检索结果-南通市图书馆

结构化学 2024年第6期43卷 45-49页

作者： Xuan Zhu Lin Zhou Xiao-Yun Huang yan-ling luo Xin Deng Xin yan yan-Juan Wang yan Qin Yuan-Yuan Tang Ordered Matter Science Research Center Nanchang UniversityNanchang330031People's Republic of China

Two-dimensional(2D)lead halide perovskites have attracted tremendous attention due to their outstanding physical ***,the presence of toxic lead is a major problem for large-scale ***,we report the synthesis,phase transition,dielectric and photoluminescence(PL)properties of a lead-free 2D Ge-based perovskite(BIM)2GeI4(BIM=benzimidazolium)which experiences a phase transition at 405 K accompanied by an order-disorder change of organic ***,the step-like dielectric transition near the phase transition temperature makes it suitable for dielectric ***,(BIM)2GeI4 has a direct bandgap of 2.23 eV and broadband emission from 550 to 1000 nm,implying its unique optical property for potential near-infrared lighting and *** work provides a fresh example for the development of lead-free 2D Ge-based perovskite with potential applications in the fields of optoelectronics and high temperature dielectric switching.

关键词： Dielectric switching Photoluminescence Two-dimensional perovskite Lead-free perovskite

Impact of next-generation sequencing on antimicrobial treatment in immunocompromised adults with suspected infections

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

World Journal of Emergency Medicine 2024年第2期15卷 105-110页

作者： Jia Li Jiazhen luo Tao Hu ling Cheng Weiwei Shang Li yan Department of Intensive Care Unit Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Department of Emergency Medicine Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Tongji Medical College Huazhong University of Science and TechnologyWuhan 430030China Department of Geriatrics Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

BACKGROUND:Prompt pathogen identification can have a substantial impact on the optimization of antimicrobial *** objective of the study was to assess the diagnostic value of next-generation sequencing(NGS)for identifying pathogen and its clinical impact on antimicrobial intervention in immunocompromised patients with suspected ***:This was a retrospective *** January and August 2020,47 adult immunocompromised patients underwent NGS testing under the following clinical conditions:1)prolonged fever and negative conventional cultures;2)new-onset fever despite empiric antimicrobial treatment;and 3)afebrile with suspected infections on *** data,including conventional microbial test results and antimicrobial treatment before and after NGS,were *** were analyzed according to documented changes in antimicrobial treatment(escalated,no change,or deescalated)after the NGS ***:The median time from hospitalization to NGS sampling was 19 *** relevant pathogens were detected via NGS in 61.7% of patients(29/47),more than half of whom suffered from fungemia(n=17),resulting in an antimicrobial escalation in 53.2% of patients(25/47)and antimicrobial de-escalation in 0.2% of patients(1/47).Antimicrobial changes were mostly due to the identification of fastidious organisms such as Legionella,Pneumocystis jirovecii,and *** the remaining three cases,NGS detected clinically relevant pathogens also detected by conventional cultures a few days *** antimicrobial treatment was subsequently adjusted according to the susceptibility test ***,NGS changed antimicrobial management in 55.3%(26/47)of patients,and conventional culture detected clinically relevant pathogens in 14.9% of the patients(7/47).CONCLUSION:With its rapid identification and high sensitivity,NGS could be a promising tool for identifying relevant pathogens and enabling rapid appropriate treatment in immunocompromised patients w

关键词： Immunocompromised patients Next-generation sequencing Antimicrobial management

Homoclinic Solutions for a Class of Perturbed Fractional Hamiltonian Systems with Subquadratic Conditions

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第5期40卷 1177-1196页

作者： Ying luo Fei GUO yan LIU School of Mathematics Tianjin UniversityTianjin 300354P.R.China Tianjin Key Laboratory of Brain-Inspired Intelligence Technology Tianjin300354P.R.China

In this paper,we consider the following perturbed fractional Hamiltonian systems{tD_(∞)^(α)(_(-∞)D_(t)^(α)u(t))+L(t)u(t)=■_(u)W(t,u(t))+■(u)G(t,u(t)),t∈R,u∈H^(α)(R,R^(N)),whereα∈(1/2,1],L∈C(R,R^(N×N))is symmetric and not necessarily required to be positive definite,W∈C1(R×R^(N,R))is locally subquadratic and locally even near the origin,and perturbed term G∈C1(R×R^(N,R))maybe has no parity in *** the perturbed method improved by the authors,a sequence of nontrivial homo clinic solutions is obtained,which generalizes previous results.

