Geochemical characteristics and environmental implications of loess sequences in the Loess

The major,trace,and rare earth elements of the Duanjiapo(DJP)section in the south of the Loess Plateau,the Jiaxian(JX)section in the north,and the Jiuzhoutai(JZT)section in the west are studied.The results show that the main elemental characteristics of loess in three profiles are consistent with the upper continental crust(UCC).In terms of trace elements,Th,Nb,Zr,Hf,Y,Cs,W,Cr,V,Li,and Pb show relative enrichment compared with UCC;Rb,Ba,Sr and Be exhibit relative depletion.The average ofΣREE is 171.91ppm with a negative anomaly forδEu and essentially no anomaly forδCe.The results of K_(2)O/Na_(2)O,Rb/Sr ratios,as well as the leaching co-efficient from three profiles,indicate DJP>JX>JZT,suggesting that DJP experiences the strongest weathering leaching effect.The chemical index of alteration(CIA)reveals that all three profiles of loess are in the primary stage of Ca and Na depletion.DJP is generally in the early to moderate stage of chemical weathering,while JX and JZT are both in the early stage.

Assessment of Surface Water Quality of King Abdullah Canal, Using Physico-Chemical Characteristics and Water Quality Index, Jordan

The main aim of this research is to evaluate the water quality of King Abdullah Canal (KAC) using the water quality index method (WQI). For this purpose, nine different sampling sites were used in the calculation of WQI during the period of January to December 2012. The samples were analyzed for various physico-chemical parameters such as pH, electrical conductivity, total suspended solids, ions of Sodium, Potassium, Calcium, Magnesium, Fluorite, Chloride, Sulfate, Bicarbonate, and Nitrate in different seasons (winter, spring, summer and autumn). The analyzed results (by WQI method) have been used to suggest models for predicting water quality. The relative weight assigned to each parameter has a range from 1 to 5, based on the important parameters for drinking purposes. The computed WQI for the nine samples has a range from 46.66 to 542.08. The analysis reveals that the water quality status of the study area is varying from excellent to good in the upper part of the canal and from poor to very poor in the lower part of the canal. Comparing with the World Health Organization (WHO) and Jordan Standard (JS), the results indicate that the lower part of the canal is polluted. Therefore, the water is not safe for domestic use and needs further treatment, especially in the lower part of the canal.

Chemical indexes of Paleoproterozoic sedimentary rocks from Liaohe Group,North China Craton:Implications for paleoclimate and provenance

Paleoproterozoic supracrustal materials have been widely identified in North China Craton,such as the Liaohe-,Hutuo-and Lyuliang groups.The Liaohe Group in the eastern part of the North China Craton is dominated by deformed and metamorphosed sedimentary and volcanic successions.Compared with that of the coeval volcanic rocks,geochemistry of the sedimentary rocks from the Liaohe Group has rarely been studied in detail,which can possibly provide information on the paleoclimate and provenance.The authors analyzed the whole-rock and detrital zircon geochemistry of sedimentary rocks from the Liaohe Group against a uniform process and proposed their different ways of paleoweathering of the lower and upper formations.That is to say,although the lower and upper formations within the Liaohe Group might be derived from the similar source composition in a tectonically active setting,the paleoclimate that they experienced was not exactly the same.The predominant derivations are the Paleoproterozoic granitoids and basalts within the Liaohe Group,with minor input of Archean continental crust.This study highlights the contributions of the Paleoproterozoic mafic sources,which has been generally overlooked in the previous researches.

The atom-bond connectivity index of chemical bicyclic graphs

The atom-bond connectivity（ABC） index provides a good model for the stability of linear and branched alkanes as well as the strain energy of cycloalkanes,which is defined as ABC（G） =∑ uv∈E（G） √d u＋dv-2 dudv,where du denotes the degree of a vertex u in G.A chemical graph is a graph in which no vertex has degree greater than 4.In this paper,we obtain the sharp upper and lower bounds on ABC index of chemical bicyclic graphs.

Darcy's Law Expressed by Chemical Index

The Darcy's formula expressed by chemical indexes (ion activity a and saturation index β) is derived with the aid of the kinetics of multi-mineral dissolution. The implication of the formula and the relationship between the formula and the original Darcy's law expressed by hydraulic index (hydraulic gradient, Ⅰ) are discussed here. An analytic expression is established in this paper for the determination of the residence time of groundwater by chemical indexes, whose equivalence to isotopic age is studied. The formulas are derived from the calculation of permeability coefficient (K), conductivity coefficient (T) and actual velocity of groundwater (U). Finally, this paper introduces hydrogeological chemical kinetics constant (k j) and its determination method, differential and integral equations for chemical kinetics of groundwater in three-dimensional space.

