Single-step ethylene polymerization over a binary catalyst,including zirconocene precatalysts of various designs,has been studied to obtain polymer compositions based on ultrahigh-molecular-weight polyethylene(UHMWPE)...Single-step ethylene polymerization over a binary catalyst,including zirconocene precatalysts of various designs,has been studied to obtain polymer compositions based on ultrahigh-molecular-weight polyethylene(UHMWPE)and low-molecular-weight HDPE(LMWPE)directly in synthesis.Zirconocenes rac-(CH_(3))_(2)Silnd_(2)ZrCl_(2)(Zr-1)and rac-(C_(6)H_(10))CplndZrCl_(2)(Zr-2)activated with methylaluminoxane(MAO)were used as the components of the binary catalyst.It has been shown that the use of Zr-1/MAO and Zr-2/MAO in ethylene polymerization at 30℃leads to the production of UHMWPE with Mw=1000 kg-mol^(-1)and LMWPE with Mw=18 kg·mol^(-1),respectively.Reactor polymer compositions(RPC)with LMWPE fraction contents ranging from 9 wt%to 42 wt%were obtained when a molar fraction of Zr-2 in the binary catalyst(Zr-1+Zr-2)/MAO va ried in the range from 0.3 to 0.85.A study of the molecular weight characteristics of RPC showed that it has a wide bimodal molecular weight distribution(MWD)and includes UHMWPE(Mw=1000 kg·mol^(-1))and LMWPE(Mw=18 kg·mol^(-1))fractions.The degree of crystallinity of the polymer products was determined using the DSC method.The tensile properties and melt indices of the materials were studied depending on the LMWPE fraction content in the polymer composition.UHMWPE/LMWPE compositions with high tensile properties and fluidity at a load of 5 kg were obtained.展开更多
In this paper we give combinatorial proofs of two recurrence relations for the special class of objects known as inplace compositions. We also obtain new identities for the numbers of inplace 1-2 compositions and pali...In this paper we give combinatorial proofs of two recurrence relations for the special class of objects known as inplace compositions. We also obtain new identities for the numbers of inplace 1-2 compositions and palindromic compositions.展开更多
Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships w...Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships with antioxidant activity and oxidative stability,gas chromatography-mass spectrometry was performed to characterize the associated fatty acid profiles.The antioxidant activity of vegetable oils,based on their DPPH-scavenging capacity(expressed as IC_(50) values),was used to assess their impact on human health,and their oxidative stability was characterized by performing lipid oxidation analysis to determine the oxidative induction time of fats and oils.In addition,correlation analyses were performed to examine associations between the fatty acid composition of the oils and DPPH-scavenging capacity and oxidative stability.The results revealed that among the assessed oils,coffee seed oil has the highest saturated fatty acid content(355.10 mg/g),whereas Garddenia jaminoides oil has the highest unsaturated fatty acid content(844.84 mg/g).Coffee seed oil was also found have the lowest DPPH IC_(50) value(2.30 mg/mL)and the longest oxidation induction time(17.09 h).Correlation analysis revealed a significant linear relationship(P<0.05)between oxidative stability and unsaturated fatty acid content,with lower contents tending to be associated with better oxidative stability.The findings of this study provide reference data for the screening of functional edible vegetable oils.展开更多
The chemical compositions of volatile oil from fruiting body of Armillaria luteo-virens in Qinghai Province were firstly analyzed with GC-MS and its relevant compositions were detected by calculating chromatographic p...The chemical compositions of volatile oil from fruiting body of Armillaria luteo-virens in Qinghai Province were firstly analyzed with GC-MS and its relevant compositions were detected by calculating chromatographic peak area with normalized method. 21 peaks were separated and 13 compositions were identified which were mainly unsaturated fatty acids, taking 97.1% of the total volatile oil.展开更多
The effect of seed oil of Korean pine (Pinus koraiensis) on the rats' blood-fat and its anti-ageing function was stud-ied for appraising the efficacy of the seed oil of Korean pine. Sixty experimental rats were ra...The effect of seed oil of Korean pine (Pinus koraiensis) on the rats' blood-fat and its anti-ageing function was stud-ied for appraising the efficacy of the seed oil of Korean pine. Sixty experimental rats were randomly divided into 5 groups (half males and half females in each group) as normal control group, high fat diet control group, and three groups (Group 1 Group 2, Group 3) that were fed with feedstuff with the contents of the seed oil of 2.0g/(kgd-1), 4.0g/(kgd-1) and 8.0g/(kgd-1), respec-tively. The indexes such as superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and anti-oxidation capacity (AOC) were measured by Reagent Kit method. It was found that the seed oil of the Korean pine could reduce the content of triglyc-eride and improve SOD as well as GSH-PX activity in serum. These indexes of the rats in Group 2 fed with Korean pine seed oil of 4.0 g/(kgd-1) reached the significant level and those of rats in Group 3 fed with the seed oil of 8.0 g/(kgd-1) reached the extremely significant level. The results indicated the seed oil of Korean pine had function of regulating the level of blood-fat and anti-ageing.展开更多
In the present study, the nutritional compositions of maca which was grown in a mountain area at an elevation of 2 200-2 800 m of Ebian County,Sichuan Province were measured, and then HPLC analysis on two representati...In the present study, the nutritional compositions of maca which was grown in a mountain area at an elevation of 2 200-2 800 m of Ebian County,Sichuan Province were measured, and then HPLC analysis on two representative active compounds（macaene and macamide） in the maca sample was performed.The results revealed that there were 24.20% total protein, 18.40% total amino acids（including 3.84% arginine）, 42.80% total sugars, 1.36% fat and kinds of minerals（including 1.14% potassium） in Ebian maca. HPLC fingerprints of macaene and macamide of Ebian maca were similar to those of Peru maca. The results suggested that maca could be cultivated with good quality in some mountain areas with an altitude1 000 m lower than the origin place in Peru.展开更多
