyrolysis. Lithologically, the N’Kappa formation is made up of dark to grey shales and fine to coarse sandtones. The mineralogic content of the shales is made up of Kaolinite, dickite, low quartz and vaterite. Those shaly facies present high amount of immature organic matter (average TOC content around 2%). The petroleum potential is fair to poor (average S2 for all the samples around 3.33 mg HC/g of rock) though some samples (M1 and M2) presenting a good petroleum potential up to 6.62 kg HC/t of rock and 6.44 kg HC/t of rock respectively. They have undergone a low degree of diagenesis (early to burying diagenesis). This is evidenced by the predominance of kaolinite and dickite, low quartz and vaterite which are minerals stable at low temperature.展开更多
This study investigated the leaching potential of diuron and linuron in different soil types in Gaza Strip, Palestine under laboratory and field conditions. Leaching potential was evaluated by tin columns and bioassay...This study investigated the leaching potential of diuron and linuron in different soil types in Gaza Strip, Palestine under laboratory and field conditions. Leaching potential was evaluated by tin columns and bioassay technique using Molokhia as test plant. The responses of the test plant were regressed versus concentrations of the herbicide to estimate linear regression equation and the regression coefficient. The obtained results indicate strong positive association between Molokhia and concentrations of diuron or linuron;accordingly it was used in the bioassay and estimation of the concentrations of the tested herbicides in the leaching depth. Leaching potential was very low in North Gaza and Kkan Younis soil, whereas in the Meddle zone soil was very large. Leaching potential under laboratory conditions was larger that under field conditions. The bioestimated concentrations in soil layer under field conditions were sever folds of magnitude lower than those under laboratory conditions. The interesting outcome of this study is that leaching potential is dependent on soil clay fraction, soil organic matter, and soil pH. These results provided answers to the questions raised by farmers in Gaza Strip.展开更多
Grassland ecosystem is an important component of the terrestrial carbon cycle system. Clear comprehension of soil organic carbon(SOC) storage and potential of grasslands is very important for the effective managemen...Grassland ecosystem is an important component of the terrestrial carbon cycle system. Clear comprehension of soil organic carbon(SOC) storage and potential of grasslands is very important for the effective management of grassland ecosystems. Grasslands in Inner Mongolia have undergone evident impacts from human activities and natural factors in recent decades. To explore the changes of carbon sequestration capacity of grasslands from 2000 to 2012, we carried out studies on the estimation of SOC storage and potential of grasslands in central and eastern Inner Mongolia, China based on field investigations and MODIS image data. First, we calculated vegetation cover using the dimidiate pixel model based on MODIS-EVI images. Following field investigations of aboveground biomass and plant height, we used a grassland quality evaluation model to get the grassland evaluation index, which is typically used to represent grassland quality. Second, a correlation regression model was established between grassland evaluation index and SOC density. Finally, by this regression model, we calculated the SOC storage and potential of the studied grasslands. Results indicated that SOC storage increased with fluctuations in the study area, and the annual changes varied among different sub-regions. The SOC storage of grasslands in 2012 increased by 0.51×1012 kg C compared to that in 2000. The average carbon sequestration rate was 0.04×1012 kg C/a. The slope of the values of SOC storage showed that SOC storage exhibited an overall increase since 2000, particularly for the grasslands of Hulun Buir city and Xilin Gol League, where the typical grassland type was mainly distributed. Taking the SOC storage under the best grassland quality between 2000 and 2012 as a reference, this study predicted that the SOC potential of grasslands in central and eastern Inner Mongolia in 2012 is 1.38×1012 kg C. This study will contribute to researches on related methods and fundamental database, as well as provide a reference for the protection of grassland ecosystems and the formulation of local policies on sustainable grassland development.展开更多
Mineral-bituminous matrix (MBM) makes up a major part of source rocks, but itspotential in hydrocarbon generation is uncertain. Mineral and organic (maceral and kerogen)compositions, organic maturity and fluorescence ...Mineral-bituminous matrix (MBM) makes up a major part of source rocks, but itspotential in hydrocarbon generation is uncertain. Mineral and organic (maceral and kerogen)compositions, organic maturity and fluorescence of MBM are studied based on source rock samples from eastern Jiuquan (Jiudong) Basin. The results show that MBM is dominated by inorganic minerals and among the small percentage of organic components those of secondary originsare predominant over the primary species. This strongly indicates that the significance of MBMin hydrocarbon generation is limited.展开更多
