This work aimed, on the one hand, to determine the mineral and phytochemical composition of Carica papaya in order to guarantee the food safety of consumers and on the other hand, to evaluate the acute toxicity of pap...This work aimed, on the one hand, to determine the mineral and phytochemical composition of Carica papaya in order to guarantee the food safety of consumers and on the other hand, to evaluate the acute toxicity of papaya seeds. The papayas were bought at the Mzée market in Lubumbashi and Selembao in Kinshasa. Fruit sampling was done according to the ISO 7002 standard on agricultural and food products;the papayas were firm, mature, and without stains or physical damage. The analysis results of the papaya pulp showed both for the samples from the city of Lubumbashi and for the city province of Kinshasa that it contains respectively 85.87% and 84.46% water, 0.59% and 0.53% ash content. The mineral evaluation of our two samples presented a potassium content of 200 ± 8 mg, magnesium 13.12 ± 3 mg, calcium 22.15 ± 2 mg, sodium 3 mg ± 0.5 for the sample from Lubumbashi and 192.32 ± 8 mg of potassium, 14.458 ± 3 mg of magnesium, 20.58 ± 2 mg of calcium and 3.58 ± 0.5 mg of sodium for the sample from Kinshasa in macroelements. Concerning the trace elements, after analysis, we found zinc content (0.29 ± 0.1 mg and 0.12 ± 0.1 mg), copper (0.02 ± 0.01 mg and 0.14 ± 0.01 mg), and iron (2.22 ± 0.5 mg and 2.04 ± 0.5 mg) respectively for Lubumbashi and Kinshasa. The chemical screening indicates the presence of alkaloids, saponosides, tannins catechics, flavonoids and anthocyanins in the palm wine and ethanolic extract of the seeds of Carica papaya and an absence of cyanogenic glycosides and gallic tannins. With mild toxicity, the seeds of the fruit of Carica papaya L. can be used with moderate risk by the population.展开更多
Because of the various elements that come into play in natural soil formation, the impact of varied proportions of mineral composition and fines amount on Atterberg limits and compaction characteristics of soils is no...Because of the various elements that come into play in natural soil formation, the impact of varied proportions of mineral composition and fines amount on Atterberg limits and compaction characteristics of soils is not well known. Three distinct soil samples were used in this investigation. The findings indicated the effect of varied mineral composition proportions and fines amount on the liquid limit, plastic limit, and plasticity index as assessed by the Casagrande test and hand-rolling method. The fluctuation of maximum dry density and optimal moisture content with these three soils has also been studied. Furthermore, correlations were established to indicate the compaction parameters and the amount of minerals and particles in the soil. The data show that the mineral content of the soil has a direct impact on the Atterberg limits and compaction characteristics. Soils containing larger percentages of expansive minerals, such as montmorillonite, have more flexibility and volume change capability. Mineral composition influences compaction parameters such as maximum dry density, ideal water content, axial strain, and axial stress. Soils with a larger proportion of fines, such as Soil 2 and Soil 3, have stronger flexibility and lower compaction qualities, with higher ideal water content and lower maximum dry density. Soil 1 has moderate flexibility and intermediate compaction qualities due to its low fines percentage. The effect of different mineral compositions and fines on the Atterberg limits and compaction characteristics of soils can be used to predict the behavior of compacted soils encountered in engineering practices, reducing the time and effort required to assess soil suitability for engineering use.展开更多
The expansion and micro-cracks of the mortar with composite mineral admixtures (fly ash, zeolite and slag) due to the alkali-silica reaction (ASR) are studied. Results show that composite mineral admixtures cannot...The expansion and micro-cracks of the mortar with composite mineral admixtures (fly ash, zeolite and slag) due to the alkali-silica reaction (ASR) are studied. Results show that composite mineral admixtures cannot absolutely diminish the ASR of mortar bars with the low-alkali cement and a highly reactive aggregate. But the expansion rate and the deleterious expansion of the mortar bar are mostly reduced with increasing composite mineral admixture. The influence of mineral admixtures on the fluidity of the paste and the strength of the mortar is also studied.展开更多
Reductive immobilization has been a commonly used technique to detoxify Cr(VI)from soil;however,it's challenging to remove the reduced Cr from soil to prevent its re-oxidation.This work explored a natural magnetic...Reductive immobilization has been a commonly used technique to detoxify Cr(VI)from soil;however,it's challenging to remove the reduced Cr from soil to prevent its re-oxidation.This work explored a natural magnetic composite for the remediation,mineralization,and magnetic removal of Cr(VI)from the soil.It consists of 77%magnetite and 23%pyrrhotite with strong magnetic properties.A series of characterization tests show that composites of magnetite and pyrrhotite are interlaced and closely bonded,and contain no other heavy metals.The Cr(VI)removal rate increases with the decrease in composite particle size.A kinetics study shows that removing Cr(VI)by the composite is likely through both adsorption and reduction.Acidic conditions are more favorable for the immobilization of Cr(VI),at 45.8 mg Cr(VI)removal per g of composite at pH 2.After 100 days of in-situ treatment by the composite,the leaching concentration(TCLP)of Cr(VI)-contaminated soil was 1.95 mg L^(-1),which was below the EPA limit(5 mg L^(-1))for hazardous waste.After reduction,the composite was separated from soil by magnetic characteristics,and 58.2%of Cr was found mineralized.The post-treatment Cr-containing composite was analyzed by SEM-EDS,Raman spectra,and XPS.It was found that Cr was mineralized on the surface of the composite in the form of Cr(OH)3,Cr_(2)O_(3),and FeCr_(2)O_(4).This indicates that reduction and mineralization of Cr(VI)in the soil can be accomplished through natural magnetic mineral composites and easily separated and removed from the soil,achieving a complete soil cleanup.展开更多
This study investigated the correlations between mechanical properties and mineralogy of granite using the digital image processing(DIP) and discrete element method(DEM). The results showed that the X-ray diffraction(...This study investigated the correlations between mechanical properties and mineralogy of granite using the digital image processing(DIP) and discrete element method(DEM). The results showed that the X-ray diffraction(XRD)-based DIP method effectively analyzed the mineral composition contents and spatial distributions of granite. During the particle flow code(PFC2D) model calibration phase, the numerical simulation exhibited that the uniaxial compressive strength(UCS) value, elastic modulus(E), and failure pattern of the granite specimen in the UCS test were comparable to the experiment. By establishing 351 sets of numerical models and exploring the impacts of mineral composition on the mechanical properties of granite, it indicated that there was no negative correlation between quartz and feldspar for UCS, tensile strength(σ_(t)), and E. In contrast, mica had a significant negative correlation for UCS, σ_(t), and E. The presence of quartz increased the brittleness of granite, whereas the presence of mica and feldspar increased its ductility in UCS and direct tensile strength(DTS) tests. Varying contents of major mineral compositions in granite showed minor influence on the number of cracks in both UCS and DTS tests.展开更多
The flotation results of a phosphate ore are improved by replacing the conventional collectors of fatty acids with composite collectors. The synergistic effect on the froth characteristics in systems using composite c...The flotation results of a phosphate ore are improved by replacing the conventional collectors of fatty acids with composite collectors. The synergistic effect on the froth characteristics in systems using composite collectors has then been studied, and the concept of 'mixed hemimicellae' has been proposed in the adsorption of composite collectors at the air/solution interfaces.展开更多
