检索结果-南通市图书馆

Performance and comparison of assessment models to predict 30-day mortality in patients with hospital-acquired pneumonia

引用

Chinese Medical Journal 2020年第24期133卷 2947-2952页

作者： Jia-Ning Wen Nan Li chen-xia guo Ning Shen Bei He Department of Respiratory Medicine Peking University Third HospitalBeijing 100191China Research Center of Clinical Epidemiology Peking University Third HospitalBeijing 100191China

Background:Hospital-acquired pneumonia(HAP)is the most common hospital-acquired infection in China with substantial morbidity and *** no specific risk assessment model has been well validated in patients with *** aim of this study was to investigate the published risk assessment models that could potentially be used to predict 30-day mortality in HAP patients in non-surgical ***:This study was a single-center,retrospective *** total,223 patients diagnosed with HAP from 2012 to 2017 were included in this *** and laboratory data during the initial 24 hours after HAP diagnosis were collected to calculate the pneumonia severity index(PSI);consciousness,urea nitrogen,respiratory rate,blood pressure,and age≥65 years(CURB-65);Acute Physiology and Chronic Health Evaluation II(APACHE II);Sequential Organ Failure Assessment(SOFA);and Quick Sequential Organ Failure Assessment(qSOFA)*** discriminatory power was tested by constructing receiver operating characteristic(ROC)curves,and the areas under the curve(AUCs)were ***:The all-cause 30-day mortality rate was 18.4%(41/223).The PSI,CURB-65,SOFA,APACHE II,and qSOFA scores were significantly higher in non-survivors than in survivors(all P<0.001).The discriminatory abilities of the APACHE II and SOFA scores were better than those of the CURB-65 and qSOFA scores(ROC AUC:APACHE II ***-65,0.863 vs.0.744,Z=3.055,P=0.002;APACHE II ***,0.863 vs.0.767,Z=3.017,P=0.003;SOFA ***-65,0.856 vs.0.744,Z=2.589,P=0.010;SOFA ***,0.856 vs.0.767,Z=2.170,P=0.030).The cut-off values we defined for the SOFA,APACHE II,and qSOFA scores were 4,14,and ***:These results suggest that the APACHE II and SOFA scores determined during the initial 24 h after HAP diagnosis may be useful for the prediction of 30-day mortality in HAP patients in non-surgical *** qSOFA score may be a simple tool that can be used to quickly identify severe infections.

关键词： Hospital-acquired pneumonia Mortality Sequential Organ Failure Assessment(SOFA) Acute Physiology and Chronic Health Evaluation II(APACHE II) Quick Sequential Organ Failure Assessment(qSOFA)

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

数字孪生技术在智慧城市建设中的应用

引用

智能建筑与智慧城市 2024年第5期 30-32页

作者：郭夏臣王甫银张可心北京新兴华安智慧科技有限公司

智慧城市建设的城市建设规划理念需要多种技术提供基本保障支持。数字孪生技术作为综合应用优势多、跨学科融合能力强的技术形式,提出了其在智慧城市建设中的应用。文章在此背景下明确了数字孪生技术所具有的特征及功能实现,并提出数字... 详细信息

智慧城市建设的城市建设规划理念需要多种技术提供基本保障支持。数字孪生技术作为综合应用优势多、跨学科融合能力强的技术形式,提出了其在智慧城市建设中的应用。文章在此背景下明确了数字孪生技术所具有的特征及功能实现,并提出数字孪生技术的应用场景,为智慧城市建设与发展提供基本的保障支持。

关键词：智慧城市数字孪生城市规划与建设

来源：

维普期刊数据库博看期刊

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

Partition of Initiators in Quasi-static Precipitation Polymerization of AAm/MAc

引用

Chinese Journal of Polymer Science 2014年第10期32卷 1400-1412页

作者：倪恨美 Hui Zhang guo-xia chen Jun-xiu Liu Ya-dong Yang Li-jun Zhang Min Wu Kan Zhan Yu-lu chen School of Chemistry and Chemical Engineering Southeast University