Reconstitution of complex multi-tissue organs is one of the most impressive feats of biology and is observed across regeneration-competent vertebrate species,including teleost fish(e.g.,zebrafish),urodeles(e.g.,axolot...Reconstitution of complex multi-tissue organs is one of the most impressive feats of biology and is observed across regeneration-competent vertebrate species,including teleost fish(e.g.,zebrafish),urodeles(e.g.,axolotls and newts),and some lizards.Regenerative ability within these species ranges from muscle(including cardiac),skeletal structures,to complex systems such as the brain,spinal cord and parts of the eye which are all capable of structural and functional repair following injury(Tanaka and Ferretti,2009).In stark contrast,re-establishment of multi-tissue structures is very rarely observed following embryogenesis in regeneration-incompetent mammals.Regrowth of digit tips is the most dramatic example of mammalian regeneration,but pales in comparison to other species in the animal kingdom.Undoubtedly,a complete recapitulation of complex organs or structures in mammals will remain out of reach for a considerable time;however,an improved understanding of regenerat i ve mechanisms would likely enhance the development of novel regenerative medicine strategies.Here we focus on the diversity and commonalities of stem cells,which could underlie complex tissue regeneration.展开更多
In order to study the hydrocarbon-generating potential of Carboniferous-Permian coal shale in Jiyang Depression,geochemistry,petroleum geology and coal geology were applied to study the residual strata distribution of...In order to study the hydrocarbon-generating potential of Carboniferous-Permian coal shale in Jiyang Depression,geochemistry,petroleum geology and coal geology were applied to study the residual strata distribution of Carboniferous-Permian in Jiyang Depression,organic matter abundance,organic matter types and organic matter maturity of mudstone.The results show that the thickness of the Carboniferous-Permian residual strata in Jiyang Depression is generally 200-800 m,with a maximum thickness of 900 m;the organic matter abundance of coal-bearing shale is good,and it is type III kerogen,which is conducive to gas generation,and the maturity of organic matter reaches a mature-higher maturity stage;the hydrocarbon generation potential of Benxi Formation and Taiyuan Formation is better;Medium to good hydrocarbon source rocks is able to be found in every sag of Shanxi Formation hydrocarbon source rocks,but the scope is limited,and the overall evaluation is still medium.Generally speaking,the Permo-Carboniferous coal-bearing shale in Jiyang Depression has certain shale gas exploration potential.展开更多
BACKGROUND Healthy vestibular system adjusts balance during static and dynamic conditions.This is important for normal development(standing up and walking).Vestipulopathies(central and peripheral)are common complicati...BACKGROUND Healthy vestibular system adjusts balance during static and dynamic conditions.This is important for normal development(standing up and walking).Vestipulopathies(central and peripheral)are common complications of diabetes in adult population.Related studies are scare in children with type 1 diabetes(T1D).AIM To assess saccular function of otolith organ in children with T1D and predictors for its dysfunction.METHODS Cervical vestibular evoked myogenic potential(cVEMP)was used for objective evaluation.RESULTS The study included 40 patients(boys=15;girls=25).Patients had mean age of 13.63±1.50 years,duration of diabetes of 5.62±2.80 years,frequent attacks of diabetic ketoacidosis(55%)and hypoglycemia(30%),hyperlipidemia(20%),hypertension(12.5%)and peripheral neuropathy(40%).Dizziness was found in 10%.Compared to healthy children(n=25),patients had prolonged cVEMP P1 and N1 latencies and reduced P1-N1 amplitude.Bilateral cVEMP abnormalities were found in 60%(vs 25%for unilateral abnormalities).Higher frequencies and severe vestibulopathies were found with chronic diabetes of>5 years,hemoglobin A1c values>7%,frequent diabetic ketoacidosis and hypoglycemic attacks and presence of dizziness.Regression analyses showed that predictors for prolonged P1 latencies and reduced P1-N1 amplitudes were only chronic diabetes(>5 years){odds ratio(OR)=2.80[95%confidence interval(CI):1.80–5.33],P=0.01;OR=3.42(95%CI:2.82–6.81)}and its severity(hemoglobin A1c>7%)[OR=3.05(95%CI:2.55–6.82),P=0.01;OR=4.20(95%CI:3.55–8.50),P=0.001].CONCLUSION Dysfunction or injury of the saccular macula and its pathways is prevalent in children with T1D.Optimum glycemic control is important to prevent diabetes related vestipulopathies.展开更多
