检索结果-南通市图书馆

Effect of stress paths on failure mechanism and progressive damage of hard-brittle rock

Journal of Mountain Science 2021年第9期18卷 2486-2502页

作者： CHEN Zi-quan HE Chuan HU Xiong-yu MA chun-chi Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China Key Laboratory of Engineering Structures of Heavy Haul Railway Ministry of EducationCentral South UniversityChangsha 410075China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China

During deep buried hard-brittle rock tunnel excavation,the surrounding rock experiences a complicated stress path and stress adjustment *** the adjusted stress exceeds the ultimate bearing capacity of rockmass,a rock failure mode defined as stress-cracking type will *** order to investigate the effect of stress paths on failure mechanism and progressive damage of deep-buried rockmass,the cyclic loading-unloading,loading-unloading,uniaxial,conventional and unloading triaxial compression tests on samples of hard-brittle sandstone were *** to the experimental results,increase in the confining pressure was beneficial to improve the mechanical parameters of rock,but it will reduce the brittle failure *** with conventional triaxial compression,the sandstone under unloading state had more remarkable stress drop and unstable failure ***,it was found that the energy dissipation and energy release in the whole process of rock deformation were the internal power of driven rock progressive *** the increase of confining pressure,the energy hardening and energy accumulation features of rock were weakened,while the progressive damage evolution characteristics could be *** unloading state,more energy could be converted into elastic energy in the energy softening phase(σeb-σP),so that the prepeak damage rate of rock was lower than that of conventional triaxial compression ***,the energy dissipation rate of rock after peak strength decreased linearly with the increase of confining pressure under conventional triaxial compression state,while in unloading state it showed the opposite law.

关键词： Hard-brittle rock Stress path Confining pressure Failure mechanism Progressive damage

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

Highly efficient Ag-modified copper phyllosilicate nanotube:Preparation by co-ammonia evaporation hydrothermal method and application in the selective hydrogenation of carbonate

引用

Journal of Materials Science & Technology 2020年第12期47卷 29-37页

作者： Huabo Li Yuanyuan Cui Yixin Liu Lu Zhang quan Zhang Juhua Zhang Wei-Lin dai Department of Chemistry&Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan UniversityShanghai200438China School of Chemistry and Chemical Engineering Henan Institute of Science and TechnologyEastern Hualan AvenueXinxiang453000China

Rapidly deactivation of Cu/SiO2 catalysts at high liquid hour space velocity(LHSV) has been an important obstacle for scale-up ***,silver modified copper phyllosilicate nanotubes were fabricated by different strategies,and implemented to the selective hydrogenation of ethylene carbonate(EC) to methanol and ethylene glycol(EG) as alternative route for the indirect utilization of *** CuPs Ag-copre catalyst synthesized by the co-ammonia evaporation hydrothermal process achieved79% methanol and 99% EG yield within various ranges of EC LHSV,which was attributed to the balanced Cu+/CuO ratio and the enhanced H2 dissociation *** silver species over copper phyllosilicate promoted the interaction between the metal and the support,which substantially regulated the reducibility and dispersion of copper species,meanwhile,increased the stability for long-term running of the catalyst.

关键词： Copper Silver Carbonate Hydrogenation Methanol Ethylene glycol

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

Response of Gas Exchange and Water Use Efficiency to Light Intensity and Temperature in Transgenic Rice Expressing PEPC and PPDK Genes

引用

Agricultural Sciences in China 2009年第11期8卷 1312-1320页

作者： ZHANG Bian-jiang CHEN quan-zhan HUA chun ZHOU Feng ZHOU quan-chen JIAO De-mao Nanjing Xiaozhuang University Nanjing 211171 P.R. China Jiangsu Academy of Agricultural Sciences Nanjing 210014 P.R. China

Aiming to controvert whether the photosynthetic capacity of transgenic rice expressing C4 genes is enhanced, with the C3-type untransformed rice （WT） and maize （a C4 plant） as controls, the activity of C4 photosynthetic enzymes, gas exchange parameters and water use efficiency （WUE） under different light intensities and temperatures, the stable carbon isotope ratio （8-3C） value and the metabolic index of active oxygen as well as plant yield parameters were determined in transgenic rice carrying the PEPC and PPDK genes （CK） in this study. The results showed that the light-saturated photosynthetic rate of CK was intermediate between that of WT and maize, with a slight bias towards that of maize. Under a high light intensity （1 200 μmol m^-2 s^-1） and high temperature （35℃）, CK still exhibited higher photosynthetic capacity, while the Gs decreased. The WUE of CK was only slightly increased, and was similar to that of WT. The δ13C value indicated that CK functioned as a C3 plant. In addition, the tolerance to photo-oxidation and grain yield of CK was enhanced by sprayed with NaHSO3. In conclusion, CK possesses higher photosynthetic productivity under the conditions of high photon flux density （PFD）, high temperature and spraying with NaHSO3 solution, thereby providing a new technical approach and physiological basis for constructing C4-like rice.

