检索结果-南通市图书馆

Ethnopharmacological Survey of Medicinal Plants in Baotou,Inner Mongolia,China

在线全文

学校读者我要写书评

暂无评论

Chinese Herbal Medicines 2012年第4期4卷 301-313页

作者： LI Min-hui LIU Yue WANG Zhen-wang cui zhan-hu huANG Lu-qi XIAO Pei-gen Institute of Chinese Materia Medica China Academy of Chinese Medical Sciences Beijing 100700 China Baotou Medical College Baotou 014060 China Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine Ministry of Education Institute of Medicinal Plant Development Chinese Academy of Medical Science Beijing 100193 China College of Life and Environmental Sciences Minzu University of China Beijing 100081 China

Objective To document the knowledge and the use of indigenous medicinal plants by traditional healers in Baotou,Inner Mongolia,*** Data were collected from 112 randomly-selected interviewees using semistructured interviews in wild herbal plant collected from 2007 to *** data from the interviewees were analyzed with two quantitative *** the informant consensus factor,the information homology was evaluated and with the fidelity level the most important species from the categories were *** One hundred and fifty-two species belonging to 112 genera in 48 families with medicinal values were *** reported medicinal plants species were used to treat 63 kinds of *** the medicinal plants in this district possessed significant potentials for their pharmacological activities in the context of ethnopharmacological knowledge,especially in the treatments of gastrointestinal,dermatological,and cardiovascular *** In this work,152 medicinal plants with their ethnopharmacological information are *** study demonstrates that many species play an important role in healing practices among inhabitants from *** ethnopharmacological information of Mongolian medicinal plants should be gathered and documented in further studies,which is a fundamental step toward developing efficacious natural drugs for various diseases.

关键词： ethnopharmacology indigenous medicinal plants informant consensus factor pharmacological activities traditional Mongolian medicine

An infinite-dimensional representation of the Ray-Knight theorems

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2024年第1期67卷 149-162页

作者： Elie Aidékon Yueyun hu zhan Shi School of Mathematical Sciences Fudan UniversityShanghai 200433China LAGA UniversitéSorbonne Paris NordVilletaneuse 93430France Institute of Applied Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China

The classical Ray-Knight theorems for the Brownian motion determine the law of its local time process either at the first hitting time of a given value a by the local time at the origin,or at the first hitting time of a given position b by the Brownian *** extend these results by describing the local time process jointly for all a and b,by means of the stochastic integral with respect to an appropriate white *** result applies toμ-processes,and has an immediate application:aμ-process is the height process of a Feller continuous-state branching process(CSBP)with immigration(Lambert(2002)),whereas a Feller CSBP with immigration satisfies a stochastic differential equation(SDE)driven by a white noise(Dawson and Li(2012));our result gives an explicit relation between these two descriptions and shows that the SDE in question is a reformulation of Tanaka’s formula.

关键词： Ray-Knight theorem μ-process white noise Tanaka's formula

Fault diagnosis of a marine power-generation diesel engine based on the Gramian angular field and a convolutional neural network

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第6期25卷 470-482页

作者： Congyue LI Yihuai hu Jiawei JIANG Dexin cui Merchant Marine College Shanghai Maritime UniversityShanghai 201306China School of Mechanical and Energy Engineering Shanghai Technical Institute of Electronics&InformationShanghai 201411China

Marine power-generation diesel engines operate in harsh *** vibration signals are highly complex and the feature information exhibits a non-linear *** is difficult to extract effective feature information from the network model,resulting in low fault-diagnosis *** address this problem,we propose a fault-diagnosis method that combines the Gramian angular field(GAF)with a convolutional neural network(CNN).Firstly,the vibration signals are transformed into 2D images by taking advantage of the GAF,which preserves the temporal *** raw signals can be mapped to 2D image features such as texture and *** integrate the feature information,the images of the Gramian angular summation field(GASF)and Gramian angular difference field(GADF)are fused by the weighted average fusion ***,the channel attention mechanism and temporal attention mechanism are introduced in the CNN model to optimize the CNN learning *** the concept of residuals in the attention mechanism improves the feasibility of ***,the weighted average fused images are fed into the CNN for feature extraction and fault *** validity of the proposed method is verified by experiments with abnormal valve *** average diagnostic accuracy is 98.40%.When−20 dB≤signal-to-noise ratio(SNR)≤20 dB,the diagnostic accuracy of the proposed method is higher than 94.00%.The proposed method has superior diagnostic ***,it has a certain anti-noise capability and variable-load adaptive capability.

