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An invariant descriptor for conjugate forced convection-conduction cooling of 3D protruding heaters in

Thiago ANTONINI ALVES,Paulo H. D. SANTOS,Murilo A. BARBUR

《机械工程前沿（英文）》 2015年第10卷第3期页码 263-276 doi: 10.1007/s11465-015-0345-y

摘要：

In this research, the temperatures of three-dimensional (3D) protruding heaters mounted on a conductive substrate in a horizontal rectangular channel with laminar airflow are related to the independent power dissipation in each heater by using a matrix G⁺ with invariant coefficients, which are dimensionless. These coefficients are defined in this study as the conjugate influence coefficients (g⁺) caused by the forced convection-conduction nature of the heaters’ cooling process. The temperature increase of each heater in the channel is quantified to clearly identify the contributions attributed to the self-heating and power dissipation in the other heaters (both upstream and downstream). The conjugate coefficients are invariant with the heat generation rate in the array of heaters when assuming a defined geometry, invariable fluid and flow rate, and constant substrate and heater conductivities. The results are numerically obtained by considering three 3D protruding heaters on a two-dimensional (2D) array by ANSYS/Fluent^TM 15.0 software. The conservation equations are solved by a coupled procedure within a single calculation domain comprising of solid and fluid regions and by considering a steady state laminar airflow with constant properties. Some examples are shown, indicating the effects of substrate thermal conductivity and Reynolds number on conjugate influence coefficients.

关键词： channel flow conjugate forced convection-conduction cooling conjugate influence coefficients discrete heating invariant descriptor thermal management

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Immunogenicity and protective immunity against otitis media caused by pneumococcus in mice of Hib conjugate

null

《医学前沿（英文）》 2016年第10卷第4期页码 490-498 doi: 10.1007/s11684-016-0470-y

摘要：

This study evaluated the immunogenicity and protective immunity of a Hemophilus influenzae b (Hib) polysaccharide conjugate vaccine with the pneumococcal surface adhesin A (PsaA) protein carrier in young mice. The Hib polysaccharide was conjugated with the rPsaA protein carrier, which was produced using recombinant DNA technology. A total of 15 young mice aged 3 weeks to 5 weeks were immunized with the conjugate vaccine, and another 15 young mice of the same age were immunized with the licensed Hib-tetanus toxoid (TT) vaccine. Furthermore, the third group of 15 young mice was inoculated with phosphate buffer saline as control. The immunized mice were inoculated with pneumococcus in the middle ear. Results showed that IgG antibody responses against both the PsaA protein and Hib polysaccharide were observed in the Hib-PsaA group. However, no statistical difference was observed in the titer of IgG against the Hib polysaccharide between Hib-PsaA and Hib-TT groups. The elimination rate of pneumococcus and the inflammation of the middle ear showed the effectiveness of protective immunity against otitis media caused by pneumococcus. Our results suggest that the Hib polysaccharide can be successfully conjugated with rPsaA via amide condensation. This new Hib-PsaA conjugate vaccine can induce both anti-PsaA and anti-Hib immune responses in young mice and elicit effective protection against acute otitis media caused by pneumococcus.

关键词： conjugate vaccine pneumococcal surface adhesin A Hemophilus influenzae b immunogenicity otitis media

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Experimental study of aerodynamic interference effects on aerostatic coefficients of twin deck bridges

Zhiwen LIU , Zhengqing CHEN , Gao LIU , Xinpeng SHAO ,

《结构与土木工程前沿（英文）》 2009年第3卷第3期页码 292-298 doi: 10.1007/s11709-009-0048-8

摘要： The aerodynamic interference effects on aerostatic coefficients of twin deck bridges with large span were investigated in detail by means of wind tunnel test. The distances between the twin decks and wind attack angles were changed during the wind tunnel test to study the effects on aerodynamic interferences of aerostatic coefficients of twin decks. The research results have shown that the drag coefficients of the leeward deck are much smaller than that of a single leeward deck. The drag coefficients of a windward deck decrease slightly compared with that of a single deck. The lift and torque coefficients of windward and leeward decks are also affected slightly by the aerodynamic interference of twin decks. And the aerodynamic interference effects on lift and torque coefficients of twin decks can be neglected.