关键词： transgenic rice photosynthetic characteristics water use efficiency stomatal conductance

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

Electroless-hydrothermal construction of nickel bridged nickel sulfide@mesoporous carbon nitride hybrids for highly efficient noble metal-free photocatalytic H2 production

引用

Journal of Materials Science & Technology 2020年第10期42卷 176-186页

作者： Lu Zhang Yuanyuan Cui Fengli Yang quan Zhang Juhua Zhang Mengting Cao Wei-Lin dai Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan UniversityShanghai200433China Shimadzu China Co.LTD. Shanghai200233China

Metallic Ni bridged Ni S@mesoporous carbon nitride hybrids were for the first time fabricated through a one-pot electroless-assisted hydrothermal *** intimate Ni bridge between the interface of mesoporous carbon nitride and Ni S was confirmed by HRTEM and in-depth XPS analysis using an Ar+-cluster sputtering gun and a possible mechanism was put forward to elucidate the formation process of the unique *** adding any noble metals as cocatalysts,the optimized catalyst 10%NiS/mCN-160-12 showed a H2 evolution rate of 1419μmol·g^-1·h^-1,which is about 34 and 14 fold higher than that of bare mesoporous carbon nitride and Ni S,*** dramatically enhanced photocatalytic performance was mainly ascribed to the synergistic effect of Ni S cocatalyst loading and the formation of metallic Ni between the interface of mesoporous carbon nitride and Ni S,which served as a charge-transfer bridge to facilitate the transfer and separation of photo-induced electron-hole pairs.

关键词： Electroless-hydrothermal method Hydrogen production NiS/mesoporous carbon nitride Hybrids photocatalysts

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

Shock wave-boundary layer interactions control by plasma aerodynamic actuation

引用

Science China(Technological Sciences) 2014年第7期57卷 1335-1341页

作者： SUN quan LI YingHong CUI Wei CHENG BangQin LI Jun dai Hui Science and Technology on Plasma Dynamics Laboratory School of Aeronautics and Astronautics Engineering Air Force Engineering University

This study demonstrates the potential for shock wave-boundary layer interaction control in air by plasma aerodynamic *** investigations on shock wave-boundary layer interactions control by plasma aerodynamic actuation are conducted in a Mach 3 in-draft air *** imaging shows that the discharges cause the oblique shock to move *** imaging and static pressure probes also show that separation phenomenon shifts backward and the size of separation is enlarged when plasma aerodynamic actuation is *** intensity of shock wave is weakened through wall pressure ***,numerical investigations on shock wave-boundary layer interactions control are conducted with plasma aerodynamic *** discharge is modeled as a steady volumetric heat source which is integrated into the energy *** input energy level is about 7 kW through discharge *** show that the separation phenomenon shifts backward and the intensity of shock is reduced with plasma *** numerical results are consistent with the experimental results.

关键词： shock wave boundary layer plasma separation flow control

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

Investigation of the radiosensitization effect in FePt nanopaticle clusters with Monte Carlo simulation

引用

Nuclear Science and Techniques 2018年第11期29卷 287-294页

作者： Peng-Yuan Qi Zhi-Tao dai Jun Zhang Hong quan Hao Peng Key Laboratory of Artificial Micro-and Nano-Structures of the Ministry of Education and Center for Electronic Microscopy and Department of Physics Wuhan UniversityWuhan 430072China Department of Radiation Oncology Zhongnan HospitalWuhan UniversityWuhan 430072China

Nanoparticles(NPs) with high-Z atoms have been widely studied as radiosensitizers for use in cancer therapy. Over the past few years, the application of FePt NPs has attracted extensive research interest. Promising results have been obtained, yet limited knowledge is available regarding its potential use as a *** goal of this study is to investigate the radiosensitization capability of FePt nanoparticle clusters(NPCs) under the exposure of kilovoltage photons using Monte Carlo simulation. First, in order to obtain a realistic distribution of NPCs on the microscopic level, Hela cells were incubated with FePt NPs, and the distribution of NPCs was obtained by optical microscope images and X-ray NanoCT experiments. Based on these images, a simplified cellmodel was developed to evaluate the DER of two material types(FePt and FePt_3). For each type, the dependence of DER on the thickness and angular distribution of NPCs on the surface of the cell membrane was studied quantitatively. Our results suggest that DER is strongly dependent on photon energy and the distance from the NPCs to the nucleus. Fe_1 Pt_3 is able to achieve a higher DER relative to Fe_1 Pt_1. For a given X-ray energy, DER demonstrates an initial increase to a maximum value but gradually saturates as the thickness of NPCs increases from 250 up to 2000 nm due to a trapping effect. The impact on DER resulting from the coexistence of the NPCs on the cell membrane and the nuclear membrane was also investigated.