Coral reef limestone at different depositional depths and facies differ remarkably on the textural and mineralogical characteristics,owing to the complex sedimentary diagenesis.To explore the effects of pore structure...Coral reef limestone at different depositional depths and facies differ remarkably on the textural and mineralogical characteristics,owing to the complex sedimentary diagenesis.To explore the effects of pore structure and mineral composition associated with diagenetic variation on the mechanical behavior of reef limestone,a series of quasi-static and dynamic compression tests along with microscopic examinations were performed on the reef limestone at shallow and deep burial depths.It is revealed that the shallow reef limestone(SRL)is classified as a porous aragonite-type carbonate rock with high porosity(55.3±3.2)%and pore connectivity.In comparison,the deep reef limestone(DRL)is mainly composed of dense calcite-type calcium carbonate with low porosity(4.9±1.6)%and pore connectivity.The DRL strengthened and stiffened by the tight grain framework consistently displays much higher values of the dynamic compressive strength,elastic modulus,brittleness index,and specific energy absorption than those of the SRL.The gap between two types of limestone further increases with an increase in strain rate.It appears that the failure pattern of SRL is dominated by the inherent defects like weak bonding interfaces and growth lines,revealed by the intricate fracturing network and mixed failure.Likewise,although the preexisting megapores in DRL may affect the crack propagation on pore tips to a certain distance,it hardly alters the axial splitting failure of DRL under impacts.The stress wave propagation and attenuation in SRL is primarily controlled by the reflection and diffusion caused by plenty mesopores,as well as an energy dissipation in layer-wise pore collapse and adjacent grain crushing,while the stress wave in DRL is highly hinged on the insulation and diffraction induced by the isolated megapores.This process is accompanied by the energy dissipation behavior of inelastic deformation resulted from the pore-emanated microcracking.展开更多
Increasing K+ adsorption can be an effective alternative in building an available K pool in soils to optimize crop recovery and minimize losses into the environment. We hypothesized that long-term fertilization might...Increasing K+ adsorption can be an effective alternative in building an available K pool in soils to optimize crop recovery and minimize losses into the environment. We hypothesized that long-term fertilization might change K+ adsorption because of changes in the chemical and mineralogical properties of a rice (Oryza sativa L.). The aims of this study were (i) to determine clay minerals in paddy soil clay size fractions using X-ray diffraction methods and a numerical diagramdecomposition method; (ii) to measure K+ adsorption isotherms before and after H202 oxidation of organic matter, and (iii) to investigate whether K+ adsorption is correlated with changes in soil chemical and mineral properties. The 30-yr longterm fertilization treatments caused little change in soil organic C (SOC) but a large variation in soil mineral composition. The whole-clay fraction (〈5 Jam) corresponded more to the fertilization treatment than the fine-clay fraction (〈1 gin) in terms of percentage of illite peak area. The total percentage of vermiculite-chlorite peak area was significantly negatively correlated with the total percentage ofillite peak area in the 〈5 lam soil particles (R=-0.946, P〈0.0006). Different fertilization treatments gave significantly different results in K+ adsorption. The SOC oxidation test showed positive effects of SOC on K+ adsorption at lower K+ concentration (≤120 mg L-0 and negative effects at higher K+ concentration (240 mg L-l). The K+ adsorption by soil clay minerals after SOC oxidization accounted for 60-158% of that by unoxidized soils, suggesting a more important role of soil minerals than SOC on K+ adsorption. The K+ adsorption potential was significantly correlated to the amount of poorly crystallized illite present (R--0.879, P=0.012). The availability of adsorbed K+ for plant growth needs further study.展开更多
The Xinjie layered intrusion in the Panxi region,SW China,hosts both Fe-Ti oxide and platinum-group element(PGE) sulfide mineralization.The intrusion can be divided,from the base upward,into UnitsⅠ,ⅡandⅢ,in terms...The Xinjie layered intrusion in the Panxi region,SW China,hosts both Fe-Ti oxide and platinum-group element(PGE) sulfide mineralization.The intrusion can be divided,from the base upward,into UnitsⅠ,ⅡandⅢ,in terms of mineral assemblages.UnitsⅠandⅡare mainly composed of wehrlite and clino-pyroxenite, whereas UnitⅢis mainly composed of gabbro.PGE sulfide-rich layers mainly occur in Unit I, whereas thick Fe-Ti oxide-rich layers mainly occur in UnitⅢ.An ilmenite-rich layer occurs at the top of UnitⅠ.Fe-Ti oxides include magnetite and ilmenite.Small amounts of cumulus and intercumulus magnetite occur in UnitsⅠandⅡ.Cumulus magnetite grains are commonly euhedral and enclosed within olivine and clinopyroxene.They have high Cr2O3 contents ranging from 6.02 to 22.5 wt.%,indicating that they are likely an early crystallized phase from magmas.Intercumulus magnetite that usually displays ilmenite exsolution occupies the interstices between cumulus olivine crystals and coexists with interstitial clinopyroxene and plagioclase.Intercumulus magnetite has Cr2O3 ranging from 1.65 to 6.18 wt.%, lower than cumulus magnetite.The intercumulus magnetite may have crystallized from the trapped liquid.Large amounts of magnetite in UnitⅢcontains Cr2O3(<0.28 wt.%) much lower than magnetite in UnitsⅠandⅡ.The magnetite in UnitⅢis proposed to be accumulated from a Fe-Ti-rich melt.The Fe-Ti-rich melt is estimated to contain 35.9 wt.%of SiO2,26.9 wt.%of FeOt,8.2 wt.%of TiO2,13.2 wt.%of CaO, 8.3 wt.%of MgO,5.5 wt.%of Al2O3 and 1.0 wt.%of P2O5.The composition is comparable with the Fe-rich melts in the Skaergaard and Sept Iles intrusions.Paired non-reactive microstructures,granophyre pockets and ilmenite-rich intergrowths,are representative of Si-rich melt and Fe-Ti-rich melt,and are the direct evidence for the existence of an immiscible Fe-Ti-rich melt that formed from an evolved ferro-basaltic magma.展开更多
This work mainly focuses on the mineralogical study of particulate matter(PM10) in Beijing. Samples were collected on polycarbonate filter from April, 2002 to March, 2003 in Beijing urban area. Scanning electronic m...This work mainly focuses on the mineralogical study of particulate matter(PM10) in Beijing. Samples were collected on polycarbonate filter from April, 2002 to March, 2003 in Beijing urban area. Scanning electronic microscopy coupled with energy dispersive X-ray(SEM/EDX) was used to investigate individual mineral particles in Beijing PM10. 1454 individual mineral particulates from 48 samples were analysed by SEM/EDX. The results revealed that mineral particulates were complex and heterogeneous. 38 kinds of minerals in PM10 were identified. The clay minerals, of annual average percentage of 30.1%, were the main composition among the identified minerals, and illite/smectite was the main composition in clay minerals, reaching up to 35%. Annual average percentage of quartz, calcite, compound particulates, carbonates were 13.5%, 10.9%, 11.95%, 10.31%, respectively. Annual average percentage less than 10% were gypsum, feldspar, dolomite, and so on. Fluorite, apatite, halite, barite and chloridize zinc(ZnCl2) were firstly identified in Beijing PM10. Sulfurization was found on surface of mineral particles, suggested extensive atmospheric reaction in air during summer.展开更多
The Lower Cretaceous Xiagou Formation contains the major source rocks for the crude oils discovered in the Qingxi Sag and the South Uplift in the Jiuquan Basin, northwestern China. The Xiagou Formation source rock was...The Lower Cretaceous Xiagou Formation contains the major source rocks for the crude oils discovered in the Qingxi Sag and the South Uplift in the Jiuquan Basin, northwestern China. The Xiagou Formation source rock was formed in a closed,anoxic, reducing, alkaline lacustrine environment with a high salinity. Its high content of brittle minerals is favorable for the fracturing of reservoirs in source rock formations in the Qingxi Sag. The Xiagou Formation contains a great number of fair to excellent source rocks, and their organic matter(OM) came chiefly from plankton/algae and high plants as well as possibly bacterial organisms. The Xiagou Formation source rocks mainly contain Type II OM and some Type III and Type I OM, with good oil-generating potential. The source rock maturity is mainly in the early-mature and mature stages, and its Rovalue corresponding to oil peak is about 0.8%, which is lower than classic oil peak Rovalue of 1.0%; therefore, a great deal of hydrocarbon was generated before the classic oil peak Ro= 1.0%. Mature source rock in the Xiagou Formation tends to be distributed in the older members and at a greater depth. There is a better exploration potential of tight oil in the deep Qingxi Sag.展开更多
