检索结果-南通市图书馆

Ti-Deoxidized Products and Formation Mechanism of Intragranular Ferrite in High Grade Pipeline Steels

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2010年第7期17卷 63-67页

作者： QI jiang-hua XUE zheng-liang WU Jie CHENG Chang-gui GAO yun-ming Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and Technology Wuhan 430081 Hubei China Wuhan Iron and Steel Group Co Wuhan 430080 Hubei China

High grade pipeline steels were prepared using vacuum carbon deoxidization process combined with a final Ti-deoxidation *** microstructure of the as-cast steels was investigated by using scanning electron microscopy（SEM）and transmission electron microscopy（TEM）.SEM observation shows that the formation of intragranular ferrite（IGF）structure is induced by fine *** selected area diffraction（SAD）patterns and elemental distribution analysis indicate that these inclusions are mainly Ti2O3 and *** is also found that Ti2O3 may act as nucleus in the formation of MnS during solidification *** spectroscopic analysis demonstrates the presence of another phase,MnTiO3,which could be formed through entrapment of Mn by *** is believed that the formation of Mn-depleted region in the inclusions and thus the formation of MnTiO3 phase will increase the Mn pickup from matrix and promote the formation of IGF during solidification of molten steel.

关键词： Ti-deoxidized product Ti2O3 intragranular ferrite Mn-depleted zone

Fujita-Liouville Type Theorem for Coupled Fourth-Order Parabolic Inequalities

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2012年第1期33卷 107-112页

作者： Zhaoxin jiang Sining zheng School of Mathematical Sciences Dalian University of TechnologyDalian 116024LiaoningChina School of Mathematical Sciences DalianUniversity of TechnologyDalian 116024LiaoningChina

This paper deals with a coupled system of fourth-order parabolic inequalities ｜u｜t ≥ -△2^u＋｜v｜^q, ｜v｜t ≥-△2v＋｜u｜p^ in S=R^n ×R^＋ withp, q 〉 1, n ≥1. AFujita- Liouville type theorem is established that the inequality system does not admit nontrivial nonnegative global solutions on S whenever n/4≤ max（ p＋1/pq-1, q＋1/pq-1 ）. Since the general maximum-comparison principle does not hold for the fourth-order problem, the authors use the test function method to get the global non-existence of nontrivial solutions.

关键词： Fujita exponent Liouville type theorem Higher-order parabolicinequalities Test function method

Demethylation treatment restores erectile function n a rat model of hyperhomocysteinemia

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2016年第5期18卷 763-768页

作者： zheng Zhan Lei-Lei Zhu He-Song jiang Hai Chen yun Chen Yu-Tian Dai Department of Andrology Affiliated Drum Tower Hospital School of Medicine Nanjing University Nanjing China

Methylation modification is an important cellular mechanism of gene expression regulation. Dimethylarginine dimethylaminohydrolase-2 （DDAH-2） protein is a pivotal molecular for endothelium function. To explore the effects of 5-aza-deoxycytidine （5-aza）, a demethylation agent, in hyperhomocysteinemia （hhcy）-related erectile dysfunction （ED） rats, 5-aza （1 mg kg-1） was administrated to Sprague-Dawley hhcy-rats induced by supplemented methionine chow diet. Erectile function, nitric oxide-cyclic guanosine monophosphate （NO-cGMP） levels, expression of DDAH-2 protein and promoter methylation status of DDAH-2 were studied in the corpora cavernosa. We found that supplemented methionine diet induced a high homocysteine level after 6 weeks of treatment. DDAH-2 protein was down-regulated in the corpora cavemosa while the administration of 5-aza up-regulated DDAH-2 expression and restored erectile function. The methionine-fed rats showed high methylation levels of DDAH-2 promoter region while the group treated with 5-aza demonstrated Iower-methylation levels when compared to the methionine-fed group. Besides, the administration of 5-aza improved NO and cGMP levels in methionine-fed rats. Therefore, the methylation mechanism involves in ED Dathogenesis. and demethvlation offers a ootential new strate~ for ED treatment.

