检索结果-南通市图书馆

Rare Metals 2015年第11期34卷 789-796页

作者： Long He Ye-Fa Tan xiao-Long wang qi-Feng Jing xiang hong College of Field Engineering PLA University of Science and Technology

To improve the wear resistance of aluminum alloy frictional parts, Ti B2particles reinforced Ni-base alloy composite coatings were prepared on aluminum alloy 7005 by laser cladding. The microstructure and tribological properties of the composite coatings were investigated. The results show that the composite coating contains the phases of Ni Al, Ni3Al, Al3Ni2, TiB2, TiB, TiC, CrB, and *** microhardness is HV0.5855.8, which is 15.4 % higher than that of the Ni-base alloy coating and is 6.7 times as high as that of the aluminum alloy. The friction coefficients of the composite coatings are reduced by 6.8 %–21.6 % and 13.2 %–32.4 % compared with those of the Ni-base alloy coatings and the aluminum alloys, while the wear losses are 27.4 %–43.2 % less than those of the Ni-base alloy coatings and are only 16.5 %–32.7 % of those of the aluminum alloys at different loads. At the light loads ranging from 3 to 6 N, the calculated maximum contact stress is smaller than the elastic limit contact stress. The wear mechanism of the composite coatings is micro-cutting wear, but changes into multi-plastic deformation wear at 9 N due to the higher calculated maximum contact stress than the elastic limit contact stress. As the loads increase to 12 N, the calculated flash temperature rises to 332.1 °*** composite coating experiences multi-plastic deformation wear, micro-brittle fracture wear, and oxidative wear.

关键词： Ti B2 Ni-base alloy Laser cladding Composite coati

Chondroitinase ABC combined with Schwann cell transplantation enhances restoration of neural connection and functional recovery following acute and chronic spinal cord injury

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第5期20卷 1467-1482页

作者： Wenrui Qu xiangbing Wu Wei Wu Ying wang Yan Sun Lingxiao Deng Melissa Walker Chen Chen Heqiao Dai qi Han Ying Ding Yongzhi Xia George Smith Rui Li Nai-Kui Liu xiao-Ming Xu Spinal Cord and Brain Injury Research Group Stark Neurosciences Research InstituteDepartment of Neurological SurgeryIndiana University School of MedicineIndianapolisINUSA Department of Hand Surgery the Second Hospital of Jilin UniversityChangchunJilin ProvinceChina Shriners Hospitals Pediatric Research Center Temple University School of MedicinePhiladelphiaPAUSA Department of Anatomy&Cell Biology Indiana University School of MedicineIndianapolisINUSA

Schwann cell transplantation is considered one of the most promising cell-based therapy to repair injured spinal cord due to its unique growth-promoting and myelin-forming properties.A the Food and Drug Administration-approved Phase I clinical trial has been conducted to evaluate the safety of transplanted human autologous Schwann cells to treat patients with spinal cord injury.A major challenge for Schwann cell transplantation is that grafted Schwann cells are confined within the lesion cavity,and they do not migrate into the host environment due to the inhibitory barrier formed by injury-induced glial scar,thus limiting axonal reentry into the host spinal *** we introduce a combinatorial strategy by suppressing the inhibitory extracellular environment with injection of lentivirus-mediated transfection of chondroitinase ABC gene at the rostral and caudal borders of the lesion site and simultaneously leveraging the repair capacity of transplanted Schwann cells in adult rats following a mid-thoracic contusive spinal cord *** report that when the glial scar was degraded by chondroitinase ABC at the rostral and caudal lesion borders,Schwann cells migrated for considerable distances in both rostral and caudal *** Schwann cell migration led to enhanced axonal regrowth,including the serotonergic and dopaminergic axons originating from supraspinal regions,and promoted recovery of locomotor and urinary bladder ***,the Schwann cell survival and axonal regrowth persisted up to 6 months after the injury,even when treatment was delayed for 3 months to mimic chronic spinal cord *** findings collectively show promising evidence for a combinatorial strategy with chondroitinase ABC and Schwann cells in promoting remodeling and recovery of function following spinal cord injury.

关键词： axonal regrowth bladder function chondroitinase ABC functional recovery glial scar lentivirus migration Schwann cell spinal cord injury transplantation

Comparison of intravitreal bevacizumab with macular photocoagulation for treatment of diabetic macular edema: a systemic review and Meta-analysis

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2014年第6期7卷 1048-1055页

作者： xiang-dong Liu xiao-dong Zhou Zhi wang hong-Jie Shen Department of Ophthalmology Affiliated Jinshan HospitalFudan University