The Jiuyishan complex massif,located in the northern section of the Nanling region,is a combination of five plutons,namely,the Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan plutons.Whole-rock geochemistry,Iminer...The Jiuyishan complex massif,located in the northern section of the Nanling region,is a combination of five plutons,namely,the Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan plutons.Whole-rock geochemistry,Imineral electron microprobe analysis,zircon U-Pb dating and Hf isotope analysis were carried out for the Jinjiling and Pangxiemu plutons.The zircon U-Pb dating yields weighted mean ages of 152.9±0.9 Ma for the Jinjiling pluton and 151.7±1.5 Ma for the Pangxiemu pluton,with a narrow gap between them.The Jinjiling and Pangxiemu plutons both have geochemical characteristics of high SiO2,Al2 O3,Na2 O,K2 O and low TiO2,MgO,CaO,P2 O5 contents,with intense depletions in Sr,Ba,Ti,Eu and enrichments in Ga,FeoOT and HFSE,and these characteristics reflect an A-type affinity.From the Jinjiling to the Pangxiemu plutons,the mineral composition of mica changes from lepidomelane to zinnwaldite,with increases in F,Li2 O and Rb2 O contents.The mineral composition of zircon changes from low Zr/Hf to high Zr/Hf,with increasing HfO2,P2 O5 and UO2+ThO2+Y2 O3 contents.The mineral compositions of feldspar indicate that the Pangxiemu pluton contains more alkali feldspar than the Jinjiling pluton.The whole-rock geochemistry and mineral compositions reveal a higher degree of differentiation for the Pangxiemu pluton.The nearly uniformεHf(t)indicates the same source region for the two plutons:both were derived from partial melting of the lower crust,with small contributions of mantle materials.In addition,higher F,lower Nb/Ta and Zr/Hf ratios in the Pangxiemu Pluton suggest a closer relationship with the rare metal mineralization than for the Jinjiling pluton.展开更多
To reveal the influence of mechanical activation on the performance of fly ash, the microanalysis(the energy spectroscopy, XRD and SEM), the distribution size of particle of fly ash and cement paste intensity of var...To reveal the influence of mechanical activation on the performance of fly ash, the microanalysis(the energy spectroscopy, XRD and SEM), the distribution size of particle of fly ash and cement paste intensity of various age for different grinding time were studied. The relationships of the activity and the composition of fly ash, microstructure and the distribution of particle size by mechanical activation of fly ash were obtained. The internal glass beads with activity were released by grinding fly ash for a certain time. The particle specific surface area was improved and the hydration reaction of the interface and the surface active center was increased by grinding. The granularity distributing of fly-ash trended towards optimization. The polar molecules or ions were easier to intrude into the internal cavity of the vitreous body. The active silica and alumina of fly ash were rapidly depolymerized. Each performance index of fly ash was increased before grinding for 20 min. Cement paste intensity of various age increased along with the grinding time, and the early strength increase range was big, but the later period intensity increase range hastened slightly. The internal part of vitreous of fly ash was destroyed if the fly ash continued to be ground and the activity of fly ash was reduced. It is suggested that Guozhuang's fly ash should be ground for 20 min.展开更多
Spectra are sensitive in detecting main minerals on the lunar surface from visible light to infrared light. Since spectral characteristics of minerals are closely related to their compositions and the maturity level o...Spectra are sensitive in detecting main minerals on the lunar surface from visible light to infrared light. Since spectral characteristics of minerals are closely related to their compositions and the maturity level of soil on the Moon, studying the compositions and distribution of elements and minerals on the lunar surface can help to understand the evolution of the Moon through remote sensing technology. The correlation between the spectral characteristics of Chang'e-1 interference imaging spectrometry(IIM) reflectance images and the mineral contents of LSCC(Lunar Soil Characterization Consortium) lunar surface mineral samples was discussed and the spatial distributions of Fe O and Al_2O_3 contained in both pyroxene and plagioclase on LQ-4 were studied using the improved angle parameter method, MNF, and band ratio statistics. A comparison of the mapping results of the optical models by Lucey, Shkuractov and other researchers on Clementine and the gamma ray spectrometry data shows that the content error is within 0.6% for lunar mare areas and close to 1% for the highland areas. The tectonic framework on the lunar surface was also investigated. And based on integrated analysis of previous findings on topography of the lunar surface, Chang'e LAM, CCD and LOLA images and the gravity anomalies data(Clementine GLGM-2), the tectonic unit subdivision was established for LQ-4, the idea of subdividing the lunar tectonic units was proposed, and this will provide a good foundation for studying the lunar tectonic evolution.展开更多
Generation, morphology, and distribution of authigenic minerals directly reflect sedimentary environment and material sources. Surface sediments were collected from the western Gulf of Thailand during 2011–2012, and ...Generation, morphology, and distribution of authigenic minerals directly reflect sedimentary environment and material sources. Surface sediments were collected from the western Gulf of Thailand during 2011–2012, and 159 samples were analyzed to determine detrital minerals. Authigenic minerals, including siderite, pyrite, and glauconite, are abundant whereas secondary minerals, such as chlorite and limonite, are distributed widely in the study area. Siderite has a maximum content of 19.98 g/kg and appears in three types from nearshore to continental shelf, showing the process of forming-maturity-oxidation. In this process, the Mn O content in siderite decreases, but FeOand Mg O content increase. Colorless or transparent siderite pellets are fresh grains generated within a short time and widely distributed throughout the region; high content appears in coastal area where river inputs are discharged. Translucent cemented double pellets appearing light yellow to red are mature grains; high content is observed in the central shelf. Red-brown opaque granular pellets are oxidized grains,which are concentrated in the eastern gulf. Pyrite is mostly distributed in the central continental shelf with an approximately north–south strip. Pyrite are mainly observed in foraminifera shell and distributed in clayey silt sediments, which is similar to that in the Yangtze River mouth and the Yellow Sea. The pyrite in the gulf is deduced from genetic types associated with sulfate reduction and organic matter decomposition. Majority of glauconite are granular with few laminar. Glauconite is concentrated in the northern and southern parts within the boundary of 9.5° to 10.5°N and is affected by river input diffusion. The distribution of glauconite is closely correlated with that of chlorite and plagioclase, indicating that glauconite is possibly derived from altered products of chlorite and plagioclase. The KO content of glauconite is low or absent, indicating its short formation time.展开更多
Mechanical properties of shales are key parameters influencing hydrocarbon production – impacting borehole stability, hydraulic fracture extension and microscale variations in in situ stress. We use Ordovician shale(...Mechanical properties of shales are key parameters influencing hydrocarbon production – impacting borehole stability, hydraulic fracture extension and microscale variations in in situ stress. We use Ordovician shale(Sichuan Basin, China) as a type-example to characterize variations in mineral particle properties at microscale including particle morphology, form of contact and spatial distribution via mineral liberation analysis(MLA) and scanning electron microscopy(SEM). Deformation-based constitutive models are then built using finite element methods to define the impact of various architectures of fracture and mineral distributions at nanometer scale on the deformation characteristics at macroscale.Relative compositions of siliceous, calcareous and clay mineral particles are shown to be the key factors influencing brittleness. Shales with similar mineral composition show a spectrum of equivalent medium mechanical properties due to differing particle morphology and mineral heterogeneity. The predominance of small particles and/or point-point contacts are conducive to brittle failure, in general, and especially so when quartz-rich. Fracture morphology, length and extent of filling all influence shale deformability. High aspect-ratio fractures concentrate stress at fracture tips and are conducive to extension, as when part-filled by carbonate minerals. As fracture spacing increases, stress transfer between adjacent fractures weakens, stress concentrations are amplified and fracture extension is favored. The higher the fractal dimension of the fracture and heterogeneity of the host the more pervasive the fractures. Moreover, when fractures extend, their potential for intersection and interconnection contributes to a reduction in strength and the promotion of brittle failure. Thus, these results provide important theoretical insights into the role of heterogeneity on the deformability and strength of shale reservoirs with practical implications for their stimulation and in the recovery of hydrocarbons from them.展开更多