Drivers of the Chemical Quality of Market Gardening Soils in the Urban and Peri-Urban Environment of Bobo-Dioulasso (Burkina Faso): Impact of Fertilizers Sources and Sites Location

Urban and peri-urban agriculture plays a key role by providing many goods and services. In particular, it provides diversified food and employment for vulnerable groups (youth and women). However, it often involves negative externalities due to non-conventional soils fertility management practices. This study aimed to investigate the chemical quality of soils over six (06) sites of the market gardening area of Bobo-Dioulasso (Burkina Faso) as affected by fertilizers uses and sites location. Thirty (30) representative market gardening farms, located in urban, semi-urban and rural areas, were randomly selected from a baseline survey database. Within each farm, composite soil samples made up of 3 individual cores were taken over the 0 - 15 cm soil depth for determining soils carbon, total nitrogen, available phosphorus contents and pH-water. These data were normalized and summarized to compute a synthetic Soil Fertility Index (SFI). The data processing was focused on a Principal Component Analysis and an Ascendant Hierarchical Classification in order to make a typology of the vegetable farms. Fertilizers management effects on soils quality were compared through Variance Analysis (ANOVA) following a GLM procedure in Rstudio software. As main results, soils chemical parameters, except for available K, were affected by the location of the sites. Soils in urban farms are less acidic (on average pH = 6.9), while semi-urban and rural sites (Samadeni, Nakaguana) have more acidic soils. However, the latter site had the highest values of C and N. Moreover, the long-term application of organic matter sources results in improving of the chemical quality of the market garden soil. The SFI is positively correlated with the rate of applied organic fertilizers, and the cultivation duration. On the other hand, soil quality tends to decrease with the expansion of the area, due to a dilution effect of the organic fertilizer doses. All these results suggest that there is a real scope to reinforce the position of the market garden as an opportunity for recycling organic wastes and sequestration of carbon by promoting relevant fertilization packages that strongly rely on organic matters sources (Compost, Biochar, etc.).

GIS-Based Assessment of Soil Chemical and Physical Properties as a Basis for Land Reclamation in Toshka Area, Aswan, EGYPT

The accurate assessment of soil properties is a crucial factor for composing and implementing reclamation plans. The main objective of this study was to evaluate soil chemical and physical properties and calculate the chemical and fertility index for assisting land reclamation in Toshka area. The Toshka area is located between latitudes 31°32'N and 31°36'N and longitudes 32°40'E and 32°60'E. GIS was used to select 16 sites. The results revealed the soil has undesirable characteristics. The soil pH ranged from slightly alkaline to moderately alkaline. Furthermore, it was characterized as saline (with a ECe of 4.65 - 11.45 dS⋅m−1) and moderately calcareous soil (with CaCO3 at 11.85% - 17.20%). The soil had a low soil organic matter content which did not exceed 0.18%. The soil was dominated by a sandy loam texture (62.50%) followed by a sandy clay loam texture (18.75%). The bulk density, total soil porosity and saturated hydraulic conductivity values varied with 1.38 - 1.55 Mg⋅cm−3, 41.85% - 48.45% and 1.20 - 3.34 cm⋅h−1, respectively. The chemical index ranged from low to moderate quality. The correlations between the parameters osculated between negative and positive. Therefore, the soil may be reclaimed if the soil properties are improved and crop selection is optimized for this soil.

Efficiencies of Chemical Techniques for Rice Grain Freshness Analysis

Two chemical methods which are commonly used for rice grain freshness determination were investigated for their efficiencies. Method 1 is made of bromothymol blue indicator, and the principle is based on indicator＇s color which is changed in according to pH of the stored rice grains. Method 2 is based on peroxidase activity which deteriorates during storage of rice grains. Both methods were used for determination of fresh-aged rice index of six Thai-rice cultivars, four from non-waxy rice cultivars （KDML 105, Chai Nat 1, Chai Nat 2 and Phitsanulok 2） and two from waxy rice cultivars （San-pah-tawng and RD6）. Rice samples were kept in the forms of paddy and polished rice. Fresh-aged rice indices were determined using both methods every two weeks over the storage period of 24 weeks （six months）. It was found that both methods were capable of detecting fresh-aged rice indices. The color of chemical solutions changed with regards to the age of rice grains and it could be detected spectrophotometrically. Rice grains which have been kept as paddy provided more consistent results. Method 1 is recommended for industrial application as it is simple, efficient and inexpensive.

