检索结果-南通市图书馆

Unusual photocarrier and coherent phonon dynamics behaviors of layered PdSe_(2)unveiled by ultrafast spectroscopy of the edge surface

引用

Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 143-152页

作者： Tiantian Yun Changfu Huo Jinluo Cheng Zhi-Bo Liu Xiao-qing yan Key Laboratory of Weak-Light Nonlinear Photonics Ministry of EducationSchool of PhysicsNankai UniversityTianjin 300071China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China GPL Photonics Laboratory Key Laboratory of Luminescence Science and TechnologyChinese Academy of Sciences&State Key Laboratory of Luminescence Science and ApplicationsChangchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China

Layered materials exhibit different electronic and phonon properties along in-plane and out-of-plane directions;existing studies focus on their in-plane behaviors,and the influence of such anisotropies on the dynamics of photocarriers and phonons is ***,we fabricate layered PdSe_(2)crystals with flat edge surfaces and compare the time-resolved ultrafast spectroscopies on their basal and edge *** differences in the transient reflection spectroscopies reveal the inconsistent photocarrier and phonon dynamics behaviors on the two surfaces:the slow hot carrier relaxation process is accelerated and the thermoelasticity-induced longitudinal coherent acoustic phonon oscillation completely vanishes on the edge surface,as compared with the basal *** analysis reveals that the inconsistent hot carrier dynamics originate from the anisotropic properties of low-energy phonons in PdSe_(2),and the absence of phonon oscillation on the edge surface results from the wavevector-limited sensitivity of acoustic B_(1u)***,polarization-dependent spectroscopies indicate the diverse optical anisotropies beyond the in-plane of PdSe_(2).This work provides a new method to explore unique physical properties and modulate the optical anisotropy of layered materials.

关键词： PdSe_(2) ultrafast spectroscopy edge surface carrier dynamics coherent phonon oscillation anisotropy

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

Flexible assistance strategy of lower limb rehabilitation exoskeleton based on admittance model

引用

Science China(Technological Sciences) 2024年第3期67卷 823-834页

作者： KOU JianGe WANG YiXuan CHEN ZhenLei SHI yan GUO qing XU Meng School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China School of Aeronautics and Astronautics University of Electronic Science and Technology of ChinaChengdu 611731China Department of Musculoskeletal Tumor Senior Department of Orthopedicsthe Fourth Medical Centerof PLA GeneralHospitalBeijing 100853China

Exercise training based on exoskeleton is an effective rehabilitation method for stroke patients. However, some rehabilitation exoskeletons still have poor wearable performance and obvious human-robot impedance during training, which easily cause secondary injuries to the patients. In this study, a variable admittance control strategy is proposed to improve the operator's wearable comfort, which can adapt to different operators by regulating admittance parameters. The admittance controller has two feedback loops: the position inner-loop and the admittance outer-loop. Meanwhile, the exoskeleton Lagrange model is constructed with unknown friction disturbance. By using Lyapunov technique and backstepping with state observer, the joint position error of exoskeleton is convergence into a zero neighborhood. The effectiveness of the proposed admittance controller is verified by both simulation and experiment. The tracking error of hip and knee joint is less than 4 degrees while the human-robot interaction torque is constrained in a tolerable range of the operator.

关键词： human-robot interaction exoskeleton backstepping admittance 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

Tailoring electron vortex beams with customizable intensity patterns by electron diffraction holography

引用

Opto-Electronic Advances 2024年第2期7卷 14-21页

作者： Pengcheng Huo Ruixuan Yu Mingze Liu Hui Zhang yan-qing Lu Ting Xu National Laboratory of Solid-State Microstructures and Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China College of Engineering and Applied Sciences Key Laboratory of Intelligent Optical Sensing and Manipulation and Jiangsu Key Laboratory of Artificial Functional MaterialsNanjing UniversityNanjing 210093China

An electron vortex beam(EVB) carrying orbital angular momentum(OAM) plays a key role in a series of fundamental scientific researches, such as chiral energy-loss spectroscopy and magnetic dichroism spectroscopy. So far, almost all the experimentally created EVBs manifest isotropic doughnut intensity patterns. Here, based on the correlation between local divergence angle of electron beam and phase gradient along azimuthal direction, we show that free electrons can be tailored to EVBs with customizable intensity patterns independent of the carried OAM. As proof-of-concept, by using computer generated hologram and designing phase masks to shape the incident free electrons in the transmission electron microscope, three structured EVBs carrying identical OAM are tailored to exhibit completely different intensity patterns. Furthermore, through the modal decomposition, we quantitatively investigate their OAM spectral distributions and reveal that structured EVBs present a superposition of a series of different eigenstates induced by the locally varied geometries. These results not only generalize the concept of EVB, but also demonstrate an extra highly controllable degree of freedom for electron beam manipulation in addition to OAM.