关键词： Perturbed fractional Hamiltonian systems subquadratic condition perturbed method homoclinic solutions multiplicity

A Survey of Knowledge Graph Construction Using Machine Learning

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第4期139卷 225-257页

作者： Zhigang Zhao Xiong luo Maojian Chen ling Ma School of Computer and Communication Engineering University of Science and Technology BeijingBeijing100083China Shunde Innovation School University of Science and Technology BeijingFoshan528399China Beijing Key Laboratory of Knowledge Engineering for Materials Science Beijing100083China

Knowledge graph(KG)serves as a specialized semantic network that encapsulates intricate relationships among real-world entities within a structured *** framework facilitates a transformation in information retrieval,transitioning it from mere string matching to far more sophisticated entity *** this transformative process,the advancement of artificial intelligence and intelligent information services is ***,the role ofmachine learningmethod in the construction of KG is important,and these techniques have already achieved initial *** article embarks on a comprehensive journey through the last strides in the field of KG via machine *** a profound amalgamation of cutting-edge research in machine learning,this article undertakes a systematical exploration of KG construction methods in three distinct phases:entity learning,ontology learning,and knowledge ***,a meticulous dissection of machine learningdriven algorithms is conducted,spotlighting their contributions to critical facets such as entity extraction,relation extraction,entity linking,and link ***,this article also provides an analysis of the unresolved challenges and emerging trajectories that beckon within the expansive application of machine learning-fueled,large-scale KG construction.

关键词： Knowledge graph(KG) semantic network relation extraction entity linking knowledge reasoning

Revealing effect of Al content on oxidation of novel Co-Cr-Nb-W carbide-strengthened superalloy

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

Rare Metals 2024年第9期43卷 4521-4534页

作者： Chen ling Shang-Ping Li Jie Hou He-Li luo Central Iron & Steel Research Institute Beijing GAONA Materials&Technology Co. Ltd.

The high-temperature oxidation behavior of novel Co-Cr-Nb-W carbide-strengthened wear-resistance alloys with different Al contents（1wt%, 2wt% and 3wt%）at 950, 1000 and 1050 °C was thoroughly investigated by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and field emission electron probe analyzer. The porous property of Nb C in-situ oxidation products（Nb2O5, Co Nb2O6and Co4Nb2O9） induces a multi-layered oxide scale with micropores and ***-Cr-Nb-W alloy with 1 wt% Al undergoes catastrophic oxidation and spalling above 1000 °C. The outward transportation of Cr and Co is effectively restrained by a continuous Al2O3scale formed around Nb C in-situ oxidation region when Al content reaches 3 wt%. The β-Co Al in Co-Cr-Nb-W alloy with 3 wt% Al has an oxidation priority over eutectic carbides and the alloy matrix which are both enriched with Cr, thereby preventing the formation of Cr-depletion area and improving the self-healing ability of the oxide film. A slight change in Al content has a remarkable influence on the cooperative effect of Al and Cr and multiplies the antioxidant capacity of Co-Cr-Nb-W alloy above 1000 °C.

关键词： High-temperature oxidation behavior Microstructure Oxidation kinetics Superalloy Wear-resistant alloy

Quick Weighing of Passing Vehicles Using the Transfer-Learning-Enhanced Convolutional Neural Network

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第6期139卷 2507-2524页

作者： Wangchen yan Jinbao yang Xin luo College of Civil Engineering Xiangtan UniversityXiangtan411105China Energy&Environmental Engineering Department China CEC Engineering CorporationChangsha410114China