Fruiting bodies(500 g per site) of Tricholoma matsutake and the surface layer of soils collected from 20 spatially distant areas with pristine backgrounds across China were analyzed for potassium,magnesium,calcium,zin...Fruiting bodies(500 g per site) of Tricholoma matsutake and the surface layer of soils collected from 20 spatially distant areas with pristine backgrounds across China were analyzed for potassium,magnesium,calcium,zinc,iron,copper,manganese and cadmium using inductively coupled plasma optical emission spectroscopy.In terms of the bioconcentration and bioexclusion concept,K,Mg,Zn,and Cu were highly bioconcentrated,and their bioconcentration factor values varied between 75-615,2-107,38-603 and 7-76,respectively,across the 20 sites.Fe,Mn and Cd were moderately bioconcentrated and their bioconcentration factors(BCFs) varied between 0.6-34.0,0.4-37.0 and 0.9-7.0 respectively.However,Ca was excluded(BCF<1).T.matsutake is a species that is harvested in the wild as a valuable food and can contain a wide spectrum of both essential and hazardous mineral compounds that accumulate at elevated concentrations even if grown in pristine areas.The estimated intake rate of Cd in the fruiting bodies indicates cause for concern associated with this metal resulting from the daily consumption of between 200 and 400 g of fruiting bodies on a frequent basis during the mushrooming season.展开更多
Natural fractures are widely distributed in shale reservoirs.During the hydraulic fracturing process,frictional slip occurring on natural fractures can increase the reservoir permeability and is of great significance ...Natural fractures are widely distributed in shale reservoirs.During the hydraulic fracturing process,frictional slip occurring on natural fractures can increase the reservoir permeability and is of great significance to improve the efficiency of reservoir stimulation.Shale contains a large amount of clay and organic matter,and its frictional behavior is different from that of other previously studied lithologies.In this paper,the frictional behavior of shale is analyzed,and the results show that the frictional behavior is controlled by the content of clay and organic matter.As the content of clay and organic matter increases,the micro support type transforms from the particle support mode by hard quartz mineral to matrix support mode by plastic clay and organic matter.Accordingly,the shear strength and friction coefficient of shale both decrease,and the shear type transforms from brittle to plastic.When the content of clay and organic matter is low,the asperity of friction surfaces will break in a brittle manner and the wear degree of surfaces is low.Therefore,fractures are still featured by moderate apertures after friction.The lower the content of clay and organic matter is,the easier the asperity of crack surfaces supports themselves,and the higher the fracture residual permeability is.Thus,promoting shear slip is the main measure of reservoir stimulation.However,when the content of clay and organic matter is high,the remaining post-slip fracture aperture is small.It is difficult to increase reservoir permeability through the frictional slip of natural fractures,and in this situation,the proppant support efficiency needs to be improved.展开更多
Spices which are widely used in Southwest Nigeria have aroma, enhance taste of food and possess medicinal values. Proximate, mineral composition and phytochemical screening of ten randomly selected spices were carried...Spices which are widely used in Southwest Nigeria have aroma, enhance taste of food and possess medicinal values. Proximate, mineral composition and phytochemical screening of ten randomly selected spices were carried out. Recommended procedures were used for the analyses. Mineral composition was determined using flame photometer, colorimeter and (Atomic Absorption Spectrophotometer). The proximate composition showed that protein was high at 12.04% in Zingiber officinale and low at 2.1% in Xylopia aethiopica. Ocimium gratissium contained high moisture content at 82.1%, while Tetrapleura tetraptera had the least value of 3.5%. High ash content was recorded in Ocimum gratissium at 13.68% and lowest 0.98% in Allium cepa. For carbohydrate, Allium cepa had the highest value of 78.36%, while Allium setiva had the least value of 19.48%. Mineral composition showed high value of calcium 712 mg/100g, magnesium 172.2 mg/100g, potassium 868.5 mg/100g, sodium 75.85 mg/100g, and manganese 95.38 mg/100g in Allium sativa, Xylopia aethiopica, Momodara myristica, Ocimum gratissimum, Tetrapleura tetraptera respectively. Aframomium meleghueta had high value of iron and zinc at 85 mg/100g and 97 mg/100g respectively and also high presence of alkaloids, glycosides, saponins and tarmis. High values of saponins and triterpenoids were observed in Zingiber officinale and Ocimum gratissimum respectively. This study showed that spices have greater use in medicine and as food supplement.展开更多
A field experiment was conducted in 2009 and 2010 growing seasons, to study the effect of foliar application of iron-chelated "Fe-EDTA" at concentration 0, 100 and 200 mg/L on the seasonal dynamic of mineral composi...A field experiment was conducted in 2009 and 2010 growing seasons, to study the effect of foliar application of iron-chelated "Fe-EDTA" at concentration 0, 100 and 200 mg/L on the seasonal dynamic of mineral composition of N, P, K, Fe and Zn in petioles and berries of Halwani Lebanon and Kamali grape cultivars, grown on a calcareous soil in Mosul region, Iraq. The results revealed that the foliar application of 200 mg Fe/L caused a significant increase of N, P, K, Fe and Zn concentrations in petioles and berries compared with the control for both seasons. Additionally, the N, P, K, Fe and Zn concentration in petioles were high at the beginning of the growth season, whereas, decrease towards in the end of the growth season in both cultivars and seasons. While the N, P, K, Fe and Zn in berry content was increased towards from berry set to veraison and ripening stage in both cultivars and seasons. So there are various element contents in the cultivars.展开更多
文摘This work aimed, on the one hand, to determine the mineral and phytochemical composition of Carica papaya in order to guarantee the food safety of consumers and on the other hand, to evaluate the acute toxicity of papaya seeds. The papayas were bought at the Mzée market in Lubumbashi and Selembao in Kinshasa. Fruit sampling was done according to the ISO 7002 standard on agricultural and food products;the papayas were firm, mature, and without stains or physical damage. The analysis results of the papaya pulp showed both for the samples from the city of Lubumbashi and for the city province of Kinshasa that it contains respectively 85.87% and 84.46% water, 0.59% and 0.53% ash content. The mineral evaluation of our two samples presented a potassium content of 200 ± 8 mg, magnesium 13.12 ± 3 mg, calcium 22.15 ± 2 mg, sodium 3 mg ± 0.5 for the sample from Lubumbashi and 192.32 ± 8 mg of potassium, 14.458 ± 3 mg of magnesium, 20.58 ± 2 mg of calcium and 3.58 ± 0.5 mg of sodium for the sample from Kinshasa in macroelements. Concerning the trace elements, after analysis, we found zinc content (0.29 ± 0.1 mg and 0.12 ± 0.1 mg), copper (0.02 ± 0.01 mg and 0.14 ± 0.01 mg), and iron (2.22 ± 0.5 mg and 2.04 ± 0.5 mg) respectively for Lubumbashi and Kinshasa. The chemical screening indicates the presence of alkaloids, saponosides, tannins catechics, flavonoids and anthocyanins in the palm wine and ethanolic extract of the seeds of Carica papaya and an absence of cyanogenic glycosides and gallic tannins. With mild toxicity, the seeds of the fruit of Carica papaya L. can be used with moderate risk by the population.