关键词： electron vortex beam orbital angular momentum diffraction holography

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

Combined effects of sea urchin-like structure and mixed Cu^(+)/Cu^(0)states on promoting C_(2)formation in electrocatalytic CO_(2)reduction

引用

Frontiers of Chemical Science and Engineering 2024年第3期18卷 63-73页

作者： Mengqing Shan Dongsheng Lu Jiatong Dong Shen yan Jinyu Han hua Wang Collaborative Innovation Center of Chemical Science and Engineering Key Laboratory for Green Chemical Technology of the Ministry of EducationSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin300354China

Surface engineering and Cu valence regulation are essential factors in improving the C_(2)selectivity during the electrochemical reduction of CO_(2).Herein,we present a sea urchin-like CuO/Cu_(2)O catalyst derived from rhombic dodecahedra Cu_(2)O through one-step oxidation/etching method where the mixed Cu^(+)/Cu^(0)states are formed via in situ reduction during *** combined effects of the morphology and the mixed Cu^(+)/Cu^(0)states on C–C coupling are evaluated by the Faradaic efficiency of C_(2)and the C_(2)/C1 ratio obtained in an H-cell.R-Cu^(O)/Cu_(2)O exhibited 49.5%Faradaic efficiency of C_(2)with a C_(2)/C1 ratio of 3.1 at−1.4 V *** hydrogen electrode,which are 1.5 and 3.2 times higher than those of R-Cu_(2)O,*** a flow-cell,68.0%Faradaic efficiency of C_(2)is achieved at a current density of 500 mA·cm^(−2).The formation of the mixed Cu^(+)/Cu^(0)states was confirmed by in situ Raman ***,the sea urchin-like structure provides more active sites and enables faster electron *** a result,the excellent C_(2)production on R-CuO/Cu_(2)O is primarily attributed to the synergistic effects of the sea urchin-like structure and the stable mixed Cu^(+)/Cu^(0)***,this work presents an integrated strategy for developing Cu-based electrocatalysts for C_(2)production through electrochemical CO_(2)reduction.

关键词： CO_(2)electrolysis sea urchin-like structure Cu^(+)/Cu^(0) C_(2)products

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

Influence of rare earth oxides on microstructure and mechanical properties of nickel-based superalloys fabricated by high energy beam processing:A review

引用

Journal of Rare Earths 2024年第9期42卷 1629-1645,I0001页

作者： Lianjie Bi hua yan Peilei Zhang Haichuan Shi Zhiyuan Li Ruidi Li School of Materials Science and Engineering Shanghai University of Engineering ScienceShanghai201620China College of Agricultural Science and Engineering Hohai UniversityNanjing211100China Department of Mechanics and Maritime Science Chalmers University of TechnologyGothenburSE41296Sweden State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China

In this paper,the effects of rare earth oxides on the micro structure and mechanical properties of nickelbased superalloys prepared by high-energy beam processing technology were critically *** focus is on the optimal amount of rare earth oxides that can produce ideal *** attention was paid to their main strengthening mechanisms,including solid solution strengthening mainly in the form of solid solution dissolved in the nickel-based alloy and improving the microstructure of the alloy by grain refinement or fine grain strengthening produced by homogenizing the distribution phase.Y_(2)O_(3),La_(2)O_(3) and CeO_(2) rare earth oxides can also improve the fluidity of the alloy molten pool and reduce the segregation of alloying *** advantages can significantly improve the mechanical properties of the ***,this paper outlines the future research directions of rare earth oxides,aiming to expand their application potential.

