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Kinetics and Mechanism of Oxidation of Lactic Acid by Dihydroxyditelluratoargentate(Ⅲ) in Alkaline Medium

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Chemical Research in Chinese Universities 2003年第2期19卷 219-221页

作者： Shan Jin huan WANG Li LIU Bao sheng SHEN Shi gang sun han wen WANG An zhou College of Chemistry and Environment Science Hebei UniversityBaoding 071002P.R.China

The kinetics of the oxidation of lactic acid(Lac) by dihydroxyditelluratoargentate(Ⅲ)[abbreviated as DDA of Ag(Ⅲ)] anions was studied in an aqueous alkaline medium by conventional spectrophotometry in a temperature range of 25- 40 ℃ . The order of the redox reaction of lactic acid and DDA was found to be first order. The rates increased with the increase in and decreased with the increase in . No free radical was detected. In the view of this the dihydroxymonotelluratoargentate(Ⅲ) species(DMA) is assumed to be the active species. A plausible mechanism involving a two electron transfer is proposed, and the rate \{equation\} derived from the mechanism can be used to explain all the experimental results. The activation parameters(25 ℃) and the rate constants of the rate determining step along with the preequilibrium constants at different temperatures were evaluated.

关键词： Dihydroxyditelluratoargentate(Ⅲ) Lactic acid Kinetics and mechanism Redox reaction

High leaf area index expands the contrasting effect of climate warming on Western Siberia taiga forests activity before and after 2000

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Journal of Geographical Sciences 2024年第1期34卷 131-145页

作者： sun han WANG Xiangping State Key Laboratory of Efficient Production of Forest Resources Beijing Forestry UniversityBeijing 100083China School of Ecology and Nature Conservation Beijing Forestry UniversityBeijing 100083China

The taiga vegetation in Western Siberia has been seriously threatened by climate warming in recent ***,how vegetation in different growing states and climate conditions responds to climate changes differently is still *** we explore the vegetation activity trends in Western Siberia taiga forests using the annual rate of change in leaf area index(LAI)during 1982–2018 so as to answer two questions:(1)how did climate warming affect taiga vegetation activity in the recent last decades?(2)Did the growing state of taiga forest affect its response to climate warming?Our results revealed that climate warming promoted taiga vegetation activity in Western Siberia before ***,continuous warming caused excessive evapotranspiration and led to decreased vegetation activity after ***,the intensity of vegetation growth response to warming was positively related to canopy height and LAI,indicating that both the positive and negative effects of warming were more significant in taiga forests in better growing *** these forests generally have higher productivity and play more important roles in ecosystem functioning(e.g.,carbon sink and biodiversity conservation),our results highlight their vulnerability to future climate change that need more research attention.

关键词： climate warming taiga forest leaf area index(LAI) vegetation activity Western Siberia

Effect of Fe_(2)O_(3)on the Structure,Physical Properties and Crystallization of CaO-Al_(2)O_(3)-SiO_(2)Glass

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 954-961页

作者：张峰 XIONG Dehua 谢俊张继红 han Jianjun CHEN Dequan wen Zhongquan FAN Zhenhua CHEN Lina sun Tengfei State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China Hepu Research Center for Silicate Materials Industry Technology Beihai 536100China Hainan Institute of Wuhan University of Technology Sanya 430079China Shenzhen Research Institute of Wuhan University of Technology Shenzhen 518000China Chongqing Polycomp Inter-national Corporation Chongqing 400400China

The calcium aluminosilicate-based glasses(CaO-Al_(2)O_(3)-SiO_(2),CAS)with different Fe_(2)O_(3)content(0.10wt%,0.50wt%,0.90wt%,and 1.30wt%)were prepared by traditional melt-quenching *** glass network structure,thermal and mechanical properties,and crystallization behavior changes were investigated by nuclear magnetic resonance spectrometer,Fourier-transform infrared spectro-photometer,X-ray diffractometer,differential scanning calorimetry and field emission scanning electron microscope *** change of Q^(n)in glass structures reveals the glass network connectivity decreases due to the increasing content of Fe_(2)O_(3)addition,resulting in the increasing of non-bridging number in glass *** glass densities slightly rise from 2.644 to 2.681 g/cm^(3),while Vickers’s hardness increases at first,from 6.469 to 6.901 GPa,then slightly drops to 6.745 GPa,with Fe_(2)O_(3)content *** is almost no thermal expansion coefficient change from different Fe_(2)O_(3)*** glass transmittance in visible range gradually decreases with higher Fe_(2)O_(3)content,resulting from the strong absorption of Fe^(2+)and Fe^(3+)*** calculated activation energy from thermal analysis results first decreases from 282.70 to 231.18 kJ/mol,and then increases to 244.02 kJ/mol,with the Fe_(2)O_(3)content increasing from 0.10wt%to 1.30wt%.Meanwhile,the maximum Avrami constant of 2.33 means the CAS glasses exhibit two-dimensional *** of the CAS glass-ceramics samples contain main crystal phase of anorthite,the microstructure appears lamellar and columnar crystals.