文摘Because of the various elements that come into play in natural soil formation, the impact of varied proportions of mineral composition and fines amount on Atterberg limits and compaction characteristics of soils is not well known. Three distinct soil samples were used in this investigation. The findings indicated the effect of varied mineral composition proportions and fines amount on the liquid limit, plastic limit, and plasticity index as assessed by the Casagrande test and hand-rolling method. The fluctuation of maximum dry density and optimal moisture content with these three soils has also been studied. Furthermore, correlations were established to indicate the compaction parameters and the amount of minerals and particles in the soil. The data show that the mineral content of the soil has a direct impact on the Atterberg limits and compaction characteristics. Soils containing larger percentages of expansive minerals, such as montmorillonite, have more flexibility and volume change capability. Mineral composition influences compaction parameters such as maximum dry density, ideal water content, axial strain, and axial stress. Soils with a larger proportion of fines, such as Soil 2 and Soil 3, have stronger flexibility and lower compaction qualities, with higher ideal water content and lower maximum dry density. Soil 1 has moderate flexibility and intermediate compaction qualities due to its low fines percentage. The effect of different mineral compositions and fines on the Atterberg limits and compaction characteristics of soils can be used to predict the behavior of compacted soils encountered in engineering practices, reducing the time and effort required to assess soil suitability for engineering use.
文摘The expansion and micro-cracks of the mortar with composite mineral admixtures (fly ash, zeolite and slag) due to the alkali-silica reaction (ASR) are studied. Results show that composite mineral admixtures cannot absolutely diminish the ASR of mortar bars with the low-alkali cement and a highly reactive aggregate. But the expansion rate and the deleterious expansion of the mortar bar are mostly reduced with increasing composite mineral admixture. The influence of mineral admixtures on the fluidity of the paste and the strength of the mortar is also studied.
基金This work was supported by the National KeyResearch and Development Project of China[2019YFC1805900].
文摘Reductive immobilization has been a commonly used technique to detoxify Cr(VI)from soil;however,it's challenging to remove the reduced Cr from soil to prevent its re-oxidation.This work explored a natural magnetic composite for the remediation,mineralization,and magnetic removal of Cr(VI)from the soil.It consists of 77%magnetite and 23%pyrrhotite with strong magnetic properties.A series of characterization tests show that composites of magnetite and pyrrhotite are interlaced and closely bonded,and contain no other heavy metals.The Cr(VI)removal rate increases with the decrease in composite particle size.A kinetics study shows that removing Cr(VI)by the composite is likely through both adsorption and reduction.Acidic conditions are more favorable for the immobilization of Cr(VI),at 45.8 mg Cr(VI)removal per g of composite at pH 2.After 100 days of in-situ treatment by the composite,the leaching concentration(TCLP)of Cr(VI)-contaminated soil was 1.95 mg L^(-1),which was below the EPA limit(5 mg L^(-1))for hazardous waste.After reduction,the composite was separated from soil by magnetic characteristics,and 58.2%of Cr was found mineralized.The post-treatment Cr-containing composite was analyzed by SEM-EDS,Raman spectra,and XPS.It was found that Cr was mineralized on the surface of the composite in the form of Cr(OH)3,Cr_(2)O_(3),and FeCr_(2)O_(4).This indicates that reduction and mineralization of Cr(VI)in the soil can be accomplished through natural magnetic mineral composites and easily separated and removed from the soil,achieving a complete soil cleanup.
基金This research was supported by the Department of Mining Engineering at the University of Utah.In addition,the lead author wishes to acknowledge the financial support received from the Talent Introduction Project,part of the Elite Program of Shandong University of Science and Technology(No.0104060540171).
文摘This study investigated the correlations between mechanical properties and mineralogy of granite using the digital image processing(DIP) and discrete element method(DEM). The results showed that the X-ray diffraction(XRD)-based DIP method effectively analyzed the mineral composition contents and spatial distributions of granite. During the particle flow code(PFC2D) model calibration phase, the numerical simulation exhibited that the uniaxial compressive strength(UCS) value, elastic modulus(E), and failure pattern of the granite specimen in the UCS test were comparable to the experiment. By establishing 351 sets of numerical models and exploring the impacts of mineral composition on the mechanical properties of granite, it indicated that there was no negative correlation between quartz and feldspar for UCS, tensile strength(σ_(t)), and E. In contrast, mica had a significant negative correlation for UCS, σ_(t), and E. The presence of quartz increased the brittleness of granite, whereas the presence of mica and feldspar increased its ductility in UCS and direct tensile strength(DTS) tests. Varying contents of major mineral compositions in granite showed minor influence on the number of cracks in both UCS and DTS tests.
文摘The flotation results of a phosphate ore are improved by replacing the conventional collectors of fatty acids with composite collectors. The synergistic effect on the froth characteristics in systems using composite collectors has then been studied, and the concept of 'mixed hemimicellae' has been proposed in the adsorption of composite collectors at the air/solution interfaces.
基金supported by the National Natural Science Foundation for Excellent Young Scholars of China(No.52222110)the Natural Science Foundation of Jiangsu Province(No.BK20211230).
