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Variations in nitrogen isotopic values among various particle-sized fractions in modern soil in northwestern China

Chinese Journal Of Geochemistry 2011年第3期30卷 295-303页

作者： LIU Weiguo WANG Zhoufeng WANG zheng fenG Xiahong ZHANG pu State Key Laboratory of Loess and Quaternary Geology lEE CAS Xi'an 710075 China School of Human Settlement and Civil Engineering Xi'an Jiaotong University Xi 'an 710049 China School of Environmental Science and Engineering Chang 'an University Xi'an 710054 China Department of Earth Sciences Dartmouth College Hanover NH 03755 USA

Ratios of stable nitrogen isotopes in organic matter derived from plants and preserved in soil are potential tracers for nitrogen cycles in natural ecosystems and valuable for evaluation of climate change. However, the rela-tionship between nitrogen isotopic compositions in surface soil and in plant litter during the decomposition process from plant litter to soil organic matter is not well understood. By using nitrogen isotopic analysis of soil parti-cle-sized fractions, nitrogen isotope discrimination between plant litter and surface soil organic matter in various modern ecosystems in northwestern China was conducted. The results of our study indicate that: (1) in general, the nitrogen isotopic compositions of particle-sized fractions from surface soil are different, and δ15N values increase from plant litter to fine soil organic matter; (2) the δ15N values in the soil particle-sized fractions become larger with increasing relative humidity and temperature, and the largest variation in the δ15N values is from -5.9‰ to -0.3‰; and (3) under a controlled climate, significant nitrogen isotope differences in δ15N values (Δδ15Nplant-soil) between plant litter and bulk soil organic matter were observed, with the values of 1.52 to 4.75 at various sites. Our results suggested that comparisons of Δδ15N values between bulk soil and the particle-sized fractions of soil could reveal the effect of humidity on transferring process of nitrogen from plant to soil in arid and semi-arid ecosystems.

关键词：稳定氮同位素中国西北地区现代土壤粒子大小自然生态系统土壤有机质颗粒大小组分

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Production of (2S)-sakuranetin from (2S)-naringenin in Escherichia coli by strengthening methylation process and cell resistance

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Synthetic and Systems Biotechnology 2022年第4期7卷 1117-1125页

作者： Qiumeng Sun Song Gao Shiqin Yu pu zheng Jingwen Zhou Science Center for Future Foods Jiangnan University1800 Lihu RoadWuxiJiangsu214122China Key Laboratory of Industrial Biotechnology Ministry of Education and School of BiotechnologyJiangnan University1800 Lihu RoadWuxiJiangsu214122China Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology Jiangnan University1800 Lihu RoadWuxiJiangsu214122China Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology Jiangnan UniversityWuxi214122China

(2S)-Sakuranetin is a 7-O-methylflavonoid that has anticancer,antiviral,and antimicrobial *** process is involved in biosynthesizing(2S)-sakuranetin from(2S)-naringenin,in which S-adenosylmethionine(SAM)serves as the methyl *** this study,after methyl donor and substrate inhibition were identified as limiting factors for(2S)-sakuranetin biosynthesis,an efficient(2S)-sakuranetin-producing strain was constructed by enhancing methyl donor supply and cell tolerance to(2S)-***,PfOMT3 from Perilla frutescens was selected as the optimal flavonoid 7-O-methyltransferase(F7-OMT)for the conversion of(2S)-naringenin to(2S)-***,the methylation process was upregulated by regulating pyridoxal 5′-phosphate(PLP)content,key enzymes in methionine synthesis pathway,and the availability of ***,genes that can enhance cell resistance to(2S)-naringenin were identified from molecular chaperones and ***,by optimizing the fermentation process,681.44 mg/L of(2S)-sakuranetin was obtained in 250-mL shake *** titer of(2S)-sakuranetin reached 2642.38 mg/L in a 5-L bioreactor,which is the highest titer ever *** work demonstrates the importance of cofactor PLP in methylation process,and provides insights to biosynthesize other O-methylated flavonoids efficiently in ***.