This article prognosticates the hydrocarbon generation potential of core samples from fields A, B, C and D in Niger delta, Nigeria. The objectives of this study are to characterize the quality of these core samples by...This article prognosticates the hydrocarbon generation potential of core samples from fields A, B, C and D in Niger delta, Nigeria. The objectives of this study are to characterize the quality of these core samples by organic geochemical analyses. A total of ten core samples collected from fields A, B, C and D in Niger delta were analyzed using total organic carbon(TOC) content analysis, rock-eval pyrolysis technique. The analytical results of the studied core samples reveal that they have generally high total organic carbon contents(TOC), suggesting that conditions in the Niger delta favour organic matter production and preservation. There is a variation in the kerogen types and this may be attributed to the relative stratigraphic positions of the core samples within the Niger delta. The rock-eval results indicate that the samples from fields C and D contain predominantly Type II kerogen with a capacity to generate oil and gas and hence have good generative potential. The samples from fields A and B contain mainly Type III kerogen and are gas-prone with moderate generative potential.展开更多
文摘Organic matter is known to be the precursor of numerous chlorination by-products. Organic matter in the secondary effluent from the Wenchang Wastewater Treatment Plant (Harbin, China) was physically separated into the following fractions: particulate organic carbon (1.2-0.45 μm), colloidal organic carbon (0.45-0.1 μm), fine colloidal organic carbon (0.1-0.025 μm), and dissolved organic carbon (DOC) (〈 0.025 μm). Moreover, 〈 0.45 μm fraction was chemically separated into hydrophobic acid (HPO-A), hydrophobic neutral (HPO-N), transphilic acid (TPI-A), transphilic neutral (TPI-N), and hydrophllic fraction (HPI). The chlorine reactivity of these organic fractions obtained from both size and XAD fractionations were evaluated. The structural and chemical compositions of the HPO-A, HPO-N, TPI-A, and TPI-N isolates were characterized using elemental analysis (C, H, O, and N), Fourier transform infrared spectroscopy (FT-IR), and proton nuclear magnetic resonance spectroscopy (1H-NMR). Results showed that DOC was dominant in terms of total concentration and trihalomethane formation potential (THMFP), and there was no statistical difference in both specific THMFP (STHMFP) and specific ultraviolet light absorbance among the 0.45, 0.1, and 0.025 ixm filtrates. HPO-A had the highest STHMFP compared to other chemical fractions. HPO-A, HPO-N, TPI-A, and TPI-N contained 3.02%-3.52% of nitrogen. The molar ratio of H/C increased in the order of HPO-A 〈 HPO-N 〈 TPI-A 〈 TPI-N. The O/C ratio was relatively high for TPI-N as compared to those for the other fractions. ^1H-NMR analysis of the four fractions indicated that the relative content of aromatic protons in HPO-A was significantly higher than those in the others. The ratio of aliphatic to aromatic protons increased in the order of HPO-A 〈 HPO-N 〈 TPI-A 〈 TPI-N. FT-IR analysis of the four fractions showed that HPO-A had greater aromatic C=C content whereas HPO-N, TPI-A, and TPI-N had greater aliphatic C-H content. TPI-N contained more oxygen-containing functional groups than the other fractions.
基金funding from the Department of Science and Technology(DST#/SR/S4/ES-528/2010)New Delhi and infrastructural facility from Department of Geology,University of Delhi.Research funding from the Council of Scientific and Industrial Research(CSIR#09/045(1021)/2010-EMR-I)the University of Delhi(Sch./UTA/2010/58053)is also gratefully acknowledged.
文摘With increase in shale gas exploration, inorganic and organic geochemical investigations of shale have become extremely important. Here, we explore the six argillaceous (shale) intervals (Arangi, Koldaha, Rampur, Bijaygarh, Rewa and Sirbu shale) from Son valley sector, Vindhyan Basin with an aim to understand provenance conditions, palaeoclimate, tectonic setting and hydrocarbon generation potential. Whole rock geochemistry indicates Vindhyan sediments derived from felsic source(s) except for Sirbu shale that indicates additional influx of mafic rocks with differentiated felsic source. A comparative study of Vindhyan shale rare earth elements (REEs) points to Mahakoshals and Chhotanagpur gneissic complex (CGC) as probable sediment provenance for Vindhyan sediments. CIA analysis, after necessary corrections for K-metasomatism, suggests evolution in weathering and palaeoclimate indicating a transformation from moderate weathering conditions with warm and humid climate during lower Vindhyan deposition to intense weathering conditions with hot and humid climate during upper Vindhyan deposition. Trace (La/Y vs. Sc/Cr) and REE analysis indicates passive margin setting for Vindhyan sediments whereas a wide range spanning passive to active continental margin setting is also inferred using (Th-Sc-Zr/10) and (Th–La-Sc) ternary diagrams. However, these tectonic discriminant diagrams lack in explaining rift- or sag-related origin of any intracratonic basin such as the Vindhyan Basin. The total organic carbon (TOC) content in Vindhyan shales ranges from 0.29% to 8.44%. The thermally liberated hydrocarbon (S1) values range from 0.01 to 0.18 mg HC/g rock (milligram hydrocarbon per gram of rock sample), whereas hydrocarbon from cracking of the kerogen (S2) shows values ranging from 0.04 to 0.47 mg HC/g rock. Based on modified Van Krevelen correlation (HI vs. Tmax) diagram, organic matter from Arangi and Bijaygarh shales is characterized as thermally mature, Type III kerogen of gas prone character indicating good to very good gas generation potential.