[Objective] The aim was to identify the nourishing compositions of Fagopyrum tataricum and screen high-quality buckwheat materials.[Method]A total of 10 species of buckwheat including T32,T31,T30,T14,T28,T23,T24,Jiuji...[Objective] The aim was to identify the nourishing compositions of Fagopyrum tataricum and screen high-quality buckwheat materials.[Method]A total of 10 species of buckwheat including T32,T31,T30,T14,T28,T23,T24,Jiujiang Buckwheat,Weiku 2 and WK-1 were employed as experimental materials,and the contents of the nutritional components（including total sugar,reducing sugar,starch,amylose,amylopectin and protein）,flavonoids content,physical and chemical characteristics（such as expansive force,water holding capacity）of them were respectively measured.[Result]There were significant differences in contents of soluble protein,total sugar,reduced sugar,amylase and expansive force among the cultivars,but the differences in contents of total starch,amylopectin,flavonoids content and water holding capacity were not significant.[Conclusion]The starch content in seeds of buckwheat was relatively high,and amylopectin was the main composition.展开更多
The Malacca Strait(MS)is a vital conduit for the exchange of water and sediment between the Indian Ocean and the Pacific Ocean,serving as a critical‘gateway'for sediment transport.Here,we present the geochemical ...The Malacca Strait(MS)is a vital conduit for the exchange of water and sediment between the Indian Ocean and the Pacific Ocean,serving as a critical‘gateway'for sediment transport.Here,we present the geochemical characteristics of surface sediments in the MS to elucidate the relationship between terrestrial material inputs and modern oceanic dynamic transport processes in the strait.The results reveal that the MS can be divided into three distinct geochemical provinces.ProvinceⅠ,located in the central region of the strait,is characterized by residual deposits.The preservation of these residual deposits can be attributed to the restricted sediment supply and the relatively weaker modern sedimentary hydrodynamic conditions.ProvinceⅡ,situated to the north of ProvinceⅠ,exhibits provenance differences between its southern and northern regions.The northern region is primarily supplied by sediments originating from the eastern shelf of the Andaman Sea,whereas sediments derived from Sumatra and the Sunda Shelf are predominantly deposited in the southern part of ProvinceⅡ.ProvinceⅢextends along the western coast of the Malaysian Peninsula,with sediments primarily sourced from the Malaysian Peninsula and the Sunda Shelf,while contributions from Sumatra and the eastern shelf of the Andaman Sea are negligible.River sediments from the Malaysian Peninsula and Sumatra are transported northwestward along their respective coasts by prevailing currents,which also facilitate the transportation of Sunda Shelf sediments within the strait,while sediments from the eastern shelf of the Andaman Sea are delivered to the MS via southward coastal currents during the southwest monsoon period.The southward currents and well-developed eddies potentially impede the northward transport of sediments from the Sunda Shelf and restrict the distribution of Andaman Sea sediments within the strait.This study substantially enhances the understanding of source-to-sink processes in the Indo-Pacific region.展开更多
Aiming to control lake eutrophication,proposed methods for convenient and faithworthy lake water quality evaluation are warranted.Optical measurement of dissolved organic matter(DOM)demonstrates great potential for es...Aiming to control lake eutrophication,proposed methods for convenient and faithworthy lake water quality evaluation are warranted.Optical measurement of dissolved organic matter(DOM)demonstrates great potential for estimating organic matter(OM)composition,and can thus serve as a proxy for conventional chemical oxygen demand(COD_(Mn))measurements,which are considered as imprecise and environmentally unfriendly.Hence,we conducted a field campaign across 30 lakes in Wuhan's metropolitan area,collecting 255 samples from varying trophic states to evaluate the predictive capability of COD_(Mn)using DOM optical measurements combined with parallel factor(PARAFAC)analysis.The DOM optical properties and chemical composition exhibited considerable variability across varying trophic state levels(TSLs).Fluorescence components C1-C3 and C5,fluorescence index(FI),and absorption at 254 nm(α_(254)),increased as TSL increased,while the DOM spectral slope(SR)decreased.COD_(Mn)was positively and significantly correlated with fluorescence components C1-C3 and C5,freshness index(β/α),autochthonous index(BIX),humification index(HIX),α_(254),the ratio ofα_(250)toα_(365)(E2/E3)while being negatively correlated with SR.Parametersα_(254),C1,C3,C4,FI,β/α,and HIX were identified as key predictors of COD_(Mn).The multiple linear regression model successfully predicted COD_(Mn)(r^(2)=0.63,p<0.01,n=1113)and demonstrated superior performance in mesotrophic lakes.These findings highlight the potential for establishing high-frequency,continuous,and multi-regional COD monitoring programs.展开更多
In this paper,we study asymptotic power series of the composition f(x)=h(g(x)),where g(x)=∑_(n=0)^(∞)b_(n)x^(-n),b_(n)∈R,and h is a given elementary function.The asymptotic expansions have been obtained for the com...In this paper,we study asymptotic power series of the composition f(x)=h(g(x)),where g(x)=∑_(n=0)^(∞)b_(n)x^(-n),b_(n)∈R,and h is a given elementary function.The asymptotic expansions have been obtained for the composition with an exponential or logarithmic function.Using the re-cursive method,we present the asymptotic expansions for the composition with seven trigonometric functions,respectively.As an application,the asymptotic expansions of roots of some equations are given.Computational results show that our recursive formula is more efficient than the method of Lagrange's inverse theorem.展开更多
