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Yellow fever and Hajj: with all eyes on Zika, a familiar flavivirus remains a threat

null

《医学前沿(英文)》 2016年 第10卷 第4期   页码 527-530 doi: 10.1007/s11684-016-0487-2

摘要:

Hajj is among the world’s largest mass gatherings, drawing between 2 and 3.5 million Muslims from 183 nations annually to perform pilgrimage in Mecca, Saudi Arabia. Infectious disease outbreaks can be imported both into the Hajj population and exported internationally by returning pilgrims. The domestic Saudi population can also be at risk of outbreaks traveling amid this mass migration. With yellow fever reported for the first time in China following the infection of expatriate Chinese workers in Angola and a full blown outbreak underway in wider West Africa, the prospect of yellow fever outbreaks in Asia threatens to impact Saudi Arabia, both during and beyond the Hajj season. With global focus trained on Zika, the rising threat of yellow fever cannot be overlooked. Strategies to mitigate risk to Saudi Arabia and the global population are thereby suggested.

关键词: yellow fever     mass gathering     Saudi Arabia     Hajj     Zika virus    

Heterogeneous influence of individuals’ behavior on mask efficacy in gathering environments

《工程管理前沿(英文)》   页码 550-562 doi: 10.1007/s42524-022-0193-5

摘要: Wearing masks is an easy way to operate and popular measure for preventing epidemics. Although masks can slow down the spread of viruses, their efficacy in gathering environments involving heterogeneous person-to-person contacts remains unknown. Therefore, we aim to investigate the epidemic prevention effect of masks in different real-life gathering environments. This study uses four real interpersonal contact datasets to construct four empirical networks to represent four gathering environments. The transmission of COVID-19 is simulated using the Monte Carlo simulation method. The heterogeneity of individuals can cause mask efficacy in a specific gathering environment to be different from the baseline efficacy in general society. Furthermore, the heterogeneity of gathering environments causes the epidemic prevention effect of masks to differ. Wearing masks can greatly reduce the probability of clustered epidemics and the infection scale in primary schools, high schools, and hospitals. However, the use of masks alone in primary schools and hospitals cannot control outbreaks. In high schools with social distancing between classes and in workplaces where the interpersonal contact is relatively sparse, masks can meet the need for prevention. Given the heterogeneity of individual behavior, if individuals who are more active in terms of interpersonal contact are prioritized for mask-wearing, the epidemic prevention effect of masks can be improved. Finally, asymptomatic infection has varying effects on the prevention effect of masks in different environments. The effect can be weakened or eliminated by increasing the usage rate of masks in high schools and workplaces. However, the effect on primary schools and hospitals cannot be weakened. This study contributes to the accurate evaluation of mask efficacy in various gathering environments to provide scientific guidance for epidemic prevention.

关键词: COVID-19     masks     behavioral heterogeneity     asymptomatic infection    

普光气田集输系统安全设计理念与认识

李时杰,范承武,聂仕荣

《中国工程科学》 2010年 第12卷 第10期   页码 65-69

摘要:

实践证明,普光集输设计具有创新性,工艺路线、总体布局、安全设计、应急防范与救援支持系统先进、合理、可行,特别是控制与安全仪表系统的设计与配置运行率高,总体是可控、有效的。安全设计理念在以下6个关键问题上得到有效实施:先进的集输工艺;合理的材料设备选择;完备的自控与监测技术;应急反应预案与紧急疏散广播;腐蚀控制与监测技术;智能清管技术与普通清管操作。普光集输设计项目实现了国内一流、国际领先的目标,可为国内其他同类项目提供借鉴。

关键词: 普光气田     集输系统     设计理念    

Information gathering and processing with fluorescent molecules

Brian DALY,Jue LING,A. Prasanna de SILVA

《化学科学与工程前沿(英文)》 2014年 第8卷 第2期   页码 240-251 doi: 10.1007/s11705-014-1432-z

摘要: Molecular information gathering and processing — a young field of applied chemistry — is undergoing good growth. The progress is occurring both in terms of conceptual development and in terms of the strengthening of older concepts with new examples. This review critically surveys these two broad avenues. We consider some cases where molecules emulate one of the building blocks of electronic logic gates. We then examine molecular emulation of various Boolean logic gates carrying one, two or three inputs. Some single-input gates are popular information gathering devices. Special systems, such as ‘lab-on-a-molecule’ and molecular keypad locks, also receive attention. A situation deviating from the Boolean blueprint is also discussed. Some pointers are offered for maintaining the upward curve of the field.