关键词： (2S)-Sakuranetin Flavonoid 7-O-methyltransferases Methylation Cell tolerance Metabolic engineering

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Facile surface regulation for highly efficient and thermally stable perovskite solar cells via chlormequat chloride

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Chinese Chemical Letters 2024年第10期35卷 517-523页

作者： Bo Yang pu-An Lin Tingwei Zhou Xiaojia zheng Bing Cai Wen-Hua Zhang Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900China School of Physical Science and Technology Southwest UniversityChongqing 400715China Yunnan Key Laboratory of Carbon Neutrality and Green Low-carbon Technologies School of Materials and EnergyYunnan UniversityKunming 650000China

Defects at the surface and grain boundaries of the perovskite films are extremely detrimental to both the efficiency and stability of perovskite solar cells(PSCs).Herein,a simple and stable quaternary ammonium halide,named chlormequat chloride(i.e.,chlorinated choline chloride,CCC),is introduced to regulate the upper surface chemical environment of perovskite *** anion(Cl^(-))and cation[ClCH_(2)CH_(2)N(CH_(3))_(3)]+in CCC could effectively self-search and passivate positively and negatively charged ionic defects in per ovskites,respectively,which contributes to inhibited nonradiative recombination and reduced energy los in *** a result,the champion power conversion efficiency(PCE)of PSCs can be significantly enhanced from 22.82%to 24.07%.Moreover,the unencapsulated device with CCC modification retains 92.0%of it original PCE even subject to thermal aging at 85℃ for 2496 *** work provides guidance for the ratio nal design of functional molecules as defect passivators in PSCs,which is beneficial for the improvement in both device performance and stability.

关键词： Perovskite solarcells Quaternary ammonium halide Chlormequat chloride Surface modulation Thermal stability

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Mono-disperse SrMoO4 nanocrystals:Synthesis,luminescence and photocatalysis

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Journal of Materials Science & Technology 2017年第8期33卷 834-842页

作者： Ya-Nan Zhu Gan-Hong zheng Zhen-Xiang Dai Jing-Jing Mu Zi-fen Yao Anhui Key Laboratory of Information Materials and Devices School of Physics and Materials SdenceAnhui UniversityHefei 230039China

Well-dispersed uniform SrMoO4 nanocrystals were synthesized by thermal decomposition of a metalorganic salt in the organic solvent under different temperatures（80, 100, 120, 140, and 160？C）. The smallest diameter of these SrMoO4 nanocrystals is only about 2 nm, which is regarded as the smallest values to date. The UV–vis absorbance spectra present that the larger absorption of our samples is mainly distributed in the visible light region and UV light region. The lowest energy gap is found to be 2.71 e *** a small gap is ascribed to the introduction of intermediate energy levels, which are due to the surface defects with decreasing the size of nanostrcutrues. The photoluminescence measurement suggests that all these samples exhibit a board and strong emission band in the range from 500 to 700 nm. Through the deconvolution of the photoluminescence spectra, the emission profiles are found to be associated with three various components（green, yellow, and red）. Moreover, the photodegration of methyl blue over our SrMoO4 samples reaches nearly 100% in 120 min. Such a high photodegration may be related to the following aspects. One is related to the size and morphology. Larger surface area leads to more absorption of methyl blue, and the small size nanoparticles lead to the efficient separation of these photogenerated electron-hole pairs. The other is related to the narrow band gap. The small gap is beneficial to more electrons to be excited from the valence band to the conduction band, and eventually more electron-hole pairs are created. Our investigations clearly suggest that thermal decomposition of one metal-organic salt in organic solvent will be a good choice to synthesize the nanoparticles with small size and uniform distribution. Our results also indicate that these SrMoO4 nanoparticles possibly have great potential utilities in photocatalysts.

关键词： SrMoO4 Nanocrystals Luminescence Photocatalyst

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Quantitative Trait Loci Associated with Micronutrient Concentrations in Two Recombinant Inbred Wheat Lines

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Journal of Integrative Agriculture 2014年第11期13卷 2322-2329页

作者： pu Zhi-en YU Ma HE Qiu-yi CHEN Guo-yue WANG Ji-rui LIU Ya-xi JIANG Qian-tao LI Wei DAI Shou-fen WEI Yu-ming zheng You-liang Triticeae Research Institute Sichuan Agricultural University College of Agronomy Sichuan Agricultural University School of Life Science and Engineering Southwest University of Science and Technology

Micronutrient malnutrition affects over three billion people worldwide, especially women and children in developing countries. Increasing the bioavailable concentrations of essential elements in the edible portions of crops is an effective resolution to address this issue. To determine the genetic factors controlling micronutrient concentration in wheat, the quantitative trait locus （QTL） analysis for iron, zinc, copper, manganese, and selenium concentrations in two recombinant inbred line populations was performed. In all, 39 QTLs for ifve micronutrient concentrations were identiifed in this study. Of these, 22 alleles from synthetic wheat SHW-L1 and seven alleles from the progeny line of the synthetic wheat Chuanmai 42 showed an increase in micronutrient concentrations. Five QTLs on chromosomes 2A, 3D, 4D, and 5B found in both the populations showed signiifcant phenotypic variation for 2-3 micronutrient concentrations. Our results might help understand the genetic control of micronutrient concentration and allow the utilization of genetic resources of synthetic hexaploid wheat for improving micronutrient efifciency of cultivated wheat by using molecular marker-assisted selection.