文摘Coral reef limestone at different depositional depths and facies differ remarkably on the textural and mineralogical characteristics,owing to the complex sedimentary diagenesis.To explore the effects of pore structure and mineral composition associated with diagenetic variation on the mechanical behavior of reef limestone,a series of quasi-static and dynamic compression tests along with microscopic examinations were performed on the reef limestone at shallow and deep burial depths.It is revealed that the shallow reef limestone(SRL)is classified as a porous aragonite-type carbonate rock with high porosity(55.3±3.2)%and pore connectivity.In comparison,the deep reef limestone(DRL)is mainly composed of dense calcite-type calcium carbonate with low porosity(4.9±1.6)%and pore connectivity.The DRL strengthened and stiffened by the tight grain framework consistently displays much higher values of the dynamic compressive strength,elastic modulus,brittleness index,and specific energy absorption than those of the SRL.The gap between two types of limestone further increases with an increase in strain rate.It appears that the failure pattern of SRL is dominated by the inherent defects like weak bonding interfaces and growth lines,revealed by the intricate fracturing network and mixed failure.Likewise,although the preexisting megapores in DRL may affect the crack propagation on pore tips to a certain distance,it hardly alters the axial splitting failure of DRL under impacts.The stress wave propagation and attenuation in SRL is primarily controlled by the reflection and diffusion caused by plenty mesopores,as well as an energy dissipation in layer-wise pore collapse and adjacent grain crushing,while the stress wave in DRL is highly hinged on the insulation and diffraction induced by the isolated megapores.This process is accompanied by the energy dissipation behavior of inelastic deformation resulted from the pore-emanated microcracking.
基金funded by the the Public Service Sectors (Agriculture) Research Special Funds, China(201203013-06)supported in partial by the International Plant Nutrition Institute (IPNI ChinaProgram: Hunan-16)the Key Technologies R&D Program of China during the 12th Five-Year-Plan period(2012BAD05B05-3)
文摘Increasing K+ adsorption can be an effective alternative in building an available K pool in soils to optimize crop recovery and minimize losses into the environment. We hypothesized that long-term fertilization might change K+ adsorption because of changes in the chemical and mineralogical properties of a rice (Oryza sativa L.). The aims of this study were (i) to determine clay minerals in paddy soil clay size fractions using X-ray diffraction methods and a numerical diagramdecomposition method; (ii) to measure K+ adsorption isotherms before and after H202 oxidation of organic matter, and (iii) to investigate whether K+ adsorption is correlated with changes in soil chemical and mineral properties. The 30-yr longterm fertilization treatments caused little change in soil organic C (SOC) but a large variation in soil mineral composition. The whole-clay fraction (〈5 Jam) corresponded more to the fertilization treatment than the fine-clay fraction (〈1 gin) in terms of percentage of illite peak area. The total percentage of vermiculite-chlorite peak area was significantly negatively correlated with the total percentage ofillite peak area in the 〈5 lam soil particles (R=-0.946, P〈0.0006). Different fertilization treatments gave significantly different results in K+ adsorption. The SOC oxidation test showed positive effects of SOC on K+ adsorption at lower K+ concentration (≤120 mg L-0 and negative effects at higher K+ concentration (240 mg L-l). The K+ adsorption by soil clay minerals after SOC oxidization accounted for 60-158% of that by unoxidized soils, suggesting a more important role of soil minerals than SOC on K+ adsorption. The K+ adsorption potential was significantly correlated to the amount of poorly crystallized illite present (R--0.879, P=0.012). The availability of adsorbed K+ for plant growth needs further study.
基金supported by a National Program on Key Basic Research Project(973 Program,Grant No.2011CB808903)National Natural Science Foundation of China(Grant Nos.41073030 and 41121002)a 'CAS Hundred Talents' project under Chinese Academy of Sciences to CYW and a GIGCAS 135 project Y234041001
文摘The Xinjie layered intrusion in the Panxi region,SW China,hosts both Fe-Ti oxide and platinum-group element(PGE) sulfide mineralization.The intrusion can be divided,from the base upward,into UnitsⅠ,ⅡandⅢ,in terms of mineral assemblages.UnitsⅠandⅡare mainly composed of wehrlite and clino-pyroxenite, whereas UnitⅢis mainly composed of gabbro.PGE sulfide-rich layers mainly occur in Unit I, whereas thick Fe-Ti oxide-rich layers mainly occur in UnitⅢ.An ilmenite-rich layer occurs at the top of UnitⅠ.Fe-Ti oxides include magnetite and ilmenite.Small amounts of cumulus and intercumulus magnetite occur in UnitsⅠandⅡ.Cumulus magnetite grains are commonly euhedral and enclosed within olivine and clinopyroxene.They have high Cr2O3 contents ranging from 6.02 to 22.5 wt.%,indicating that they are likely an early crystallized phase from magmas.Intercumulus magnetite that usually displays ilmenite exsolution occupies the interstices between cumulus olivine crystals and coexists with interstitial clinopyroxene and plagioclase.Intercumulus magnetite has Cr2O3 ranging from 1.65 to 6.18 wt.%, lower than cumulus magnetite.The intercumulus magnetite may have crystallized from the trapped liquid.Large amounts of magnetite in UnitⅢcontains Cr2O3(&lt;0.28 wt.%) much lower than magnetite in UnitsⅠandⅡ.The magnetite in UnitⅢis proposed to be accumulated from a Fe-Ti-rich melt.The Fe-Ti-rich melt is estimated to contain 35.9 wt.%of SiO2,26.9 wt.%of FeOt,8.2 wt.%of TiO2,13.2 wt.%of CaO, 8.3 wt.%of MgO,5.5 wt.%of Al2O3 and 1.0 wt.%of P2O5.The composition is comparable with the Fe-rich melts in the Skaergaard and Sept Iles intrusions.Paired non-reactive microstructures,granophyre pockets and ilmenite-rich intergrowths,are representative of Si-rich melt and Fe-Ti-rich melt,and are the direct evidence for the existence of an immiscible Fe-Ti-rich melt that formed from an evolved ferro-basaltic magma.
基金The National Natural Science Foundation of China(No.40275040) and the Shanghai Leading Academic Disciplines(No. T0105)
文摘This work mainly focuses on the mineralogical study of particulate matter(PM10) in Beijing. Samples were collected on polycarbonate filter from April, 2002 to March, 2003 in Beijing urban area. Scanning electronic microscopy coupled with energy dispersive X-ray(SEM/EDX) was used to investigate individual mineral particles in Beijing PM10. 1454 individual mineral particulates from 48 samples were analysed by SEM/EDX. The results revealed that mineral particulates were complex and heterogeneous. 38 kinds of minerals in PM10 were identified. The clay minerals, of annual average percentage of 30.1%, were the main composition among the identified minerals, and illite/smectite was the main composition in clay minerals, reaching up to 35%. Annual average percentage of quartz, calcite, compound particulates, carbonates were 13.5%, 10.9%, 11.95%, 10.31%, respectively. Annual average percentage less than 10% were gypsum, feldspar, dolomite, and so on. Fluorite, apatite, halite, barite and chloridize zinc(ZnCl2) were firstly identified in Beijing PM10. Sulfurization was found on surface of mineral particles, suggested extensive atmospheric reaction in air during summer.