关键词： FePt nanoparticle Radiosensitization GEANT4 Dose enhancement ratio

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

Tempering Process to Improve Hardness Uniformity of Plastic Mould Steel

引用

Journal of Iron and Steel Research International 2012年第12期19卷 53-58页

作者： MIN Yong-an ZHOU quan LUO Yi LI Dan WU Xiao-chun School of Materials Science and Engineering Shanghai University Shanghai 200072 China

A new design of copper-bearing non-quenched plastic mold steel is presented and explained. Two kinds of microstrueture can be obtained from this new type copper-bearing steel via cooling with different cooling rates, bain- ite and a mixed microstructure consisting of ferrite and bainite. It is found that, after proper tempering process, the hardness will be increased. Moreover, the hardness difference between different microstructures will be reduced. For further investigation, the samples tempered at different temperatures were examined by XRD and 3PAP （three di- mensional atom probe） analysis. Results show that the improvement is contributed mainly by the precipitation of Cu phase and transformation of residual austenite.

关键词： plastic mould steel tempering process Cu precipitation residual austenite

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

Self-assembly of insulated molecular wires of a water-soluble cationic PPV and anionic dendrons

引用

Chinese Science Bulletin 2009年第14期54卷 2451-2456页

作者： FENG XueLing YAO ZhiYi LI chun SHI Gao quan Key Laboratory of Bio-organic Phosphorous Chemistry and Chemical Biology Department of Chemistry Tsinghua University Beijing 100084 China

Insulated molecular wires of poly(phenylenevinylene) (PPV) were prepared by wrapping the conjugated backbones with dendrons through a noncovalent approach. It was found that electrostatic interaction between the quaternary ammonium groups of PPV-1 and the carboxylate moieties in dendrons induced the packing of dendrons along PPV-1 conjugated backbones. Absorption and emission spectroscopic examinations in solution and solid film indicated that the PPV-1 backbones adopted a more planar and isolated conformation in the complexes. Furthermore, interchain interactions in the complexes could be greatly reduced, improving the quantum yield of PPV-1.

关键词：导线绝缘乙烯分子阴离子阳离子水溶性自组装静电相互作用

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

Selection rules for electric multipole transition of triatomic molecule in scattering experiments

引用

Chinese Physics B 2018年第4期27卷 258-263页

作者： Hong-chun Tian Long-quan Xu Lin-Fan Zhu Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics University of Science and Technology of China Hefei 230026 China Synergetic Innovation Center of quantum Information and quantum Physics University of Science and Technology of China Hefei 230026 China

In the electron or x-ray scattering experiment,the measured spectra at larger momentum transfer are dominated by the electric dipole-forbidden transitions,while the corresponding selection rules for triatomic molecules have not been clearly *** this work,based on the molecular point group,the selection rules for the electric multipolarities of the electronic transitions of triatomic molecules are derived and summarized into several tables with the variation of molecular geometry in the transition process being *** on the summarized selection rules,the electron energy loss spectra of H2O,CO2,and N2O are identified,and the momentum transfer dependence behaviors of their valence-shell excitations are explained.

关键词： electric multipole transition selection rule molecular point group electron scattering

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

High Speed Aircraft Robust Fuzzy Controller Design Based on H_∞Performance

引用

Journal of Electronic Science and Technology 2017年第1期15卷 83-89页

作者： chun-Ning Yang Zhen-Yang Chai quan-Jun Liu Hui Ge School of Aeronautics and Astronautics Zhejiang UniversityHangzhou 310027China Science and Technology on Space Physics Laboratory Nanjing 210000China Institute of Spaceflight Control Technology Shanghai 200000China

The dynamics of the high-speed vehicle（HSV） is partially or completely unknown because of various reasons, such as modeling errors, in-flight failure, and external disturbances. In this paper, a global stability robust fuzzy controller is designed to control the flight F-16 with uncertain perturbation. For the desired H_∞ output-feedback controllers, a necessary and sufficient condition of quadratic stability is derived with the well-established results of the Lyapunov stability theory and nonnegative matrix. The controllers not only guarantee the global asymptotically stability of the resultant closed-loop system with external disturbance and parameter perturbation, but also have a desired H∞ performance in a large flight envelop（LFE）.

关键词： desired disturbance uncertain asymptotically guarantee quadratic perturbation Performance resultant partially

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：