检索结果-南通市图书馆

Particle size spatial distribution in landslide dams

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 Mountain Science 2024年第6期21卷 1886-1903页

作者： zhang Jingyi zhang Jianmin State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610064China

The particle composition and spatial distribution of landslide-induced dam bodies are critical geotechnical parameters for studying the hazards of dam-break floods.However,current research often neglects the influence of the initial particle composition and spatial distribution of the landslide on the particle composition and spatial distribution of the landslide dam.This study investigated the impact of initial particle size distribution,volume,and sliding length on the energy and velocity changes of characteristic particles during the sliding process and the spatial distribution of particle sizes in the landslide dam body.Numerical simulations and physical models were employed to examine the effects of sequential gradient arrangements(where particle sizes decrease from top to bottom)and four other different initial particle arrangements on the energy and velocity changes of particles and the spatial distribution of particle sizes in the dam body.The study reveals the characteristics of translational and rotational energy of different particles and the laws of mechanical energy conversion,obtaining the spatial distribution patterns of particle sizes in landslide-induced dams.The results show that under the sequential gradient arrangement,the energy dissipation of the landslide movement is lower,with larger particles mainly distributed at the distal end and smaller particles at the proximal end of the landslide dam.In contrast,under the reverse gradient arrangement,the energy dissipation of the landslide movement is higher,and the distribution pattern of the dam particles is opposite to that of the sequential gradient arrangement.For the other arrangement modes,the spatial distribution of dam particles falls between the aforementioned two.There is a positive correlation between particle size and translational kinetic energy within the particle flow during the landslide process,and rotational motion increases energy dissipation.Under constant slope conditions,sliding length does not affect the movement pattern of

关键词： Particle size distribution Landslide Numerical simulation Discrete element method

维普期刊数据库

A Bionic Starfish Adsorption Crawling Soft Robot

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第1期21卷 149-165页

作者： Xiangang Huang Chenghao zhang Wenqi Feng Xiangye zhang Deyuan zhang Yanqiang Liu Institute of Bionic and Micro-Nano Systems School of Mechanical Engineering and AutomationBeihang UniversityBeijing 100191China

A variety of soft wall-climbing robots have been developed that can move in certain patterns.Most of these soft robots can only move on conventional surfaces and lack adaptability to complex surfaces.Improving the adaptability of soft robots on complex surfaces is still a challenging problem.To this end,we study the layered structure of the starfish tube foot and the valve flap structure in the water vascular system,and use an ultrasonic stress detector to study the stiffness distribution of the arm structure.Inspired by the motion of the starfish,we present a bionic soft wall-climbing robot,which is driven by two groups of pneumatic feet and achieves body bending through active adaptation layers.We design the structure of the foot to flex to provide driving force,and there are suction cups at the end of the foot to provide suction.The soft foot has a simple structure design,adapts to a variety of surfaces,and does not damage the surface of the substrate.Variable stiffness layers achieve stiffness changes by the principle of line blocking.The Central Pattern Generator theory is introduced to coordinately control the multiple feet of the robot.After experiments,we verify the adaptability of the soft robot to curved surfaces.The research may provide a reference for the design and development of crawling soft robots on complex surfaces.

关键词： Starfish Tube foot Biomimetic robot Soft robot Climbing robot

Flexible regulation engineering of titanium nitride nanofibrous membranes for efficient electromagnetic microwave absorption in wide temperature spectrum

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第3期17卷 1666-1675页

作者： Cuiping Li Lu zhang Shuai zhang Qiqi Yu Dan Li Lei zhang Chunhong Gong Jingwei zhang Institute of Functional Polymer Composites College of Chemistry and Molecular SciencesHenan UniversityKaifeng 475004China National&Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials Henan UniversityKaifeng 475004China

Simultaneous development of well impedance matching and strong loss capability has become a mainstream method for achieving outstanding electromagnetic microwave absorption(EMWA)performances over wide temperature range.However,it is difficult to pursue both due to the mutual restraint of relationship between impedance matching and loss capability about temperature.Here,we propose a flexible regulation engineering of titanium nitride(TiN)nanofibrous membranes(NMs,TNMs),which could be distributed uniformly in the polydimethylsiloxane(PDMS)matrix and contributed to the formation of abundant local conductive networks,generating the local conductive loss and enhancing the loss ability of EMWs.Moreover,when the TNMs are used as functional units and dispersed in the matrix,the corresponding composites exhibit an outstanding anti-reflection effect on microwaves.As hoped,under the precondition of good impedance matching,local conductive loss and polarization loss together improve the loss capacity at room temperature,and polarization loss can compensate the local conductive loss to acquire effective dielectric response at elevated temperature.Benefiting from the reasonably synergistic loss ability caused by flexible regulation engineering,the corresponding composites exhibit the perfect EMWA performances in a wide temperature range from 298 to 573 K.This work not only elaborates the ponderable insights of independent membrane in the composition-structure-function connection,but also provides a feasible tactic for resolving coexistence of well impedance matching and strong loss capability issues in wide temperature spectrum.