关键词： twin decks aerodynamic interference effects aerostatic coefficients wind tunnel test

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Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gases

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

《能源前沿（英文）》 2014年第8卷第1期页码 41-48 doi: 10.1007/s11708-013-0292-4

摘要： Narrow-band transmissivities in the spectral range of 150 to 9300 cm and at a uniform resolution of 25 cm were calculated using the statistical narrow-band (SNB) model with the band parameters of Soufiani and Taine, the more recent parameters of André and Vaillon, and the line-by-line (LBL) method along with the HITEMP-2010 spectroscopic database. Calculations of narrow-band transmissivity were conducted for gas columns of different lengths and containing different isothermal and non-isothermal CO -H O-N mixtures at 1 atm. Narrow-band transmissivities calculated by the SNB model are in large relative error at many bands. The more recent SNB model parameters of André and Vaillon are more accurate than the earlier parameters of Soufiani and Taine. The Planck mean absorption coefficients of CO , H O, CO, and CH in the temperature range of 300 to 2500 K were calculated using the LBL method and different versions of the high resolution transmission (HITRAN) and high-temperature spectroscopic absorption parameters (HITEMP) spectroscopic databases. The SNB model was also used to calculate the Planck mean absorption coefficients of these four radiating gases. The LBL results of the Planck mean absorption coefficient were compared with the classical results of Tien and those from the SNB model.

关键词： transimissity HITEMP HITRAN Planck mean absorption coefficients

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微分和表观静摩擦系数的表式

王渭源

《中国工程科学》 2001年第3卷第8期页码 29-32

摘要：

当前，工程师和科学家都对微牛和纳牛量级载荷静摩擦系数（以下简称微牛纳牛静摩擦系数）很感兴趣。但文献中至今没有详细讨论过微牛纳牛静摩擦系数与载荷的关系，而且发表的实验结果都不相互讨论。从微分静摩擦系数的定义出发，导出几种典型模型下微分静摩擦系数和表观静摩擦系数的表式，并据此广泛讨论这些文献中的实验结果。

关键词：微分静摩擦系数微牛纳牛静摩擦系数表观静摩擦系数宏观静摩擦系数

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干旱和复水对冬小麦光合产物分配格局的影响

谷艳芳,丁圣彦,高志英,邢倩

《中国工程科学》 2012年第14卷第3期页码 59-64

摘要：

于2005—2006年在中国科学院封丘农田生态实验站研究了不同水分处理下冬小麦光合产物分配格局及其动态。实验设全生育期干旱处理和充分供水处理以及干旱后拔节期、孕穗期、开花期复水处理。结果显示：不同生育期复水对冬小麦由于干旱胁迫引起的生物量下降有补偿作用；干旱和复水能改变器官水平上光合产物的分配格局；干旱胁迫引起叶、穗分配降低，并使茎、叶鞘和根分配指数上升；拔节期复水使叶光合产物分配指数增加、茎分配指数下降；孕穗期和开花期复水能提高光合产物在茎和穗中的分配；不同时期复水对干旱胁迫引起的产量下降均有不同程度的补偿作用，拔节期复水主要提高小麦单株穗数、孕穗期和开花期复水以提高千粒重为主。

关键词：光合产物分配指数可溶性糖冬小麦干旱和复水

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Measurement of activity coefficients at infinite dilution for hydrocarbons in imidazolium-based ionic

ZHU Jiqin, YU Yanmei, CHEN Jian, FEI Weiyang

《化学科学与工程前沿（英文）》 2007年第1卷第2期页码 190-194 doi: 10.1007/s11705-007-0035-3

摘要： The separations of olefin/paraffin, aromatic/aliphatic hydrocarbons or olefin isomers using ionic liquids instead of volatile solvents have interested many researchers. Activity coefficients γ at infinite dilution of a solute in ionic liquid are generally used in the selection of solvents for extraction or extractive distillation. In fact, the measurement of γ by gas-liquid chromatography is a speedy and cost-saving method. Activity coefficients at infinite dilution of hydrocarbon solutes, such as alkanes, hexenes, alkylbenzenes, styrene, in 1-allyl-3-methylimidazolium tetrafluoroborate ([AMIM][BF]) and 1-butyl-3-methyl imidazolium hexafluorophosphate ([BMIM][PF6]), 1-isobutenyl-3-methylimidazolium tetrafluoroborate ([MPMIM][BF]) and [MPMIM][BF]-AgBF have been determined by gas-liquid chromatography using ionic liquids as stationary phase. The measurements were carried out at different temperatures from 298 to 318 K. The separating effects of these ionic liquids for alkanes/hexane, aliphatic hydrocarbons/benzene and hexene isomers have been discussed. The hydrophobic parameter, dipole element, frontier molecular orbital energy gap and hydration energy of these hydrocarbons were calculated with the PM3 semi-empirical quantum chemistry method. The quantitative relations among the computed structure parameters and activity coefficients at infinite dilution were also developed. The experimental activity coefficient data are consistent with the correlated and predicted results using QSPR models.