关键词: molecular logic     molecular computation     molecular sensor     fluorescent molecular device     fluorescent sensor    

从大连输油管爆炸反思油气设备驱动方式——非能动控制驱动对油气储运的特殊意义

曾祥炜,陈崑,邱小平,曾小舸,向北平,臧红彬,石磊,龚伟

《中国工程科学》 2010年 第12卷 第9期   页码 34-38

摘要:

通过分析大连输油管爆炸,对当今国内外油气储运设备驱动方式进行反思。提出非能动控制原理和方法,阐述非能动控制梭式核心元件的结构和原理;对非能动梭式控制管道爆破保护系统、巨型油罐梭式消防止回阀进行分析,得出非能动控制驱动对油气储运具有特殊意义。

关键词: 非能动     控制     油气储运     泄漏    

Thermo-fluidic devices and materials inspired from mass and energy transport phenomena in biological

Jian XIAO , Jing LIU ,

《能源前沿(英文)》 2009年 第3卷 第1期   页码 47-59 doi: 10.1007/s11708-008-0068-4

摘要: Mass and energy transport consists of one of the most significant physiological processes in nature, which guarantees many amazing biological phenomena and activities. Borrowing such idea, many state-of-the-art thermo-fluidic devices and materials such as artificial kidneys, carrier erythrocyte, blood substitutes and so on have been successfully invented. Besides, new emerging technologies are still being developed. This paper is dedicated to presenting a relatively complete review of the typical devices and materials in clinical use inspired by biological mass and energy transport mechanisms. Particularly, these artificial thermo-fluidic devices and materials will be categorized into organ transplantation, drug delivery, nutrient transport, micro operation, and power supply. Potential approaches for innovating conventional technologies were discussed, corresponding biological phenomena and physical mechanisms were interpreted, future promising mass-and-energy-transport-based bionic devices were suggested, and prospects along this direction were pointed out. It is expected that many artificial devices based on biological mass and energy transport principle will appear to better improve various fields related to human life in the near future.

关键词: bionics     mass transport     energy transport     artificial devices and materials     biology system     nature phenomena     medical device.    

Convective mass transfer from a horizontal rotating cylinder in a slot air jet flow

Hongting MA , Dandan MA , Na YANG ,

《能源前沿(英文)》 2009年 第3卷 第3期   页码 289-296 doi: 10.1007/s11708-009-0019-8

摘要: The effects of air jet impinging on the mass transfer characteristics from a rotating spinning cylinder surface were experimentally investigated. The effects of rotational Reynolds number

关键词: air jet impinging     rotating cylinder     critical point     mass transfer characteristics    

Parametric control of structural responses using an optimal passive tuned mass damper under stationary

Min-Ho CHEY, Jae-Ung KIM

《结构与土木工程前沿(英文)》 2012年 第6卷 第3期   页码 267-280 doi: 10.1007/s11709-012-0170-x

摘要: In this study, the structural control strategy utilizing a passive tuned mass damper (TMD) system as a seismic damping device is outlined, highlighting the parametric optimization approach for displacement and acceleration control. The theory of stationary random processes and complex frequency response functions are explained and adopted. For the vibration control of an undamped structure, the optimal parameters of a TMD, such as the optimal tuning frequency and optimal damping ratio, to stationary Gaussian white noise acceleration are investigated by using a parametric optimization procedure. For damped structures, a numerical searching technique is used to obtain the optimal parameters of the TMD, and then the explicit formulae for these optimal parameters are derived through a sequence of curve-fitting schemes. Using these specified optimal parameters, several different controlled responses are examined, and then the displacement and acceleration based control effectiveness indices of the TMD are examined from the view point of RMS values. From the viewpoint of the RMS values of displacement and acceleration, the optimal TMDs adopted in this study shows clear performance improvements for the simplified model examined, and this means that the effective optimization of the TMD has a good potential as a customized target response-based structural strategy.

关键词: tuned mass damper     parametric optimization     passive control     white noise     earthquake excitation    

Numerical modeling of mass transfer processes coupling with reaction for the design of the ozone oxidation

Hong Li, Fang Yi, Xingang Li, Xin Gao

《化学科学与工程前沿(英文)》 2021年 第15卷 第3期   页码 602-614 doi: 10.1007/s11705-020-1963-4

摘要: A computational model for an ozone oxidation column reactor used in dyeing wastewater treatment is proposed to represent, simulate, and predict the ozone bubble process. Considering the hydrodynamics, mass transfer, and ozone oxidation reaction, coupling modeling can more realistically calculate the ozone oxidation bubble process than the splitting methods proposed in previous research. The modeling is validated and shows great consistency with experimental data. The verified model is used to analyze the effect of operating conditions, such as the initial gas velocity and the ozone concentration, and structural conditions, such as multiple gas inlets. The ozone consumption is influenced by the gas velocity and the initial ozone concentration. The ozone’s utilization decreases with the increasing gas velocity while nearly the same at different initial ozone concentrations. Simulation results can be used in guiding the practical operation of dyeing wastewater treatment and in other ozonation systems with known rate constants in wastewater treatment.

