风冷电子设备中压降的自动测量

风冷电子设备中压降的自动测量吴青（石家庄煤炭工业学校，０５００６１）１引言当电子设备中的热流密度超过０．２Ｗ／ｃｍ２（温升４５℃）时，则应采用强制对流冷却的方法，以控制功率电子元件或整机的温升，目的在于减少因过高温度造成的电子元件失效的增加，以保证整...

CPU开发工具链的自动设计

EDA技术的成熟和进步,缩短了微处理器硬件设计和综合的周期。同时,开发工具链设计的自动化,已成了高效率、高质量嵌入式微处理器设计的重要内容。该文提出了采用体系结构描述语言(ADL)实现微处理器开发工具链自动设计的有效方法。介绍了这种方法在CK*CORE开发工具链设计中的应用情况,并探讨了体系结构描述语言的一些问题及进一步发展方向。

CoFe_2O_4磁性液体的正电子湮没谱分析

对CoFe2O4磁性液体进行了正电子湮没谱研究。结果显示，CoFe2O4磁性液体的正电子湮没谱存在3种寿命成分，分别为τ1=151．0ps，τ2=457．9ps，τ3=2325．6ps。表明在CoFe2O4超微粒表面存在大量空位和空位团。

美国强化电子垃圾回收再利用

美国联邦政府是美国国内电子产品消费最多和更新最快的部门。根据最新统计数据,除军队系统和法律系统外,美国联邦政府共有270万名雇员,每年丢弃的电子垃圾约有240万吨。如今联邦政府开始反思,表示将强化电子产品的回收、

A review on the cooling of energy conversion and storage systems using thermoelectric modules

Exploitation of sustainable energy sources requires the use of unique conversion and storage systems,such as solar panels,batteries,fuel cells,and electronic equipment.Thermal load management of these energy conversion and storage systems is one of their challenges and concerns.In this article,the thermal management of these systems using thermoelectric modules is reviewed.The results show that by choosing the right option to remove heat from the hot side of the thermoelectric modules,it will be a suitable local cooling,and the thermoelectric modules increase the power and lifespan of the system by reducing the spot temperature.Thermoelectric modules were effective in reducing panel temperature.They increase the time to reach a temperature above 50℃ in batteries by 3 to 4 times.Also,in their integration with fuel cells,they increase the power density of the fuel cell.

Design of new biomedical titanium alloy based on d-electron alloy design theory and JMatPro software

A new kind offl biomedical titanium alloy, Ti-35Nb-4Sn-6Mo-9Zr, composed of non-toxic elements Nb, Mo, Zr and Sn with lower elastic modulus and higher strength was designed based on d-electron alloy design theory and JMatPro software using orthogonal experiment. The microstructure and basic mechanical properties of designed alloy were investigated. The results show that the alloy is composed of single fl equiaxed grains after solution treatment at 800 ~C. Compared with Ti-6A1-4V, the mechanical properties of the designed alloy are more excellent： E=65 GPa, σb=834 MPa, σ0.2=802 MPa, and σ=11%, which is expected to become a promising new type implanted material. The research approach adopted can reduce the experimental time and cost effectively, and get the ideal experimental results.

The Research and Application of the Anti-Interference Techniques of Electronic Device in Power System

This paper presents the study and application of the electronic device anti-interference techniques underhigh voltage and/or heavy current electro-magnetic circumstance in power system.[

Molecular Design and Electronic Structure Investigation of Novel Nitrogen Heteroatom 2-β-Naphthylbenzoxazoles

For the aim of finding new available functional materials, a series of nitrogen heteroatom 2 β naphthylbenzoxazole molecules were designed based on the experiment and theoretical studies of 2 β naphthylbenzoxazole molecule. Geometry optimization of the 2 β naphthylbenzoxazole was carried out by using Hyperchem Molecular Mechanics plus MM+. The planar molecular structure was obtained. The quantum chemistry calculating method PPP SCF CI, which is specially available to treat electron spectrum, was applied to investigate each novel designed molecules. Their electronic structures were analyzed in detail, it shows that total π electron energy decreased linearly with the number of replaced nitrogen. Single nitrogen atom located in benzoxazole ring or naphthalene ring results in contrary changes of level difference of FMO; multiple nitrogen atoms located in different molecular positions will lead to polarization of extremum in the level difference of FMO; and 5 nitrogen heteroatoms reach the culmination. Considering other electronic structure information, some favorable designed molecules were identified.