基金supported by the Fourth Petroleum Resource Evaluation Project of China (Grant No. 2013E050209)the National S&T Major Project of China (Grant No. 2012E330)
文摘The Lower Cretaceous Xiagou Formation contains the major source rocks for the crude oils discovered in the Qingxi Sag and the South Uplift in the Jiuquan Basin, northwestern China. The Xiagou Formation source rock was formed in a closed,anoxic, reducing, alkaline lacustrine environment with a high salinity. Its high content of brittle minerals is favorable for the fracturing of reservoirs in source rock formations in the Qingxi Sag. The Xiagou Formation contains a great number of fair to excellent source rocks, and their organic matter(OM) came chiefly from plankton/algae and high plants as well as possibly bacterial organisms. The Xiagou Formation source rocks mainly contain Type II OM and some Type III and Type I OM, with good oil-generating potential. The source rock maturity is mainly in the early-mature and mature stages, and its Rovalue corresponding to oil peak is about 0.8%, which is lower than classic oil peak Rovalue of 1.0%; therefore, a great deal of hydrocarbon was generated before the classic oil peak Ro= 1.0%. Mature source rock in the Xiagou Formation tends to be distributed in the older members and at a greater depth. There is a better exploration potential of tight oil in the deep Qingxi Sag.
基金financially supported by the Key R&D Program of China(Grant No.2017YFC0602402)the Innovationdriven Plan of Central South University,China(Grant No.2015CX008)+2 种基金the China Postdoctoral Science Foundation(Grant No.2017M622597)Open Research Fund Program of Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University),Ministry of Education(Grant No.2019YSJS23)the Natural Science Foundation of Hunan Province(Grant No.2017JJ3138)
文摘The Jiuyishan complex massif,located in the northern section of the Nanling region,is a combination of five plutons,namely,the Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan plutons.Whole-rock geochemistry,Imineral electron microprobe analysis,zircon U-Pb dating and Hf isotope analysis were carried out for the Jinjiling and Pangxiemu plutons.The zircon U-Pb dating yields weighted mean ages of 152.9±0.9 Ma for the Jinjiling pluton and 151.7±1.5 Ma for the Pangxiemu pluton,with a narrow gap between them.The Jinjiling and Pangxiemu plutons both have geochemical characteristics of high SiO2,Al2 O3,Na2 O,K2 O and low TiO2,MgO,CaO,P2 O5 contents,with intense depletions in Sr,Ba,Ti,Eu and enrichments in Ga,FeoOT and HFSE,and these characteristics reflect an A-type affinity.From the Jinjiling to the Pangxiemu plutons,the mineral composition of mica changes from lepidomelane to zinnwaldite,with increases in F,Li2 O and Rb2 O contents.The mineral composition of zircon changes from low Zr/Hf to high Zr/Hf,with increasing HfO2,P2 O5 and UO2+ThO2+Y2 O3 contents.The mineral compositions of feldspar indicate that the Pangxiemu pluton contains more alkali feldspar than the Jinjiling pluton.The whole-rock geochemistry and mineral compositions reveal a higher degree of differentiation for the Pangxiemu pluton.The nearly uniformεHf(t)indicates the same source region for the two plutons:both were derived from partial melting of the lower crust,with small contributions of mantle materials.In addition,higher F,lower Nb/Ta and Zr/Hf ratios in the Pangxiemu Pluton suggest a closer relationship with the rare metal mineralization than for the Jinjiling pluton.
基金Funded by the National Natural Science Foundation of China(No.51574055)
文摘To reveal the influence of mechanical activation on the performance of fly ash, the microanalysis(the energy spectroscopy, XRD and SEM), the distribution size of particle of fly ash and cement paste intensity of various age for different grinding time were studied. The relationships of the activity and the composition of fly ash, microstructure and the distribution of particle size by mechanical activation of fly ash were obtained. The internal glass beads with activity were released by grinding fly ash for a certain time. The particle specific surface area was improved and the hydration reaction of the interface and the surface active center was increased by grinding. The granularity distributing of fly-ash trended towards optimization. The polar molecules or ions were easier to intrude into the internal cavity of the vitreous body. The active silica and alumina of fly ash were rapidly depolymerized. Each performance index of fly ash was increased before grinding for 20 min. Cement paste intensity of various age increased along with the grinding time, and the early strength increase range was big, but the later period intensity increase range hastened slightly. The internal part of vitreous of fly ash was destroyed if the fly ash continued to be ground and the activity of fly ash was reduced. It is suggested that Guozhuang's fly ash should be ground for 20 min.
基金jointly supported by a grant from the National Natural Science Foundation of China(No.41490634)the National Key Basic Research Special Foundation of China(No.2015FY210500)
文摘Spectra are sensitive in detecting main minerals on the lunar surface from visible light to infrared light. Since spectral characteristics of minerals are closely related to their compositions and the maturity level of soil on the Moon, studying the compositions and distribution of elements and minerals on the lunar surface can help to understand the evolution of the Moon through remote sensing technology. The correlation between the spectral characteristics of Chang'e-1 interference imaging spectrometry(IIM) reflectance images and the mineral contents of LSCC(Lunar Soil Characterization Consortium) lunar surface mineral samples was discussed and the spatial distributions of Fe O and Al_2O_3 contained in both pyroxene and plagioclase on LQ-4 were studied using the improved angle parameter method, MNF, and band ratio statistics. A comparison of the mapping results of the optical models by Lucey, Shkuractov and other researchers on Clementine and the gamma ray spectrometry data shows that the content error is within 0.6% for lunar mare areas and close to 1% for the highland areas. The tectonic framework on the lunar surface was also investigated. And based on integrated analysis of previous findings on topography of the lunar surface, Chang'e LAM, CCD and LOLA images and the gravity anomalies data(Clementine GLGM-2), the tectonic unit subdivision was established for LQ-4, the idea of subdividing the lunar tectonic units was proposed, and this will provide a good foundation for studying the lunar tectonic evolution.
基金The National Programme on Global Change and Air-sea Interaction under contract No.GASI-02-SCS-CJ03China Geological Survey:Continental Shelf Drilling Program under contract No.GZH201100202China-Thailand Cooperation Project"Research on Vulnerability of Coastal Zones"
文摘Generation, morphology, and distribution of authigenic minerals directly reflect sedimentary environment and material sources. Surface sediments were collected from the western Gulf of Thailand during 2011–2012, and 159 samples were analyzed to determine detrital minerals. Authigenic minerals, including siderite, pyrite, and glauconite, are abundant whereas secondary minerals, such as chlorite and limonite, are distributed widely in the study area. Siderite has a maximum content of 19.98 g/kg and appears in three types from nearshore to continental shelf, showing the process of forming-maturity-oxidation. In this process, the Mn O content in siderite decreases, but FeOand Mg O content increase. Colorless or transparent siderite pellets are fresh grains generated within a short time and widely distributed throughout the region; high content appears in coastal area where river inputs are discharged. Translucent cemented double pellets appearing light yellow to red are mature grains; high content is observed in the central shelf. Red-brown opaque granular pellets are oxidized grains,which are concentrated in the eastern gulf. Pyrite is mostly distributed in the central continental shelf with an approximately north–south strip. Pyrite are mainly observed in foraminifera shell and distributed in clayey silt sediments, which is similar to that in the Yangtze River mouth and the Yellow Sea. The pyrite in the gulf is deduced from genetic types associated with sulfate reduction and organic matter decomposition. Majority of glauconite are granular with few laminar. Glauconite is concentrated in the northern and southern parts within the boundary of 9.5° to 10.5°N and is affected by river input diffusion. The distribution of glauconite is closely correlated with that of chlorite and plagioclase, indicating that glauconite is possibly derived from altered products of chlorite and plagioclase. The KO content of glauconite is low or absent, indicating its short formation time.