文摘The Bozhong Sag is the largest petroliferous sag in the Bohai Bay Basin,and the source rocks of Paleogene Dongying and Shahejie Formations were buried deeply.Most of the drillings were located at the structural high,and there were few wells that met good quality source rocks,so it is difficult to evaluate the source rocks in the study area precisely by geochemical analysis only.Based on the Rock-Eval pyrolysis,total organic carbon(TOC)testing,the organic matter(OM)abundance of Paleogene source rocks in the southwestern Bozhong Sag were evaluated,including the lower of second member of Dongying Formation(E_(3)d2L),the third member of Dongying Formation(E_(3)d_(3)),the first and second members of Shahejie Formation(E_(2)s_(1+2)),the third member of Shahejie Formation(E_(2)s_(3)).The results indicate that the E_(2)s_(1+2)and E_(2)s_(3)have better hydrocarbon generative potentials with the highest OM abundance,the E_(3)d_(3)are of the second good quality,and the E_(3)d2L have poor to fair hydrocarbon generative potential.Furthermore,the well logs were applied to predict TOC and residual hydrocarbon generation potential(S_(2))based on the sedimentary facies classification,usingΔlogR,generalizedΔlogR,logging multiple linear regression and BP neural network methods.The various methods were compared,and the BP neural network method have relatively better prediction accuracy.Based on the pre-stack simultaneous inversion(P-wave impedance,P-wave velocity and density inversion results)and the post-stack seismic attributes,the three-dimensional(3D)seismic prediction of TOC and S_(2)was carried out.The results show that the seismic near well prediction results of TOC and S_(2)based on seismic multi-attributes analysis correspond well with the results of well logging methods,and the plane prediction results are identical with the sedimentary facies map in the study area.The TOC and S_(2)values of E_(2)s_(1+2)and E_(2)s_(3)are higher than those in E_(3)d_(3)and E_(3)d_(2)L,basically consistent with the geochemical analysis results.This method makes up the deficiency of geochemical methods,establishing the connection between geophysical information and geochemical data,and it is helpful to the 3D quantitative prediction and the evaluation of high-quality source rocks in the areas where the drillings are limited.
基金Project(2011ZX05002-006)supported by the National Science and Technology Project,China
文摘From the outcrops in the Yaomoshan and Hongyanchi sections,oil shales,deep dark mudstones or black mudstones with better organic richness were found.Through the analysis of the samples in the organic petrology method,the microscope features of the sedimentary organic matter were studied.The results indicate that three types of kerogens present in the measured samples.Kerogen type Ⅰ consists of the laminate algainite,abundant sporinite and only little content of cutinite,which can mainly generate oil.The generation hydrocarbon components of the type Ⅱ kerogen are dominated by the sporinite,cutinite and little the exinite debris.The type Ⅲ kerogen is comprised of the sporinite and debris of the exinite with some components of gas generation.Through the analysis of the experiments,the organic kerogen of the Lucaogou formation is mostly comprised of the type Ⅰ,partially type Ⅱ,and particularly type Ⅲ.In Hongyanchi formation,the organic type is mixed by the types Ⅱ and Ⅲ.The plot of the (S1 +S2) or TOC value and the content of exinite show two trends.From the evolution of burial and the Permian source rocks in Changji Depression,the Permian formation source rock has ended the generation of hydrocarbon.A significant difference in constituents of the organic macerals among three kerogens in these samples leads to the distinction of the potential hydrocarbon generation.The Lucaogou formation for kerogen type Ⅰ has better potential hydrocarbon generation.It can reach the oil peak with Ro ratio of 0.9%.For the kerogen Ⅱ,the oil peak of the source rocks comes late with the Ro ratio of 1.0% with less quantity of the generation hydrocarbon than the kerogen Ⅰ.For type Ⅲ,it can mainly generate gas and reach the gas peak with the Ro ratio of 1.3%.In a word,the Lucaogou formation and Hongyanchi formation source rocks with high organic richness in Permian source rocks have well exploration prospects.
文摘The paper presented an assessment of the resource potentials of composting organic waste materials arising from the municipal solid waste stream from cities in Nigeria. Through a review of quantitative data, the composition of municipal solid waste arising within cities in Nigeria was examined in order to identify the potentials for composting organic materials from the waste stream composition. The data showed that the average majority of the waste stream was organic materials which implied high potentials for composting organic waste materials from Nigerian cities. The review also identified further potentials for composting was associated with the large population and the majority of them engaged in agriculture, as a high potential market for compost manure in Nigeria. There were more potentials derivable from the current policies of importing and supplying chemical fertilizer with huge subsidies for domestic agriculture in the country. The need to substitute these policies of chemical fertilizer with the use of compost manure implied high potentials for composting in the country. The paper also identified numerous benefits of composting in general and with particular reference to the Nigerian situation which includes, among others a reduction of the vast quantity of solid waste for final disposal, reducing air pollution and ground water leachate and also employment generation and increased income. Therefore, the paper recommended a deliberate government policy to promote composting of organic solid wastes material and marketing of compost manure to substitute the current policies of importing chemical fertilizer with subsidy for domestic agriculture as a strategy to achieve sustainable waste management in Nigeria.