Characteristics Analysis of Chemical Concentration Sensor Based on Three-layer FBG

The three-layer structure model of the fiber Bragg grating is proposed in this paper. And through experimental study and reasoning calculation to verify the three layer structure of the optical waveguide model, so the sensitivity characteristic of the Bragg wavelength to the refractive index of chemical solution is obtained. And the relationships between the concentration and the shift of Bragg wavelength of sucrose, ethanol, and Nacl solution are achieved. Finally the shifts of the Bragg wavelength with the external concentration are obtained by experiments. A kind of simple structure, small size, good stability, high sensitivity chemical concentration sensor is obtained.

Geochemical characteristics of Holocene sediments from Chuadanga district, Bangladesh: Implications for weathering, climate, redox conditions, provenance and tectonic setting

The present research deals with the geochemical characteristics of the Holocene sediments from Alamdanga area, Chuadanga district, Bangladesh. Main goals of the study are to delineate source rock characteristics, degree of chemical weathering and sorting processes and behavior of redox conditions during deposition of the sediments. Geochemical characteristics of the sediments show comparatively a wide variation in accordance with stratigraphy in their major element contents(e.g. Si O2 69.46–82.13, Al2O3 2.28–8.88 in wt%), reflecting the distinctive provenance and in part an unstable period in terms of tectonic activity. Geochemical classification of the sediments shows mostly sub-arkose with few sub-litharenites. Some major and trace elements display comprehensible correlation with Al2O3 confirming their possible hydraulic fractionation. The chemical index of alteration(CIA*), W* index, index of compositional variability(ICV), plagioclase index of alteration(PIA*) values and the ratio of Si O2/Al2O3, suggest low degrees of chemical weathering in the source areas as well as immature to moderately mature the sediments. The sediments suggest semi-arid climatic trends within oxic deltaic depositional conditions during the Holocene, at 3–12 ka. Whole rock geochemistry and discrimination diagrams demonstrate the continental signature derivatives, which might have been derived from the felsic to intermediate igneous rocks(granitic plutonic rocks) as well as from quartzose sedimentary/metamorphic provenance. These typical sources are present in a vast region of the Himalayan belt and catchment areas of Ganges. The tectonic setting of the sediments demarcates typically passive margin with slightly continental arc system.

Chemical Effect Analyses of 3d Elements by Study of X-Ray Fluorescence Spectra

Spectra of KX-rays emitted from pure 3 dtransition metals and their oxide and sulfate compounds were measured using a single crystal wavelength dispersive X-ray spectroscopy(WDXRF).The measurements were performed using a ZSX-100 esequential spectrometer equipped with an RhX-ray tube operated.An accurate analytical representation of each line was obtained by a fit to a Lorentz function.The spectra were analyzed in order to examine the KX-ray peak parameters such as asymmetry index,peak energy and relative intensity ratios.The energy shifts and relative intensities weredetermined tobetter understand the chemical effect.

Impact of intensity variability of the Asian summer monsoon anticyclone on the chemical distribution in the upper troposphere and lower stratosphere

During the Asian summer monsoon(ASM)season,the process of stratosphere-troposphere exchange significantly affects the concentration and spatial distribution of chemical constituents in the upper troposphere and lower stratosphere(UTLS).However,the effect of the intensity of the Asian summer monsoon anticyclone(ASMA)on the horizontal distribution of chemical species within and around the ASMA,especially on the daily time scale,remains unclear.Here,the authors use the MERRA-2 reanalysis dataset and Aura Microwave Limb Sounder observations to study the impact of ASMA intensity on chemical distributions at 100 hPa during the ASM season.The intraseasonal variation of ASMA is classified into a strong period(SP)and weak period(WP),which refer to the periods when the intensity of ASMA remains strong and weak,respectively.The relatively low ozone(O_(3))region is found to be larger at 100 hPa during SPs,while its mixing ratio is lower than during WPs in summer.In June,analysis shows that the O_(3) horizontal distribution is mainly related to the intensity of AMSA,especially during SPs in June,while deep convections also impact the O_(3) horizontal distribution in July and August.These results indicate that the intraseasonal variation of the ASMA intensity coupled to deep convection can significantly affect the chemical distribution in the UTLS region during the ASM season.