关键词： calcium aluminosilicate glass network structure physical properties crystallization

Visible-light-driven photocatalysis degradation of antibiotic pollutants by La-doped CeO_(2) nanorods:synergy of La doping and oxygen vacancy

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Rare Metals 2024年第7期43卷 3134-3145页

作者： Shi-Hai Cao Jing-Ru Qu Yu-Qi Zhao Yun-Tong sun wen-Tong Gao Bing han Yao Lu College of Environmental Engineering Nanjing Institute of TechnologyNanjing 211167China School of Materials Science and Engineering Nanjing Institute of TechnologyNanjing 211167China School of Chemistry Chemical Engineering and BiotechnologyNanyang Technological UniversitySingapore 637459Singapore Institute of Environmental Health and Ecological Security School of Environment and Safety EngineeringJiangsu UniversityZhenjiang 212013China Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment Suzhou University of Science and TechnologySuzhou215009China

Elemental doping is an effective strategy to enhance photocatalytic activity and extend the light absorption range of single-component *** this work,a series of La-doped CeO_(2) nanorods(La-CeO_(2)-x) with La content of 1 wt%-15 wt% are synthesized by a simple hydrothermal method and further used as photocatalyst for sulfamerazine(SMR) *** prepared La-CeO_(2)-x nanorods exhibit a great improvement in electron-hole pair migration and visible-light response due to the synergistic effect of abundant oxygen vacancies and heterogeneous elements(La).Consequently,La-CeO_(2)-x exhibited excellent visible-light photocatalytic performances and chemical stability for SMR degradation,the La-CeO_(2)-5 sample achieved the highest SMR degradation rate of 81%,which was 3.4 times higher than that of the original CeO_(2).Furthermore,three possible degradation pathways of SMR in La-CeO_(2) photocatalytic reactions were proposed by liquid chromatography-mass spectrometry ***,density functional theory calculations were carried out to provide an in-depth understanding of the structure-performance *** its excellent properties and better photocatalytic performance,this study demonstrates that La doping in CeO_(2) is an effective way to increase oxygen vacancy and improve the photochemical properties of photocatalysts.

关键词： CeO_(2)nanorod La-doped Photocatalysis Oxygen vacancy Sulfamerazine

过渡金属元素氢化物发生-原子荧光增敏效应研究

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光谱学与光谱分析 2008年第11期28卷 2684-2690页

作者：孙汉文锁然河北大学化学与环境科学学院河北省分析科学技术重点实验室河北保定071002 河北农业大学食品科学系河北保定071001

基于反应介质酸度对Zn,Cd,Cu和Ni的氢化物发生影响的考察,揭示了氢转移过渡中间态[H+BH4-]*分解反应氢化物生成机理。分别考察了Co2+离子、Ni2+离子、邻菲咯啉、羟基喹啉对Zn,Cd,Cu和Ni氢化物发生原子荧光信号的影响,探讨了其增敏机理... 详细信息

基于反应介质酸度对Zn,Cd,Cu和Ni的氢化物发生影响的考察,揭示了氢转移过渡中间态[H+BH4-]*分解反应氢化物生成机理。分别考察了Co2+离子、Ni2+离子、邻菲咯啉、羟基喹啉对Zn,Cd,Cu和Ni氢化物发生原子荧光信号的影响,探讨了其增敏机理。由于Co和Ni的挥发性物种分解抑制了Cd和Zn氢化物在传输过程中的分解损失,明显提高了Cd和Zn氢化物的传输效率。邻菲咯啉与Co2+离子或8-羟基喹啉与Co2+离子对Zn和Cd信号均具有协同增敏效应,8-羟基喹啉和邻菲咯啉对Zn和Cd信号则没有协同增敏效应。考察了阳离子、阴离子和非离子表面活性剂对氢化物发生的促进作用。结果证实阳离子和非离子表面活性剂均对分析物信号有明显的增敏效果,其原因在于表面活性剂的存在引起溶液的表面张力显著的降低。以石墨炉原子吸收法进一步考察了分析物从表面活性剂吸收液中逸出特性,提出了表面活性剂在氢化物发生和传输过程中的增敏机理。

关键词：过渡金属元素氢化物原子荧光增敏效应机理

On the global smooth solutions of 3D incompressible Hall-MHD equations

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 319-327页

作者： YUE Gao-cheng sun wen-da School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106China

The present paper is devoted to the well-posedness issue for the 3D incompressible Hall-MHD system obtained from kinetic models. Our analysis strongly relies on the use of the Fourier analysis. We establish the global existence of smooth solutions for a class of large initial data, this result implies the initial velocity and magnetic field can be arbitrarily large.

