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Vibration testing of a steel girder bridge using cabled and wireless sensors

Dapeng ZHU, Yang WANG, James BROWNJOHN

《结构与土木工程前沿（英文）》 2011年第5卷第3期页码 249-258 doi: 10.1007/s11709-011-0113-y

摘要： Being able to significantly reduce system installation time and cost, wireless sensing technology has attracted much interest in the structural health monitoring (SHM) community. This paper reports the field application of a wireless sensing system on a 4-span highway bridge located in Wayne, New Jersey in the US. Bridge vibration due to traffic and ambient excitation is measured. To enhance the signal-to-noise ratio, a low-noise high-gain signal conditioning module is developed for the wireless sensing system. Nineteen wireless and nineteen cabled accelerometers are first installed along the sidewalk of two neighboring bridge spans. The performance of the wireless sensing system is compared with the high-precision cabled sensing system. In the next series of testing, 16 wireless accelerometers are installed under the deck of another bridge span, forming a 4 × 4 array. Operating deflection analysis is successfully conducted using the wireless measurement of traffic and ambient vibrations.

关键词： wireless sensing structural health monitoring (SHM) signal conditioning operating deflection analysis ambient vibration

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Investigation on regeneration and energy storage characteristics of a solar liquid desiccant air-conditioning

SHI Mingheng, DU Bin, ZHAO Yun

《能源前沿（英文）》 2007年第1卷第1期页码 85-90 doi: 10.1007/s11708-007-0008-8

摘要： Solar liquid desiccant air-conditioner is a new air-conditioning system in which liquid desiccant can be regenerated by solar energy and energy can be stored in the form of chemical energy in the liquid desiccant. In this paper regeneration and energy storage characteristics were studied theoretically and experimentally. Two criterion equations for heat and mass transfer in the regeneration process were obtained. The main factors that influence the regeneration process were analyzed. A principal solar liquid desiccant air-conditioning system under energy storage operating mode is proposed.

关键词： desiccant air-conditioning regeneration process air-conditioning system energy regeneration

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New developments in mobile air conditioning systems in China

Jiangping CHEN, Yu ZHAO, Zhaogang QI

《能源前沿（英文）》 2011年第5卷第1期页码 53-58 doi: 10.1007/s11708-010-0137-3

摘要： Global warming poses serious global concerns, and the mobile air conditioning (MAC) industry must be promoted to reduce greenhouse gas emissions. In this paper, the development of the MAC system and components for new energy vehicles, low global warming potential (GWP) refrigerants, methods to control refrigerant leakage, and new energy-saving technologies in China are introduced.

关键词： global warming potential mobile air conditioning (MAC) energy saving new developments

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Experimental investigation on desiccant air-conditioning system in India

Vijay MITTAL, B. Kant KHAN,

《能源前沿（英文）》 2010年第4卷第2期页码 161-165 doi: 10.1007/s11708-009-0070-5

摘要： An experimental investigation in India was presented to evaluate the performance and energy saving capacity of a desiccant air-conditioning system composed of a silica gel bed, a split type air-conditioner (1.0 ton refrigeration) installed in a room with a volume of 86.4 m, air ducts and a blower. The experiment was made in such a way that the percentages of return air, outdoor air and indoor air mixed with the air leaving the desiccant and desiccant bed thickness could be adjusted. Tests were conducted on several days with relatively similar ambient conditions. Under the test conditions in this experiment, a 7cm bed thickness is recommended with a maximum adsorption rate of 403g/h. The optimum percentages of air ratios were as follows: 10% of outdoor air, 10% of return air (mixed together at the desiccant bed inlet) and 80% of indoor air mixed with the dry air leaving the desiccant. The corresponding electricity saving was about 19%. As expected, simple economic analysis indicates that the desiccant air-conditioning is not viable for smaller cooling capacities.

关键词： air ratios ambient conditions desiccant air-conditioning silica gel

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Interactions between remote ischemic conditioning and post-stroke sleep regulation

《医学前沿（英文）》 2021年第15卷第6期页码 867-876 doi: 10.1007/s11684-021-0887-9

摘要： Sleep disturbances are common in patients with stroke, and sleep quality has a critical role in the onset and outcome of stroke. Poor sleep exacerbates neurological injury, impedes nerve regeneration, and elicits serious complications. Thus, exploring a therapy suitable for patients with stroke and sleep disturbances is imperative. As a multi-targeted nonpharmacological intervention, remote ischemic conditioning can reduce the ischemic size of the brain, improve the functional outcome of stroke, and increase sleep duration. Preclinical/clinical evidence showed that this method can inhibit the inflammatory response, mediate the signal transductions of adenosine, activate the efferents of the vagal nerve, and reset the circadian clocks, all of which are involved in sleep regulation. In particular, cytokines tumor necrosis factor α (TNFα) and adenosine are sleep factors, and electrical vagal nerve stimulation can improve insomnia. On the basis of the common mechanisms of remote ischemic conditioning and sleep regulation, a causal relationship was proposed between remote ischemic conditioning and post-stroke sleep quality.

