检索结果-南通市图书馆

Enhanced hydrogen evolution performance by 3D ordered macroporous Ru-CoP@NC electrocatalysts

Rare Metals 2024年第3期43卷 1095-1107页

作者： chen-chen zhang Sheng Wei Li-Xian Sun Yi-Fang Ouyang Fen Xu Hai-Liang Chu Hong-GePan Li-Xin chen Xue-zhang Xiao School of Material Science and Engineering Guilin University of Electronic TechnologyGuilin541004China School of Chemistry and Chemical Engineering Guangxi UniversityNanning530004China Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen518055GuangdongChina Institute of Science and Technology for New Energy Xi'an Technological UniversityXi'an710021China School of Materials Science and Engineering Zhejiang UniversityHangzhou310058China

Electrocatalytic water splitting coupled with sustainable energies is identified as an environmentally friendly and renewable strategy to generate high-quality hydrogen for the fuel ***,the main challenge is to develop high performance,low cost and chemically stable electrocatalysts to decline the energy barriers and enhance the sluggish kinetics of hydrogen evolution reaction(HER).Herein,a three-dimensional hierarchically ordered macroporous Ru-CoP@NC electrocatalyst(3DOM Ru-CoP@NC)derived from ordered macro-microporous metal-organic frameworks has been prepared using the precursor@template and double-solvent *** prepared 3DOM Ru-CoP@NC catalyst exhibits an overpotential of 15 mV(j=10 mA·cm^(-2))and a reaction Tafel slope of 38 mV·dec^(-1)in alkaline electrolyte,which are superior to commercial Pt@C ***,the overpotential and reaction Tafel slope of this catalyst in acidic media are 45 mV and 50 mV·dec^(-1),*** outstanding HER activities of 3DOM Ru-CoP@NC catalysts are ascribed to the 3D highly interconnectedreticular nanospaces that can increase effective reaction active *** N dope d carbon framework improves the electronic properties and ***,the strong interaction of Ru and CoP nanoparticles also boosts the HER *** results indicate that 3DOM Ru-CoP@NC catalysts with high catalytic activities have a broad application prospect in the future.

关键词： Hydrogen evolution reaction Template method 3D ordered macroporous Ru-CoP@NC

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Modulated noble metal/2D MOF heterostructures for improved hydrogen storage of MgH_(2)

引用

Rare Metals 2024年第4期43卷 1672-1685页

作者： Zeng-Yi Li Li-Xian Sun Fen Xu Yu-Mei Luo Yong-Peng Xia Sheng Wei chen-chen zhang Ri-Guang cheng Chao-Feng Ye Meng-Yuan Liu Ju-Lan Zeng Zhong Cao Hong-Ge Pan School of Material Science and Engineering Guilin University of Electronic TechnologyGuilin541004China School of Chemistry and Chemical Engineering Changsha University of Science and TechnologyChangsha410114China Institute of Science and Technology for New Energy Xi’an Technological UniversityXi’an710021China

The conjugation of external species with twodimensional(2D)materials has broad application *** this study,we have explored the potential of noble metal/2D MOF heterostructures in hydrogen ***,the MgH_(2)-Ni-MOF@Pd system has shown remarkable hydrogen desorption/sorption performances,starting to liberate hydrogen at 1810C,which is 2300C lower than that of pristine *** the catalytic effect of Ni-MOF@Pd,the dehydrogenation apparent activation energy of MgH2 is noticeably decreased from(133.5±17.5)to(34.58±1.87)kJ·moL^(-1),and the hydrogenation apparent activation energy is reduced from(70.41±7.43)to(25.78±4.64)kJ·moL^(-1),which is lowered by 63.4%.The fully-dehydrogenated MgH2-NiMOF@Pd composite rapidly uptakes hydrogen,with 2.62wt%at 100℃and 6.06 wt%at 150℃within 300 s,*** mechanism analysis of MgH2 catalyzed by Ni-MOF@Pd has revealed that the transformation of Mg_2Ni and Mg_2NiH_4 could act as a"hydrogen pump",providing numerous channels for fast diffusion and transport of hydrogen ***,in the dehydrogenation process,the element Pd reacts with MgH_(2)to form the MgPd alloy phase,which makes MgH_(2)take precedence to decompose through the Mg-Pd alloy rather than self-decomposition,further reducing thermal stability and improving de/hydrogenation *** synergistic effect of Mg-Pd,Mg_2Ni,and the special ultra-thin 2D sheet structure of the additive is the main reason for the good hydrogen storage property of MgH_(2)-Ni-MOF@*** findings provide inspiration for designing efficient multifunctional additives with unique morphologies to optimize the hydrogen desorption/sorption behaviors of hydrogen storage materials.