In order to investigate the partition of initiators for quasi-static precipitation polymerization of acrylamide （AAm） and methacrylic acid （MAc） in ethanol, azo-initiators were employed with various functional groups such as --COOCH3 （V- 601, dimethyl 2,2＇-azobis（isobutyrate））, --CN （V-65, 2,2＇-Azobis（2,4-diemthylvaleronitrile））, --COOH （V-501, 4,4＇-azobis（4-cyanovaleric acid）） and --NH-（VA-061, 2,2＇-azobis[2-（2-imidazolin-2-yl）propane]）, respectively. Particle size, induction time and kinetics of polymerization were investigated by the scanning electron microscopy （SEM） and gravimetry. It was observed that the polymerization parameters, such as the particle size, induction time and polymerization rate, were considerably affected by the functional groups of initiators. Besides, the monomer concentration also played important roles in the particle formation. By using V-601, the polymerization rate was strongly correlated with the total surface area of particles and the concentration of initiators. However, by using V-50 l, the polymerization rate was strongly related to WoQo, where W0 is the initial concentration of monomers and Ci,0, the initial concentration of initiators. The results indicated that the different functional groups determined the different partition types of initiators between the minimonomer droplets and the continuous phase due to the molecular interactions of initiator and monomers. V-601 was all partitioned in the continuous phase, but a part of V-65 was partitioned in the minimonomer droplets. Besides the V-501 dissolved in the continuous phase, a part of V-501 was adsorbed on the surface of minimonomer droplets. VA-061 destroyed the stability of minimonomer droplets by the formation of zwitterions with MAA.

关键词： Partition of initiator Precipitation of polymerization Quasi-static state Methacrylic acid and acrylamide

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

Two-stage Planning Method for Energy Router Considering Its Optimal Operation in Distribution Networks

引用

CSEE Journal of Power and Energy Systems 2024年第2期10卷 605-616页

作者： Meifu chen Mingchao xia Qifang chen School of Electrical Engineering Beijing Jiaotong UniversityBeijing 100044China

An energy router can effectively optimize the network loss and power quality of distribution networks. The optimal configuration of the energy router is relatively complex because issues dynamically influence each other, such as the location of the energy router, optimal number and capacity of its ports, and building new distribution lines for the ports. Presently, there has been very few research studies on the practical problems for the energy router. In this paper, a planning model of an energy router combined with the distribution network is established, which fully exploits the active and reactive power control abilities of the energy router to optimize the operation of the grid. The configuration problem is decoupled into two stages. The upper layer determines the location of the energy router and the parameters of the candidate new distribution lines for the ports. The lower layer calculates the optimal configuration of the energy router by minimizing the total annual cost. Because of the same rated bus voltage in the distribution network, the existing structure of the energy router is changed to be more applicable for the distribution network, and then the power flow model of the energy router is also modified. Due to the nonlinearity of the model, the planning model is converted into a mixed-integer second-order cone model to solve efficiently. In addition, some core factors influencing the optimal scheme of the energy router are also analyzed in this paper. Simulation results show that the optimal scheme of the energy router can significantly improve the economic deployment of the energy router, and optimize the network loss and power quality of the distribution network.

关键词： Capacity allocation distribution network energy router optimal operation

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

Minimum mass-entransy dissipation profile for one-way isothermal diffusive mass-transfer process with mass-resistance and massleakage

引用

Science China(Technological Sciences) 2024年第8期67卷 2427-2435页

作者： chen LinGen xia ShaoJun Institute of Thermal Science and Power Engineering Wuhan Institute of TechnologyWuhan 430205China School of Mechanical Electrical EngineeringWuhan Institute of TechnologyWuhan 430205China School of Power Engineering Naval University of EngineeringWuhan 430033China