关键词： DDAH-2 erectile dysfunction hyperhomocysteinemia methylation

Nonlinear optimal predictive controller for static var compensator to improve power system damping and to maintain voltage

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

Frontiers of Electrical and Electronic Engineering in China 2006年第4期1卷 380-384页

作者： jiang Tie-zheng CHEN Chen CAO Guo-yun Department of Electrical Engineering Changsha University of Science and TechnologyChangsha 410076China School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

The main objectives of this paper are to simul-taneously improve power system damping and to maintain voltage at the static var compensator(SVC)location bus simultaneously.A new controller for SVC with closed-form analytic solution nonlinear optimal predictive control(NOPC)law was *** controller does not require online optimization and the huge calculation burden can be avoided,so that the demand of real-time control can be *** addition,there are only two design parameters,which are the predictive period and control order;so it is easy to implement and test in practical *** results have shown that the controller can not only attenuate power system oscillation effectively but can also maintain voltage at the SVC bus location.

关键词： SVC NOPC power system damping closed-form analytic solution control law

Boosting cell performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode material via structure design

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

Journal of Energy Chemistry 2021年第4期30卷 114-123页

作者： Lin-bo Tang Yang Liu Han-xin Wei Cheng Yan Zhen-jiang He yun-jiao Li Jun-chao zheng School of Metallurgy and Environment Central South UniversityChangsha 410083HunanChina National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals Central South UniversityChangsha 410083HunanChina Engineering Research Center of the Ministry of Education for Advanced Battery Materials Central South UniversityChangsha 410083HunanChina School of Mechanical Medical and Process EngineeringQueensland University of TechnologyBrisbaneQueensland 4001Australia

Ni-rich cathodes exhibit appealing properties,such as high capacity density,low cost,and prominent energy ***,the inferior ionic conductivity and bulk structural degradation become bottlenecks for Ni-rich cathodes and severely limit their commercial *** coating and doping methods suffer fatal drawbacks in functioning as a unit and cannot radically promote material performance to meet the needs of Li-ion batteries(LIBs).Herein,we successfully devised an ingenious and facile synthetic method to establish Ni-rich oxides with a La_(2)Zr_(2)O_(7) coating and Zr *** coating layer improves the ion diffusion kinetics and enhances Li-ion transportation while Zr doping effectively suppresses the phase transition of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) *** to the synergetic effect of Zr doping and La_(2)Zr_(2)O_(7) coating,the modified material shows prominent initial discharge capacity of 184.7 m Ah g^(-1) at 5℃ and maintains 177.5 m Ah g^(-1) after 100 cycles at 1℃.Overall,the proposed feasible electrode design method can have a far-reaching impact on further fabrication of advanced cathodes for high-performance LIBs.

关键词： Lithium ion battery Ni-rich material La_(2)Zr_(2)O_(7)coating Zr doping Electrochemical performance

A field study of advanced municipal wastewater treatment technology for artificial groundwater recharge

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2006年第6期18卷 1056-1060页

作者： PI yun-zheng WANG Jian-long Laboratory of Environmental Technology Institute of Nuclear and New Energy Tsinghua University Beijing 100084 China

Field studies were conducted to investigate the advanced treatment of the municipal secondary effluent and a subsequent artificial groundwater recharge at Gaobeidian Wastewater Treatment Plant, Beijing. To improve the secondary effluent quality, the combined process of powdered activated carbon adsorption, flocculation and rapid sand filtration was applied, which could remove about 400 dissolved organic carbon （DOC） and 70% adsorbable organic halogens. The results of liquid size exclusion chromatography indicate that in the adsorption unit the removed organic fraction was mainly low molecular weight compounds. The fractions removed by the flocculation unit were polysaccharides and high molecular weight compounds. The retention of water in summer in the open recharge basins resulted in a growth of algae. Consequently, DOC increased in the polysaccharide and high molecular weight humic substances fraction. The majority of the DOC removal during soil passage took place in the unsaturated area. A limited reduction of DOC was observed in the aquifer zone.