关键词： micronutrient concentration synthetic hexaploid wheat QTL

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Comparison of microstructure,mechanical property,and degradation rate of Mg-1Li-1Ca and Mg-4Li-1Ca alloys

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Bioactive Materials 2023年第8期26卷 279-291页

作者： Li-Xin Long fen-fen Chen Lan-Yue Cui Ze-Song Wei Hai-Tao Wang Rong-Chang Zeng Yu-feng zheng College of Materials Science and Engineering Shandong University of Science and TechnologyQingdao266590China Institute of Corrosion Science and Technology Guangzhou510530China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou450002China School of Materials Science and Engineering Peking UniversityBeijing100871China International Research Organization for Advanced Science and Technology(IROAST) Kumamoto University2-39-2 Kumamoto860-8555Japan

Mg-1 wt.%Li-1 wt.%Ca(LX11)and Mg-4 wt.%Li-1 wt.%Ca(LX41)alloys share the same hexagonal closed-packed crystalline ***,the differences in microstructure,mechanical properties,and degradation rates between the two alloys are not well ***,the above three aspects of LX11 and LX41 alloys were studied via optical microscopy,tensile tests,and electrochemical polarization and electrochemical impedance spectroscopy,together with hydrogen *** concentration of the released Mg^(2+),Ca^(2+),and Li+ions was analyzed using a flame atomic absorption *** demonstrated that the LX11 alloy was composed of finerα-Mg grains,fewer twins,and smaller volume fractions of the intermetallic phases Mg_(2)Ca than the LX41 *** increasing Li concentration generated a weak decrease in the yield strength of the Mg-Li-Ca alloys,a remarkable increase in elongation to failure,and a stable ultimate tensile *** LX11 alloy had better corrosion resistance than the LX41 *** release rate of the cations(Mg^(2+),Ca^(2+),and Li+)varied significantly with *** release rate of metallic ions in Hank’s solution cannot reflect the true corrosion rate of Mg-Li-Ca alloys due to the formation of the precipitated corrosion products and their difference in *** dealloying corrosion mechanism of the Mg_(2)Ca phase in Mg-Li-Ca alloys was proposed.

关键词： Magnesium alloys Dealloying Intermetallic compound Biomaterial Ionic release

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Borohydride Ammoniate Solid Electrolyte Design for All-Solid-State Mg Batteries

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Energy & Environmental Materials 2024年第1期7卷 100-106页

作者： Yuepeng Pang zhengfang Nie fen Xu Lixian Sun Junhe Yang Dalin Sun Fang Fang Shiyou zheng School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China Guangxi Key Laboratory of Information Materials&Guangxi Collaborative Innovation Centre of Structure and Property for New Energy and Materials Guilin University of Electronic TechnologyGuilin 541004China Department of Materials Science Fudan UniversityShanghai 200433China

Searching for novel solid electrolytes is of great importance and challenge for all-solid-state Mg *** this work,we develop an amorphous Mg borohydride ammoniate,Mg(BH_(4))_(2)·2NH_(3),as a solid Mg electrolyte that prepared by a NH_(3)redistribution between 3D framework-γ-Mg(BH_(4))_(2)and Mg(BH_(4))_(2)·6NH_(3).Amorphous Mg(BH_(4))_(2)·2NH_(3)exhibits a high Mg-ion conductivity of 5×10^(-4)S cm^(-1)at 75℃,which is attributed to the fast migration of abundant Mg vacancies according to the theoretical ***,amorphous Mg(BH_(4))_(2)·2NH_(3)shows an apparent electrochemical stability window of 0-1.4 V with the help of in-situ formed interphases,which can prevent further side reactions without hindering the Mg-ion *** on the above superiorities,amorphous Mg(BH_(4))_(2)·2NH_(3)enables the stable cycling of all-solid-state Mg cells,as the critical current density reaches 3.2 mA cm^(-2)for Mg symmetrical cells and the reversible specific capacity reaches 141 mAh g^(-1)with a coulombic efficiency of 91.7%(first cycle)for Mg||TiS_(2)cells.