[Objective] The aim was to explore the inheritance of fat and fatty acid compositions in peanut.[Method] Genetic and correlation analyses were performed using a mixed genetic model of major gene plus polygene with 215...[Objective] The aim was to explore the inheritance of fat and fatty acid compositions in peanut.[Method] Genetic and correlation analyses were performed using a mixed genetic model of major gene plus polygene with 215 F9 RILs and their parents ZHENG 8903 and YUHUA No.4.[Result] The optimal genetic model of the fat content was two linked complementary major gene plus polygene inheritance model.The heritability of major genes was 22.88%.Oleic,linoleic,and palmitic acid content were controlled by two major genes and the heritability was 75.11%,75.00% and 60.95%,respectively.Stearic and arachidic acid content were controlled by two major genes plus polygenes,the heritability of major genes was 26.43% and 33.17%,respectively.O/L ratio and behenic acid content were controlled by three major genes,the heritability was 70.65% and 30.70%,respectively.[Conclusion] The result in this study was that accumulating polygenes should be emphasized in the improvement of fat content,while utilization of major genes is enhanced in improvement of oleic and linoleic acids.展开更多
During November–December 2010 aerosol scattering coefficients were monitored using a single-waved （525 nm） Nephelometer at a regional monitoring station in the central Pearl River Delta region and 24-hr fine partic...During November–December 2010 aerosol scattering coefficients were monitored using a single-waved （525 nm） Nephelometer at a regional monitoring station in the central Pearl River Delta region and 24-hr fine particle （PM 2.5） samples were also collected during the period using quartz filters for the analysis of major chemical components including organic carbon （OC）,elemental carbon （EC）,sulfate,nitrate and ammonium.In average,these five components accounted for about 85% of PM 2.5 mass and contributed 42% （OC）,19% （SO 4 2 -）,12% （NO 3 -）,8.4% （NH 4＋） and 3.7% （EC）,to PM 2.5 mass.A relatively higher mass scattering efficiency of 5.3 m 2/g was obtained for fine particles based on the linear regression between scattering coefficients and PM 2.5 mass concentrations.Chemical extinction budget based on IMPROVE approach revealed that ammonium sulfate,particulate organic matter,ammonium nitrate and EC in average contributed about 32%,28%,20% and 6% to the light extinction coefficients,respectively.展开更多
Kudingcha, a commonly used traditional Chinese medicine, has multiple functions in anti-radiation, anti-aging, quickening the blood vessels, reducing blood lipid and blood pressure and so forth. Therefore, this articl...Kudingcha, a commonly used traditional Chinese medicine, has multiple functions in anti-radiation, anti-aging, quickening the blood vessels, reducing blood lipid and blood pressure and so forth. Therefore, this article reviews the origins of Kudingcha, and analyzes the major triterpenoids and volatile chemicals, with an at- tempt to provide more references for the development and utilization of Kudingcha.展开更多
[Objective] The research was aimed to study the main chemical composi- tions of rice straw in the three different areas of Jiangsu Province. [Method] The cellulose, hemicellulose, lignin and crude ash of rice straw co...[Objective] The research was aimed to study the main chemical composi- tions of rice straw in the three different areas of Jiangsu Province. [Method] The cellulose, hemicellulose, lignin and crude ash of rice straw collected in Huaian, Changzhou and Zhenjiang of Jiangsu Province during 2011-2013 were determined. [Result] The change trends of cellulose and hemicellulose in three arrears in differ- ent years were consistent. The cellulose content increased after falling, and hemi- cellulose content presented declining tendency. The lignin content of rice straw fist rose then declined in Huaian and Changzhou in different years, while it presented the declining tendency in Zhenjiang. The ash content of rice straw changed little and was all less than 65% in the three areas in different years. And the chemical composition of rice straw changed significantly in different years. [Conclusion] The research could provide basis for high added-value use of crop straw.展开更多
[Objective] To compare the regional differences of the conventional chemi- cal compositions in the K326 B2F tobacco from different tobacco-planting areas of Yunnan Province. [Methed] Continuous flow analyzer was used ...[Objective] To compare the regional differences of the conventional chemi- cal compositions in the K326 B2F tobacco from different tobacco-planting areas of Yunnan Province. [Methed] Continuous flow analyzer was used to detect the con- ventional chemical compositions, and SPSS 17.0 statistical package was used to conduct data statistical analysis and variance analysis. [Result] Significant differences were existed among most of the indicators for conventional chemical compositions of K326 tobacco in different areas： the differences of total sugar, reducing sugar and nicotine reached a high Significant level; potassium ion and total nitrogen differences reached a significant level, while there was no significant difference in chlorine ion. Most of the conventional chemical compositions in K326 B2F tabacco planted in Yuxi region and those planted in Qujing, Dali and Chuxiong were significantly different. The total sugar, reducing sugar and nicotine contents of tobacco planted in eastern Yunnan, central Yunnan and western Yunnan were significantly different; while the conventional chemical compositions contents in the tobacco planted in Chuxiong and Dali, which all belong to western Yunnan, showed no obvious significant difference, indicating different ecological environments in large area had a great impact on the tobacco of Yunnan Province. [Conclusion] It revealed the regional characteristics of the conventional chemical compositions in K326 flue-cured tobacco leaves from Yunnan Province, providing references for the cigarette blending and production of high-quality tobacco with characteristics.展开更多