Transfer learning could reduce the time and resources required by the training of new models and be therefore important for generalized applications of the trainedmachine learning *** this study,a transfer learningenhanced convolutional neural network(CNN)was proposed to identify the gross weight and the axle weight of moving vehicles on the *** proposed transfer learning-enhanced CNN model was expected to weigh different bridges based on a small amount of training datasets and provide high identification *** of all,a CNN algorithm for bridge weigh-in-motion(B-WIM)technology was proposed to identify the axle weight and the gross weight of the typical two-axle,three-axle,and five-axle vehicles as they crossed the bridge with different loading routes and ***,the pre-trained CNN model was transferred by fine-tuning to weigh themoving vehicle on another ***,the identification accuracy and the amount of training data required were compared between the two CNN *** showed that the pre-trained CNN model using transfer learning for B-WIM technology could be successfully used for the identification of the axle weight and the gross weight for moving vehicles on another bridge while reducing the training data by 63%.Moreover,the recognition accuracy of the pre-trained CNN model using transfer learning was comparable to that of the original model,showing its promising potentials in the actual applications.

关键词： Bridge weigh-in-motion transfer learning convolutional neural network

Contrast-enhanced ultrasound for predicting differentiation degree of hepatocellular carcinoma

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

中国医学影像技术 2024年第8期40卷 1199-1203页

作者： REN Youxiang ling Wenwu luo yan yanG Lulu Department of Ultrasound West China HospitalSichuan UniversityChengdu 610041China

Objective To explore the value of contrast-enhanced ultrasound(CEUS)for predicting differentiation degree of hepatocellular carcinoma(HCC).Methods Totally 86 HCC patients confirmed by postoperative pathology were retrospectively enrolled and divided into poorly differentiated,moderately differentiated and highly differentiated groups according to postoperative Edmondson-Steiner *** CEUS parameters were compared among groups,and binary logistic regression was used to analyze CEUS-related independent predictors of HCC with different *** receiver operating characteristic curves of parameters being significant different among groups were drawn,the areas under the curve(AUC)were calculated,and the efficacy for predicting HCC with different differentiation degree was *** There were 29 cases in poorly differentiated group,37 in moderately differentiated group and 20 cases in highly differentiated *** arrival time of contrast agent in poorly differentiated group was earlier than that in moderately and high differentiated groups(both P0.05).The washout grade were significantly different between each 2 groups(all P<0.05).The arrival time of contrast agent and washout grade were independent predictors of highly or poorly differentiated,moderately or poorly differentiated,moderate-highly or poorly differentiated HCC,and washout grade also was independent predictor of highly or moderately differentiated HCC(all P<0.05).The AUC of the arrival time of contrast agent for predicting highly or moderately differentiated,highly or poorly differentiated,moderately or poorly differentiated,moderate-highly or poorly differentiated HCC was 0.615,0.787,0.690 and 0.724,respectively,while of washout grade was 0.801,0.927,0.795 and 0.841,*** CEUS could be used to effectively predict differentiation de

关键词： carcinoma,hepatocellular ultrasonography pathological differentiation

Study of the pressure transient behavior of directional wells considering the effect of non-uniform flux distribution

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 1765-1779页

作者： yan-Zhong Liang Bai-Lu Teng Wan-Jing luo School of Energy Resources China University of Geosciences(Beijing)Beijing100083China

During the production,the fluid in the vicinity of the directional well enters the wellbore with different rates,leading to non-uniform flux distribution along the directional ***,in all existing studies,it is oversimplified to a uniform flux distribution,which can result in inaccurate results for field ***,this paper proposes a semi-analytical model of a directional well based on the assumption of non-uniform flux ***,the direction well is discretized into a carefully chosen series of linear sources,such that the complex well trajectory can be captured and the nonuniform flux distribution along the wellbore can be considered to model the three-dimensional flow *** using the finite difference method,we can obtain the numerical solutions of the transient flow within the *** the aid of Green's function method,we can obtain the analytical solutions of the transient flow from the matrix to the *** complete flow behavior of a directional well is perfectly represented by coupling the above two types of transient ***,on the basis of the proposed model,we conduct a comprehensive analysis of the pressure transient behavior of a directional *** computation results show that the flux variation along the direction well has a significant effect on pressure *** addition,the directional well in an infinite reservoir may exhibit the following flow regimes:wellbore afterflow,transition flow,inclined radial flow,elliptical flow,horizontal linear flow,and horizontal radial *** horizontal linear flow can be observed only if the formation thickness is much smaller than the well ***,a dip region that appears on the pressure derivative curve indicates the three-dimensional flow behavior near the wellbore.

