广义不可逆Miller热机循环的性能优化

建立了考虑工质变温热容、热漏、有限时间传热、摩擦损失、非等熵绝热压缩和非等熵绝热膨胀过程的空气标准的不可逆Miller热机循环模型.应用有限时间热力学理论导出了该模型下的输出功率和效率的解析表达式.通过数值计算,得出了输出功率与效率之间的关系,并作图来反映它们的变化情况.讨论了热漏损失、摩擦损失、内不可逆性和工质变温热容对该热机各种性能参数的影响,同时给出了一些重要参数的优化范围.所得结果对实际Miller热机的优化设计提供了理论依据.     

Isolation and identification of a sulfate reducing bacteria and sequence analysis of its dissimilatory sulfite reductase gene

A sulfate reducing bacteria was isolated from mining sewage of Daqing Oilfield by Hungate anaerobic technology. Physiological-biochemical analysis showed that the strain could utilize polyacrylamide as sole carbon and nitrogen source. The sequence analysis of 16S rDNA illustrated that the similarity of F8 and Desulfovibrio desulfuricans (AF192153) was 99%, and the similarity sequence of dissimilatory sulfite reductase gene (DSR) cloned from the strain and Desulfovibrio desulfuricans (AF273034) was 98%. Their phylogenitic analysis was basically anastomosed, and thus temporarily named as Desulfovibrio desulfuricans F8. The DSR cloned from F8 strain was 2740 bp in length consisting of three ORF, DSRA, DSRB and DSRD as a single operon (DSRABD) regulated by the same operator. DSRA contained typical conservative box of sulfate—sulfite reducing enzyme (SiteⅠand SiteⅡ), which could bind siroheme and [Fe4S4]. DSRB retained a [Fe4S4] binding site, with an uncomplimentary structure for siroheme binding. There was no conservative box in DSRD. Sequence analysis of DSR will provide a theoretical basis for quantitative detection, metabolic pathway modification through gene engineering, and sulfate reducing bacteria (SRB) suppression.     

Oil monitoring methods based on information theory

To evaluate the wear condition of machines accurately,oil spectrographic entropy,mutual information and ICA analysis methods based on information theory are presented. A full-scale diagnosis utilizing all channels of spectrographic analysis can be obtained. By measuring the complexity and correlativity,the characteristics of wear condition of machines can be shown clearly. The diagnostic quality is improved. The analysis processes of these monitoring methods are given through the explanation of examples. The availability of these methods is validated and further research fields are demonstrated.     

Geological factors associated with unsuccessful exploration wells in the northern margin of the Qaidam basin

We investigated the geological factors associated with unsuccessful exploration wells in the northern margin of the Qaidam basin to better understand their cause. The structural situation, the hydrocarbon accumulation mechanism and unsuccessful well data collected from 1996 to 2005 were studied. The results show that the main geological factors associated with unsuccessful exploration wells are a lack of effective source rocks and a lack of effective traps, as well as the migration-accumulation conditions that exist in this area. The basin was reformed by Meso-Cenozoic tectonic evolution. Multi-stage tectonic activities have both positive and negative effects on hydrocarbon accumulation. Source rocks distribution, effective migration channels, effective traps and the tectonic evolution effects on hydrocarbons should be the key objects for further studies.     

Remaining oil distribution in Ng3^3 bottom water reservoir of Lin 2-6 fault-block in Huimin depression and potential tapping in horizontal well

Oil reservoirs with secondary bottom water in Ng33 members (in Guantao formation, Paleogene system) of Lin2-6 fault block in Huimin depression (Bohai Bay Basin) have entered the late stage of ultra-high water-containing-exploitation. Oil exploita-tion from vertical wells is becoming more and more inefficient. The reservoir type, with water displacing oil and the remaining oil distribution are specifically studied in order to improve the efficiency of the recovery ratio. An integrated scheme for adjusting horizontal wells has been designed and the key technique of the scheme optimized. The study shows that: 1) the positive rhythm of fluvial depositional features is the internal cause of the flooding of oil reservoirs while water injection, injection-production patterns and accumulative petroleum production are the external causes; 2) oil-water driving patterns have transferred from edge water ad-vancing to bottom-water-coning; distribution of the remaining oil mainly concentrates in the upper rhythm and top of the middle rhythm in Ng33 members; 3) a great deal of remaining oil is enriched in high positions of faults, in axes of tiny structures, in stagna-tion areas among water-injection wells and oil-wells and in tectonic saddle areas with sparse wells. Compared with vertical wells, horizontal wells have advantages such as high recovery, high off-take potential, high critical output, large controlling areas and long time of bottom-water breakthrough.     

运行中汽轮机油质变差的原因分析及对策

某机组汽轮机油在较短的使用时间内,油质却发生了很大的变化.汽轮机油质的好坏直接影响到油品在设备中运行时间的长短,关系到用油设备的安全及用油单位的经济成本.通过实验找出影响汽轮机油质变化的因素,以便在今后使用过程中采取相应的对策,提高油的品质,延长使用寿命.     

蔗糖酯对精炼大豆油氧化稳定性的影响

以不含抗氧化荆的精炼大豆油为原料,研究了加入蔗糖酯对其氧化稳定性的影响,结果表明：在低温时（烘箱法）,HLB13的蔗糖酯具有一定的延缓大豆油氧化的作用,其中0．5‰添加量（质量分数）时延缓氧化效果最好;高温条件下（110℃）HLB13、HLB11、HLB9的蔗糖酯在不同浓度条件下有一定的加速氧化作用．     

微波辅助提取柑橘皮中的挥发油

采用微波辅助提取柑橘皮中挥发油,其最佳提取条件为：30g柑橘皮粉末浸在60mL无水乙醇中,微波功率为300W,微波辐射时间为150s。采用溴加成法对挥发油进行定量分析,经测定挥发油的含量为2．77％。实验表明．微波法具有提取率较高、时间短、成本低和污染少等优点。     

基于设计模式的阴影管理模块的结构研究

给出了一种基于设计模式的游戏引擎中阴影管理模块结构的设计方法．通过对阴影管理模块的任务分析,设计了该模块的功能交互结构和算法框架结构．该设计结构的优点是,使得游戏引擎的阴影管理模块更易于使用且便于扩展,同时可以更有效地利用图形硬件所支持的高级特性．     

3D Simulation Research on Urea-SCR DeNO<em>x Catalyst for Diesel Engine

In order to reduce oxides of nitrogen (NOx) emanated from a diesel eng ine, a comprehensive urea selective catalyst reduction (SCR) DeNOx catalys t was modeled in which numerical simulations were used as a complementary tool f or the experimental investigations to make the design decisions, and hence short en the development process. In this approach, relevant conversion reactions were studied in 1D model, and the parameters obtained in this way were transferred t o 3D simulations. According to the results ...