Analysis of Physical and Chemical Indices and Quality of Blueberry Wines from Gardenblue and Baldwin

Gardenblue and baldwin rabbiteye blueberry are the alien varieties. The physical and chemical indices of the fresh fruits of the two varieties were analyzed. The results showed that the sugar-acid ratio was higher in gardenblue than in baldwin, and the content of anthocyanins was also higher in gardenblue than in baldwin, so the quality of gardenblue was better. The gardenblue wine has better quality than the baldwin wine, and the two kinds of wines both have good quality. Therefore, gardenblue and baldwin both are suitable for the brewing red wine as the raw material.

Analysis of the Correlation among Three Oxygen Demand Indexes in Surface Water

Based on the monitoring data of chemical oxygen demand(COD),permanganate index(I Mn)and five-day biochemical oxygen demand(BOD 5)of surface water in Tongling section of Yangtze River,the linear relationship among the three indexes in the annual data analysis and the internal reasons,as well as the linear relationship and changes among the three indexes in different seasons were analyzed.The results reveal that in terms of the whole year,COD,I Mn and BOD 5 had a significant correlation and good linear relationship.The fitting slopes of the three indexes were 3.89 of COD/I Mn,4.39 of COD/BOD 5 and 1.16 of I Mn/BOD 5,respectively,which corresponded to the proportional relationship among the three indexes.From the perspective of seasonal changes,there was a very significant correlation between the three indexes in spring and summer.In autumn and winter,only COD and I Mn had a good correlation,but they had a poor correlation with BOD 5.

化学封顶对不同果枝数棉田株型和产量的影响及其评价指标的筛选

【目的】研究化学封顶对不同果枝数棉田株型和产量的影响及其评价指标的筛选,分析棉花化学封顶剂摇钱素和向铃转的最佳施药时期,优选化学封顶效果评价指标,为化学封顶筛选应用提供支撑。【方法】采用完全随机区组试验设计,以人工打顶为对照,选择化学封顶剂摇钱素和向铃转,分别设置果枝数9台时、果枝数10台时、果枝数11台时、果枝数12台时4个化学封顶处理,测量棉花株高及株高增长量、倒1果枝~倒4果枝长度、有效果枝数、单株果节数、茎粗、主茎节间数、棉铃空间分布和籽棉产量。【结果】与人工打顶相比,果枝数9台时化学封顶处理的棉花株高显著增加,果枝数10台时施用向铃转、果枝数11台和12台时喷施摇钱素后单株果节数增加,化学封顶后主茎节间数增多、倒1果枝~倒4果枝长度变短,果枝数10台时施用向铃转后有效果枝率、化学封顶后茎粗、除果枝数9台时喷施摇钱素后上部铃占比外棉铃空间分布均变化不大。果枝数10台时喷施向铃转、果枝数11台和12台时喷施摇钱素后籽棉产量与人工打顶相比差异不显著。单株有效果枝率(以下简称果枝率)可作为化学封顶对棉花株型调控的评价指标。【结论】果枝数10台时喷施向铃转、果枝数11台时喷施摇钱素后棉花有效果枝率和单株果节数最高、株高增长量不高、籽棉产量不降低,有效果枝率可用于评价化学封顶对棉花株型调控的首选指标。

不同配比基质对草莓扦插苗生长的影响

为筛选适合培育草莓扦插苗的基质配方,本研究以草莓品种天使8号为试验材料,通过测定不同配比基质的理化指标及草莓扦插苗的生长指标,分析不同基质对草莓扦插苗生长的影响。结果表明,不同配比基质的总孔隙度、持水孔隙度、通气孔隙度存在差异,并且不同配比基质对草莓扦插苗生长的影响不同。其中椰糠∶草炭∶珍珠岩=4∶1∶1(重量比)为最佳基质配比,该配比基质的容重、总孔隙度、持水孔隙度较高。使用该基质培育的草莓扦插苗的叶柄粗、株高、茎粗、叶柄长、叶长和叶宽较大,地下部鲜重和地下部干重较大,同时草莓扦插苗气孔导度、胞间CO 2浓度、蒸腾速率较高。本研究结果为草莓穴盘扦插育苗的基质配置提供了参考。