关键词： Multi-attention mechanisms(MAM) Convolutional neural network(CNN) Gramian angular field(GAF) Image fusion Marine power-generation diesel engine Fault diagnosis

Reduced-complexity multiple parameters estimation via toeplitz matrix triple iteration reconstruction with bistatic MIMO radar

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 Aeronautics 2024年第7期37卷 482-495页

作者： Chenghong zhan Guoping hu Junpeng SHI Fangzheng ZHAO Hao ZHOU Graduate College Air Force Engineering UniversityXi’an 710051China Air and Missile Defense College Air Force Engineering UniversityXi’an 710051China College of Electronic Countermeasure National University of Defense TechnologyHefei 230037China Beijing Aeronautical Technology Research Center Beijing 100076China

In this advanced exploration, we focus on multiple parameters estimation in bistatic Multiple-Input Multiple-Output(MIMO) radar systems, a crucial technique for target localization and imaging. Our research innovatively addresses the joint estimation of the Direction of Departure(DOD), Direction of Arrival(DOA), and Doppler frequency for incoherent targets. We propose a novel approach that significantly reduces computational complexity by utilizing the TemporalSpatial Nested Sampling Model(TSNSM). Our methodology begins with a multi-linear mapping mechanism to efficiently eliminate unnecessary virtual Degrees of Freedom(DOFs) and reorganize the remaining ones. We then employ the Toeplitz matrix triple iteration reconstruction method, surpassing the traditional Temporal-Spatial Smoothing Window(TSSW) approach, to mitigate the single snapshot effect and reduce computational demands. We further refine the highdimensional ESPRIT algorithm for joint estimation of DOD, DOA, and Doppler frequency, eliminating the need for additional parameter pairing. Moreover, we meticulously derive the Cramér-Rao Bound(CRB) for the TSNSM. This signal model allows for a second expansion of DOFs in time and space domains, achieving high precision in target angle and Doppler frequency estimation with low computational complexity. Our adaptable algorithm is validated through simulations and is suitable for sparse array MIMO radars with various structures, ensuring higher precision in parameter estimation with less complexity burden.

关键词： MIMO Radar Multipleparameters estimation Temporal-spatial Nested Sampling Multi-linear mapping mechanism Toeplitz matrix triple iteration reconstruction Reduce computational complexity

Dual-aligned porous electrodes for enhanced hydrogen evolution in alkaline water electrolysis

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 3835-3843页

作者： Yuqi zhang Wenzhi cui Longjian Li Chongbo Wang Chen zhan Xiaojun Quan School of Energy and Power Engineering Chongqing UniversityChongqing 400030China Key Laboratory of Low-grade Energy Utilization Technologies and Systems Chongqing UniversityChongqing 400030China School of Mechanical Engineering Shanghai Jiao-Tong UniversityShanghai 200240China

The efficiency of water electrolysis is significantly affected by the bubbles on the surface and inside the *** enhance the gas-liquid transfer within the porous electrodes,we developed an innovative design termed dual-aligned porous electrode(D-APE),achieved by integrating magnetic alignment with freeze casting *** paper investigates the hydrogen evolution performance of porous electrodes prepared using four different methods:evaporation,magnetic-aligned evaporation,freeze casting,and dual-aligned *** findings demonstrate that the magnetic-aligned process effectively alters the electrode structure,resulting in improved hydrogen evolution ***,among all the examined electrodes,the D-APE exhibits the highest hydrogen evolution performance,with further enhancements observed with prolonged the time of magnetic ***,a comparison is made between electrodes prepared using the freeze casting method and the dual-aligned method at various *** results show that the thinner D-APE exhibits excellent hydrogen evolution performance at high current ***,the D-APE demonstrates significantly improved material utilization rates compared to the conventional freeze casting method,offering promising prospects for enhancing the efficiency of water electrolysis.

关键词： hydrogen evolution reaction dual-aligned magnetic-aligned freeze casting

Transient features of graphitization and nitrogen-vacancy color centers in a diamond fabricated by localization femtosecond laser direct writing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第8期67卷 2530-2536页

作者： cui Lin YIN SiYu hu ZiFan WANG Lei State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012China

Femtosecond laser direct writing provides an efficient approach to fabricating single nitrogen vacancy(NV) color centers with a relatively high yield. Different from previously reported NV color centers with a random distribution in a bulk diamond or nanocrystals, this gives an opportunity to study the photophysical properties of single NV color centers with precise numbers and positions. However, ultrafast studies on single NV color centers prepared by localization femtosecond laser direct writing are still rare, especially for the graphitization inside a diamond and its relationship with single NV color centers. Here, we report the broadband transient absorption(TA) spectroscopic features of the graphitization and NV color centers in a diamond fabricated by localization femtosecond laser direct writing at room temperature under 400 nm excitation. In comparison with the graphene oxide film, the bleaching features of the graphitization point array in a diamond are similar to reduced graphene oxide,accompanied by excited state absorption signals from local carbon atom vacancy defects in graphene-like structures induced by laser writing. On the other hand, transient features of laser processing array containing single NV color centers with a yield of~50% are different from those of the graphitization point array. Our findings suggest that for ultrashort pulse processing of diamonds, broadband TA spectral signals are sensitive to the surrounding atomic environment of processing sites, which could be applied to laser writing point defects in other materials used as solid-state single photon sources.

