检索结果-南通市图书馆

Journal of Natural Gas Chemistry 2007年第1期16卷 6-11页

作者： Yonggang wei hua Wang Fang he Xianquan Ao Chiyuan Zhang Faculty of Materials and Metallurgy Engineering Kunming University of Science and Technology Kunming 650093 Yunnan China

A new technique -- the direct partial oxidation of methane to synthesis gas using lattice oxygen in molten salts medium has been introduced. Using CeO2 as the oxygen carrier, thermodynamic data were calculated in the reaction process, and the results indicated that direct partial oxidation of methane to synthesis gas using lattice oxygen of cerium oxide is feasible in theory. In a stainless steel reactor, the effects of temperature and varying amounts of γ-Al2O3 supported CeO2 on cn4 conversion, H2 and CO selectivity, were investigated, respectively. The results show that 10% CeO2/γ-Al2O3 has the maximal reaction activity at a temperature of 865 ℃ and above, the H2/CO ratio in the gas that has been produced reaches 2 and the CH4 conversion, H2 and CO selectivity reached the following percentages： i.e. 61%, 89%, and 91% at 870 ℃, respectively. In addition, increase of reaction temperature is favorable for the partial oxidation of methane.

关键词： partial oxidation methane cerium oxide synthesis gas molten salt

Ricci-flat Graphs with Girth Four

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2021年第11期37卷 1679-1691页

作者： wei hua he Jun LUO Chao YANG wei YUAN Hui Chun ZHANG School of Mathematics and Statistics Guangdong University of TechnologyGuangzhou 510520P.R.China School of Mathematics Sun Yat-sen UniversityGuangzhou 510275P.R.China School of Mathematics and Statistics Guangdong University of Foreign StudiesGuangzhou 510006P.R.China

Lin-Lu-Yau introduced a notion of Ricci curvature for graphs and obtained a complete classification for all Ricci-flat graphs with girth at least *** this paper,we characterize all Ricci-flat graphs of girth four with... 详细信息

关键词： Ricci curvature Ricci-flat graph vertex-disjoint

Linear Arboricity of Regular Digraphs

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2017年第4期33卷 501-508页

作者： wei hua he Hao LI Yan Dong BAI Qiang SUN Department of Applied Mathematics Guangdong University of TechnologyGuangzhou 510006P.R.China Laboratoire de Recherche en Informatique UMR 8623C.N.R.S.-Universitg de Paris-sud91405-Orsay cedexFrance

A linear directed forest is a directed graph in which every component is a directed *** linear arboricity la(D) of a digraph D is the minimum number of linear directed forests in D whose union covers all arcs of D. For every d-regular digraph D, Nakayama and P′eroche conjecture that la(D) = d + 1. In this paper, we consider the linear arboricity for complete symmetric digraphs,regular digraphs with high directed girth and random regular digraphs and we improve some wellknown results. Moreover, we propose a more precise conjecture about the linear arboricity for regular digraphs.

关键词： Linear arboricity digraph Lovász Local Lemma random regular digraphs

Recent Advances of DNA Hydrogels in Biomedical Applications

在线全文

学校读者我要写书评

暂无评论

Journal of Analysis and Testing 2021年第2期5卷 155-164页

作者： huai-Qing Chen Wan Yang hua Zuo hua-wei he Ye-Jing Wang State Key Laboratory of Silkworm Genome Biology Biological Science Research CenterSouthwest UniversityChongqing 400715China College of Pharmaceutical Sciences Southwest UniversityChongqing 400715China Chongqing Key Laboratory of Sericultural Science Chongqing Engineering and Technology Research Center for Novel Silk MaterialsSouthwest UniversityChongqing 400715China Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing Chongqing 400715China

DNA hydrogel is one of DNA-based nanomaterials with unique advantages such as precise self-assembly,programmability,addressability,high stability,excellent biocompatibility and biodegradability,and tunable *** features have greatly promoted the development of DNA hydrogels in various applications,especially molecular diagnostics,biosensing,drug delivery,and cancer *** this review,we briefly review the history of DNA hydrogels,the latest advances of DNA hydrogels in biomedical applications especially in biosensing,drug delivery and cancer therapy,and prospect the key challenges and future directions.

关键词： DNA hydrogels Self-assembly Biosensing Drug carrier Cancer therapy

Enhancing the electrocatalytic performance of nitrate reduction to ammonia by in-situ nitrogen leaching

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第2期35卷 564-569页

作者： Mimi Fu Yini Mao hua Wang wei Luo Yimin Jiang wei Shen Ming Li Rongxing he College of Chemistry and Chemical Engineering Southwest UniversityChongqing 400715China