关键词： Rare earths High energy beam Nickel-based superalloys Microstructure Mechanical properties

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

Distributed Platooning Control of Automated Vehicles Subject to Replay Attacks Based on Proportional Integral Observers

引用

IEEE/CAA Journal of Automatica Sinica 2024年第9期11卷 1954-1966页

作者： Meiling Xie Derui Ding Xiaohua Ge qing-Long Han Hongli Dong yan Song Department of Control Science and Engineering University of Shanghai for Science and TechnologyShanghai 200093China School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourne VIC 3122Australia Artificial Intelligence Energy Research Institute Northeast Petroleum UniversityDaqing 163318the Heilongjiang Provincial Key Laboratory of Networking and Intelligent ControlNortheast Petroleum UniversityDaqing 163318 Sanya Offshore Oil&Gas Research Institute Northeast Petroleum UniversitySanya 572024China

Secure platooning control plays an important role in enhancing the cooperative driving safety of automated vehicles subject to various security *** paper focuses on the distributed secure control issue of automated vehicles affected by replay attacks.A proportional-integral-observer(PIO)with predetermined forgetting parameters is first constructed to acquire the dynamical information of ***,a time-varying parameter and two positive scalars are employed to describe the temporal behavior of replay *** light of such a scheme and the common properties of Laplace matrices,the closed-loop system with PIO-based controllers is transformed into a switched and time-delayed ***,some sufficient conditions are derived to achieve the desired platooning performance by the view of the Lyapunov stability *** controller gains are analytically determined by resorting to the solution of certain matrix inequalities only dependent on maximum and minimum eigenvalues of communication ***,a simulation example is provided to illustrate the effectiveness of the proposed control strategy.

关键词： Automated vehicles platooning control proportional-integral-observers(PIOs) replay attacks time-delays

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

Layered coordination polymer with two-dimensional covalent bismuth-organic networks:Semiconductor and lithium ion storage

引用

Nano Research 2024年第3期17卷 2181-2185页

作者： Mu-qing Li Yulin Cao Lei Qin hua Cheng Weimin yang Zhouguang Lu School of Materials Science and Environmental Engineering Shenzhen Polytechnic UniversityShenzhen 518055China Industrial Training Center Shenzhen Polytechnic UniversityShenzhen 518055China Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Department of Chemistry Southern University of Science and TechnologyShenzhen 518055China

Single crystals of a bismuth-based coordination polymer(CP)with carboxyl-thiol ligands,[Bi(C_(8)H_(2)O_(4)S_(2))(C2H8N)]n(Bi-DSBDC-DMA,DMBDC=2,5-disulfur-1,4-dicarboxylate,DMA=dimethylamine),have been successfully synthesized.X-ray diffraction analysis reveals that Bi-DSBDC-DMA possesses a layered structure,with two-dimensional(2D)Bi-DSBDC networks alternating with layers composed of dimethylamine *** material demonstrates semiconducting properties,featuring an optical bandgap of 2.2 eV and an electrical conductivity of 2×10^(-8) S/***,electrodes based on this material exhibit a capacity of 250 mAh/g after 200 cycles for lithium-ion storage.

关键词： bismuth layer coordination polymer(CP) semiconductor lithium ion storage

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

PDOL-Based Solid Electrolyte Toward Practical Application:Opportunities and Challenges

引用

Nano-Micro Letters 2024年第7期16卷 109-141页

作者： hua yang Maoxiang Jing Li Wang Hong Xu Xiaohong yan Xiangming He Institute for Advanced Materials School of Materials Science and EngineeringJiangsu UniversityZhenjiang 212013People’s Republic of China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084People’s Republic of China

Polymer solid-state lithium batteries(SSLB)are regarded as a promising energy storage technology to meet growing demand due to their high energy density and *** conductivity,interface stability and battery assembly process are still the main challenges to hurdle the commercialization of *** the main component of SSLB,poly(1,3-dioxolane)(PDOL)-based solid polymer electrolytes polymerized in-situ are becoming a promising candidate solid elec-trolyte,for their high ion conductivity at room temperature,good battery elec-trochemical performances,and simple assembly *** review analyzes opportunities and challenges of PDOL electrolytes toward practical application for polymer *** focuses include exploring the polymerization mechanism of DOL,the performance of PDOL composite electrolytes,and the application of ***,we provide a perspective on future research directions that need to be emphasized for commercialization of PDOL-based electrolytes in *** exploration of these schemes facilitates a comprehensive and profound understanding of PDOL-based polymer electrolyte and provides new research ideas to boost them toward practical application in solid-state batteries.