关键词: ozone     wastewater treatment     numerical simulation     mass transfer    

Simulation of blast induced crater in jointed rock mass by discontinuous deformation analysis method

Youjun NING, Xinmei AN, Jun YANG, Guowei MA,

《结构与土木工程前沿(英文)》 2010年 第4卷 第2期   页码 223-232 doi: 10.1007/s11709-010-0022-5

摘要: Rock blasting is a dynamic process accompanied with the propagations of shock waves and the dispersion of the explosion gas. This paper adopts the discontinuous deformation analysis (DDA) method to simulate the rock blasting process. A dynamic parameter adjustment and the non-reflecting boundary condition are implemented in the DDA method. The sub-block DDA method to simulate fracture problems is used. The blasting process in jointed rock mass is simulated by application of the explosion gas pressure on the expanding borehole walls and induced connected fracture surfaces around the boreholes. The blast craters with different overburdens are derived. The whole process including the explosion gas dispersion, borehole expansion, rock mass failure and cast, and the formation of the final blasting piles in rock blasting are well reproduced numerically. Parametric study for different overburdens is carried out, and the results are analyzed and discussed.

关键词: blast crater     jointed rock mass     explosion gas pressure     discontinuous deformation analysis (DDA) method    

Factors influencing peak bone mass gain

Xiaowei Zhu, Houfeng Zheng

《医学前沿(英文)》 2021年 第15卷 第1期   页码 53-69 doi: 10.1007/s11684-020-0748-y

摘要: Bone mass is a key determinant of osteoporosis and fragility fractures. Epidemiologic studies have shown that a 10% increase in peak bone mass (PBM) at the population level reduces the risk of fracture later in life by 50%. Low PBM is possibly due to the bone loss caused by various conditions or processes that occur during adolescence and young adulthood. Race, gender, and family history (genetics) are responsible for the majority of PBM, but other factors, such as physical activity, calcium and vitamin D intake, weight, smoking and alcohol consumption, socioeconomic status, age at menarche, and other secondary causes (diseases and medications), play important roles in PBM gain during childhood and adolescence. Hence, the optimization of lifestyle factors that affect PBM and bone strength is an important strategy to maximize PBM among adolescents and young people, and thus to reduce the low bone mass or osteoporosis risk in later life. This review aims to summarize the available evidence for the common but important factors that influence bone mass gain during growth and development and discuss the advances of developing high PBM.

关键词: peak bone mass     children     adolescents     genetic     risk factors    

The role of single deformed bubble on porous foam tray with submerged orifices on the mass transfer enhancement

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 2127-2143 doi: 10.1007/s11705-023-2363-3

摘要: Foam trays with porous submerged orifices endow bubbles uniformly distributed, which are considered attractive column internals to enhance the gas-liquid mass transfer process. However, its irregular orifice and complex gas-liquid flow make it lack pore-scale investigations concerning the transfer mechanism of dynamic bubbling. In this work, the actual porous structure of the foam tray is obtained based on micro computed tomography technology. The shape, dynamic, and mass transfer of rising bubbles at porous orifices are investigated using the volume of fluid and continue surface force model. The results demonstrate that the liquid encroaching on the gas channels causes the increasing orifices velocity, which makes the trailing bubble easily detach from the midst of the leading bubble and causes pairing coalescence. Additionally, we found that the central breakup regimes significantly improve the gas-liquid interface area and mass transfer efficiency. This discovery exemplifies the mechanism of mass transfer intensification for foam trays and serves to promote its further development.

关键词: bubble formation     porous submerged orifices     process intensification     foam tray    

Heat, mass, and work exchange networks

Zhiyou CHEN, Jingtao WANG

《化学科学与工程前沿(英文)》 2012年 第6卷 第4期   页码 484-502 doi: 10.1007/s11705-012-1221-5

摘要: Heat (energy), water (mass), and work (pressure) are the most fundamental utilities for operation units in chemical plants. To reduce energy consumption and diminish environment hazards, various integration methods have been developed. The application of heat exchange networks (HENs), mass exchange networks (MENs), water allocation heat exchange networks (WAHENs) and work exchange networks (WENs) have resulted in the significant saving of energy and water. This review presents the main works related to each network. The similarities and differences of these networks are also discussed. Through comparing and discussing these different networks, this review inspires researchers to propose more efficient and convenient methods for the design of existing exchange networks and even new types of networks including multi-objective networks for the system integration in order to enhance the optimization and controllability of processes.