Objective The Late Cretaceous Xiuwacu ore-bearing porphyry is located in the Geza area of southern Yidun arc, SW China. In this area, the rock mass is mainly composed of three lithofacies： biotite granite porphyry, ...Objective The Late Cretaceous Xiuwacu ore-bearing porphyry is located in the Geza area of southern Yidun arc, SW China. In this area, the rock mass is mainly composed of three lithofacies： biotite granite porphyry, monzonitic granite and light alkali feldspar granite. As a part of the Yidun arc, the Geza arc has common structure and temporal- spatial evolution with the ~idun arc, which has experienced three stages of oceanic crust subduction, collision orogeny and intracontinent convergence stages. The molybdenite ores in the area are mainly hosted in monzonitic granite-porphyry and structural fracture zone, and the ore bodies are strictly controlled by faults. In recent years, great geological prospecting results have been achieved in Xiuwacu, and the deposit has reached a medium scale. However, there are few researches on the metallogenic porphyry. Based on the previous research, we determined the rock-forming and ore-forming age of the porphyry, and found that there were two stages of magmatism intrusion in Xiuwacu： Indosinian and Yanshanian. We also discussed the geochemical characteristics and source area of the rocks in the area.展开更多
The effects of magnesium/polytetrafluoroethylene(Mg/PTFE)pyrotechnic compositions on the coupled flow field and reignition mechanism are important aspects governing the perfommance and range of base bleed projectiles(...The effects of magnesium/polytetrafluoroethylene(Mg/PTFE)pyrotechnic compositions on the coupled flow field and reignition mechanism are important aspects governing the perfommance and range of base bleed projectiles(BBPs).Owing to a decrease in pressure and temperature when the BBP leaves the muzzle,rapid depressurization occurs,which extinguishes the base bleed propellant.The Mg/PTFE py-rotechnic composition pressed in the igniter of the base bleed unit(BBU)provides additional energy to the BBU via a chemical reaction.Thus,the extinguished base bleed propellant is reignited under the effect of high-temperature combustion gas jets from the igniter.In this study,a numerical analysis is conducted to evaluate the effects of PTFE and Mg granularity as well as Mg/PTFE pyrotechnic compo-sitions.Owing to the rapid depressurization,the temperature and pressure was found to decrease fordifferent Mg/PIFE pyrotechnic compositions.However,the depressurization time increased as the PTFE granularity increased,the Mg granularity decreased,and the Mg content increased.When the pressure in the combustion chamber of the BBU decreased to the atmospheric pressure,the combustion gas jets from the igniter expand upstream(rather than downstream).However,these combustion gas jets exhibit different axial and radial expansion characteristics depending on the pyrotechnic compositions used,The results show that the reignition delay time,ta,of the base bleed propellant was 377.608,94.27,387.243,523.966,and 221.094 ms for cases A-E,respectively.Therefore,it was concluded that the Mg/PTFE pyrotechnic composition of case B was the most beneficial for the reignition of the base bleed propellant,with the earliest addition of energy and mass to the BBP.展开更多
Banded Iron Formations（BIFs） are chemical sediments, ubiquitously distributed in the Precambrian supracrustal belts; thus their trace element compositions are helpful for deciphering geochemical evolution on the Ear...Banded Iron Formations（BIFs） are chemical sediments, ubiquitously distributed in the Precambrian supracrustal belts; thus their trace element compositions are helpful for deciphering geochemical evolution on the Earth through time. However, it is necessary to elucidate factors controlling the whole-rock compositions in order to decode the ancient seawater compositions because their compositions are highly variable. We analyzed major and trace element contents of the BIFs in the 3.8-3.7 Ga Isua supracrustal belt（ISB）, southern West Greenland. The BIFs are petrographically classified into four types：Black-,Gray-, Green-and White-types, respectively. The Green-type BIFs contain more amphiboles, and are significantly enriched in Co, Ni, Cu, Zn, Y, heavy rare earth element（HREE） and U contents. However,their bulk compositions are not suitable for estimate of seawater composition because the enrichment was caused by secondary mobility of metamorphic Mg, Ca and Si-rich fluid, involvement of carbonate minerals and silicate minerals of olivine and pyroxene and/or later silicification or contamination of volcanic and clastic materials. The White-type BIFs are predominant in quartz, and have lower transition element and REE contents. The Gray-type BIFs contain both quartz and magnetite. The Black-type BIFs are dominated by magnetite, and contain moderate to high transition element and REE contents. But,positive correlations of V, Ni, Zn and U contents with Zr contents suggest that involvement of detrital,volcanic and exhalative materials influences on their contents. The evidence for significant influence of the materials on the transition element contents such as Ni in the BIFs indicates the transition element contents in the Archean ocean were much lower than previously estimated. We reconstructed secular variations of V,Co, Zn and U contents of BIFs through time, which show Ni and Co contents decreased whereas V, Zn and U contents increased through time. Especially, the Ni and Co contents drastically decreased in the Mesoarchean rather than around the Great Oxidation Event. On the other hand, the V,Zn and U contents progressively increased from the Mesoarchean to the Proterozoic. Stratigraphical trends of the BIFs show increase in Y/Ho ratios and decrease in positive Eu anomaly upwards, respectively. The stratigraphic changes indicate that a ratio of hydrothermal fluid to seawater component gradually decrease through the deposition, and support the Eoarchean plate tectonics, analogous to the their stratigraphic variations of seafloor metalliferous sediments at present and in the Mesoarchean.展开更多
We report geochemical data, SHRIMP zircon ages and Hf-in-zircon isotopic compositions for Cenozoic granitoids from major fault systems in the Tethyan belt in western Yunnan Province, southwestern China.Four magmatic p...We report geochemical data, SHRIMP zircon ages and Hf-in-zircon isotopic compositions for Cenozoic granitoids from major fault systems in the Tethyan belt in western Yunnan Province, southwestern China.Four magmatic pulses occurred in the Paleogene, namely at ca.57 Ma, ca.50 Ma, 45–40 Ma, and 38–34 Ma.Early magmatism of this episode（57–50 Ma） produced S-type granites whose zircons yielded εHf（t） values of-5.0 to-0.3.In contrast, late magmatism of this episode reflects heterogeneous sources.Zircons from a granite porphyry along the Ailaoshan-Red River fault system have slightly positive εHf（t） values suggesting derivation from relatively young crust and/or a juvenile source.However, zircons from a granite along the Gaoligong fault system have strongly negative εHf（t） values and suggest derivation from a Paleoproterozoic crustal source.The composition of the granitoids varies with age（from ca.57 Ma to ca.34 Ma） from peraluminous to metaluminous and also suggests a change from syn-collisional to late-orogenic tectonic setting.A new tectonic model, impacting lithospheric wedge（ILW） is shown for the origin of Paleogene granitoids in this paper.展开更多