关键词： Poly(1,3-dioxolane) Solid electrolyte Polymerization mechanism Composite electrolyte Practical application

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

Low Concentration of Wenyang Tonglin Decoction Promotes Conjugation and Transfer of Drug-Resistant Plasmids among Heterologous Strains

引用

Chinese Journal of Integrative Medicine 2024年第8期30卷 721-728页

作者： WANG Bi-yan BU Hong-shi XIA Li-bo JIANG Xiang-yu TONG yan-qing Department of Traditional Chinese Medicine Changchun University of Traditional Chinese MedicineChangchun130000China

Objective To investigate the effect of low concentration of Wenyang Tonglin Decoction(WTD)on the binding conditions of R45 plasmid conjugative transfer under liquid phase conjugation and its *** Escherichia coli CP9(R45)and Staphylococcus aureus RN450RF were cultured in medium containing WTD,and their minimum inhibitory concentration(MIC)values were *** promoter fusion technology,*** CP9(R45)containing a promoter fusion was obtained.β-Galactosidase activity of TrfAp and TrbBp was tested,and the mRNA expression of regulatory factors(TrbA,KorA,and KorB)was detected by real-time fluorescent quantitative polymerase chain *** The MIC of *** CP9(R45)was 400 g/L and that of *** RN450RF was 200 g/*** the drug concentration in the culture medium was 200 g/L,the highest number of conjugants was(3.47±0.20)×10^(7) CFU/mL At 90 h of conjugation,the maximum number of conjugants was(1.15±0.06)×10^(8) CFU/mL When the initial bacterial concentration was 10^(8) CFU/mL,the maximum number of conjugants was(3.47±0.20)×10^(7) CFU/*** the drug concentration was 200 g/L,theβ-galactosidase activity of TrfAp and TrbBp significantly increased;the relative quantification of TrbA,KorA and KorB were significantly *** Low concentration of WTD promoted the development of bacterial resistance by affecting promoters and inhibiting the expression of regulatory factors.

关键词： urinary tract infection Chinese medicine drug-resistant plasmid heterozygous strains conjugation transfer

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

Chinese Medicine Combined with Adjuvant Chemotherapy for Improving Myelosuppression in Colorectal Cancer Patients:A Systematic Review and Network Meta-Analysis

引用

Chinese Journal of Integrative Medicine 2024年第7期30卷 643-652页

作者： LI Rui ZHANG Tong yan Shao-hua yan Yun-zi DING Ya-cong WANG yan-song yanG Yu-fei Department of Oncology China Academy of Chinese Medical SciencesXiyuan HospitalBeijing100091China Department of Oncology Dongfang Hospital Beijing University of Chinese MedicineBeijing100078China Graduate School Beijing University of Chinese MedicineBeijing100029China

Objective To assess the effectiveness of Chinese herbal medicine(CHM)combined with adjuvant chemotherapy on myelosuppression for colorectal cancer(CRC)patients using network meta-analysis(NMA).Methods Literature searches in both international(PubMed,Embase,Web of Science,and Cochrane Library)and Chinese(China Science and Technology Journal Database,Wanfang Data,China National Knowledge Infrastructure)databases for relevant randomized controlled trials(RCTs)were conducted from inception until October 10,*** included RCTs of patients who received CHM combined with chemotherapy,including FOLFOX,XELOX,FOLFIRI,and other relevant regimens in the CHM treatment *** outcomes included the incidence of myelosuppression,leukopenia,hemoglobin reduction,and *** reviewers independently screened the databases,extracted the data,and assessed the risk of bias and credibility of *** 5.4.1 software and STATA 14.0 were used to perform the *** A total of 31 RCTs were included,published from 2008 to 2021 in *** these,2,314 participants comparing the following 9 CHMs were identified:Shengbai Recipe(SBR),Bazhen Decoction(BZD),Jianpi Jiedu Recipe(JJR),Jianpi Recipe(JR),Compound Cantharis Capsule(CCC),Zaofan Pill(ZFP),Guilu Erxian Gel(GL),Buzhong Tiaogan Decoction(BZ),and Qiamagu Capsule(QM).The results of NMA found an indirect *** on the surface under the cumulative ranking curve(SUCRA),the ZFP+chemotherapy group had the lowest incidence of myelosuppression,with an odds ratio(OR)of 0.08[95%confidence interval(CI):0.01,0.76],whereas the GL+chemotherapy group had the lowest incidence of leukopenia,hemoglobin reduction,and thrombocytopenia,with an OR of 5.25(95%CI:2.41,11.43),4.66(95%CI:2.23,9.72),and 0.27(95%CI:0.13,0.54),***,BZD+chemotherapy could alleviate leukopenia,hemoglobin reduction,and thrombocytopenia(P<0.01).Pairwise comparison showed that there was no difference in the efficacy among the 8 CHMs+c

关键词： Chinese herbal medicine colorectal cancer network meta-analysis systematic review myelosuppression chemotherapy

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：