关键词： cost-saving consistent coefficient measurement separating

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Effect of friction coefficients on the dynamic response of gear systems

Lingli JIANG, Zhenyong DENG, Fengshou GU, Andrew D. BALL, Xuejun LI

《机械工程前沿（英文）》 2017年第12卷第3期页码 397-405 doi: 10.1007/s11465-017-0415-4

摘要：

The inevitable deterioration of the lubrication conditions in a gearbox in service can change the tribological properties of the meshing teeth. In turn, such changes can significantly affect the dynamic responses and running status of gear systems. This paper investigates such an effect by utilizing virtual prototype technology to model and simulate the dynamics of a wind turbine gearbox system. The change in the lubrication conditions is modeled by the changes in the friction coefficients, thereby indicating that poor lubrication causes not only increased frictional losses but also significant changes in the dynamic responses. These results are further demonstrated by the mean and root mean square values calculated by the simulated responses under different friction coefficients. In addition, the spectrum exhibits significant changes in the first, second, and third harmonics of the meshing components. The findings and simulation method of this study provide theoretical bases for the development of accurate diagnostic techniques.

关键词： dynamic response friction coefficient wind loads wind turbine gearbox

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Smart model for accurate estimation of solar radiation

Lazhar ACHOUR, Malek BOUHARKAT, Ouarda ASSAS, Omar BEHAR

《能源前沿（英文）》 2020年第14卷第2期页码 383-399 doi: 10.1007/s11708-017-0505-3

摘要： Prediction of solar radiation has drawn increasing attention in the recent years. This is because of the lack of solar radiation measurement stations. In the present work, 14 solar radiation models have been used to assess monthly global solar radiation on a horizontal surface as function of three parameters: extraterrestrial solar irradiance ( ), duration sunshine ( ) and daylight hours ( ). Since it has been observed that each model is adequate for some months of the year, one model cannot be used for the prediction of the whole year. Therefore, a smart hybrid system is proposed which selects, based on the intelligent rules, the most suitable prediction model of the 14 models listed in this study. For the test and evaluation of the proposed models, Tamanrasset city, which is located in the south of Algeria, is selected for this study. The meteorological data sets of five years (2000–2004) have been collected from the Algerian National Office of Meteorology (NOM), and two spatial databases. The results indicate that the new hybrid model is capable of predicting the monthly global solar radiation, which offers an excellent measuring accuracy of values ranging from 93% to 97% in this location.

关键词： global solar radiation statistical indicator hybrid model spatial database correlation coefficients

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Invading target cells: multifunctional polymer conjugates as therapeutic nucleic acid carriers

Ulrich L?CHELT, Ernst WAGNER

《化学科学与工程前沿（英文）》 2011年第5卷第3期页码 275-286 doi: 10.1007/s11705-011-1203-z

摘要： Polymer-based conjugates are an interesting option and challenge for the design of nano-sized drug-delivery systems, as they require advanced conjugation chemistry and precise engineering. In the case of nucleic acid therapy, non-viral carriers face several biological barriers during the delivery process, namely 1) protection of the cargo from extracellular degradation, 2) avoidance of non-specific interactions with non-targeted tissues, 3) efficient entry into the target cells, 4) intracellular trafficking to the site of action and 5) cargo release. To take on these obstacles, multifunctional conjugates can act as “smart polymers” with microenvironment-sensing dynamics to facilitate the separate delivery steps. Synthesis of defined polymer architectures with precise functionalization enables structure-activity relationships to be investigated and the integration of key functions for efficient delivery. Thus bioresponsive polymer conjugates, which are equipped with molecular devices responding to the certain microenvironments within the delivery pathway (e.g. pH, redox potential, enzymes) can be assembled. This review focuses on the modular engineering and conjugation of multifunctional polymeric structures for the utilization as “tailor-made” nucleic acid carriers.

关键词： conjugate DNA gene transfer polymer RNA targeting

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Identifying spreading influence nodes for social networks

《工程管理前沿（英文）》页码 520-549 doi: 10.1007/s42524-022-0190-8

摘要： The identification of spreading influence nodes in social networks, which studies how to detect important individuals in human society, has attracted increasing attention from physical and computer science, social science and economics communities. The identification algorithms of spreading influence nodes can be used to evaluate the spreading influence, describe the node’s position, and identify interaction centralities. This review summarizes the recent progress about the identification algorithms of spreading influence nodes from the viewpoint of social networks, emphasizing the contributions from physical perspectives and approaches, including the microstructure-based algorithms, community structure-based algorithms, macrostructure-based algorithms, and machine learning-based algorithms. We introduce diffusion models and performance evaluation metrics, and outline future challenges of the identification of spreading influence nodes.