基金financially supported by the Fundamental Research Program of the Russian Academy of Sciences for the Semenov Research Center of Chemical Physics,Russian Academy of Sciences。
文摘Single-step ethylene polymerization over a binary catalyst,including zirconocene precatalysts of various designs,has been studied to obtain polymer compositions based on ultrahigh-molecular-weight polyethylene(UHMWPE)and low-molecular-weight HDPE(LMWPE)directly in synthesis.Zirconocenes rac-(CH_(3))_(2)Silnd_(2)ZrCl_(2)(Zr-1)and rac-(C_(6)H_(10))CplndZrCl_(2)(Zr-2)activated with methylaluminoxane(MAO)were used as the components of the binary catalyst.It has been shown that the use of Zr-1/MAO and Zr-2/MAO in ethylene polymerization at 30℃leads to the production of UHMWPE with Mw=1000 kg-mol^(-1)and LMWPE with Mw=18 kg·mol^(-1),respectively.Reactor polymer compositions(RPC)with LMWPE fraction contents ranging from 9 wt%to 42 wt%were obtained when a molar fraction of Zr-2 in the binary catalyst(Zr-1+Zr-2)/MAO va ried in the range from 0.3 to 0.85.A study of the molecular weight characteristics of RPC showed that it has a wide bimodal molecular weight distribution(MWD)and includes UHMWPE(Mw=1000 kg·mol^(-1))and LMWPE(Mw=18 kg·mol^(-1))fractions.The degree of crystallinity of the polymer products was determined using the DSC method.The tensile properties and melt indices of the materials were studied depending on the LMWPE fraction content in the polymer composition.UHMWPE/LMWPE compositions with high tensile properties and fluidity at a load of 5 kg were obtained.
基金Supported by the National Natural Science Foundation of China(Grant No.11461020)
文摘In this paper we give combinatorial proofs of two recurrence relations for the special class of objects known as inplace compositions. We also obtain new identities for the numbers of inplace 1-2 compositions and palindromic compositions.
文摘Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships with antioxidant activity and oxidative stability,gas chromatography-mass spectrometry was performed to characterize the associated fatty acid profiles.The antioxidant activity of vegetable oils,based on their DPPH-scavenging capacity(expressed as IC_(50) values),was used to assess their impact on human health,and their oxidative stability was characterized by performing lipid oxidation analysis to determine the oxidative induction time of fats and oils.In addition,correlation analyses were performed to examine associations between the fatty acid composition of the oils and DPPH-scavenging capacity and oxidative stability.The results revealed that among the assessed oils,coffee seed oil has the highest saturated fatty acid content(355.10 mg/g),whereas Garddenia jaminoides oil has the highest unsaturated fatty acid content(844.84 mg/g).Coffee seed oil was also found have the lowest DPPH IC_(50) value(2.30 mg/mL)and the longest oxidation induction time(17.09 h).Correlation analysis revealed a significant linear relationship(P<0.05)between oxidative stability and unsaturated fatty acid content,with lower contents tending to be associated with better oxidative stability.The findings of this study provide reference data for the screening of functional edible vegetable oils.
基金the National Natural Science Foundation of China (30460083)the Key Science and Technology Project of Chinese Ministry of Education (205164)~~
文摘The chemical compositions of volatile oil from fruiting body of Armillaria luteo-virens in Qinghai Province were firstly analyzed with GC-MS and its relevant compositions were detected by calculating chromatographic peak area with normalized method. 21 peaks were separated and 13 compositions were identified which were mainly unsaturated fatty acids, taking 97.1% of the total volatile oil.
文摘The effect of seed oil of Korean pine (Pinus koraiensis) on the rats' blood-fat and its anti-ageing function was stud-ied for appraising the efficacy of the seed oil of Korean pine. Sixty experimental rats were randomly divided into 5 groups (half males and half females in each group) as normal control group, high fat diet control group, and three groups (Group 1 Group 2, Group 3) that were fed with feedstuff with the contents of the seed oil of 2.0g/(kgd-1), 4.0g/(kgd-1) and 8.0g/(kgd-1), respec-tively. The indexes such as superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and anti-oxidation capacity (AOC) were measured by Reagent Kit method. It was found that the seed oil of the Korean pine could reduce the content of triglyc-eride and improve SOD as well as GSH-PX activity in serum. These indexes of the rats in Group 2 fed with Korean pine seed oil of 4.0 g/(kgd-1) reached the significant level and those of rats in Group 3 fed with the seed oil of 8.0 g/(kgd-1) reached the extremely significant level. The results indicated the seed oil of Korean pine had function of regulating the level of blood-fat and anti-ageing.
基金Supported by the Fund for Talented Scholars of Sichuan Academy of Agricultural SciencesSpecial Fund for New Subjects from the Innovation Capability Promotion Project of Sichuan Provincial Department of Finance(2013xxxk-020)~~
文摘In the present study, the nutritional compositions of maca which was grown in a mountain area at an elevation of 2 200-2 800 m of Ebian County,Sichuan Province were measured, and then HPLC analysis on two representative active compounds（macaene and macamide） in the maca sample was performed.The results revealed that there were 24.20% total protein, 18.40% total amino acids（including 3.84% arginine）, 42.80% total sugars, 1.36% fat and kinds of minerals（including 1.14% potassium） in Ebian maca. HPLC fingerprints of macaene and macamide of Ebian maca were similar to those of Peru maca. The results suggested that maca could be cultivated with good quality in some mountain areas with an altitude1 000 m lower than the origin place in Peru.
