高浓度煤粉输送燃烧技术的利弊分析

推广一种新型的高效、清洁和稳燃技术——高浓度煤粉燃烧技术。分析了该技术所特有的输粉系统简化、燃烧稳定、污染物NOx排放低等特性,阐述了高浓度煤粉系统所带来的输送稳定性、煤粉燃尽和炉膛结渣等问题,并提出了相应的解决方案,比较了常规煤粉系统与高浓度煤粉系统的经济性。试验结果表明：与常规系统相比,正压高浓度煤粉系统具有显著的经济性,负压高浓度煤粉系统的经济性取决于系统的汽耗量。图5表3参10     

功率VDMOSFET单粒子效应研究

阐述了空间辐射环境下n沟功率VDMOSFET发生单粒子栅穿(SEGR)和单粒子烧毁(SEB)的物理机理。研究了多层缓冲局部屏蔽抗单粒子辐射的功率VDMOSFET新结构及相应硅栅制作新工艺。通过对所研制的漏源击穿电压分别为65V和112V两种n沟功率VDMOS-FET器件样品进行锎源252Cf单粒子模拟辐射实验,研究了新技术VDMOSFET的单粒子辐射敏感性。实验结果表明,两种器件样品在锎源单粒子模拟辐射实验中的漏源安全电压分别达到61V和110V,验证了新结构和新工艺在提高功率VDMOSFET抗单粒子效应方面的有效性。     

槽栅型SiC MOSFET器件单粒子响应特性研究

利用TCAD Sentaurus模拟仿真软件,研究分析了三种不同结构的槽栅型1 200 V SiC MOSFET单粒子响应特性,器件包括传统单沟槽MOSFET、双沟槽MOSFET和非对称沟槽MOSFET结构。仿真结果表明,双沟槽MOSFET的抗单粒子特性优于其它两种结构器件。通过分析可知,双沟槽MOSFET结构的优越性在于有较深的源极深槽结构,有助于快速收集单粒子碰撞过程产生的载流子,从而缓解大量载流子聚集带来的内部电热集中,相比其它两种结构能有效抑制引起单粒子烧毁的反馈机制。     

Burnout of the organic vehicle in an electrically conductive thick-film paste

The burnout of the organic vehicle in a silver-particle, glass-free, electrically conductive, thick-film paste during firing in air was studied. For a vehicle consisting of ethyl cellulose dissolved in ether, burnout primarily involves the thermal decomposition of ethyl cellulose. The presence of ether with dissolved ethyl cellulose facilitates the burnout of ethyl cellulose. Excessive ethyl cellulose hinders the burnout. A high heating rate results in more residue after burnout. By interrupting the heating at 160°C for 15 min, the residue after subsequent burnout is diminished probably because of reduced temporal overlap of the processes of organic burnout and silver particle necking. By interrupting the heating at either 300°C or 385°C for 30 min, the temperature required for complete burnout is reduced. The addition of silver particles facilitates drying at room temperature and burnout upon heating.     

医护人员职业倦怠研究进展

医护人员是职业倦怠的高发人群,本文就职业倦怠的概念及内涵、医护人员职业倦怠现状、危害、原因及预防进行了综述,同时指出针对医护人员职业倦怠的不同影响因素探索有效的干预方法是未来职业倦怠的研究方向之一.     

Gender and work setting differences in career-sustaining behaviors and burnout among professional psychologists.

What factors relate to levels of burnout experienced by male and female psychologists? Five hundred ninety-five psychologists responded to a survey about professional activities, work demands and resources, career-sustaining behaviors, and burnout. Respondents in solo or group independent practice reported a greater sense of personal accomplishment, more sources of satisfaction, fewer sources of stress, and more control at work than respondents in agency settings. In addition, women in independent practice reported less emotional exhaustion than women in agency settings. In general, women tended to give higher ratings to the importance of career-sustaining behaviors; however, 6 strategies emerged as highly important for all respondents: maintain sense of humor, maintain self-awareness/self-monitoring, maintain balance between personal and professional lives, maintain professional identity/values, engage in hobbies, and spend time with spouse, partner, or family. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Balancing Work and Home: How Job and Home Demands Are Related to Burnout.

The aim of the present study was to make a clear distinction between work and home domains in the explanation of burnout. First, a 3-factor structure of job and home demands was hypothesized, consisting of quantitative demands, emotional demands, and mental demands. Next, a model was tested that delineates how demands in both life domains are related to occupational burnout through work-home interference (WHI) and home-work interference (HWI). In doing so, the partial mediating role of WHI and HWI was examined. Consistent with hypotheses, empirical support was found for the 3-factor structure of both job and home demands as well as for the partial mediating effects of both WHI and HWI. Job demands and home demands appeared to have a direct and indirect effect (through WHI and HWI, respectively) on burnout. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

生物质在增氧气氛下燃烧行为的研究

研究了3种生物质在不同O₂摩尔分数的O₂/N₂气氛下的着火特性,其中生物质粒径为500～700μm, O₂摩尔分数为21%、30%、50%、70%和100%。结果表明:O₂摩尔分数决定了生物质着火机理的转变,随着O₂摩尔分数的升高,稻谷壳、竹子和黄豆秆的着火机理分别在100%、70%和30%O₂摩尔分数下由均相着火转变为非均相着火。O₂摩尔分数能影响3种生物质的着火距离及燃尽时间,并且着火距离和燃尽时间均随O₂摩尔分数的增加而减小。     

IGBT单粒子烧毁效应的二维仿真

通过二维TCAD仿真,对IGBT的单粒子入射作用过程做了原理性的分析,据此在理论上将单粒子对器件的作用进行了分类。针对阻断态、贯通烧毁的情况,给出了IGBT加固的一般思路,提出并仿真验证了多种具体的加固方法,与文献测试结果相符。     

混煤燃烧过程中的交互作用:掺混方式对混煤燃烧特性的影响

在沉降炉上开展了高、低挥发分煤不同配比(贫煤掺混烟煤比例0,25%,50%,75%,100%)下混煤燃烧特性实验,研究了"炉外"和"炉内"两种掺烧方式对混煤燃尽与NO_x排放特性的影响。结果表明,混煤燃烧过程中烟煤对贫煤存在促进和抑制两种作用,两者的竞争共同决定了混煤的燃尽特性。"炉外"掺烧方式下,掺烧烟煤比例较小时,促进大于抑制作用,有利于混煤燃尽;进一步提高烟煤掺烧的比例,抑制作用增加并大于促进作用,不利于混煤的燃尽;NO_x排放量随烟煤掺烧比例增加基本呈线性增加规律。掺烧烟煤比例控制在25%以内有利于提高混煤燃尽率;掺烧烟煤比例为75%时,混煤燃尽率显著降低。"炉内"掺烧方式下,混煤燃烧中的促进与抑制作用会同时减弱;掺烧大比例烟煤时,烟煤与贫煤混合越晚越有利于混煤燃尽;NO_x排放量随着烟煤延迟混合而逐渐降低。"炉内"掺烧烟煤且烟煤延迟送入炉内有利于混煤燃尽率,且NO_x的排放降低明显;而贫煤延迟送入炉内则会导致混煤燃尽率进一步降低,但NO_x排放降低程度低于前者。