As a new concept,mass-entransy is one of the twins in the core of entransy *** can describe mass-transfer ability for masstransfer processes(MTPes),just as thermal-entransy for describing heat-transfer ***,mass-entransy dissipation can be utilized to evaluate the loss of mass-transfer *** mass-entransy dissipation(MMED) is utilized to optimize one-way isothermal diffusive MTPes with mass-leakage and mass-transfer law(g ∝ Δ(c),where c means concentration).For a given net amount of mass-transferred key components at the low-concentration side,optimality-condition for the MMED of isothermal diffusive MTPes is obtained by using the *** of the amount of mass-transferred and mass-leakage on optimal results are analyzed,and the obtained optimization profiles are compared with those for MTP profiles of constant-concentration-difference(c_1-c_2=const) and constant-concentration-ratio(c_1/c_2=const).The product of square of key-component-concentration(KCC) difference between high-and low-concentration sides and inert component concentration at high-concentration side for the MMED of the MTP with no mass-leakage is a constant,and the optimal relationship of the KCCs between high-and low-concentration sides with mass-leakage is significantly different from the *** mass-leakage is relatively small,the MTP with c_1-c_2=const strategy is superior to that with c_1/c_2=const strategy,and the latter is superior to the former with an increase in mass-leakage.A combination of mass-entransy concept,finite-time thermodynamics,and averaged-optimization-method is a meaningful tool for optimizing MTPes.

关键词： diffusive mass-transfer-law mass-leakage one-way isothermal mass-transfer minimum mass-entransy dissipation finite-time thermodynamics averaged-optimization-method

来源：

维普期刊数据库

同方期刊数据库

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

Planning Model for Energy Routers Considering Peer-to-Peer Energy Transactions Among Multiple Distribution Networks

引用

CSEE Journal of Power and Energy Systems 2024年第3期10卷 1026-1043页

作者： Meifu chen Mingchao xia Qifang chen School of Electrical Engineering Beijing Jiaotong UniversityBeijing 100044China IEEE

A high proportion of renewable energy affects the power quality of distribution networks,and surplus energy will be sold to the upstream grid at a low *** this paper,considering peer-to-peer energy transactions,the energy router-based multiple distribution networks are analyzed to solve the above problems and realize collaborative consumption of renewable ***,the investing cost of an energy router is high,and research on the economic operation of energy routers in distribution networks is ***,this paper establishes a planning model for energy routers considering peer-to-peer energy transactions among distribution networks,and explores the benefits of peer-to-peer energy transactions through energy router based multiple distribution networks.A structure of an energy router suitable for peer-to-peer energy transactions is selected,and a power flow calculation model based on a multilayer structure is *** energy router’s scheduling model is established,and unique functions of the energy router and revenue of each distribution network are considered.A power flow calculation model based on peer-to-peer interconnection of multiple distribution networks through energy routers is also ***,simulation results verify the effectiveness of the proposed planning *** show that peer-topeer energy transaction among distribution networks through energy routers can effectively reduce the comprehensive cost of distribution networks,significantly improve the power quality of the distribution networks,and reduce the impact of power fluctuation on the upstream grid incurred by the distribution network.

关键词： Capacity allocation energy router multiple distribution networks peer-to-peer energy transaction power flow optimization

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

“Buckets effect”in the kinetics of electrocatalytic reactions

引用

Journal of Energy Chemistry 2024年第2期89卷 388-396,I0010页

作者： Haowen Cui Yan-xia chen Hefei National Laboratory for Physical Sciences at Microscale Department of Chemical PhysicsUniversity of Science and Technology of ChinaHefei 230026AnhuiChina

In this study,we systematically investigated the effect of proton concentration on the kinetics of the oxygen reduction reaction(ORR)on Pt(111)in acidic *** results demonstrate a rectangular hyperbolic relationship,i.e.,the ORR current excluding the effect of other variables increases with proton concentration and then tends to a constant *** consider that this is caused by the limitation of ORR kinetics by the trace oxygen concentration in the solution,which determines the upper limit of ORR kinetics.A model of effective concentration is further proposed for rectangular hyperbolic relationships:when the reactant concentration is high enough to reach a critical saturation concentration,the effective reactant concentration will become a constant *** could be due to the limited concentration of a certain reactant for reactions involving more than one reactant or the limited number of active sites available on the *** study provides new insights into the kinetics of electrocatalytic reactions,and it is important for the proper evaluation of catalyst activity and the study of structureperformance relationships.