关键词： flexible titanium nitride nanofibrous membranes local conductive loss dielectric loss electromagnetic microwave absorption wide temperature spectrum

High-performance terahertz modulators induced by substrate field in Te-based all-2D heterojunctions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第3期13卷 577-586页

作者： Pujing zhang Qihang Liang Qingli Zhou Jinyu Chen Menglei Li Yuwang Deng Wanlin Liang Liangliang zhang Qinghua zhang Lin Gu Chen Ge Kui-juan Jin Cunlin zhang Guozhen Yang Department of Physics Key Laboratory of Terahertz OptoelectronicsMinistry of Educationand Beijing Advanced Innovation Center for Imaging Theory and TechnologyCapital Normal UniversityBeijing 100048China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Department of Materials Science and Engineering Beijing National Center for Electron Microscopy and Laboratory of Advanced MaterialsTsinghua UniversityBeijing 100084China

High-performance active terahertz modulators as the indispensable core components are of great importance for the next generation communication technology.However,they currently suffer from the tradeoff between modulation depth and speed.Here,we introduce two-dimensional(2D)tellurium(Te)nanofilms with the unique structure as a new class of optically controlled terahertz modulators and demonstrate their integrated heterojunctions can successfully improve the device performances to the optimal and applicable levels among the existing all-2D broadband modulators.Further photoresponse measurements confirm the significant impact of the stacking order.We first clarify the direction of the substrate-induced electric field through first-principles calculations and uncover the unusual interaction mechanism in the photoexcited carrier dynamics associated with the charge transfer and interlayer exciton recombination.This advances the fundamental and applicative research of Te nanomaterials in high-performance terahertz optoelectronics.

关键词： performance field terahertz

Unveiling the mechanisms of Fe(Ⅲ)-loaded chitosan composite(CTS-Fe)in enhancing anaerobic digestion of waste activated sludge

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 2024年第4期138卷 200-211页

作者： Boaiqi zhang Ziwen Zhao RuiMa Nan Chen Zhe Kong Zhongfang Lei Zhenya zhang Graduate School of Life and Environmental Sciences University of Tsukuba1-1-1 TennodaiTsukubaIbaraki 305-8572Japan The Key Laboratory of Water and Sediment Sciences Ministry of Education/State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems/College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China South China Institute of Environmental Sciences Ministry of Ecology and EnvironmentGuangzhou 510345China School of Water Resources and Environment China University of Geosciences(Beijing)Beijing 100083China School of Environmental Science and Engineering Suzhou University of Science and TechnologySuzhou 215009China

Anaerobic digestion(AD)of waste activated sludge(WAS)is usually limited by the low generation efficiency of methane.Fe(Ⅲ)-loaded chitosan composite(CTS-Fe)have been reported to effectively enhanced the digestion of WAS,but its role in promoting anaerobic sludge digestion remains unclear.In present study,the effects of CTS-Fe on the hydrolysis and methanogenesis stages of WAS anaerobic digestion were investigated.The addition of CTSFe increased methane production potential by 8%-23%under the tested conditions with the addition of 5-20 g/L CTS-Fe.Besides,the results demonstrate that the addition of CTS-Fe could effectively promote the hydrolysis of WAS,evidenced by lower protein or polysaccharides concentration,higher soluble organic carbon in rector adding CTS-Fe,as well as the increased activity of extracellular hydrolase with higher CTS-Fe concentration.Meanwhile,the enrichment of Clostridia abundance(iron-reducing bacteria(IRBs))was observed in CTS-Fe adding reactor(8.9%-13.8%),which was higher than that in the control reactor(7.9%).The observation further suggesting the acceleration of hydrolysis through dissimilatory iron reduction(DIR)process,thus providing abundant substrates for methanogenesis.However,the presence of CTS-Fe was inhibited the acetoclastic and hydrogenotrophic methanogenesis process,which could be ascribed to the Fe(Ⅲ)act as electron acceptor coupled to methane for anaerobic oxidation.Furthermore,coenzyme F420 activity in the CTS-Fe added reactor was 34.9% lower than in the blank,also abundance of microorganisms involved in hydrogenotrophic methanogenesis was decreased.Results from this study could provide theoretical support for the practical applications of CTS-Fe.