关键词： Directional well Pressure transient behavior Semi-analytical model Non-uniform flux

Numerical and experimental investigation on hydraulic-electric rock fragmentation of heterogeneous granite

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2024年第1期34卷 15-29页

作者： Xiaohua Zhu ling He Weiji Liu Yunxu luo Youjian Zhang Wuji Tang School of Mechatronic Engineering Southwest Petroleum UniversityChengdu 610500China School of Mechanical Engineering Sichuan University of Science and EngineeringYibin 643002China

Hydraulic-electric rock fragmentation(HERF)plays a significant role in improving the efficiency of high voltage pulse rock ***,the underlying mechanism of HERF remains *** this study,considering the heterogeneity of the rock,microscopic thermodynamic properties,and shockwave time domain waveforms,based on the shockwave model,digital imaging technology and the discrete element method,the cyclic loading numerical simulations of HERF is achieved by coupling electrical,thermal,and solid mechanics under different formation temperatures,confining pressure,initial peak voltage,electrode bit diameter,and loading ***,the HERF discharge system is conducive to the laboratory experiments with various electrical parameters and the resulting broken pits are numerically reconstructed to obtain the geometric *** results show that,the completely broken area consists of powdery rock *** the pre-broken zone,the mineral cementation of the rock determines the transition of type CⅠcracks to type CⅡand type CⅢ***,the peak pressure of the shockwave increased with initial peak voltage but decreased with electrode bit diameter,while the wave front time ***,increasing well depth,formation temperature and confining pressure augment and inhibit HERF,but once confining pressure surpassed the threshold of 60 MPa for 152.40,215.90,and 228.60 mm electrode bits,and 40 MPa for 309.88 mm electrode bits,HERF is ***,for the same kind of rock,the volume and width of the broken pit increase with higher initial peak voltage and rock fissures will promote ***,the electrode drill bit with a 215.90 mm diameter is more suitable for drilling pink *** research contributes to a better microscopic understanding of HERF and provides valuable insights for electrode bit selection,as well as the optimization of circuit parameters for HERF technology.

关键词： Hydraulic-electric rock fragmentation Shockwave Thermodynamics Microcracks Weak Linear Parallel Bond Model

Performance improvements in complementary metal oxide semiconductor devices and circuits based on fin field-effect transistors using 3-nm ferroelectric Hf_(0.5)Zr_(0.5)O_(2)

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第7期43卷 3242-3249页

作者： Zhao-Hao Zhang yan-Na luo Gao-Bo Xu Jia-Xin Yao Zhen-Hua Wu Hong-Bin Zhao Qing-Zhu Zhang Hua-Xiang Yin Jun luo Wen-Wu Wang Hai-ling Tu Integrated Circuit Advanced R&D Center Institute of Microelectronics of Chinese Academy of SciencesBeijing 100029China School of Integrated Circuits University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Advanced Materials for Smart Sensing General Research Institute for Nonferrous MetalsBeijing 100088China

In this work,a conventional HfO_(2) gate dielectric layer is replaced with a 3-nm ferroelectric(Fe) HZO layer in the gate stacks of advanced fin field-effect transistors(FinFETs).Fe-induced characteristics,e.g.,negative drain induced barrier lowering(N-DIBL) and negative differential resistance(NDR),are clearly observed for both p-and n-type HZO-based *** characteristics are attributed to the enhanced ferroelectricity of the 3-nm hafnium zirconium oxide(HZO) film,caused by Al doping from the TiAlC capping *** mechanism is verified for capacitors with structures similar to the *** to the enhanced ferroelectricity and N-DIBL phenomenon,the drain current(I_(DS))of the HZO-FinFETs is greater than that of HfO_(2)-FinFETs and obtained at a lower operating ***,circuits based on HZO-FinFET achieve higher performance than those based on HfO_(2)-FinFET at a low voltage drain(V_(DD)),which indicates the application feasibility of the HZO-FinFETs in the ultralow power integrated circuits.

关键词： FinFET Ferroelectric Hafnium zirconium oxide Subthreshold swing Low power