关键词： all-solid-state Mg batteries amorphization Mg borohydride ammoniate Mg vacancy migration solid electrolyte

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Self-assembly of Polyaniline： Mechanism Study

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Chinese Journal of Chemical Physics 2008年第2期21卷 187-192页

作者： Shi-yan Song Li-jia Pan Yun Li Yi Shi Lin pu Rong Zhang You-dou zheng National Laboratory of Solid State Microstructures Nanjing Department of Physics Nanjing University Nanjing 210093 China

Anisotropic polyaniline （PAni） plates decorated with self-aligned nanofiber arrays were synthesized under the hydrothermaI conditions. The formation mechanism of the self-assembled structures was investigated by studying the effect on PAni micro-structure with additive electrolyte in reaction system, and numerical simulation for dependence of systematic electrostatic energy on cross angles of self-assembled nanofiber arrays in grid textured PAni plates. It is proposed that the electrostatic interaction based on ionic doping charges plays an important role in the formation of the self-assembled PAni structures.

关键词： Polyaniline Self-assembly Ionic charge

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Constitutive Modeling for Flow Behaviors of Superaustenitic Stainless Steel S32654 during Hot Deformation

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Journal of Iron and Steel Research International 2016年第2期23卷 178-184页

作者： En-xiang pu Han fenG Min LIU Wen-jie zheng Han DONG Zhi-gang SONG Central Iron and Steel Research Institute Beijing 100081China School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

Hot deformation behavior of superaustenitic stainless steel S32654 was investigated with hot compression tests at temperatures of 950-1250 C and strain rates of 0. 001-10 s-1. Above 1150 ℃, with strain rate lower than 0.1 s -1 , the flow curves exhibit nearly steady state behavior, while at higher strain rate, continuous flow softening occurs. To provide a precise prediction of flow behavior for the alloy, the constitutive modeling considering effect of strain was derived on the basis of the obtained experimental data and constitutive relationship which incorporated Ar- rhenius term and hyperbolic sine type equation. The material constants α, n, Q and lnA are found to be functions of the strain and can be fitted employing eighth-order polynomial. The developed constitutive model can be employed to describe the deformation behavior of superaustenitic stainless steel S32654.

关键词： S32654 superaustenitic stainless steel hot deformation constitutive modeling

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Effects of Siqi Decoction on Concentration of Nitric Oxide and Activity of Nitric Oxide Synthase in Blood Serum of Rats with Myocardial Ischemia

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Chemical Research in Chinese Universities 2008年第1期24卷 65-68页

作者： SU Yan-bin LI zheng-qiang SU Yan-wen ZHANG fen-rong School of Chemical and Pharmaceutical Engineering Jilin Institute of Chemical Technology Jilin 132022 P. R. China Key Laboratory of Molecular Etymology and Engineering Ministry of Education Jilin University Changchun 130021 P. R. China Jilin Provincial Institute for Drug and Food Control Changchun 130033 P. R. China

To study the effects of Siqi decoction on rats with Myocardial Ischemia, the model of Myocardium Ischemia was made for the Wistar rats cured with posterior pituitary injection through vein in tail. Siqi decoction, Diaoxinxuekang（DK） and Fufangdanshenpian（FD）, the latter two drugs of which were effective TCM drugs of anti-Myocardial Ischemia at present, were administrated to the rats with Myocardium Ischemia for 5 days to compare the effect of anti-Myocardium Ischemia as reference drugs by measuring the changes of NO concentration and activity of NOS in the rat blood serum with Myocardial Ischemia. There was a remarkable increase in the NO concentration and activity of NOS in serum in Siqi decoction groups compared with those in control group（p〈0.05）. The results of the prevention group in experiment of Siqi decoction are better than those of the cure group. Siqi decoction was really fit for Myocardium Ischemia via increasing NO concentration by stimulating the activity of NOS in serum. The effect of Siqi decoction against Myocardium Ischemia in preventive group is better than the curative that of Siqi decoction in the curative group.

关键词： Siqi decoction Myocardial Ischemia Posterior pituitary Nitric oxide(NO) Nitric oxide synthase(NOS)

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