基金Supported by Science and Technology Foundation of Guizhou Province([2009]2108)Doctoral Scientific Research Foundation of Guizhou Normal University[2008],Key Program of Student Scientific Research Foundation of Guizhou Normal University[2010]~~
文摘[Objective] The aim was to identify the nourishing compositions of Fagopyrum tataricum and screen high-quality buckwheat materials.[Method]A total of 10 species of buckwheat including T32,T31,T30,T14,T28,T23,T24,Jiujiang Buckwheat,Weiku 2 and WK-1 were employed as experimental materials,and the contents of the nutritional components（including total sugar,reducing sugar,starch,amylose,amylopectin and protein）,flavonoids content,physical and chemical characteristics（such as expansive force,water holding capacity）of them were respectively measured.[Result]There were significant differences in contents of soluble protein,total sugar,reduced sugar,amylase and expansive force among the cultivars,but the differences in contents of total starch,amylopectin,flavonoids content and water holding capacity were not significant.[Conclusion]The starch content in seeds of buckwheat was relatively high,and amylopectin was the main composition.
基金the National Natural Science Foundation of China(Nos.42206076,42476078)the National Program on Global Change and Air-Sea Interaction(No.GASI-02-SCSCJB01)the China-Malaysia Cooperation Project‘Effect on variability of seasonal monsoon on sedimentary process in Peninsular Malaysia waters’。
文摘The Malacca Strait(MS)is a vital conduit for the exchange of water and sediment between the Indian Ocean and the Pacific Ocean,serving as a critical‘gateway'for sediment transport.Here,we present the geochemical characteristics of surface sediments in the MS to elucidate the relationship between terrestrial material inputs and modern oceanic dynamic transport processes in the strait.The results reveal that the MS can be divided into three distinct geochemical provinces.ProvinceⅠ,located in the central region of the strait,is characterized by residual deposits.The preservation of these residual deposits can be attributed to the restricted sediment supply and the relatively weaker modern sedimentary hydrodynamic conditions.ProvinceⅡ,situated to the north of ProvinceⅠ,exhibits provenance differences between its southern and northern regions.The northern region is primarily supplied by sediments originating from the eastern shelf of the Andaman Sea,whereas sediments derived from Sumatra and the Sunda Shelf are predominantly deposited in the southern part of ProvinceⅡ.ProvinceⅢextends along the western coast of the Malaysian Peninsula,with sediments primarily sourced from the Malaysian Peninsula and the Sunda Shelf,while contributions from Sumatra and the eastern shelf of the Andaman Sea are negligible.River sediments from the Malaysian Peninsula and Sumatra are transported northwestward along their respective coasts by prevailing currents,which also facilitate the transportation of Sunda Shelf sediments within the strait,while sediments from the eastern shelf of the Andaman Sea are delivered to the MS via southward coastal currents during the southwest monsoon period.The southward currents and well-developed eddies potentially impede the northward transport of sediments from the Sunda Shelf and restrict the distribution of Andaman Sea sediments within the strait.This study substantially enhances the understanding of source-to-sink processes in the Indo-Pacific region.
基金This study was funded by Wuhan Institute of Technology(Grant Nos.24QD26,21QD02,22QD64)National Natural Science Foundation of China(Grant No.32102823).
文摘Aiming to control lake eutrophication,proposed methods for convenient and faithworthy lake water quality evaluation are warranted.Optical measurement of dissolved organic matter(DOM)demonstrates great potential for estimating organic matter(OM)composition,and can thus serve as a proxy for conventional chemical oxygen demand(COD_(Mn))measurements,which are considered as imprecise and environmentally unfriendly.Hence,we conducted a field campaign across 30 lakes in Wuhan's metropolitan area,collecting 255 samples from varying trophic states to evaluate the predictive capability of COD_(Mn)using DOM optical measurements combined with parallel factor(PARAFAC)analysis.The DOM optical properties and chemical composition exhibited considerable variability across varying trophic state levels(TSLs).Fluorescence components C1-C3 and C5,fluorescence index(FI),and absorption at 254 nm(α_(254)),increased as TSL increased,while the DOM spectral slope(SR)decreased.COD_(Mn)was positively and significantly correlated with fluorescence components C1-C3 and C5,freshness index(β/α),autochthonous index(BIX),humification index(HIX),α_(254),the ratio ofα_(250)toα_(365)(E2/E3)while being negatively correlated with SR.Parametersα_(254),C1,C3,C4,FI,β/α,and HIX were identified as key predictors of COD_(Mn).The multiple linear regression model successfully predicted COD_(Mn)(r^(2)=0.63,p<0.01,n=1113)and demonstrated superior performance in mesotrophic lakes.These findings highlight the potential for establishing high-frequency,continuous,and multi-regional COD monitoring programs.
基金Supported by The Innovation Fund of Postgraduate,Sichuan University of Science&Engineering(Y2024336)NSF of Sichuan Province(2023NSFSC0065).
文摘In this paper,we study asymptotic power series of the composition f(x)=h(g(x)),where g(x)=∑_(n=0)^(∞)b_(n)x^(-n),b_(n)∈R,and h is a given elementary function.The asymptotic expansions have been obtained for the composition with an exponential or logarithmic function.Using the re-cursive method,we present the asymptotic expansions for the composition with seven trigonometric functions,respectively.As an application,the asymptotic expansions of roots of some equations are given.Computational results show that our recursive formula is more efficient than the method of Lagrange's inverse theorem.