基金The National Natural Science Foundation of China under contract No.41576061the Basic Scientific Fund for National Public Research Institutes of China under contract No.2017Q03
文摘Located between terrestrial and marine ecosystems,mangrove forests are sensitive to changes in climate.The responses of mangrove ecosystems to climate change in the future can be understood by reconstructing past mangrove dynamics using proxies preserved in the intertidal sediments.Considering the complexity of the proxies commonly used,it is necessary to develop a relatively simple,inexpensive proxy.In this study,available chemical tracers(δ13Corg and C:N)of the four cores(YLW02,YLW03,O18,and Q37)from the intertidal zone of the northern Beibu Gulf(NBG)and a three-end-member(mangrove,sea grass,and suspended particulate matter)model was utilized to determine the contribution of mangrove-derived organic matter(CMOM)in carbonate-free sediments.Compared with the summed concentration of mangrove pollen(SCMP),a significant positive correlation between CMOM and SCMP is displayed.The calculated CMOM for an additional 210Pb-dated sediment core from the Yingluo Bay,NBG(YLW01)clearly indicates a mangrove development going through degradation,flourishing,relative degradation,and relative flourishing,which are separately in correspondence with the lowest,highest,lower,and higher air temperature and rainfall in the time intervals of 1890–1918 AD,1919–1956 AD,1957–1990 AD,and 1991–2010 AD.This suggests that CMOM preserved in intertidal sediments has a potential to reconstruct historical mangrove development in high resolution,at the very least,along the coasts of the NBG.
文摘This paper intends to clarify the needs serendipity in creating new business. The authors will show that serendipity is capability method of finding potential needs and/or new markets. In economic society, potential needs and/or new markets are only partially exposed, such as an iceberg. Serendipity is a capability that can expose the potential hidden part through accidental opportunity. Something more concrete can be formed from the exposed parts. The authors describe cases that demonstrate the usefulness of serendipity. In one case, a high-tech start-up had intended to use medical electronic equipment and/or industrial electronic equipment as the first application of their core technology. In these markets, they were competing with established major companies, so this start-up had difficulty entering these markets. However, a specific distributor found potential needs that were met by the start-up's products, and has created a new market by combining their core technology with social needs. The authors define serendipity capability by analyzing this case example and argue that serendipity can contribute to finding opportunities and solving social issues.
基金the National College Students’Innovation and Entrepreneurship Training Program(202110341014).
文摘Soil potentially hazardous metal(PHM)is continually attracting public attention worldwide,due to its highly toxic properties and potentially huge damage to human being through food chain.Phytoremediation is an effective and eco-friendly way in remediation technology.A pot experiment was carried out to investigate the effect of different organic materials(biogas residue(BR),mushroom residue(MR),and bamboo-shoot shell(BS))application on phytoremediation of two PHM-contaminated soils(Fuyang soil as‘heavily-polluted soil’and Wenzhou soil as‘moderately-polluted soil’,respectively)by Sedum alfrecdii Hance.The results indicated:1)for moderately-polluted soil,the 5%BR treatment had the strongest activation to Cu and Zn,for heavily-polluted soil,1%BS treatment had the highest activation effect for Cu,Zn,Pb and Cd.2)the above-ground biomass of Sedum alfredii Hance increased with the addition rate of organic materials.3)for Cd uptake of Sedum alfredii Hance in moderately-polluted soil,only 1%BS treatment had a better accumulation effect,compared to the control,for Zn element,MR treatments were weaker than the control,while other treatments were better than the control,of which 5%BR,1%BS and 5%BS accumulated more Zn element by 39.6%,32.6%and 23.8%,respectively;in heavily-polluted soil,the treatments of 5%BS,1%BR and 5%BR accumulated more Cd than the control by 12.9%,12.8%and 6.2%,respectively,the treatments with organic materials addition promoted Zn accumulation in shoots of Sedum alfredii Hance,and the best treatment was 5%BS.Therefore,an appropriate application rate of BS and BR could improve the remediation efficiency for Zn/Cd contaminated soils by Sedum alfredii Hance.