关键词： Chitosan-Fe(Ⅲ)composite Methanogenesis Dissimilatory iron reduction Enzyme activity Microbial community structure

维普期刊数据库

Multi-instance partial-label learning: towards exploiting dual inexact supervision

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第3期67卷 48-61页

作者： Wei TANG Weijia zhang Min-Ling zhang School of Computer Science and Engineering Southeast University Key Laboratory of Computer Network and Information Integration (Southeast University) Ministry of Education School of Information and Physical Sciences The University of Newcastle

Weakly supervised machine learning algorithms are able to learn from ambiguous samples or labels, e.g., multi-instance learning or partial-label learning. However, in some real-world tasks, each training sample is associated with not only multiple instances but also a candidate label set that contains one groundtruth label and some false positive labels. Specifically, at least one instance pertains to the ground-truth label while no instance belongs to the false positive labels. In this paper, we formalize such problems as multi-instance partial-label learning(MIPL). Existing multi-instance learning algorithms and partial-label learning algorithms are suboptimal for solving MIPL problems since the former fails to disambiguate a candidate label set, and the latter cannot handle a multi-instance bag. To address these issues, a tailored algorithm named MIPLGP, i.e., multi-instance partial-label learning with Gaussian processes, is proposed.MIPLGP first assigns each instance with a candidate label set in an augmented label space, then transforms the candidate label set into a logarithmic space to yield the disambiguated and continuous labels via an exclusive disambiguation strategy, and last induces a model based on the Gaussian processes. Experimental results on various datasets validate that MIPLGP is superior to well-established multi-instance learning and partial-label learning algorithms for solving MIPL problems.

关键词： machine learning multi-instance partial-label learning multi-instance learning partial-label learning Gaussian processes

Identification of fangchinoline as a broad-spectrum enterovirus inhibitor through reporter virus based high-content screening

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Virologica Sinica 2024年第2期39卷 301-308页

作者： Qiu-Yan zhang Jia-Qi Li Qi Li Yang zhang Zhe-Rui zhang Xiao-Dan Li Hong-Qing zhang Cheng-Lin Deng Feng-Xia Yang Yi Xu Bo zhang The Joint Center of Translational Precision Medicine Department of Infections and DiseasesGuangzhou Institute of PediatricsGuangzhou Women and Children's Medical CenterGuangzhou510623China Key Laboratory of Special Pathogens and Biosafety Wuhan Institute of VirologyCenter for Biosafety Mega-ScienceChinese Academy of SciencesWuhan430071China University of Science and Technology of China Department of Life Sciences and MedicineHefei230026China Hunan Normal University School of MedicineChangsha410081China

Hand,foot,and mouth disease(HFMD)is a common pediatric illness mainly caused by enteroviruses,which are important human pathogens.Currently,there are no available antiviral agents for the therapy of enterovirus infection.In this study,an excellent high-content antiviral screening system utilizing the EV-A71-eGFP reporter virus was developed.Using this screening system,we screened a drug library containing 1042 natural compounds to identify potential EV-A71 inhibitors.Fangchinoline(FAN),a bis-benzylisoquinoline alkaloid,exhibits potential inhibitory effects against various enteroviruses that cause HFMD,such as EV-A71,CV-A10,CV-B3 and CV-A16.Further investigations revealed that FAN targets the early stage of the enterovirus life cycle.Through the selection of FAN-resistant EV-A71 viruses,we demonstrated that the VP1 protein could be a potential target of FAN,as two mutations in VP1(E145G and V258I)resulted in viral resistance to FAN.Our research suggests that FAN is an efficient inhibitor of EV-A71 and has the potential to be a broad-spectrum antiviral drug against human enteroviruses.