关键词： complex network network science spreading influence machine learning

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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

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Wind tunnel test study on the wind pressure coefficient of claddings of high-rise buildings

Yong QUAN, Yi LIANG, Fei WANG, Ming GU

《结构与土木工程前沿（英文）》 2011年第5卷第4期页码 518-524 doi: 10.1007/s11709-011-0128-4

摘要： The area-averaged most unfavorable wind pressure coefficients (MUWPCs) on various regions of building surfaces and the influence of the side ratio and the terrain category were studied based on wind tunnel test data of scale models of typical high-rise buildings with rectangular cross-sections. The negative area-averaged MUWPCs in the middle-height edge areas generally increased with an increasing / side ratio. The area-averaged MUWPCs can be well fitted with a function of the average area reduced by the square of the building depth, . In addition, no unique pattern was found for the effect of the terrain category on the MUWPCs.

关键词： side ratio area-averaged pressure coefficients cladding terrain category

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社会影响力分析——模型、方法和评价 Review

李侃, 张林, 黄河燕

《工程（英文）》 2018年第4卷第1期页码 40-46 doi: 10.1016/j.eng.2018.02.004

摘要：

社会影响力分析（SIA）是一个广泛的研究领域，吸引了诸多研究者的兴趣。本文总结了SIA 相关的模型、方法和评价方面代表性的工作，并将SIA 模型归纳为两种类型：微观模型和宏观模型。微观模型考虑人与人之间的相互影响和影响的过程，而宏观模型认为每个人具有相同的传播概率和影响力。本文分析了包括影响最大化、影响最小化、影响流和个人影响力等的社会影响力分析方法；介绍了影响力评价指标，并分析了社会影响力评价模型。本文的目标是对社会影响力提供全面的分析，旨在辅助理解社会行为，为舆论影响提供理论基础，并揭示未来的研究方向和潜在的应用。

关键词：社会影响力分析在线社交网络社会影响力分析模型影响力评价

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Numerical investigation of the effectiveness of effusion cooling for plane multi-layer systems with different base-materials

Dieter BOHN, Robert KREWINKEL

《能源前沿（英文）》 2009年第3卷第4期页码 406-413 doi: 10.1007/s11708-009-0041-x

摘要： Within Collaborative Research Center (SFB) 561 “Thermally Highly Loaded, Porous and Cooled Multi-Layer Systems for Combined Cycle Power Plants” at RWTH Aachen University, an effusion-cooled multi-layer plate configuration is investigated numerically by the application of a three-dimensional in-house fluid flow and heat transfer solver, CHTflow. CHTflow is a conjugate code, which yields information on the temperature distribution in the solid body. This enables a detailed discussion of the effects of a change in materials. The geometrical set-up and the fluid flow conditions derive from modern gas turbine combustion chambers and bladings. Within the SFB, two different multi-layer systems, one consisting of substrate made of CMSX-4 (a single-crystal super-alloy), an MCrAlY-bondoat and a ZrO thermal barrier coating (TBC), and the other consisting of a NiAl-alloy and a graded bondcoat/TBC, have been investigated. The grading will increase the life-span of the TBC as it can better compensate the different thermal expansion coefficients of different materials. The main focus in this study is on the different substrate materials, because the thermal conductivity of the NiAl is considerably higher than that of CMSX-4, which leads to different temperature profiles in the components. The numerical grid for the simulations contains the coolant supply (plenum), the solid body for the conjugate calculations, and the main flow area on the plate. The effusion-cooling is realized by finest drilled shaped holes with a diameter of 0.2mm. The investigation is concentrated on a cooling hole geometry with a laterally widened fan-shaped outlet, contoured throughout, and one without lateral widening that is only shaped in the TBC-region of the system. Two blowing ratios, =0.28 and =0.48, are investigated, both for a hot gas Mach number of 0.25. The results for the lower blowing ratio and the fully contoured hole are discussed as well as those of the higher blowing ratio and the non-laterally widened hole. These represent two characteristic cases.

关键词： conjugate calculation effectiveness of effusion cooling multi-layer systems CMSX-4 NiAl-FG75