关键词： Oxygen reduction reaction Kinetics Zero order Rectangular hyperbolic relationship pH effect

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

Review of reflective fiber optic sensors for surface topography measurement

引用

Journal of Measurement Science and Instrumentation 2018年第1期9卷 59-67页

作者： YANG Rui-feng HU chen-hao guo chen-xia GAI Ting LANG guo-wei School of Instrument and Electronics North University of ChinaTaiyuan 030051China Automatic Test Equipment and System Engineering Research Center of Shanxi Taiyuan 030051China

Different from the traditional contact surface topography measurement,reflective intensity-modulated fiber optic sensor(RIM-FOS)has the unique advantages of non-contact nondestructive *** paper briefly introduces the principle and performance of RIM-FOS for surface topography measurement and compares with several other methods of topography *** on the review of its development process,this paper summarizes and analyses the hot issues of RIM-FOS in the surface topography measurement,then predicts the future trend for a guidance of the further study.

关键词： reflective intensity-modulated fiber optic sensor(RIM-FOS) topography measurement probe structure interference compensation

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

Electromagnetic anisotropic homogeneous model for eddy-current field in single-phase wound core

引用

High Voltage 2024年第1期9卷 172-181页

作者： Lijun Zhou Woyang Li Yingyi xia Jiawei chen chenqingyu Zhang xiaohu Cai Lei guo Dongyang Wang School of Electrical Engineering Southwest Jiaotong UniversityChengduChina

The analysis of the eddy-current field in the wound core widely used in the field of transformer energy conservation is taken as the *** the homogenisation idea to consider the unique geometry of the wound core and features of its equivalent multi-stage circular cross-section magnetic boundary,a homogeneous model consisting of a columnar material with continuous homogeneous electromagnetic anisotropy is established by deriving the Maxwell equations of the magnetic quasi-static field in the columnar coordinate ***,a homogeneous fine element model for the eddycurrent field in the wound core is established and the accuracy of the model has been verified by the test *** result shows that the homogeneous model can be effectively used for the analysis of the eddy-current field in the wound core,and the error of calculating the eddy-current loss under different excitation conditions is less than 6%under the premise of extremely saving the engineering calculation cost,which will help improve the operational performance of the wound core and contribute to the energysaving goal of the high-voltage equipment.

关键词： anisotropic coordinate excitation

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

Emerging direct current triboelectric nanogenerator for high-entropy mechanical energy harvesting

引用

Science China(Technological Sciences) 2024年第5期67卷 1297-1316页

作者： chen Jie guo RuiLong guo HengYu College of Physics and Electronic Engineering Chongqing Normal UniversityChongqing 401331China Department of Applied Physics Chongqing UniversityChongqing 401331China

In the era of the Internet of Things(IoT),the provision of sustainable power to distributed,mobile,and low-power-consumption electronic devices is a critical *** overcome this challenge,the triboelectric nanogenerator(TENG),a highly efficient high-entropy mechanical energy harvesting device,was developed in *** device enables the direct conversion of irregular and low-frequency mechanical energy into pulsed alternating current(AC)***,the incompatibility of most electronic devices with AC signals necessitates rectifier circuits or generators that deliver direct current(DC)*** recent years,DC-TENGs have undergone extensive development,achieving significant milestones in various application fields while also facing crucial challenges that require *** this review,three categories of DC-TENG devices with distinct operating mechanisms are comprehensively explored:multiphase coupling,mechanical rectification,and air *** typical structures and working mechanisms are thoroughly discussed,and specific output performance limitations,along with corresponding optimization strategies,are ***,the applications of DC-TENGs in various scenarios are ***,the challenges faced by DC-TENGs and potential solutions are analyzed to guide further advancements in this technology.

关键词： TENG direct current working mechanisms output performance limitations optimization strategies

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：