基金Science and Technology Innovation Talents Scheme in Henan Prov-ince (104200510003)~~
文摘[Objective] The aim was to explore the inheritance of fat and fatty acid compositions in peanut.[Method] Genetic and correlation analyses were performed using a mixed genetic model of major gene plus polygene with 215 F9 RILs and their parents ZHENG 8903 and YUHUA No.4.[Result] The optimal genetic model of the fat content was two linked complementary major gene plus polygene inheritance model.The heritability of major genes was 22.88%.Oleic,linoleic,and palmitic acid content were controlled by two major genes and the heritability was 75.11%,75.00% and 60.95%,respectively.Stearic and arachidic acid content were controlled by two major genes plus polygenes,the heritability of major genes was 26.43% and 33.17%,respectively.O/L ratio and behenic acid content were controlled by three major genes,the heritability was 70.65% and 30.70%,respectively.[Conclusion] The result in this study was that accumulating polygenes should be emphasized in the improvement of fat content,while utilization of major genes is enhanced in improvement of oleic and linoleic acids.
基金supported by the National Natural Science Foundation of China (No. 40821003,41025012)NSFC-Guangdong Joint Funds (No. U0833003)+1 种基金the Natural Science Foundation of Guangdong (No. 7118013)the Bureau of Science,Technology and Information of Guangzhou (No. 2010U1-E00601-2)
文摘During November–December 2010 aerosol scattering coefficients were monitored using a single-waved （525 nm） Nephelometer at a regional monitoring station in the central Pearl River Delta region and 24-hr fine particle （PM 2.5） samples were also collected during the period using quartz filters for the analysis of major chemical components including organic carbon （OC）,elemental carbon （EC）,sulfate,nitrate and ammonium.In average,these five components accounted for about 85% of PM 2.5 mass and contributed 42% （OC）,19% （SO 4 2 -）,12% （NO 3 -）,8.4% （NH 4＋） and 3.7% （EC）,to PM 2.5 mass.A relatively higher mass scattering efficiency of 5.3 m 2/g was obtained for fine particles based on the linear regression between scattering coefficients and PM 2.5 mass concentrations.Chemical extinction budget based on IMPROVE approach revealed that ammonium sulfate,particulate organic matter,ammonium nitrate and EC in average contributed about 32%,28%,20% and 6% to the light extinction coefficients,respectively.
基金Supported by the Systematic Research Project of Guangxi Provincial Key Laboratory of Chinese Medicine Quality Standards(201209)~~
文摘Kudingcha, a commonly used traditional Chinese medicine, has multiple functions in anti-radiation, anti-aging, quickening the blood vessels, reducing blood lipid and blood pressure and so forth. Therefore, this article reviews the origins of Kudingcha, and analyzes the major triterpenoids and volatile chemicals, with an at- tempt to provide more references for the development and utilization of Kudingcha.
基金Supported by the Speical Fund for Agro-Scientific Research in the Public Interest(201003063)~~
文摘[Objective] The research was aimed to study the main chemical composi- tions of rice straw in the three different areas of Jiangsu Province. [Method] The cellulose, hemicellulose, lignin and crude ash of rice straw collected in Huaian, Changzhou and Zhenjiang of Jiangsu Province during 2011-2013 were determined. [Result] The change trends of cellulose and hemicellulose in three arrears in differ- ent years were consistent. The cellulose content increased after falling, and hemi- cellulose content presented declining tendency. The lignin content of rice straw fist rose then declined in Huaian and Changzhou in different years, while it presented the declining tendency in Zhenjiang. The ash content of rice straw changed little and was all less than 65% in the three areas in different years. And the chemical composition of rice straw changed significantly in different years. [Conclusion] The research could provide basis for high added-value use of crop straw.
基金Supported by the Science and Technology Project of Yunnan Reascend Tobacco Technology(Group)Co.,Ltd.(2010RS06)the Science and Technology Project of China Tobacco Yunnan Industrial Co.,Ltd.(2008YL07,2009YL02-2)the Science and Technology Project of HONGYUNHONGHE Tobacco(Group)Co.,Ltd.,(YHH2010-YL02,YHH2010YL04)~~
文摘[Objective] To compare the regional differences of the conventional chemi- cal compositions in the K326 B2F tobacco from different tobacco-planting areas of Yunnan Province. [Methed] Continuous flow analyzer was used to detect the con- ventional chemical compositions, and SPSS 17.0 statistical package was used to conduct data statistical analysis and variance analysis. [Result] Significant differences were existed among most of the indicators for conventional chemical compositions of K326 tobacco in different areas： the differences of total sugar, reducing sugar and nicotine reached a high Significant level; potassium ion and total nitrogen differences reached a significant level, while there was no significant difference in chlorine ion. Most of the conventional chemical compositions in K326 B2F tabacco planted in Yuxi region and those planted in Qujing, Dali and Chuxiong were significantly different. The total sugar, reducing sugar and nicotine contents of tobacco planted in eastern Yunnan, central Yunnan and western Yunnan were significantly different; while the conventional chemical compositions contents in the tobacco planted in Chuxiong and Dali, which all belong to western Yunnan, showed no obvious significant difference, indicating different ecological environments in large area had a great impact on the tobacco of Yunnan Province. [Conclusion] It revealed the regional characteristics of the conventional chemical compositions in K326 flue-cured tobacco leaves from Yunnan Province, providing references for the cigarette blending and production of high-quality tobacco with characteristics.
基金financially supported by the National Natural Science Foundation of China(grant No.41502076)the Science Research Fund of Yunnan Provincial Education Department(grant No.2015Y066)+1 种基金the Provincial People Training Program of Kunming University of Science and Technology(grant No.KKSY201421042)the Project of China Geological Survey(grant No.12120114013701)
文摘Objective The Late Cretaceous Xiuwacu ore-bearing porphyry is located in the Geza area of southern Yidun arc, SW China. In this area, the rock mass is mainly composed of three lithofacies： biotite granite porphyry, monzonitic granite and light alkali feldspar granite. As a part of the Yidun arc, the Geza arc has common structure and temporal- spatial evolution with the ~idun arc, which has experienced three stages of oceanic crust subduction, collision orogeny and intracontinent convergence stages. The molybdenite ores in the area are mainly hosted in monzonitic granite-porphyry and structural fracture zone, and the ore bodies are strictly controlled by faults. In recent years, great geological prospecting results have been achieved in Xiuwacu, and the deposit has reached a medium scale. However, there are few researches on the metallogenic porphyry. Based on the previous research, we determined the rock-forming and ore-forming age of the porphyry, and found that there were two stages of magmatism intrusion in Xiuwacu： Indosinian and Yanshanian. We also discussed the geochemical characteristics and source area of the rocks in the area.