关键词： 3D Hall-MHD well-posedness Fourier analysis

Prediction of lime utilization ratio of dephosphorization in BOF steelmaking based on online sequential extreme learning machine with forgetting mechanism

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International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 508-517页

作者： Runhao Zhang Jian Yang han sun wenkui Yang State Key Laboratory of Advanced Special Steel School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

The machine learning models of multiple linear regression(MLR),support vector regression(SVR),and extreme learning ma-chine(ELM)and the proposed ELM models of online sequential ELM(OS-ELM)and OS-ELM with forgetting mechanism(FOS-ELM)are applied in the prediction of the lime utilization ratio of dephosphorization in the basic oxygen furnace steelmaking *** ELM model exhibites the best performance compared with the models of MLR and ***-ELM and FOS-ELM are applied for sequential learning and model *** optimal number of samples in validity term of the FOS-ELM model is determined to be 1500,with the smallest population mean absolute relative error(MARE)value of 0.058226 for the *** variable importance analysis reveals lime weight,initial P content,and hot metal weight as the most important variables for the lime utilization *** lime utilization ratio increases with the decrease in lime weight and the increases in the initial P content and hot metal weight.A prediction system based on FOS-ELM is applied in actual industrial production for one *** hit ratios of the predicted lime utilization ratio in the error ranges of±1%,±3%,and±5%are 61.16%,90.63%,and 94.11%,*** coefficient of determination,MARE,and root mean square error are 0.8670,0.06823,and 1.4265,*** system exhibits desirable performance for applications in actual industrial pro-duction.

关键词： basic oxygen furnace steelmaking machine learning lime utilization ratio dephosphorization online sequential extreme learning machine forgetting mechanism

Hierarchical Spinning of Janus Textiles with Anisotropic Wettability for Wound Healing

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Research 2024年第1期2023卷 97-105页

作者： han Zhang Lingyu sun Jiahui Guo Yuanjin Zhao Department of Rheumatology and Immunology Nanjing Drum Tower HospitalSchool of Biological Science and Medical EngineeringSoutheast UniversityNanjingJiangsu 210096China Oujiang Laboratory(Zhejiang Lab for Regenerative Medicine Vision and Brain Health)Wenzhou InstituteUniversity of Chinese Academy of SciencesWenzhouZhejiang 325001China

Wound healing and tissue repair are recognized as basic human health problems *** to accelerate the reparative process are focused on developing functional wound ***,we present novel Janus textiles with anisotropic wettability from hierarchical microfluidic spinning for wound *** hydrophilic hydrogel microfibers from microfluidics are woven into textiles for freeze-drying treatment,followed by the deposition of electrostatic spinning nanofibers composed of hydrophobic polylactic acid(PLA)and silver *** electrospun nanofiber layer can be well coupled with the hydrogel microfiber layer to generate Janus textiles with anisotropic wettability due to the roughness of the hydrogel textile surface and the incomplete evaporation of PLA solution when reaching the *** wound treatment with the hydrophobic PLA side contacting the wound surface,the wound exudate can be pumped from the hydrophobic to the hydrophilic side based on the wettability differential derived drainage *** this process,the hydrophobic side of the Janus textile can prevent excess fluid from infiltrating the wound again,preventing excessive moisture and preserving the breathability of the *** addition,the silver nanoparticles contained in the hydrophobic nanofibers could impart the textiles with good antibacterial effect,which further promote the wound healing *** features indicate that the described Janus fiber textile has great application potential in the field of wound treatment.

关键词： silver spinning healing

Effect of nourishing Yin and purging fire Chinese herbal mixture on delaying light-induced premature puberty in rats

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Journal of Traditional Chinese Medicine 2024年第1期44卷 95-102页

作者： sun Yanyan XUE Yuanyuan sun wen WANG Yonghong YU Jian Department of Traditional Chinese Medicine Children's Hospital of Fudan UniversityShanghai 201102China Department of Pediatrics Zibo Central HospitalZibo 255000China

OBJECTIVE:To elucidate the mechanism of the nourishing Yin and purging fire Chinese herbal mixture(NYPF)in delaying light-induced premature puberty in ***:Twenty-one days old female SpragueDawley rats were randomly assigned to normal group(N),long light exposure group(L),NYPF and normal saline group(NS).Rats in the L,NYPF and NS groups were exposed to 16 h:350 lux light/8 h:dark,while rats in the N group were exposed to 12 h:50 lux light/12 h:*** and normal saline was administered to the rats in the NYPF group or NS group,respectively,from day *** rats in every group were sacrificed at 9 *** day 28(P28),on the day when rat's vulva opened in the L group(L-VO),on the day when the first estrous interphase occurred in rats of L group(L-E1),and on the day when the second estrous interphase occurred in rats of L group(L-E2),***:On day 34,all rats in the L group,80%of rats in the NS group,40%of rats in the N group,and 20%of rats in the NYPF group showed complete opening of the *** P28,m RNA level of hypothalamic kisspeptin(Kiss-1)in the L group was significantly higher than that in the N group(Phan those in the N group(Phan that in the L group(Phan that of the N group(Phan that of the N and NS groups(Phan that in the N and NYPF groups(Phan that in the N group(Phan that of the N group(P<0.01),wher

关键词： light puberty precocious kisspeptins RFRP-3 melatonin Nourishing Yin and Purging Fire