Electrochemical nitrate reduction reaction (NITRR) is regarded as a “two birds-one stone” method for the treatment of nitrate contaminant in polluted water and the synthesis of valuable ammonia, which is retarded by the lack of highly reactive and selective electrocatalysts .herein, for the first time, nickel foam supported Co_(4) N was designed as a high-performance NITRR catalyst by an in-situ nonmetal leaching-induced *** the optimal potential, the Co_(4) N/NF catalyst achieves ultra-high Faraday efficiency and NH_(3) selectivity of 95.4% and 99.4%, *** situ X-ray absorption spectroscopy (XAS), together with other experiments powerfully reveal that the nitrogen vacancies produced by nitrogen leaching are stable and play a key role in boosting nitrate reduction to *** calculations confirm that Co_(4) N with abundant nitrogen vacancies can optimize the adsorption energies of NO_(3)^(-) and intermediates, lower the free energy (Δ G ) of the potential-determining step (*NH_(3) to NH_(3) ) and inhibit the formation of N-containing *** addition, we also conclude that the nitrogen vacancies can stabilize the adsorbed hydrogen, making H_(2) quite difficult to produce, and lowering ΔG from *NO to *NOH, which facilitates the selective reduction of *** study reveals significant insights about the in-situ nonmetal leaching to enhance the NITRR activity.

关键词： Co4N Nitrate reduction In-situ nonmetal leaching Nitrogen vacancy Mechanism

Effect of resveratrol treatment on apoptosis and apoptotic pathways during boar semen freezing

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2020年第6期21卷 485-494页

作者： wei-hua he Xiao-hu ZHAI Xiu-jun DUAN he-shuang DI Jiangsu Agri-animal Husbandry Vocational College Taizhou 225300China

Resveratrol(3,5,4’-trihydroxystilbene,RSV) has been widely used in mammalian cells,but whether it can be used during freezing boar semen is still *** effects of RSV treatment during boar semen freezing on its anti-freezing ability,apoptosis,and possible apoptotic pathways were observed in this *** motility,mitochondrial membrane potential(ΔΨm),adenosine triphosphate(ATP) content,terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick-end labeling(TUNEL)-positive apoptotic state,and messenger RNA(mRNA) expression levels of apoptotic genes involved in different apoptotic pathways after freezing with or without RSV treatment were *** results showed that:(1) Compared with fresh sperm,the motility,normal acrosome rate,and plasma membrane integrity rate of frozen boar sperm decreased significantly(Phe sperm motility(0.44 vs.0.40,P>0.05),but it did significantly improve the normal acrosome rate(57.65% vs.47.00%,Phe rate of high mitochondrial ΔΨm of boar sperm.(3) RSV treatment significantly decreased reactive oxygen species(ROS) levels(58.65% vs.88.41%,Phe ATP content(0.49 μmol/L vs.0.25 μmol/L,Phe apoptotic rate of the freezing group(80.41%) with TUNEL detection increased significantly compared to the fresh group(9.70%,Phe apoptotic rate(68.32%,Phe genes from the death receptor-mediated apoptotic pathway(tumor necrosis factor-α(TNF-α),Fas ligand(FasL),and Caspase-8),but also the genes from the mitochondria-mediated apoptotic pathway(manganese superoxide dismutase(MnSOD),B-cell lymphoma 2(Bcl-2),Bcl-2-associated X protein(Bax),and Caspase-9) were both signific

关键词： Resveratrol(RSV) Boar semen freezing Antioxidant Mitochondrial function Apoptotic pathway

Synergistic catalysis of the N-hydroxyphthalimide on flower-like bimetallic metal-organic frameworks for boosting oxidative desulfurization

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第1期21卷 674-682页

作者： Jing he Kun Zhu wei Jiang Dong-Ao Zhu Lin-hua Zhu Hai-Yan huang Wen-Shuai Zhu hua-Ming Li Institute for Energy Research Jiangsu UniversityZhenjiang212013JiangsuChina College of Chemistry and Chemical Engineering Hainan Normal UniversityKey Laboratory of Water Pollution Treatment and Resource Reuse of Hainan ProvinceHaikou571158HainanChina

Synergic catalytic effect between active sites and supports greatly determines the catalytic activity for the aerobic oxidative desulfurization of fuel *** this work,Ni-doped Co-based bimetallic metal-organic framework(CoNi-MOF)is fabricated to disperse N-hydroxyphthalimide(NHPI),in which the whole catalyst provides plentiful synergic catalytic effect to improve the performance of oxidative desulfurization(ODS).As a bimetallic MOF,the second metal Ni doping results in the flower-like morphology and the modification of electronic properties,which ensure the exposure of NHPI and strengthen the synergistic effect of the overall *** with the monometallic Co-MOF and naked NHPI,the NHPI@CoNi-MOF triggers the efficient activation of molecular oxygen and improves the ODS performance without an *** sulfur removal of dibenzothiophene-based model oil reaches 96.4%over the NHPI@CoNi-MOF catalyst in 8 h of ***,the catalytic product of this aerobic ODS reaction is sulfone,which is adsorbed on the catalyst surface due to the difference in *** work provides new insight and strategy for the design of a strong synergic catalytic effect between NHPI and bimetallic supports toward high-activity aerobic ODS materials.