关键词： Hand,foot,and mouth disease(HFMD) Enterovirus EV-A71 High-content screening Fangchinoline(FAN)

Efficacy and Safety of Bufei Jiedu Granules in Treating Multidrug-Resistant Pulmonary Tuberculosis: A Multi-center, Double-Blinded and Randomized Controlled Trial

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 Journal of Integrative Medicine 2024年第7期30卷 579-587页

作者： zhang Shao-yan QIU Lei zhang Shun-xian XIAO He-ping CHU Nai-hui zhang Xia zhang Hui-qiang ZHENG Pei-yong zhang Hui-yong LU Zhen-hui Institute of Respiratory Diseases Longhua Hospital Shanghai University of Traditional Chinese Medicine Clinical Research Center Shanghai University of Traditional Chinese Medicine Department of Tuberculosis Shanghai Pulmonary HospitalTongji University Department of Tuberculosis Beijing Chest Hospital Capital Medical University Department of Tuberculosis the Second Hospital of Nanjing Department of Tuberculosis the First Hospital Affiliated to Xinxiang Medical College

Objective: To assess the efficacy and safety of Bufei Jiedu(BFJD) Granules as adjuvant therapy for patients with multidrug-resistant pulmonary tuberculosis(MDR-PTB). Methods: A large-scale, multi-center, double-blinded, and randomized controlled trial was conducted in 18 sentinel hospitals in China from December 2012 to December 2016. A total of 312 MDR-PTB patients were randomly assigned to BFJD Granules or placebo groups(1:1) using a stratified randomization method, which both received the long-course chemotherapy regimen for 18 months(6 Am-Lfx-P-Z-Pto, 12 Lfx-P-Z-Pto). Meanwhile, patients in both groups also received BFJD Granules or placebo twice a day for a total of 18 months, respectively. The primary outcome was cure rate. The secondary outcomes included time to sputum-culture conversion, changes in lung cavities and quality of life(QoL) of patients. Adverse reactions were monitored during and after the trial. Results: A total of 216 cases completed the trial, 111 in the BFJD Granules group and 105 in the placebo group. BFJD Granules, as adjuvant treatment, increased the cure rate by 13.6% at the end of treatment, compared with the placebo(58.4% vs. 44.8%, P=0.02), and accelerated the median time to sputum-culture conversion(5 months vs. 11 months). The cavity closure rate of the BFJD Granules group(50.6%, 43/85) was higher than that of the placebo group(32.1%, 26/81; P=0.02) in patients who completed the treatment. At the end of the intensive treatment, according to the 36-item Short Form, the BFJD Granules significantly improved physical functioning, general health, and vitality of patients relative to the placebo group(all P<0.01). Overall, the death rates in the two groups were not significantly different; 5.1%(8/156) in the BFJD Granules group and 2.6%(4/156) in the placebo group. Conclusions: Supplementing BFJD Granules with the long-course chemotherapy regimen significantly increased the cure rate and cavity closure rate, and rapidly improved QoL of patients with MDR-PTB(Registration No. ChiCTR-TRC-

关键词： alternative medicine Chinese herbal formula Bufei Jiedu Granules multidrug-resistant tuberculosis long-course chemotherapy regimen randomized controlled trial

Bioinspired 3D flexible devices and functional systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第3期11卷 271-295页

作者： Xu Cheng zhangming Shen Yihui zhang Applied Mechanics Laboratory Department of Engineering Mechanics Tsinghua University Laboratory of Flexible Electronics Technology Tsinghua University

Flexible devices and functional systems with elaborated three-dimensional(3D) architectures can endow better mechanical/electrical performances, more design freedom, and unique functionalities, when compared to their two-dimensional(2D) counterparts. Such 3D flexible devices/systems are rapidly evolving in three primary directions, including the miniaturization, the increasingly merged physical/artificial intelligence and the enhanced adaptability and capabilities of heterogeneous integration.Intractable challenges exist in this emerging research area, such as relatively poor controllability in the locomotion of soft robotic systems, mismatch of bioelectronic interfaces, and signal coupling in multi-parameter sensing. By virtue of long-time–optimized materials, structures and processes, natural organisms provide rich sources of inspiration to address these challenges, enabling the design and manufacture of many bioinspired 3D flexible devices/systems. In this Review, we focus on bioinspired 3D flexible devices and functional systems, and summarize their representative design concepts, manufacturing methods, principles of structure-function relationship and broad-ranging applications. Discussions on existing challenges, potential solutions and future opportunities are also provided to usher in further research efforts toward realizing bioinspired 3D flexible devices/systems with precisely programmed shapes,enhanced mechanical/electrical performances, and high-level physical/artificial intelligence.

关键词： bioinspired designs biomimetic 3D structures 3D flexible electronics 3D functional systems direct 3D manufacture 2D-to-3D assembly