AIM: To further evaluate the efficacy and safety of intravitreal bevacizumab(IVB) versus macular photocoagulation(MPC) in treatment of diabetic macular edema(DME) by Meta-analysis. METHODS: Pertinent publications were identified through systemic searches of Pub Med, Medline,EMBASE, and the Cochrane Controlled Trials Register up to 30 November, 2013. Changes in central macular thickness(CMT) in μm and best-corrected visual acuity(BCVA) in log MAR equivalents were extracted at 1, 3, 6,12 and 24 mo after initial treatment, and a Meta-analysis was carried out to compare results between groups receiving IVB and ***: Five randomized controlled trial(RCTs) and one high-quality comparative study were identified and included. Our Meta-analysis revealed that both IVB and MPC resulted in the improvements of CMT and BCVA in eyes with DME at 1mo after initial treatment, with IVB being significantly superior to MPC(P =0.01 and 0.02,respectively). The improvements of both measure outcomes at 3, 6, 12 and 24 mo after treatment did not vary significantly between the IVB groups and MPC groups(CMT at 3mo, P =0.85; at 6mo, P =0.29; at 12 mo,P =0.56; at 24 mo, P =0.71; BCVA at 3mo, P =0.31; at 6mo,P =0.30; at 12 mo, P =0.23; at 24 mo, P =0.52). However,the number of observed adverse events was low in all ***: Current evidence shows IVB treatment trends to be more effective in improvements of macular edema and vision in eyes with DME at an earlier follow up(1mo) compared with MPC. At other time, both interventions have comparable efficacy without statistical significances.

关键词： intravitreal injection bevacizumab photocoagulation diabetic macular edema Meta-analysis

Biodecolorization and partial mineralization of Reactive Black 5 by a strain of Rhodopseudomonas palustris

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 Environmental Sciences 2008年第10期20卷 1218-1225页

作者： wang, Xingzu CHENG, xiang SUN, Dezhi qi, hong School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China

A strain of photosynthetic bacterium, Rhodopseudomonas palustris W1, isolated from a lab-scale anaerobic moving bed biofilm reactor (MBBR) treating textile e?uent was demonstrated to decolorize Reactive Black 5 (RB5) effciently under anaerobic condition. By a series of batch tests, the suitable conditions for RB5 decolorization were obtained, namely, pH < 10, light presence, glutamine or lactate as carbon source with concentration more than 500 mg/L when lactate is selected, NH4Cl as a nitrogen source wi...

关键词： decolorization mineralization Reactive Black 5 (RB5) photosynthetic bacterium metabolite analysis

Space time frequency coding for dual polarization MIMO in hybrid mobile satellite system

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2013年第4期20卷 8-14页

作者： wang Kai-dong GUO Ling-zhi tao xiao-feng CUI qi-mei Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications

The hybrid mobile satellite system operating in a single frequency network （SFN） mode is increasingly becoming attractive. The combination of satellite component （SC） and terrestrial component （TC） promises a better quality of service （QoS）. Multimedia broadcast and multicast services （MBMS） are expected to be prevailed in this kind of system. Several space frequency （SF） or space time （ST） codes have been proposed to enhance the system performance due to the lack of reverse link and omni-directional transmission. However, they mostly consider the system with only one SC and one TC and fail to make full use of available diversities. This paper presents a novel way to realize the dual polarization multiple input multiple output （MIMO） transmission by using the space time frequency （STF） code. The theoretical analysis and simulations indicate that the application of STF code can improve the system performance dramatically. A higher diversity gain can be achieved due to the cooperative transmission of SC and TC, while the coding gain can be enhanced by the reusing of STF code between SCs or TCs. Even if some of the links are lost, it can still work properly and benefit from the STF code. The relative relay can result in a degradation up to 0.5 dB in the coding gain.

关键词： MIMO dual polarization hybrid mobile satellite system SFN STF code diversity gain

Superior corrosion resistance-dependent laser energy density in(CoCrFeNi)95Nb5 high entropy alloy coating fabricated by laser cladding

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2021年第5期28卷 888-897页

作者： Wen-rui wang Wu qi xiao-li Zhang xiao Yang Lu Xie dong-yue Li Yong-hua xiang School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory of Fluid Interaction with Material Ministry of EducationBeijing 100083China R&D management department China nuclear power technology research institute Co.Ltd.Shenzhen 518031China Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China Unit 92228 People’s Liberation ArmyBeijing 100072China

(CoCrFeNi)95Nb5 high entropy alloy(HEA)coatings were successfully fabricated on a substrate of Q235 steel by laser cladding ***(CoCrFeNi)95Nb5 HEA coatings possess excellent properties,particularly corrosion resistance,which is clearly superior to that of some typical bulk HEA and common engineering *** order to obtain appropriate laser cladding preparation process parameters,the effects of laser energy density on the microstructure,microhardness,and corrosion resistance of(CoCrFeNi)95Nb5 HEA coating were closely *** showed that as the laser energy density increases,precipitation of the Laves phase in(CoCrFeNi)95Nb5 HEA coating gradually decreases,and diffusion of the Fe element in the substrate intensifies,affecting the integrity of the(CoCrFeNi)95Nb5 *** decreases the microhardness of(CoCrFeNi)95Nb5 HEA ***,the relative content of Cr2O3,Cr(OH)3,and Nb2O5 in the surface passive film of the coating decreases with increasing energy density,causing corrosion resistance to *** study demonstrates the controllability of a high-performance HEA coating using laser cladding technology,which has significance for the laser cladding preparation of other CoCrFeNi-system HEA coatings.