基金supported by the National Natural Science Foundation of China (Grant No. 42072194, U1910205)the Fundamental Research Funds for the Central Universities (800015Z1190, 2021YJSDC02)。
文摘Mechanical properties of shales are key parameters influencing hydrocarbon production – impacting borehole stability, hydraulic fracture extension and microscale variations in in situ stress. We use Ordovician shale(Sichuan Basin, China) as a type-example to characterize variations in mineral particle properties at microscale including particle morphology, form of contact and spatial distribution via mineral liberation analysis(MLA) and scanning electron microscopy(SEM). Deformation-based constitutive models are then built using finite element methods to define the impact of various architectures of fracture and mineral distributions at nanometer scale on the deformation characteristics at macroscale.Relative compositions of siliceous, calcareous and clay mineral particles are shown to be the key factors influencing brittleness. Shales with similar mineral composition show a spectrum of equivalent medium mechanical properties due to differing particle morphology and mineral heterogeneity. The predominance of small particles and/or point-point contacts are conducive to brittle failure, in general, and especially so when quartz-rich. Fracture morphology, length and extent of filling all influence shale deformability. High aspect-ratio fractures concentrate stress at fracture tips and are conducive to extension, as when part-filled by carbonate minerals. As fracture spacing increases, stress transfer between adjacent fractures weakens, stress concentrations are amplified and fracture extension is favored. The higher the fractal dimension of the fracture and heterogeneity of the host the more pervasive the fractures. Moreover, when fractures extend, their potential for intersection and interconnection contributes to a reduction in strength and the promotion of brittle failure. Thus, these results provide important theoretical insights into the role of heterogeneity on the deformability and strength of shale reservoirs with practical implications for their stimulation and in the recovery of hydrocarbons from them.
基金funded by the National Science&Technology Pillar Program of Sichuan(2013NZ0029,2015NZ0092&2014FZ0004)the Youth Foundation Program of the Financial&Innovational Capacity Building Project of Sichuan(2014CXSF-030)
文摘Fruiting bodies(500 g per site) of Tricholoma matsutake and the surface layer of soils collected from 20 spatially distant areas with pristine backgrounds across China were analyzed for potassium,magnesium,calcium,zinc,iron,copper,manganese and cadmium using inductively coupled plasma optical emission spectroscopy.In terms of the bioconcentration and bioexclusion concept,K,Mg,Zn,and Cu were highly bioconcentrated,and their bioconcentration factor values varied between 75-615,2-107,38-603 and 7-76,respectively,across the 20 sites.Fe,Mn and Cd were moderately bioconcentrated and their bioconcentration factors(BCFs) varied between 0.6-34.0,0.4-37.0 and 0.9-7.0 respectively.However,Ca was excluded(BCF<1).T.matsutake is a species that is harvested in the wild as a valuable food and can contain a wide spectrum of both essential and hazardous mineral compounds that accumulate at elevated concentrations even if grown in pristine areas.The estimated intake rate of Cd in the fruiting bodies indicates cause for concern associated with this metal resulting from the daily consumption of between 200 and 400 g of fruiting bodies on a frequent basis during the mushrooming season.
基金sponsored by the Natural Science Youth Project of University Scientific Research Plan in Xinjiang(XJEDU2021Y053)the Talent introduction research project of China University of Petroleum-Beijing at Karamay(XQSQ20200056)the Strategic Cooperation Tech-nology Projects of CNPC and CUPB(Grant No.ZLZX2020-01).
文摘Natural fractures are widely distributed in shale reservoirs.During the hydraulic fracturing process,frictional slip occurring on natural fractures can increase the reservoir permeability and is of great significance to improve the efficiency of reservoir stimulation.Shale contains a large amount of clay and organic matter,and its frictional behavior is different from that of other previously studied lithologies.In this paper,the frictional behavior of shale is analyzed,and the results show that the frictional behavior is controlled by the content of clay and organic matter.As the content of clay and organic matter increases,the micro support type transforms from the particle support mode by hard quartz mineral to matrix support mode by plastic clay and organic matter.Accordingly,the shear strength and friction coefficient of shale both decrease,and the shear type transforms from brittle to plastic.When the content of clay and organic matter is low,the asperity of friction surfaces will break in a brittle manner and the wear degree of surfaces is low.Therefore,fractures are still featured by moderate apertures after friction.The lower the content of clay and organic matter is,the easier the asperity of crack surfaces supports themselves,and the higher the fracture residual permeability is.Thus,promoting shear slip is the main measure of reservoir stimulation.However,when the content of clay and organic matter is high,the remaining post-slip fracture aperture is small.It is difficult to increase reservoir permeability through the frictional slip of natural fractures,and in this situation,the proppant support efficiency needs to be improved.
文摘Spices which are widely used in Southwest Nigeria have aroma, enhance taste of food and possess medicinal values. Proximate, mineral composition and phytochemical screening of ten randomly selected spices were carried out. Recommended procedures were used for the analyses. Mineral composition was determined using flame photometer, colorimeter and (Atomic Absorption Spectrophotometer). The proximate composition showed that protein was high at 12.04% in Zingiber officinale and low at 2.1% in Xylopia aethiopica. Ocimium gratissium contained high moisture content at 82.1%, while Tetrapleura tetraptera had the least value of 3.5%. High ash content was recorded in Ocimum gratissium at 13.68% and lowest 0.98% in Allium cepa. For carbohydrate, Allium cepa had the highest value of 78.36%, while Allium setiva had the least value of 19.48%. Mineral composition showed high value of calcium 712 mg/100g, magnesium 172.2 mg/100g, potassium 868.5 mg/100g, sodium 75.85 mg/100g, and manganese 95.38 mg/100g in Allium sativa, Xylopia aethiopica, Momodara myristica, Ocimum gratissimum, Tetrapleura tetraptera respectively. Aframomium meleghueta had high value of iron and zinc at 85 mg/100g and 97 mg/100g respectively and also high presence of alkaloids, glycosides, saponins and tarmis. High values of saponins and triterpenoids were observed in Zingiber officinale and Ocimum gratissimum respectively. This study showed that spices have greater use in medicine and as food supplement.
文摘A field experiment was conducted in 2009 and 2010 growing seasons, to study the effect of foliar application of iron-chelated "Fe-EDTA" at concentration 0, 100 and 200 mg/L on the seasonal dynamic of mineral composition of N, P, K, Fe and Zn in petioles and berries of Halwani Lebanon and Kamali grape cultivars, grown on a calcareous soil in Mosul region, Iraq. The results revealed that the foliar application of 200 mg Fe/L caused a significant increase of N, P, K, Fe and Zn concentrations in petioles and berries compared with the control for both seasons. Additionally, the N, P, K, Fe and Zn concentration in petioles were high at the beginning of the growth season, whereas, decrease towards in the end of the growth season in both cultivars and seasons. While the N, P, K, Fe and Zn in berry content was increased towards from berry set to veraison and ripening stage in both cultivars and seasons. So there are various element contents in the cultivars.