文摘Azerbaijan is a country with a huge range of different soil types, which is due to its geographical location. The country is located in two climatic thermal zones, subboreal and subtropical, characterized by a peculiar hydrothermal regime, diverse vegetation and soil fauna. For proper zoning of the soil cover of bioclimatic landscape zones and the development of effective organization of management systems, assessment of assimilation potential is of great importance, i.e. self-cleaning potential. The purpose of our research was to assess the actual assimilation capacity and self-cleaning ability of alpine and subalpine meadow soils and meadow steppes in case of their contamination with organic pollutants based on a comprehensive system analysis of biogenic and abiogenic factors. The collected material was comprehensively analyzed from the standpoint of the biogenicity and self-purification capacity of soils of various bioclimatic landscape zones from the standpoint of the danger of soil contamination with organic matter, based on the natural features of the soil and biogenic and abiogenic factors, and appropriately grouped according to the landscape feature. The analysis of the obtained data allows us to position the soils of the Alpine and subalpine meadows and meadow steppes on the growth of the assimilation potential in relation to organic pollutants in the following sequence: Mountain-meadow chernozem-like> Mountain-forest meadow> Mountain- meadow steppe> Mountain-meadow sod.
基金Supported by Science and Technology Program of Fujian Province(2017R1016-4)Natural Science Foundation of Fujian Province(2017J01072)
文摘The Red Soil Hilly Region in South China, where there is a high capacity of carbon(C), and the land use and vegetation cover change greatly, is an important ecological area in the world, and has an important impact on the global carbon cycle and the seasonal fluctuation of atmospheric CO_2. To better evaluate the effects of reclamation systems in orchards converted from grasslands on soil carbon sequestration, we investigated soil organic carbon(SOC) content and stable C isotope(δ^(13)C)composition in three nectarine orchards at Yuchi Experimental Station in South China. Compared with the sloping clean tillage orchard and terraced clean tillage orchard, SOC content in the terraced orchard with grass cover was increased by 14.90% to 38.49%, and 7.40% to 15.33%, respectively. During the 14 years after orchard establishment, the soil organic matter sources influenced both δ^(13)C distribution with depth and carbon replacement. SOC turnover of the upper soil layer in the terraced orchard with grass cover(a mean 63.05% of replacement in the 20 cm after 14 years) was 1.59 and 1.41 times larger than that of the sloping clean tillage orchard and terraced clean tillage orchard under subtropical conditions, respectively. The equilibrium value of soil organic carbon in the three treatments ranged from 16.067 to 25.608 g/kg under the experimental conditions. The equilibrium value of soil organic carbon in the surface layer under grass cover was 54.801 t/hm^2, and the carbon sequestration potential was 24.695 1 t/hm^2.
文摘An analytical procedure involving Rock-Eval pyrolysis of whole-rocks was adopted on fresh outcrop samples covering the three lithostratigraphic units in the Afikpo Basin of the Lower Benue Trough. Three petroleum systems are present in the Cretaceous delta frame: the Asu-River Group, the Eze-Aku Group and proto-Niger Delta sequences. The Afikpo Basin has been correlated to three petroleum systems in the Lower Congo Basin, Niger Delta and the Anambra Basin. The organic geochemistry of the shales, carbonaceous mudstones and coal beds show relatively moderate to high total organic carbon contents. The best potential hydrocarbon source rocks are the Eze-Aku Group and proto-Niger Delta shales, carbonaceous mudstones and coal beds where maturation was attained. The high total organic contents, thermal maturity and terrigenous characters of the Asu-River Group, Eze-Aku Group and proto-Niger Delta sediments, suggest the presence of a large amount of natural gas with a small quantity of oil accumulation. Variations in source rock facies were observed from one lithostratigraphic unit to another, and initial HI values as a function of TOC were proposed for each lithostratigraphic unit. The results also show that TOC, HI, OI, S2 and Tmax vary from older to younger rocks. The Tmax values discriminate the rocks into immature and mature source rocks. Source rocks with high Tmax suggest high geothermal gradient/or recycled organic matter. Also high Tmax and S2 yield indicate late and post maturity. Recycled organic matter is characterized by low Tmax. The principal source rocks for gas in the Afikpo Basin are the Eze-Aku Group and proto-Niger Delta beds deltaic systems, consisting mainly of III to IV kerogens with a subordinate amount of type II organic matter. Based on the obtained results, it is concluded that the Cretaceous shales, carbonaceous mudstones and coals in the Afikpo Basin of the Lower Benue Trough are capable of generating and expelling hydrocarbons in the case of sufficient maturity.