关键词: process system engineering     integration methods     heat exchange network     mass exchange network     work exchange network    

Detection of geosmin and 2-methylisoborneol by liquid-liquid extraction-gas chromatograph mass spectrum(LLE-GCMS) and solid phase extraction-gas chromatograph mass spectrum (SPE-GCMS)

MA Xiaoyan, CHEN Beibei, LI Qingsong, ZHANG Qiaoli, GU Guofen

《环境科学与工程前沿(英文)》 2007年 第1卷 第3期   页码 286-291 doi: 10.1007/s11783-007-0048-7

摘要: Two sample preparation methods were introduced and compared in this paper to establish a simple, quick and exact analysis of geosmin and 2-methylisoborneol. LC-18 column was employed in solid phase extraction (SPE), 1.0 mL of hexane was adopted in liquid-liquid extraction (LLE), and the extracts were analyzed by gas chromatograph mass spectrum (GCMS) in selected ion mode. Mean recoveries of SPE were low for 2-methylisoborneol (2-MIB) and geosmin (GSM) with values below 50%. For LLE, the recoveries were satisfyingly above 50% for 2-MIB and 80% for GSM. Detection limits of the LLE method were as low as 1.0 ng/L for GSM and 5.0 ng/L for 2-MIB. A year-long investigation on odor chemicals of drinking water in Shanghai demonstrated that in the summer, there was a serious odor problem induced by a high concentration of 2-MIB. The highest concentration of 152.82 ng/L appeared in July in raw water, while GSM flocculation was minimal with concentrations below odor threshold.

关键词: summer     flocculation     simple     Shanghai     spectrum    

Mass and heat balance calculations and economic evaluation of an innovative biomass pyrolysis project

Quanyuan WEI, Yongshui QU, Tianwei TAN

《化学科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 355-361 doi: 10.1007/s11705-010-0567-9

摘要: Biomass can be converted into flammable gas, charcoal, wood vinegar, wood tar oil and noncombustible materials with thermo-chemical pyrolysis reactions. Many factors influence these processes, such as the properties of the raw materials, and temperature control and these will affect the products that are produced. Based on the data from a straw pyrolysis demonstration project, the mass and heat balance of the biomass pyrolysis process were analyzed. The statistical product and service solutions (SPSS) statistical method was used to analyze the data which were monitored on-site. A cost-benefit analysis was then used to study the viability of commercializing the project. The analysis included net present value, internal rate of return and investment payback period. These results showed that the straw pyrolysis project has little risk, and will produce remarkable economic benefits.

关键词: mass balance     heat balance     biomass pyrolysis     economic benefit    

标题 作者 时间 类型 操作

Yellow fever and Hajj: with all eyes on Zika, a familiar flavivirus remains a threat

null

期刊论文

Heterogeneous influence of individuals’ behavior on mask efficacy in gathering environments

期刊论文

普光气田集输系统安全设计理念与认识

李时杰,范承武,聂仕荣

期刊论文

Information gathering and processing with fluorescent molecules

Brian DALY,Jue LING,A. Prasanna de SILVA

期刊论文

从大连输油管爆炸反思油气设备驱动方式——非能动控制驱动对油气储运的特殊意义

曾祥炜,陈崑,邱小平,曾小舸,向北平,臧红彬,石磊,龚伟

期刊论文

Thermo-fluidic devices and materials inspired from mass and energy transport phenomena in biological

Jian XIAO , Jing LIU ,

期刊论文

Convective mass transfer from a horizontal rotating cylinder in a slot air jet flow

Hongting MA , Dandan MA , Na YANG ,

期刊论文

Parametric control of structural responses using an optimal passive tuned mass damper under stationary

Min-Ho CHEY, Jae-Ung KIM

期刊论文

Numerical modeling of mass transfer processes coupling with reaction for the design of the ozone oxidation

Hong Li, Fang Yi, Xingang Li, Xin Gao

期刊论文

Simulation of blast induced crater in jointed rock mass by discontinuous deformation analysis method

Youjun NING, Xinmei AN, Jun YANG, Guowei MA,

期刊论文

Factors influencing peak bone mass gain

Xiaowei Zhu, Houfeng Zheng

期刊论文

The role of single deformed bubble on porous foam tray with submerged orifices on the mass transfer enhancement

期刊论文

Heat, mass, and work exchange networks

Zhiyou CHEN, Jingtao WANG

期刊论文

Detection of geosmin and 2-methylisoborneol by liquid-liquid extraction-gas chromatograph mass spectrum(LLE-GCMS) and solid phase extraction-gas chromatograph mass spectrum (SPE-GCMS)

MA Xiaoyan, CHEN Beibei, LI Qingsong, ZHANG Qiaoli, GU Guofen

期刊论文

Mass and heat balance calculations and economic evaluation of an innovative biomass pyrolysis project

Quanyuan WEI, Yongshui QU, Tianwei TAN

期刊论文