零距离接触致命病毒——加拿大BSL4实验室

2006年9月,加拿大马尼托巴省首府温尼伯,在一幢绿树环绕的五层楼房内,似乎是与外界截然调的电子设备,房间的一侧悬挂着巨幅等离子屏幕,封闭其中的氖氙气体在电压作用下产生出紫外光,物细胞的三维模型。陌生感加重了这里的诡异气氛,但周围的人却似乎并不为此而紧张。

前沿

7个原子造出的晶体管半个世纪前,初级的计算机要占据几个房间。而今,新型的笔记本电脑可以装在文件夹里随身携带。电子设备究竟可以做到多小?澳大利亚新南威尔士大学(the University of New South Wales)和美国威斯康星大学(University of Wisconsin)

联通“班班通”:实现家校共育

"‘班班通’正在让我的孩子从‘要我学’变为‘我要学’,逐渐地把学习作为一种兴趣。"一位学生家长介绍道,"孩子的学习积极性提高了,前两天甚至告诉我暑期要预习五年级的知识,这是我以前想都不敢想的事情。"随着互联网时代的来临,我们身边出现了越来越多的电子设备,大部分时间人们都生活在虚拟世界中,真实有效的沟通逐渐变少。在教育领域,传统的教学模式是老师讲、学生听,方式枯燥、单一。对于老师、

A Theoretical Framework and Methodology for Urban Activity Spatial Structure in E-society: Empirical Evidence for Nanjing City, China

The existing researches on the influence of information and communication technology （ICT） are mainly focused on human activity, whilst with few efforts on urban space. In the e-society, the widespread adoption of 1CT devices not only affects almost every aspect of people＇s daily life and thereby reshapes the spatial development of regions and cities, but also generates a large amount of real-time activity data with location information. These georeferenced data, however, have relatively recently attracted attention from geographers. Adapted from Lynch＇s framework based on people＇s perceptions, this paper proposes a framework of urban spatial struc- ture based on people＇s actual activity, including five elements, namely activity path, activity node, central activity zone （CAZ）, activity district, and activity edge. In the empirical study, by using one week＇s check-in tweets （from February 25 to March 3 in 2013） collected in Nanjing City, the five elements are recognized and analyzed. Through the comparison between our results and urban spatial structure based on population （and land use）, we argue that ICT uses： 1） lead to polarize, rather than to smooth, the urban structural hierarchy, due to the dual role of distance; 2） enable a partial decoupling of activity and activity space node, which challenges our conventional under- standing of the role of home and the utility of travel; 3） blur the boundaries of activity districts and hence may play a positive role in enriching districts＇ functions, which should not be overlooked in the current urban transformation in China.

The effect of digital health technologies on managing symptoms across pediatric cancer continuum:A systematic review

Objective:Pediatric cancer patients endure multiple symptoms during treatment and also in survivorship.Digital health technologies provide an innovative way to support their symptom management.This review aimed to examine the effect of digital health technologies on managing symptoms among across pediatric cancer continuum.Methods:A systematic literature search of six English and three Chinese electronic databases was combined with hand searching,to identify eligible research studies from database establishment to November 30,2019.Two reviewers carried out data selection,data extraction,and quality appraisal independently.A narrative approach was taken to summarize data.Results:Four randomized control trials,two quasi-experiments,and five one group pre-posttest designed studies,were included in the review with a total of 425 participants.The methodological quality of the studies was generally fair.Seven symptoms(anxiety,depression,pain,anger,fatigue,fear,distress)and seven digital health technologies(visual reality,website,humanoid robot,app,wearable devices,short messages and videoconference)were reported in the included studies.Conclusions:Current evidence supports the effect of digital health technologies is generally mixed and inconclusive.There is a trend of positive effects found in the interventions that feature digital health technologies’interactive function.This review highlights the need for further investigation with rigorous research designs and the consideration of influencing factors from the symptoms,participants,and context levels to inform a better digital health implementation.