关键词： nitrogen-vacancy color center graphitization diamond femtosecond laser direct writing ultrafast spectroscopy

Water and other volatiles on Mars

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第6期11卷 12-14页

作者： Sen hu Yubing Gao zhan Zhou Liang Gao Yangting Lin Key Laboratory of the Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of Sciences College of Earth and Planetary Sciences University of Chinese Academy of Sciences

Mars, the intriguing red planet, is one of the planets most similar to the Earth in our solar system. It is widely accepted that Mars could have had a warm and wet climate in its early history supported by numerous lines of evidence, e.g. topography, canyons, outflow channels, presence of phyllosilicates and evaporative salts,sedimentary formation, and many others (e.g.[1]), and thus Mars is believed to once have a potentially habitable environment which could be able to supply fundamental conditions for the evolution of potential lives.

关键词： ISOTOPIC COMPOSITION MARTIAN ATMOSPHERE SUBSURFACE WATER ABUNDANCE TISSINT H2O CO2

Triple signal amplification electrochemical sensing platform for Hg^(2+) in water without direct modification of the working electrode

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2024年第7期18卷 157-167页

作者： Liuyin hu Jiahua cui Tao Lu Yalin Wang Jinping Jia School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China International Copper Association Ltd.Shanghai 200020China

An ultrasensitive electrochemical biosensor to detect trace Hg^(2+)in environmental samples was developed utilizing nanogold-decorated magnetic reduced graphene oxide(MrGO-AuNPs),exonuclease III-assisted target cycle(Exo Ⅲ-ATC)and hybridization chain reaction(HCR)synergistic triple signal *** MrGO-AuNPs is a superior carrier for capture DNA(cDNA)and acts as magnetic media for automatic separation and *** innovative utilization of the magnetism and improved sensing efficiency obviates the need for direct modification and repeated polishing of the working ***,the three DNA hairpins(cDNA,methylene blue(MB)labeled HP1 and HP2)further contribute to biosensor specificity and *** cDNA captures Hgt,it activates Exo Ⅲ-ATC due to the formation of a sticky end in the DNA stem via thymine-Hig-thymidine(T-Hg^(2+)-T),this leads to the hydrolysis of self-folded DNA by Exo Ⅲ-ATC to form"key"DNA(kDNA).The kDNA subsequently initiates HCR,resulting in massive super-sandwich structures(kDNA-[HP1/HP2])carrying signaling molecules on MrGO-AuNPs,and this overall structure serves as a signal probe(SP).Leveraging magnetic adsorption,the SP was automatically adsorbed onto the magneto-glass carbon electrode(MGCE),generating an amplified *** biosensor's detection limit(LOD)was 3.14 pmol/L,far below the limit of 10 nmol/L for mercury in drinking water set by the US *** biosensor also showed excellent selectivity when challenged by interfering ions,and the results of its application in actual samples indicate that it has good potential for practical applications in environmental monitoring.

关键词： Electrochemical sensing Hg^(2+) Amplification Graphene Hybridization chain reaction Exonuclease Ⅲ

Dynamic Characteristics of Functionally Graded Timoshenko Beams by Improved Differential Quadrature Method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第8期140卷 1647-1668页

作者： Xiaojun huang Liaojun zhang Hanbo cui Gaoxing hu School of Architecture and Civil Engineering Anhui Polytechnic UniversityWuhu241000China College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China

This study proposes an effective method to enhance the accuracy of the Differential Quadrature Method(DQM)for calculating the dynamic characteristics of functionally graded beams by improving the form of discrete node ***,based on the first-order shear deformation theory,the governing equation of free vibration of a functionally graded beam is transformed into the eigenvalue problem of ordinary differential equations with respect to beam axial displacement,transverse displacement,and cross-sectional rotation angle by considering the effects of shear deformation and rotational inertia of the beam ***,ignoring the shear deformation of the beam section and only considering the effect of the rotational inertia of the section,the governing equation of the beam is transformed into the eigenvalue problem of ordinary differential equations with respect to beam transverse *** on the differential quadrature method theory,the eigenvalue problem of ordinary differential equations is transformed into the eigenvalue problem of standard generalized algebraic ***,the first several natural frequencies of the beam can be *** feasibility and accuracy of the improved DQM are verified using the finite element method(FEM)and combined with the results of relevant literature.

关键词： Timoshenko beams functionally graded materials dynamic characteristics natural frequency improved differential quadrature method