基金This work was supported by the Fundamental Research Funds for the Central Universities(No.30918011324).
文摘The effects of magnesium/polytetrafluoroethylene(Mg/PTFE)pyrotechnic compositions on the coupled flow field and reignition mechanism are important aspects governing the perfommance and range of base bleed projectiles(BBPs).Owing to a decrease in pressure and temperature when the BBP leaves the muzzle,rapid depressurization occurs,which extinguishes the base bleed propellant.The Mg/PTFE py-rotechnic composition pressed in the igniter of the base bleed unit(BBU)provides additional energy to the BBU via a chemical reaction.Thus,the extinguished base bleed propellant is reignited under the effect of high-temperature combustion gas jets from the igniter.In this study,a numerical analysis is conducted to evaluate the effects of PTFE and Mg granularity as well as Mg/PTFE pyrotechnic compo-sitions.Owing to the rapid depressurization,the temperature and pressure was found to decrease fordifferent Mg/PIFE pyrotechnic compositions.However,the depressurization time increased as the PTFE granularity increased,the Mg granularity decreased,and the Mg content increased.When the pressure in the combustion chamber of the BBU decreased to the atmospheric pressure,the combustion gas jets from the igniter expand upstream(rather than downstream).However,these combustion gas jets exhibit different axial and radial expansion characteristics depending on the pyrotechnic compositions used,The results show that the reignition delay time,ta,of the base bleed propellant was 377.608,94.27,387.243,523.966,and 221.094 ms for cases A-E,respectively.Therefore,it was concluded that the Mg/PTFE pyrotechnic composition of case B was the most beneficial for the reignition of the base bleed propellant,with the earliest addition of energy and mass to the BBP.
基金partially supported by JSPS grants (No. 26220713) from the Ministry of Education, Culture, Sports, Science and Technology of Japan
文摘Banded Iron Formations（BIFs） are chemical sediments, ubiquitously distributed in the Precambrian supracrustal belts; thus their trace element compositions are helpful for deciphering geochemical evolution on the Earth through time. However, it is necessary to elucidate factors controlling the whole-rock compositions in order to decode the ancient seawater compositions because their compositions are highly variable. We analyzed major and trace element contents of the BIFs in the 3.8-3.7 Ga Isua supracrustal belt（ISB）, southern West Greenland. The BIFs are petrographically classified into four types：Black-,Gray-, Green-and White-types, respectively. The Green-type BIFs contain more amphiboles, and are significantly enriched in Co, Ni, Cu, Zn, Y, heavy rare earth element（HREE） and U contents. However,their bulk compositions are not suitable for estimate of seawater composition because the enrichment was caused by secondary mobility of metamorphic Mg, Ca and Si-rich fluid, involvement of carbonate minerals and silicate minerals of olivine and pyroxene and/or later silicification or contamination of volcanic and clastic materials. The White-type BIFs are predominant in quartz, and have lower transition element and REE contents. The Gray-type BIFs contain both quartz and magnetite. The Black-type BIFs are dominated by magnetite, and contain moderate to high transition element and REE contents. But,positive correlations of V, Ni, Zn and U contents with Zr contents suggest that involvement of detrital,volcanic and exhalative materials influences on their contents. The evidence for significant influence of the materials on the transition element contents such as Ni in the BIFs indicates the transition element contents in the Archean ocean were much lower than previously estimated. We reconstructed secular variations of V,Co, Zn and U contents of BIFs through time, which show Ni and Co contents decreased whereas V, Zn and U contents increased through time. Especially, the Ni and Co contents drastically decreased in the Mesoarchean rather than around the Great Oxidation Event. On the other hand, the V,Zn and U contents progressively increased from the Mesoarchean to the Proterozoic. Stratigraphical trends of the BIFs show increase in Y/Ho ratios and decrease in positive Eu anomaly upwards, respectively. The stratigraphic changes indicate that a ratio of hydrothermal fluid to seawater component gradually decrease through the deposition, and support the Eoarchean plate tectonics, analogous to the their stratigraphic variations of seafloor metalliferous sediments at present and in the Mesoarchean.
基金financially supported by Geological Survey of China Projects(Nos.1212010814054,1212010911049)Ministry of land and resources of public welfare scientific research(No.201311116)
文摘We report geochemical data, SHRIMP zircon ages and Hf-in-zircon isotopic compositions for Cenozoic granitoids from major fault systems in the Tethyan belt in western Yunnan Province, southwestern China.Four magmatic pulses occurred in the Paleogene, namely at ca.57 Ma, ca.50 Ma, 45–40 Ma, and 38–34 Ma.Early magmatism of this episode（57–50 Ma） produced S-type granites whose zircons yielded εHf（t） values of-5.0 to-0.3.In contrast, late magmatism of this episode reflects heterogeneous sources.Zircons from a granite porphyry along the Ailaoshan-Red River fault system have slightly positive εHf（t） values suggesting derivation from relatively young crust and/or a juvenile source.However, zircons from a granite along the Gaoligong fault system have strongly negative εHf（t） values and suggest derivation from a Paleoproterozoic crustal source.The composition of the granitoids varies with age（from ca.57 Ma to ca.34 Ma） from peraluminous to metaluminous and also suggests a change from syn-collisional to late-orogenic tectonic setting.A new tectonic model, impacting lithospheric wedge（ILW） is shown for the origin of Paleogene granitoids in this paper.