关键词： remote ischemic conditioning sleep regulation stroke

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Research progress in liquid desiccant air-conditioning devices and systems

Xiaohua LIU, Yi JIANG, Shuanqiang LIU, Xiaoyang CHEN,

《能源前沿（英文）》 2010年第4卷第1期页码 55-65 doi: 10.1007/s11708-009-0082-1

摘要： The developments on liquid desiccant air-conditioning systems were illustrated and summarized in this paper. In order to obtain a better dehumidification (or humidification) performance, liquid desiccant should be cooled (or heated) rather than air. Two fundamental modules were proposed, including basic spray module with extra heat exchanger and total heat recovery device, which could be combined to set up various kinds of liquid desiccant air processors. The operating principle of heat pump-driven outdoor air processor as well as heat-driven outdoor air processor was analyzed. The COP of the heat pump (or power)-driven outdoor air processor could be as high as 5.0 both in summer and in winter operating conditions. The COP of the hot water-driven processor (65°C–80°C) was 1.19 and 0.93, respectively, using evaporative indoor exhaust air or cooling water to cool the dehumidification process. The liquid desiccant air processor-based temperature and humidity-independent control air-conditioning system could save 20%–30% operating energy compared with the conventional air-conditioning system.

关键词： liquid desiccant heat and mass transfer performance air-conditioning

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Engine-driven hybrid air-conditioning system

Chaokui QIN , Hongmei LU , Xiong LIU , Gerhard SCHMITZ ,

《能源前沿（英文）》 2009年第3卷第1期页码 109-116 doi: 10.1007/s11708-009-0003-3

摘要： A hybrid air-conditioning system that combines an engine-driven chiller with desiccant dehumidification was configured and experimentally tested to provide reliable data for energy consumption and operation cost. The engine performance and the desiccant wheel performance were measured and a numeric model previously set up for dehumidification capacity prediction was validated. For a reference building, the results based upon measured data show that under present electricity/gas price ratio, more than 40% of operation cost can be saved by the hybrid system.

关键词： engine-driven chiller desiccant wheel hybrid air-conditioning system energy consumption

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concept of capillary active, dynamic insulation integrated with heating, cooling and ventilation, air conditioning

Mark BOMBERG

《结构与土木工程前沿（英文）》 2010年第4卷第4期页码 431-437 doi: 10.1007/s11709-010-0071-9

摘要： When a historic fa?ade needs to be preserved or when the seismic considerations favor use of a concrete wall system and fire considerations limit exterior thermal insulation, one needs to use interior thermal insulation systems. Interior thermal insulation systems are less effective than the exterior systems and will not reduce the effect of thermal bridges. Yet they may be successfully used and, in many instances, are recommended as a complement to the exterior insulation. This paper presents one of these cases. It is focused on the most successful applications of capillary active, dynamic interior thermal insulation. This happens when such insulation is integrated with heating, cooling and ventilation, air conditioning (HVAC) system. Starting with a pioneering work of the Technical University in Dresden in development of capillary active interior insulations, we propose a next generation, namely, a bio-fiber thermal insulation. When completing the review, this paper proposes a concept of a joint research project to be undertaken by partners from the US (where improvement of indoor climate in exposed coastal areas is needed), China (indoor climate in non-air conditioned concrete buildings is an issue), and Germany (where the bio-fiber technology has been developed).

关键词： capillary active insulation integrated heating cooling and ventilation air conditioning (HVAC) and building enclosure dynamic insulation switchable thermal resistance variable U-value walls

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Experimental investigation on oil-gas separator of air-conditioning systems

Dianbo XIN,Shuliang HUANG,Song YIN,Yuping DENG,Wenqiang ZHANG

《能源前沿（英文）》 2019年第13卷第2期页码 411-416 doi: 10.1007/s11708-017-0447-9

摘要： The oil-return system plays an important role in the variable refrigerant flow (VRF) systems because it ensures the reliable operation of the VRF systems. The oil-gas separator is the most essential component of the oil-return system, and the separation efficiency of the separator directly influences the performance of the VRF systems. Therefore, in this paper, a test rig was built to measure the oil discharge ratio of the compressor and the separation efficiency of the oil-gas separator. A sound velocity transducer was used to measure the oil mass concentration instantaneously, because the sound velocity was changed with the mass ratio of oil to refrigerant. The separation efficiency of the separator could be obtained by comparing the mass fraction of oil to refrigerant before and after the separator was connected to the system.