关键词： high entropy alloy coating laser cladding technology laser energy density corrosion resistance

Reliable, environmentally friendly method for the recycling of spent Ag/α-Al2O3 catalysts using (NH4)2Ce(NO3)6

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2018年第10期26卷 2169-2175页

作者： Xulong dong Jian Li qinggui xiao Hui Zhang tao qi University of Chinese Academy of Sciences Beijing 100049 China National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Institute of Process Chinese Academy of Sciences Beijing 100190 China Key Laboratory of Green Process and Engineering Institute of Process Chinese Academy of Sciences Beijing 100190 China

Traditionally,Ag-containing solid wastes are leached by nitric acid in order to recycle the noble ***,the huge amounts of emission of toxic nitrogen oxides demand the development of a new method for silver ***,considering the Ce(Ⅳ)solution could be regenerated with electrolyzation method,our group invented a novel environmentally friendly process by using Ce(Ⅳ)as the oxidant to dissolve silver from the spent Ag/ɑ-Al_2O_3 catalysts without NO_x *** find out the optimal parameters,in this work,the leaching reaction was thoroughly investigated with respect to the temperature,oxidant and HNO_3 concentrations,stirring speed,and *** optimized leaching reaction gave the leaching silver rate 99.8% in 1 *** kinetic plots suggested a shrinking core model with the internal diffusion-controlled process and the activation energy of 38.83 k J·mol^(-1).The order in which the experimental conditions influence the reaction was determined through orthogonal analysis:temperature N oxidant concentration N HNO_3 concentration N stirring speed.

关键词： Cerium ammonium nitrate (CAN) Silver Spent catalyst Leaching Kinetics

Recyclable Polyurea-Urethane Thermosets with De-Crosslinking Capability in Acetic Acid

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2023年第6期41卷 859-865,I0006页

作者： Xinglei tao Wentian Yi xiao-qi Xu Yapei wang Key Laboratory of Advanced Light Conversion Materials and Biophotonics Department of ChemistryRenmin University of ChinaBejing 100872China

Covalent crosslinking points within thermosets generally result in excellent mechanical properties and solvent resistance yet lead to limited degradability and *** thermosets become degradable or recyclable if crosslinking points are cleavable or *** this principle,we report a kind of polyurea-urethane thermoset with borate ester as its crosslinking point to enable a controllable decrosslinking in response to acetate *** a thermoset presents remarkable mechanical properties as well as outstanding solvent resistance capability,due to the high crosslinking density and intermolecular hydrogen ***,the de-crosslinked product can be reporcessed to generate a brand new thermoplastic material.

关键词： material. crosslinking reversible

Elimination of HBr from CH_3Br by Cu^+ and Au^+:A DFT study

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2008年第7期19卷 881-884页

作者： tao hong Li Chuan Ming wang xiang Yi Liu xiao Guang Xie Faculty of Chemistry Southwest Forestry University Kunming 650224 China Department of Biology Honghe University Menzi 661100 China Department of Chemistry Yunnan University Kunming 650091 China

The elimination of HBr from CH3Br by ground state of Cu＋ and Au＋ has been investigated by using DFT methods. A mechanism of one-step HBr elimination leading to CuCH2＋ was identified. For the formation of AuCH2＋, besides the one-step mechanism, another two-step HBr elimination pathway through a C-Br bond insertion intermediate was also found, and this pathway is energetically more favorable than the one-step mechanism. The calculated reaction energy barriers show that the formation of AuCH2＋ is energetically much more favorable than the formation of CuCH2＋. The experimental observations are well explained.

关键词： Copper and gold Alkyl halide HBr elimination

Oxidation behavior of high Hf nickel-based superalloy in air at 900, 1000 and 1100℃

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2021年第12期28卷 1957-1965页

作者： Jiu-han xiao Ying Xiong Li wang xiang-wei Jiang dong wang Kai-wen Li Jia-sheng dong Lang-hong Lou Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China China National South Aviation Industry Company Limited Zhuzhou 412002China

To investigate the oxidation behavior of a nickel-based superalloy with high hafnium content(1.34 wt%),this study performed isothermal oxidation tests at 900,1000,and 1100℃for up to 200 h.X-ray diffraction and scanning electron microscopy with energy-dispersive X-ray spectroscopy were applied to study the oxidation *** weight gain of the high Hf nickel-based superalloy exhibited a parabolalike curve,and no spallation of the oxide scale was observed during the oxidation *** alloy presented excellent oxidation resistance,and no HfO_(2) was observed in the oxide scale at 900℃.With the increase of the oxidation temperature to 1000℃,HfO_(2) particles formed in the spinel phases of the scale,and"peg-like"HfO_(2) was observed within and beneath the inner layer of Al2O_(3) after *** the oxidation temperature rose to 1100℃,"peg-like"HfO_(2) was observed at the early stage of the oxidation test(within 25 h).The formation mechanism of HfO_(2) and its impact on oxidation resistance were investigated based on the analysis of the oxidation test results at different temperatures.

关键词： superalloy resistance alloy