关键词： Hydrogen storage Magnesium hydride 2D metal-organic framework nanosheets Ni/Pd Synergistic catalysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of dietary with Zhibai dihuang pills and gonadotropinreleasing-hormone-analogue on girls with precocious and rapidly progressive puberty

引用

World Journal of Clinical Cases 2024年第24期12卷 5534-5541页

作者： Xue-Mei Wang Wei Li Liu-Qing Yang Rui Luo chen-chen zhang Department of Pediatrics Ma’anshan Maternal and Child Health HospitalMa’anshan 243011Anhui ProvinceChina

BACKGROUND At present,the clinical mechanisms underlying precocious puberty remain unclear,making effective intervention for children experiencing this condition and rapidly progressive puberty *** To explore the effects of Zhibai dihuang pills and gonadotropin-releasing hormone analogue(GnRHa)on growth and ovarian function in girls with precocious *** The clinical data of 84 adolescent girls with precocious puberty and rapidly progressive puberty from February 2017 to August 2023 were retrospectively *** were divided into a control group and an observation group,with 42 cases in each *** control group received diet intervention combined with GnRHa treatment,while the observation group received diet intervention combined with Zhibai dihuang pills+GnRHa *** such as clinical efficacy,growth indicators,ovarian function,and adverse reactions were compared between the two *** The observation group showed superior clinical efficacy compared to the control group(P0.05).Post-intervention,the observation group exhibited significantly lower rates in growth,height,and bone age,along with reduced levels of progesterone,testosterone,estradiol,prolactin,luteinizing hormone,and follicle-stimulating hormone compared to the control group(P0.05).CONCLUSION Combining Zhibai dihuang pills with GnRHa and dietary intervention effectively improves growth,enhances ovarian function,and minimizes adverse reactions in adolescent girls with precocious and rapidly progressive puberty.

关键词： Zhibai dihuang pills Gonadotropin-releasing hormone analogue Dietary intervention Precocious puberty Rapidly progressive puberty Ovarian function

来源：

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

Mechanism of Locust Air Posture Adjustment

引用

Journal of Bionic Engineering 2015年第3期12卷 418-431页

作者： Diansheng chen Kewei chen Ziqiang zhang Benguang zhang Robotic Institute in School of Mechanical Engineering and Automation Beihang University Beijing 100191 China

Stimulated locusts often tumble during the jumping process. Locusts can also recover their bodies in the air for flight or landing stability. To increase jumping distance and avoid landing collision of bio-inspired jumping robots, the mechanism of air posture adjustment of locusts is examined in this research. This mechanism can be used to improve the stability of robot. The abdomen swings, wing motions, and the variations in body angle are recorded by a high-speed camera when locusts free fall in air with normal or upside-down initial posture. Results indicate that the wings and abdomen are mainly utilized for air posture adjustment. Moreover, abdomen swing and forewing rotation have positive effects on body pitch. However, locusts have dif- ficulty in recovering their bodies from the upside-down posture without wings, although the body pitch caused by unpredictable perturbation in air can be compensated through abdomen swing. Consequently, body roll is attributed to the wing motion, which is related to two factors, namely, the different flapping amplitudes of the wings on both sides, and the different flapping velocities of wings during the upstroke and downstroke periods. This research may provide reference for the design of jumping robots.

关键词： locusts air posture adjustment abdomen swing asymmetric flapping wings

来源：

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

A distributed inverse iteration method for eigenvalue analysis of interconnected power systems

引用

Science China(Technological Sciences) 2007年第6期50卷 774-785页

作者： SHEN chen chen Ying zhang Xu State Key Laboratory of Power Systems Department of Electrical Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Power Systems Department of Electrical Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Power Systems Department of Electrical Engineering Tsinghua University Beijing 100084 China

Since China power grids have a hierarchical architecture in operation and man- agement, centralized computation patterns are difficult to meet the demands of small-signal-stability analysis of the bulk interconnected power systems. A dis- tributed eigenvalue algorithm derived from the inverse iteration method is pro- posed. It can not only obtain eigenvalues and eigenvectors from power system state matrix but also provide participation factors of all generators. In the comput- ing process, the algorithm only requires exchanging data of boundary nodes and a small amount of other information of different regions. Therefore, it is very suitable to be deployed in a WAN (wide area network) based distributed environment. The algorithm has been tested on an IEEE39 system.