关键词： variable refrigerant flow system oil-gas separator separation efficiency

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心肌远程调节及其临床相关性：现在一起来！ Review

Kristin Luther,Yang Song,Yang Wang,Xiaoping Ren,W. Keith Jones

《工程（英文）》 2015年第1卷第4期页码 490-499 doi: 10.15302/J-ENG-2015117

摘要：

急性心肌梗死(AMI) 是世界上致死和致残的主要病因。及时再灌注法是AMI的标准疗法，能够缩小梗死面积，提高患者存活率和改善预后。然而，25 %的患者在患心肌梗死(Ml) 后会进一步发展成为心力衰竭(HF)，且其中50%的患者会在5年内死亡。由于梗死面积是预断病人病情( 包括HF的形成) 的主要指标，因此，改善心肌的治疗方法具有极大的应用前景。在过去30年中，研究者已发现多种能够刺激内源性心肌保护通道的刺激物，这些刺激物能在缺血预适应(IPC)和缺血后适应以及心肌缺血情况下启动保护机制。当在心肌缺血发生前、发生期间或发生后即刻使用刺激物，在远离心脏的血管床中发生的短暂、可逆性局部缺血就会即刻引发心肌保护机制——这种现象被分别称为远程缺血预适应，远程缺血期适应和远程缺血后适应。尽管目前的研究尚未完全阐明远程缺血预适应(RIPC) 的作用机制，但RIPC与IPC在机制上有很多共同之处。RIPC的发现使研究转向了远程非缺血刺激的应用，包括神经刺激( 脊髓刺激和迷走神经刺激) 以及电针(EA)。笔者与其他研究人员发现并阐述了非缺血现象的机制，并将其定义为远程创伤预适应(RPCT)。通过刺激皮肤感觉神经来启动RPCT，这与穴位处神经刺激和EA既有相似性又有一定差异性。笔者在此次研究中还发现，可通过采用腹中线电刺激(与EA疗法相似) 来模拟RPCT，而且作为预适应刺激和后适应刺激( 在应用再灌注法时)，这种激活心肌保护机制的模式是非常有效的。通过对这些心肌保护现象的研究，学术界对心肌保护机制形成了一种全面且综合的理解，而且在过去的5~10 年期间, 这种理解变得逐渐清晰，即无论是缺血性刺激诱导还是非缺血性刺激诱导，其机制均相似。通过对文献中多种数据的综合考虑，我们认为所有的这些心肌保护“适应”现象均表示心肌保护机制的启动是从心肌适应网(含有特定介质和心肌细胞生存感受器) 的不同切入点进行的，该切入点包括NF-κB、Stat3/5、蛋白激酶C、舒缓激肽和mitoK_ATP 通道。神经系统传导通路可能代表了一种激活心脏和其他器官适应的新机制。研究表明，由于IPC和RIPC存在一定风险并且无法应用于某些患者，所以它们很难被转化为临床应用。因此，近期又新兴了一种神经刺激和痛感刺激的应用，这是一种激活心肌适应的潜在的非缺血性无创方法。作为引起心脏保护作用众多方法之一的后适应重点强调了临床相关性，这种临床相关性有助于在现有成熟的药物与电子疗法中加速新的治疗方向的突破。

关键词：远程心肌保护心肌适应非缺血性适应末端疼痛性刺激神经和分子机制临床可行性电子疗法

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CHARACTERISTICS OF HERBIVORY/WOUND-ELICITED ELECTRICAL SIGNAL TRANSDUCTION IN TOMATO

《农业科学与工程前沿（英文）》 2021年第8卷第2期

摘要：

Electrical signals commonly occur in plants in response to various environmental changes and have a dominant function in plant acclimation. The transduction of wound-elicited electrical signals in the model plant species Arabidopsis has been characterized but the characteristics of electrical signal transduction in response to herbivory or wounding in crop species remain unknown. Here, the features of electrical signals elicited by insect herbivory and wounding in tomato were investigated. Unlike those in Arabidopsis, wounding tomato leaves did not cause leaf-to-leaf electrical signal transduction. In contrast, electrical signals elicited in response to petiole wounding were stronger and more strongly transduced. Leaflet wounding also activated electrical signal transduction and jasmonic acid (JA) signaling within the whole compound leaf. It was also demonstrated that tomato glutamate receptor-like 3.3 (GLR3.3) and GLR3.5 mediated leaflet-to-leaflet electrical signal transduction. Herbivory-induced JA accumulation and Helicoverpa armigera resistance were reduced in glr3.3/3.5 plants. This work reveals the nature of electrical signal transduction in tomato and emphasizes the key roles of GLR3.3 and GLR3.5 in electrical signal transduction and JA signaling activation.