关键词： Metal-organic frameworks Doped Bimetallic N-hydroxyphthalimide Aerobic processes Oxidative desulfurization

Solidification crack characteristics and sensitivity of peritectic steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第7期31卷 1668-1679页

作者： Ya-qiang Li Jian-hua Liu Zi-ming Wang Ying-ying Li Yang he Xiao-wei Li Department of Automotive Engineering Hebei Vocational University of Technology and EngineeringXingtai 054000HebeiChina hebei Special Vehicle Modification Technology Innovation Center Hebei Vocational University of Technology and EngineeringXingtai 054000HebeiChina Institute of Engineering Technology University of Science and Technology BeijingBeijing 100083China School of Petroleum and Natural Gas Engineering Changzhou UniversityChangzhou 213164JiangsuChina

The characteristics and sensitivity of solidification cracks in peritectic steels were investigated using directional solidifi-cation *** cracks were observed in both hypoperitectic steels(12CrlMoV,15CrMo)and hyper-peritectic steel(20CrMo)during solidification at growth velocities of 15,50,and 80 pm/*** the dendritic boundaries,sulphide precipitates were found,promoting crack *** on the statistical analysis of interdendritic cracks in peritectic steels,the area ratio(RA)of interdendritic cracks in a directional solidification structure was proposed to evaluate the crack sensitivity of peritectic ***,the crack sensitivities of peritectic steels(12CrlMoV,15CrMo,and 20CrMo)were tested,evaluated,and compared with the surface crack rates of three types of steels produced from a steel *** results demonstrated that RA was in good agreement with that of the steel plant,and the crack sensitivity of 12CrlMoV steel was the strongest,followed by that of 15CrMo and 20CrMo ***,RA can be used to evaluate the crack sensitivity of peritectic steel.

关键词： Peritectic steel-Directional solidification Growth velocity Dendritic structure Solidification crack Crack sensitivity

SYMBOLIC ANALYTICAL SYSTEM DEVELOPED ON MICROCOMPUTER AND SOME EXAMPLES

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 1992年第4期 234-242页

作者： Cao Da-wei,he hua-can,Chen Qiu(Northwestern Polytechnical University,Xi’an China)

By referring to REDUCE system,a new system or a language of non-numerical manipulationfor symbolic analysis has been built on PC *** symbolic analyticalsystem is a mathematical expert system,which makes use of the principles andmethods of artificial intelligence to the algebra,calculus and other calculating *** to being a system for calculating manipulation,it is also a language for thestatement of *** a set of simple syntax,users write program in its own *** system can operate both in interactive manner or in program *** are given in two-dimensional analysis form or FORTRAN source program formwhich may be used in numerical calculation *** system has complete systematic controlfunctions and error-handling capability,allowing job—*** job may be interruptedif *** and function-keys provide great convenience to *** two non-numerical examples of the system are presented.

关键词： RK SYMBOLIC ANALYTICAL SYSTEM DEVELOPED ON MICROCOMPUTER AND SOME EXAMPLES LISP

Decreases of voltage-dependent K~+ currents densities in ventricular myocytes of guinea pigs by chronic oxidant stress

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2004年第6期25卷 49-53页

作者： De-li DONG, Yan LIU, Yu-hong ZHOU,wei-hua SONG, he WANG, Bao-feng YANG2 Department ofpharmacology, Harbin Medical University, Harbin 150086, China Department of pharmacology Harbin Medical University Harbin 150086

AIM: To determine the changes of delayed rectifier K+ currents (Ik) and inward rectifier K+ currents (Ik1) in the ventricular myocytes of guinea pigs during the gradual apoptotic process by the chronic oxidant stress treatment. METHODS: H2O250 μmol/L (24 h) was used for inducing apoptosis in the cardiomyocytes culture of neonatal rats and to treat the isolated ventricular myocytes of adult guinea pigs in vitro for 24 h. Apoptosis was evaluated by TUNEL methods and voltage-dependent K+ currents were recorded by patch-clamp techniques. RESULTS: H2O2 50 μmol/L (24 h)induced cell apoptosis in the cardiomyocytes culture of neonatal rats. This concentration was used to treat the isolated ventricular myocytes of adult guinea pigs in vitro for 24 h and the voltage-dependent K+ currents densities (Ik, Ik1) were down-regulated. The densities of the delayed rectifier K+ currents (Ik) in 50 μmol/L H2O2 group were 2.52±0.57 pA/pF vs 5.73±1.84 pA/pF in the control group at +50 mV (n=8, Phe densities of the inward rectifier K+ currents (Ik1) in 50 μmol/L H2O2 group were -13.9± 2.70 pA/pF, 2.52±0.57 pA/pF vs -59.7±11.9 pA/pF, 5.73±1.84 pA/pF in the control group at -120 mV (n=8, Phe extent of inward rectifier property of Ik1 was weakened by 50 μmol/L H2O2treatment. CONCLUSION: The densities of Ik, Ik1 in the cardiomyocytes of guinea pigs were down- regulated and the inward rectifier property of Ik1 was weakened during the gradual apoptotic process after 50 μmol/L H2O2 treatment for 24 h.

关键词： hydrogen peroxide potassium apoptosis cardiac myocytes