关键词： artificial groundwater recharge soil aquifer treatment dissolved organic carbon

在线全文

学校读者我要写书评

暂无评论

载药外泌体在中枢神经系统疾病中的热点问题

中国组织工程研究 2025年第23期29卷 5013-5021页

作者：林慧洁黄云黄志华江丽霞赣南医科大学第一临床医学院江西省赣州市341000 赣南医科大学心脑血管重点实验室江西省赣州市341000 赣南医科大学基础医学院江西省赣州市341000 赣南医科大学第一附属医院检验科江西省赣州市341000

背景:利用外泌体作为药物载体不仅可以精确靶向治疗部位,还能提高局部浓度,为药物进入中枢神经系统开辟了一条新途径。目的:探讨外泌体的生物发生、生物学功能,综述当前有关细胞外囊泡作为药物载体在中枢神经系统疾病治疗中的最新进展... 详细信息

背景:利用外泌体作为药物载体不仅可以精确靶向治疗部位,还能提高局部浓度,为药物进入中枢神经系统开辟了一条新途径。目的:探讨外泌体的生物发生、生物学功能,综述当前有关细胞外囊泡作为药物载体在中枢神经系统疾病治疗中的最新进展。方法:由第一作者检索Web of Science、Pub Med和中国知网数据库1976年1月至2024年1月发表的相关文献,以“exosomes,extracellular vesicles,central nervous system,drug delivery,ischemic stroke,Alzheimer’s disease,Parkinson’s disease,spinal cord injury,brain tumor”为英文检索词,以“外泌体,细胞外囊泡,中枢神经系统疾病,载药,脑卒中,阿尔兹海默病,帕金森病,脊髓损伤、脑肿瘤”为中文检索词,最终纳入94篇文献进行分析。结果与结论:(1)外泌体可以轻易通过血脑屏障输送蛋白质、代谢物和核酸到受体细胞中,调节细胞代谢。由于外泌体是由细胞分泌的小囊泡,具有更低的循环免疫原性,在体内循环中能够更少被巨噬细胞识别清除。(2)外泌体可以被设计为递送不同的治疗成分,包括RNA、蛋白质、化疗药物和免疫调节剂,能够将治疗成分传送至期望的目标。经过工程修饰的外泌体具有更好的靶向性,并且这种外泌体介导的传递免疫原性极低,有望为将来中枢神经系统疾病的精准治疗提供更加安全有效的方法。

关键词：中枢神经系统疾病外泌体药物递送脑卒中阿尔茨海默病帕金森病脊髓损伤脑肿瘤

Disjoint Cliques in Claw-free Graphs

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2018年第1期34卷 19-34页

作者： Su-yun jiang Jin YAN School of Mathematics Shandong University

A graph is said to be claw-free if it does not contain an induced subgraph isomorphic to K_（1,3）. Let s and k be two integers with 0≤s≤k and let G be a claw-free graph of order n. In this paper, we investigate clique partition problems in claw-free graphs. It is proved that if n≥3 s ＋4（k-s） and d（x）＋ d（y）≥n-2 s ＋2 k ＋1 for any pair of non-adjacent vertices x, y of G, then G contains s disjoint K3 s and k-s disjoint K4 s such that all of them are disjoint. Moreover, the degree condition is sharp in some cases.

关键词： claw-free graphs disjoint clique degree condition

Fractal Analysis of Robertson-Stiff Fluid Flow in Porous Media

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2012年第6期29卷 203-206页

作者： yun Mei-Juan zheng Wei Key Laboratory of Systems Science in Metallurgical Process of Hubei Province Wuhan University of Science and TechnologyWuhan 430081 State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500 State Key Laboratory of Geodesy and Earth’s Dynamics Institute of Geodesy and GeophysicsChinese Academy of SciencesWuhan 430077

The Robertson-Stiff (RS) fluid is the representative fluid which may be reduced to Bingham,power-law and Newtonian fluids under appropriate *** present fractal models for the flow rate,velocity,starting pressure gradient and effective permeability for RS fluids in porous media based on the fractal characteristics of porous media and capillary *** proposed models are expressed as functions of the fractal dimensions,porosity,maximum pore size and the representative length of the porous *** parameter in the proposed expressions has clear physical meaning,and the proposed models relate the flow characteristics of the RS fluids to the structural parameters of the porous *** analytical expressions reveal the physical principles of RS fluid flow in porous media.

关键词： fractal porous dimensions