基金supported by the National Key R&D Program of China (No.2018YFC1800506)the Key R&D Program of Zhejiang Province (No.2020C03083)。
文摘Persulfate is considered a convenient and efficient remediation agent for organic contaminated soil.However,the potential risk of sulfur into the soil remediation by persulfate remains ignored.In this study,glass bottles with different persulfate dosages and groundwater tables were set up to simulate persulfate remediation of organic pollutants(aniline).The results found sulfate to be the main end-product(83.0%–99.5%)of persulfate remediation after10 days.Moreover,H_(2)S accounted for 93.4%–99.4%of sulfur reduction end-products,suggesting that H_(2)S was the final fate of sulfur.H_(2)S was released rapidly after one to three days at a maximum concentration of 33.0 ppm,which is sufficient to make a person uncomfortable.According to the fitted curve results,H_(2)S concentration decreased to a safe concentration(0.15 ppm)after 20–85 days.Meanwhile,the maximum concentration of methanethiol reached 0.6 ppm.These results indicated that secondary pollution from persulfate remediation could release harmful gases over a long time.Therefore,persulfate should be used more carefully as a remediation agent for soil contamination.
文摘The aim of this research work was to report a facies analysis of the N’Kappa formation, identified the clay minerals present in those facies and evaluate their oil potential. For that to be done, Lithostratigraphic descriptions were performed on three natural outcrops chosen in three different localities of the northern border of Douala sedimentary basin. Ten shaly samples were then collected on those outcrops and submit to X ray diffraction and Rock-Eval pyrolysis. Lithologically, the N’Kappa formation is made up of dark to grey shales and fine to coarse sandtones. The mineralogic content of the shales is made up of Kaolinite, dickite, low quartz and vaterite. Those shaly facies present high amount of immature organic matter (average TOC content around 2%). The petroleum potential is fair to poor (average S2 for all the samples around 3.33 mg HC/g of rock) though some samples (M1 and M2) presenting a good petroleum potential up to 6.62 kg HC/t of rock and 6.44 kg HC/t of rock respectively. They have undergone a low degree of diagenesis (early to burying diagenesis). This is evidenced by the predominance of kaolinite and dickite, low quartz and vaterite which are minerals stable at low temperature.
文摘This study investigated the leaching potential of diuron and linuron in different soil types in Gaza Strip, Palestine under laboratory and field conditions. Leaching potential was evaluated by tin columns and bioassay technique using Molokhia as test plant. The responses of the test plant were regressed versus concentrations of the herbicide to estimate linear regression equation and the regression coefficient. The obtained results indicate strong positive association between Molokhia and concentrations of diuron or linuron;accordingly it was used in the bioassay and estimation of the concentrations of the tested herbicides in the leaching depth. Leaching potential was very low in North Gaza and Kkan Younis soil, whereas in the Meddle zone soil was very large. Leaching potential under laboratory conditions was larger that under field conditions. The bioestimated concentrations in soil layer under field conditions were sever folds of magnitude lower than those under laboratory conditions. The interesting outcome of this study is that leaching potential is dependent on soil clay fraction, soil organic matter, and soil pH. These results provided answers to the questions raised by farmers in Gaza Strip.
基金funded by the National Technology & Science Support Program of China (2012BAD16B02)
文摘Grassland ecosystem is an important component of the terrestrial carbon cycle system. Clear comprehension of soil organic carbon(SOC) storage and potential of grasslands is very important for the effective management of grassland ecosystems. Grasslands in Inner Mongolia have undergone evident impacts from human activities and natural factors in recent decades. To explore the changes of carbon sequestration capacity of grasslands from 2000 to 2012, we carried out studies on the estimation of SOC storage and potential of grasslands in central and eastern Inner Mongolia, China based on field investigations and MODIS image data. First, we calculated vegetation cover using the dimidiate pixel model based on MODIS-EVI images. Following field investigations of aboveground biomass and plant height, we used a grassland quality evaluation model to get the grassland evaluation index, which is typically used to represent grassland quality. Second, a correlation regression model was established between grassland evaluation index and SOC density. Finally, by this regression model, we calculated the SOC storage and potential of the studied grasslands. Results indicated that SOC storage increased with fluctuations in the study area, and the annual changes varied among different sub-regions. The SOC storage of grasslands in 2012 increased by 0.51×1012 kg C compared to that in 2000. The average carbon sequestration rate was 0.04×1012 kg C/a. The slope of the values of SOC storage showed that SOC storage exhibited an overall increase since 2000, particularly for the grasslands of Hulun Buir city and Xilin Gol League, where the typical grassland type was mainly distributed. Taking the SOC storage under the best grassland quality between 2000 and 2012 as a reference, this study predicted that the SOC potential of grasslands in central and eastern Inner Mongolia in 2012 is 1.38×1012 kg C. This study will contribute to researches on related methods and fundamental database, as well as provide a reference for the protection of grassland ecosystems and the formulation of local policies on sustainable grassland development.
文摘Mineral-bituminous matrix (MBM) makes up a major part of source rocks, but itspotential in hydrocarbon generation is uncertain. Mineral and organic (maceral and kerogen)compositions, organic maturity and fluorescence of MBM are studied based on source rock samples from eastern Jiuquan (Jiudong) Basin. The results show that MBM is dominated by inorganic minerals and among the small percentage of organic components those of secondary originsare predominant over the primary species. This strongly indicates that the significance of MBMin hydrocarbon generation is limited.