The gender difference of utilization of cardiac implantable electronic device in China： data from Arrhythmia Interventional Therapy Data Registry

Background Cardiac implantable electronic devices （CIEDs） greatly improve survival and life quality of patients. However, there are gender differences regarding both the utilization and benefit of these devices. In this prospective CIED registry, we aim to appraise the gender differences in CIED utilization in China. Methods Twenty centers from 14 provinces in China were included in our registry study. All patients who underwent a CIED implantation in these twenty centers between Jan 2015 and Dec 2016 were included. Results A total of 8570 patients were enrolled in the baseline cohort, including 7203 pacemaker, 664 implantable cardiac defibrillators （ICD） implants and 703 cardiac resynchronization therapy device （CRT/D）. Totally, 4117 （48.0%） CIED patients were female, and more than 59% pacemaker patients were female, but women account only one third of ICD or CRT/D implantation in this registry. There were significant differences between genders at pacemaker and ICD indications. Female was more likely received a pacemaker due to sick sinus syndrome （SSS） （63.9% vs. 51.0%, P 〈 0.001）. Female patients receiving an ICD were more likely due to cardiac ion channel disease （29.2% vs. 4.2%, P 〈 0.001）. The percentage of utilization of dual-chamber pacemaker in female patients was significantly higher than male （85.3% vs. 81.1%, P 〈 0.001）. But male patients were more likely received a cardiac resynchronization therapy devices with defibrillator than female （56.5% vs. 41.9%, P = 0.001）. In pacemaker patient, male was more likely to have structure heart disease （31.3% vs. 28.0%, P = 0.002）. In ICD patient, male patients were more likely to have ischemic heart disease （48.2% vs. 29.2%, P 〈 0.001）. The mean age of women at the time of CRT/D implantation was older than men （P = 0.014）. Nonischemic cardiomyopathy （70.9%） was the most common etiology in the patients who underwent the treat？ment of CRT/D, no matter male or female. Conclusions In real-world setting, female do have different epidemiology, pathophysiology and clinical presentation of many cardiac rhythm disorders when compared with male, and all these factors may affect the utilization of CIED implantation. But it also possibility that cultural and socioeconomic features may play a role in this apparent discrimination.

Technical issues and new devices of ESD of early gastric cancer

Endoscopic submucosal dissection(ESD) is a highly refined technique compared to conventional endoscopic mucosal resection.It enables complete resection of early gastric cancer(EGC) which has no possibility of lymph node metastasis.Indication for ESD of EGC generally entails early gastric cancer confined to the mucosa with well differentiated histology,though there are clinically suitable expanded criteria.As ESD requires specific skill and expertise,endoscopists need to be familiarized with basic methods and the use of special devices.The essence of the technique is to dissect the submucosal layer with direct vision and maintain thecutting plane above the underlying proper muscle layer.Although there are some differences in the detailed technical aspect,the cardinal method of ESD is now well established and standardized.Furthermore,research and development of new ESD devices that render more efficient,safe ESD are still in progress to improve the overall result of ESD on early gastric cancer.

Recent progress of fiber-shaped batteries towards wearable application

Rapid development of portable or wearable devices, which is inspired by requirements of instant messaging,health monitoring and handling official business, urgently demands more tiny, flexible and light power sources. Fibershaped batteries explored in recent years become a prospective candidate to satisfy these demands. With 1D architecture,the fiber-shaped batteries could be adapted to various deformations and integrated into soft textile and other devices.Numerous researches have been reported and achieved huge promotion. To give an overview of fiber-shaped batteries,we summarized the development of fiber-shaped batteries in this review, and discussed the structure and materials in fiber-shaped batteries. The flexibility of batteries with the potential application of the batteries was also exhibited and showed the future perspective. Finally, challenges in this field were discussed, hoping to reveal research direction towards further development of fiber-shaped batteries.

ACCELERATED LIFE TEST STUDIES OF NEW COATED DISPENSER CATHODES

The life of impregnated Ba-W cathodes with a new construction have been evaluated using an accelerated life test at three different temperatures (1170℃,1130℃,1090℃) and constant current density (2A/cm^2).According to the relationship of life with operating temperatures,an accelerated equation has been set up.The cathode life at normal operating temperature is deducted based on the accelerated equation.The results show that life of the novel cathode exceeds 190,000 hour at a current density of 2A/cm^2.

Obsolescence optimization of electronic and mechatronic components by considering dependability and energy consumption

Nowadays, rapid technological progress influences the dependability of equipments and also causes rapid obsolescence. The mechatronic and electronic equipment components are mostly affected by obsolescence. A new challenger unit possesses identical functionalities, but with higher performances. This work aims to find the optimal number of components which should be replaced by new-type units, under budgetary constraints. In this work, the new challenger unit is characterized by lower energy consumption and the optimization steps are based on genetic algorithm (GA). The result shows the importance of this type of replacement in order to economize energy consumption and to deal with obsolescence.