关键词： distributed computing, eigenvalue, small signal stability, inverse iteration method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Stability of flow between rotating cylinders with axial buoyancy effect

引用

Science China(Physics,Mechanics & Astronomy) 2006年第5期49卷 564-575页

作者： chen Jianguo chen Haixin zhang Guanghua FU Song Department of Engineering Mechanics School of AerospaceTsinghua UniversityBeijing 100084China Department of Engineering MechanicsSchool of AerospaceTsinghua UniversityBeijing 100084China Department of Engineering MechanicsSchool of AerospaceTsinghua UniversityBeijing 100084China Department of Engineering MechanicsSchool of AerospaceTsinghua UniversityBeijing 100084China

The linear stability of a fluid confined between two coaxial cylinders rotating independently with axial buoyancy induced flow is examined. Buoyancy is included through the Boussinesq approximation. The numerical investigation is restricted to radius ratio 0.5 at Prandtl number 0.709 with co-rotation situation. The outer rotating cylinder’s Couette flow Reynolds number is restricted to 200. Zeroth-order discontinuities are found in the critical surface, which are explained as the result of the competition between the centrifugal and axial buoyancy induced shear instability mechanisms. Due to the competition, the neutral stability curves develop islands of instability, which considerably lower the instability threshold. Specific and robust numerical methods to handle these geometrical complexities are developed.

关键词： island of instability cylinder rotation buoyancy flow

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Failure of EB-PVD Thermal Barrier Coatings Subjected to Thermo-Mechanical Loading

引用

Chinese Journal of Aeronautics 2006年第B12期19卷 82-85页

作者： chen chen zhang Chun-xia GUO Hong-bo GONG Sheng-kai zhang Yue School of Materials Science and Engineering Beij＇ing University of Aeronautics and Astronautics Beijing 100083 China

Thermal barrier coatings （TBCs） were developed to protect metallic blades and vanes working in turbo-engines. The two-layered structure TBCs, consisting of NiCoCrAlY bond coat and yttria stabilized zirconia （YSZ）, were deposited on a cylinder of superalloy substrate by the electron beam-physical vapor deposition （EB-PVD）. The failure mechanism of the TBCs was investigated with a thermo-mechanical fatigue testing system under the service condition similar to that for turbine blades. Non-destructive evaluation of the coated specimens was conducted through the impedance spectroscopy. It is found that the crack initiation mainly takes place on the top coat at the edge of the heated zones.

关键词： electron beam-physical vapor deposition (EB-PVD) thermal barrier coatings (TBCs) thermal-mechanical loading impedance spectroscopy failure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

MXene-wrapped ZnCo_(2)S_(4)core-shell nanospheres via electrostatic self-assembly as positive electrode materials for asymmetric supercapacitors

引用

Rare Metals 2022年第8期41卷 2633-2644页

作者： Ji-Qiu Qi chen-chen zhang Hao Liu Lei Zhu Yan-Wei Sui Xiu-Juan Feng Wen-Qing Wei Hao zhang Peng Cao Jiangsu Province Engineering Laboratory of High Efficient Energy Storage Technology and Equipments School of Materials Science and PhysicsChina University of Mining and TechnologyXuzhou221116China The School of Mines China University of Mining and TechnologyXuzhou221116China School of Mechanical-Electronic and Vehicle Engineering Weifang UniversityWeifang261061China Ningbo Institute of Materials Technology&Engineering Chinese Academy of SciencesNingbo315201China Department of Chemical&Materials Engineering University of AucklandAuckland1142New Zealand