文摘Reconstitution of complex multi-tissue organs is one of the most impressive feats of biology and is observed across regeneration-competent vertebrate species,including teleost fish(e.g.,zebrafish),urodeles(e.g.,axolotls and newts),and some lizards.Regenerative ability within these species ranges from muscle(including cardiac),skeletal structures,to complex systems such as the brain,spinal cord and parts of the eye which are all capable of structural and functional repair following injury(Tanaka and Ferretti,2009).In stark contrast,re-establishment of multi-tissue structures is very rarely observed following embryogenesis in regeneration-incompetent mammals.Regrowth of digit tips is the most dramatic example of mammalian regeneration,but pales in comparison to other species in the animal kingdom.Undoubtedly,a complete recapitulation of complex organs or structures in mammals will remain out of reach for a considerable time;however,an improved understanding of regenerat i ve mechanisms would likely enhance the development of novel regenerative medicine strategies.Here we focus on the diversity and commonalities of stem cells,which could underlie complex tissue regeneration.
文摘In order to study the hydrocarbon-generating potential of Carboniferous-Permian coal shale in Jiyang Depression,geochemistry,petroleum geology and coal geology were applied to study the residual strata distribution of Carboniferous-Permian in Jiyang Depression,organic matter abundance,organic matter types and organic matter maturity of mudstone.The results show that the thickness of the Carboniferous-Permian residual strata in Jiyang Depression is generally 200-800 m,with a maximum thickness of 900 m;the organic matter abundance of coal-bearing shale is good,and it is type III kerogen,which is conducive to gas generation,and the maturity of organic matter reaches a mature-higher maturity stage;the hydrocarbon generation potential of Benxi Formation and Taiyuan Formation is better;Medium to good hydrocarbon source rocks is able to be found in every sag of Shanxi Formation hydrocarbon source rocks,but the scope is limited,and the overall evaluation is still medium.Generally speaking,the Permo-Carboniferous coal-bearing shale in Jiyang Depression has certain shale gas exploration potential.
文摘BACKGROUND Healthy vestibular system adjusts balance during static and dynamic conditions.This is important for normal development(standing up and walking).Vestipulopathies(central and peripheral)are common complications of diabetes in adult population.Related studies are scare in children with type 1 diabetes(T1D).AIM To assess saccular function of otolith organ in children with T1D and predictors for its dysfunction.METHODS Cervical vestibular evoked myogenic potential(cVEMP)was used for objective evaluation.RESULTS The study included 40 patients(boys=15;girls=25).Patients had mean age of 13.63±1.50 years,duration of diabetes of 5.62±2.80 years,frequent attacks of diabetic ketoacidosis(55%)and hypoglycemia(30%),hyperlipidemia(20%),hypertension(12.5%)and peripheral neuropathy(40%).Dizziness was found in 10%.Compared to healthy children(n=25),patients had prolonged cVEMP P1 and N1 latencies and reduced P1-N1 amplitude.Bilateral cVEMP abnormalities were found in 60%(vs 25%for unilateral abnormalities).Higher frequencies and severe vestibulopathies were found with chronic diabetes of>5 years,hemoglobin A1c values>7%,frequent diabetic ketoacidosis and hypoglycemic attacks and presence of dizziness.Regression analyses showed that predictors for prolonged P1 latencies and reduced P1-N1 amplitudes were only chronic diabetes(>5 years){odds ratio(OR)=2.80[95%confidence interval(CI):1.80–5.33],P=0.01;OR=3.42(95%CI:2.82–6.81)}and its severity(hemoglobin A1c>7%)[OR=3.05(95%CI:2.55–6.82),P=0.01;OR=4.20(95%CI:3.55–8.50),P=0.001].CONCLUSION Dysfunction or injury of the saccular macula and its pathways is prevalent in children with T1D.Optimum glycemic control is important to prevent diabetes related vestipulopathies.
文摘This article prognosticates the hydrocarbon generation potential of core samples from fields A, B, C and D in Niger delta, Nigeria. The objectives of this study are to characterize the quality of these core samples by organic geochemical analyses. A total of ten core samples collected from fields A, B, C and D in Niger delta were analyzed using total organic carbon(TOC) content analysis, rock-eval pyrolysis technique. The analytical results of the studied core samples reveal that they have generally high total organic carbon contents(TOC), suggesting that conditions in the Niger delta favour organic matter production and preservation. There is a variation in the kerogen types and this may be attributed to the relative stratigraphic positions of the core samples within the Niger delta. The rock-eval results indicate that the samples from fields C and D contain predominantly Type II kerogen with a capacity to generate oil and gas and hence have good generative potential. The samples from fields A and B contain mainly Type III kerogen and are gas-prone with moderate generative potential.