关键词： electrical signal / glutamate receptor-like / herbivory / jasmonic acid / tomato

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Acoustic fault signal extraction via the line-defect phononic crystals

《机械工程前沿（英文）》 2022年第17卷第1期页码 10-10 doi: 10.1007/s11465-021-0666-y

摘要： Rotating machine fault signal extraction becomes increasingly important in practical engineering applications. However, fault signals with low signal-to-noise ratios (SNRs) are difficult to extract, especially at the early stage of fault diagnosis. In this paper, 2D line-defect phononic crystals (PCs) consisting of periodic acrylic tubes with slit are proposed for weak signal detection. The defect band, namely, the formed resonance band of line-defect PCs enables the incident acoustic wave at the resonance frequency to be trapped and enhanced at the resonance cavity. The noise can be filtered by the band gap. As a result, fault signals with high SNRs can be obtained for fault feature extraction. The effectiveness of weak harmonic and periodic impulse signal detection via line-defect PCs are investigated in numerical and experimental studies. All the numerical and experimental results indicate that line-defect PCs can be well used for extracting weak harmonic and periodic impulse signals. This work will provide potential for extracting weak signals in many practical engineering applications.

关键词： phononic crystals line-defect fault signal extraction acoustic enhancement

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提高地下金属管振动波测试中冲击响应信号的信噪比

韩修廷,王洁春,焦振强,高飞,宋宇波

《中国工程科学》 2005年第7卷第10期页码 64-68

摘要：

提出了在套损振动波检测过程中提高信号信噪比的方法。检测过程中，在井口敲击套管并接收、分析套管的回波，以了解介质的变化情况。由于反射波信号强度较微弱，单纯用一组接收信号无法进行正确的套损分析，采用信号增强方法，即利用多个类似信号进行叠加，增强反射波的有效信号，降低背景噪声，从而得到有用信息，进行正确的套损状况分析。开发了相应的信号处理软件，提高了信号处理速度。通过10井次的测试表明，技术原理可行，软件工作稳定、可靠，便于操作，可以进行多种方法的信号处理，极大地提高了工作效率。

关键词：振动波反射波信号增强信号叠加

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The role of protein kinase C epsilon in neural signal transduction and neurogenic diseases

null

《医学前沿（英文）》 2011年第5卷第1期页码 70-76 doi: 10.1007/s11684-011-0119-9

摘要：

Protein kinase C epsilon (PKC ?) is one of major isoforms in novel PKC family. Although it has been extensively characterized in the past decade, the role of PKC ? in neuron is still not well understood. Advances in molecular biology have now removed significant barriers to the direct investigation of PKC ? functions in vivo, and PKC ? has been increasingly implicated in the neural biological functions and associated neurogenic diseases. Recent studies have provided important insights into the influence of PKC ? on cortical processing at both the single cell level and network level. These studies provide compelling evidence that PKC ? could regulate distinct aspects of neural signal transduction and suggest that the coordinated actions of a number of molecular signals contribute to the specification and differentiation of PKC ? signal pathway in the developing brain.

关键词： protein kinase C ? signal transduction neurogenic disease

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Usability perceptions and beliefs about smart thermostats by chi-square test, signal detection theory

Pedro PONCE, Therese PEFFER, Arturo MOLINA

《能源前沿（英文）》 2019年第13卷第3期页码 522-538 doi: 10.1007/s11708-018-0562-2

摘要： It is well known that smart thermostats (STs) have become key devices in the implementation of smart homes; thus, they are considered as primary elements for the control of electrical energy consumption in households. Moreover, energy consumption is drastically affected when the end users select unsuitable STs or when they do not use the STs correctly. Furthermore, in future, Mexico will face serious electrical energy challenges that can be considerably resolved if the end users operate the STs in a correct manner. Hence, it is important to carry out an in-depth study and analysis on thermostats, by focusing on social aspects that influence the technological use and performance of the thermostats. This paper proposes the use of a signal detection theory (SDT), fuzzy detection theory (FDT), and chi-square (CS) test in order to understand the perceptions and beliefs of end users about the use of STs in Mexico. This paper extensively shows the perceptions and beliefs about the selected thermostats in Mexico. Besides, it presents an in-depth discussion on the cognitive perceptions and beliefs of end users. Moreover, it shows why the expectations of the end users about STs are not met. It also promotes the technological and social development of STs such that they are relatively more accepted in complex electrical grids such as smart grids.

关键词： thermostats perceptions beliefs signal detection theory (SDT) fuzzy signal detection theory (FSDT) chi-square (CS) test