Constructing electrode materials with large capacity and good conductivity is an effective approach to improve the capacitor performance of asymmetric supercapacitors(ASCs).In this paper,ZnCo_(2)S_(4)core-shell nanospheres are constructed by two-step hydrothermal *** order to improve the chemical activity of ZnCo_(2)S_(4),ZnCo_(2)S_(4)is activated using cetyltrimethylammonium bromide(CTAB).Then,MXene nanosheets are fixed on the surface of ZnCo_(2)S_(4)by electrostatic selfassembly method to improve the specific surface area of ZnCo_(2)S_(4)and MXene-wrapped ZnCo_(2)S_(4)composite is prepared in this *** to the synergy effect between MXene nanosheets and ZnCo_(2)S_(4)core-shell nanospheres,the as-prepared composite displays fast ion transfer rate and charge/discharge *** capacity of the MXenewrapped ZnCo_(2)S_(4)composite can reach 1072 F·g^(-1),which is far larger than that of ZnCo_(2)S_(4)(407 F·g^(-1))at 1 A·g^(-1).An ASC device is assembled,which delivers 1.7 V potential window and superior cyclic stability(95.41%capacitance retention).Furthermore,energy density of this device is up to 30.46 Wh·kg^(-1)at a power density of850 W·kg^(-1).The above results demonstrate that MXenewrapped ZnCo_(2)S_(4)composite has great application prospects in electrochemical energy storage field.

关键词： Asymmetric supercapacitors ZnCo_(2)S_(4)coreshell nanospheres MXene nanosheets Wrapped structure Electrostatic self-assembly

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Fragmentation Study on Four Oligostilbenes by Electrospray Tandem Mass Spectrometry

引用

Natural Products and Bioprospecting 2019年第4期9卷 279-286页

作者： chen‑chen zhang Chang‑An Geng Ji‑Jun chen State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of Sciences132#Lanhei RoadKunming 650201YunnanPeople’s Republic of China Yunnan Key Laboratory of Natural Medicinal Chemistry Kunming 650201People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China

Oligostilbenes have attracted much interest due to their intricate structures and diverse *** this study,two stilbene dimers,(−)-7,8-cis-ε-viniferin(1)and carasiphenol A(2),and two trimers,suffruticosol A(3)and suffruticosol C(4),were investigated by electrospray ionization ion-trap time-of-flight multistage mass spectrometry(ESI-IT-TOF-MS^(n)).Based on the MS^(n) study,the fragmentation pathways and diagnostic ions of four oligostilbenes in both positive and negative modes were *** consecutive elimination of phenol(C_(6)H_(6)O)and resorcinol(C_(6)H_(6)O_(2))moieties were the particular dissociation for oligostilbenes due to the presence of 1,2-diphenylethylene *** present MS^(n) fragmentation study will provide valuable information for the fast characterization of oligostilbenes from complicated natural mixtures.

关键词： ESI-IT-TOF-MS^(n) Fragmentation rules Oligostilbenes

来源：

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

Generation of a monkey with MECP2 mutations by TALEN-based gene targeting

引用

Neuroscience Bulletin 2014年第3期30卷 381-386页

作者： Zhen Liu Xue Zhou Ying Zhu Zhi-Fang chen Bin Yu Yan Wang chen-chen zhang Yan-Hong Nie Xiao Sang Yi-Jun Cai Yue-Fang zhang chen zhang Wen-Hao Zhou Qiang Sun Zilong Qiu Institute of Neuroscience Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Department of Neonatology Children’s Hospital of Fudan University State Key Laboratory of Biomembrane and Membrane Biotechnology School of Life Sciences PKU-IDG/McGovern Institute for Brain Research Peking University

Gene editing in model organisms has provided critical insights into brain development and diseases. Here, we report the generation of a cynomolgus monkey （Macaca fascicularis） carrying MECP2 mutations using transcription activator-like effector nucleases （TALENs）-mediated gene targeting. After injecting TALENs mRNA into monkey zygotes achieved by in vitro fertilization and embryo transplantation into surrogate monkeys, we obtained one male newborn monkey with an MECP2 deletion caused by frame- shifting mutation in various tissues. The monkey carrying the MECP2 mutation failed to survive after birth, due to either the toxicity of TALENs or the critical requirement of MECP2 for neural development. The level of MeCP2 protein was essentially depleted in the monkey＇s brain. This study demonstrates the feasibility of introducing genetic mutations in non-human primates by site-specific gene-editing methods.

关键词： monkey TALEN MeCP2 Rett syndrome

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：