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991.
A new model for analyzing laminar forced convective enhanced heat transfer in latent functionally thermal fluid 总被引:3,自引:1,他引:2
LUWenqiang BAIFengwu 《科学通报(英文版)》2004,49(14):1457-1464
In this paper, a new model to analyze laminar forced convective enhanced heat transfer in latent functionally thermal fluid is developed. The main characteristics of the model are- i) a new formula of the specific heat at constant pressure is used; ii ) a real heat transfer process is considered; that is, heat transfer processes occur not only between working fluid and microcapsules, but also between the mixture and tube wall; iii) the new method, which combines the newly developed axisymmetrical dual reciprocity boundary element method (DRBEM) with finite difference method (FDM), is used to solve the control equations of this problem. The new model is validated by experimental data. Some new physical results on the variational characteristics of the specific heat at constant pressure with space and time during phase-change process, the time-marching history of the phase-change interfaces and so on are obtained. Several main physical factors that affect enhanced heat transfer in latent functionally thermal fluid are numerically analyzed. Some new understandings for the mechanism of enhanced heat transfer in the functionally fluid are obtained. 相似文献
992.
用元评估分析政府绩效评估偏差 总被引:7,自引:0,他引:7
基于元评估的思想,利用肯德尔和谐系数、克朗巴赫系数、内容效度比等分析方法对政府绩效评估的主体一致性信度、评估指标体系信度与效度、评估数据测量信度、评估结果效度进行检测,为控制政府绩效评估偏差,提高评估活动的权威性、科学性和有效性提供了一个可行的途径。 相似文献
993.
LIUChunlin RUANYing GUANChunyun 《科学通报(英文版)》2004,49(24):2643-2644
β-ocimene, a kind of monoterpene, was found recently as a plant communication signal molecule. It has two isomeric forms in nature: cis-β-ocimene and trans-β-ocimene. According to recent reports, all investigated plants, such as corn, cotton, lima bean, potato, tobacco, arabidopsis, and Mediterranean pine, could release the chemical component β-ocimene after fed by arthropod herbivores, 相似文献
994.
芽孢杆菌植酸酶基因在毕赤酵母中的胞内表达 总被引:2,自引:0,他引:2
根据已知的枯草芽孢杆菌WHNB02植酸酶phyC基因全序列设计一对引物,采用PCR法从含有该基因的pUC18-phyC质粒上获得了长约1.1kb不含有信号肽序列的植酸酶phyC基因表达片段.经T载体克隆及序列测定后,构建毕赤巴斯德表达载体pPIC3.5K-phyC,并电转化毕赤巴斯德酵母宿主菌GS115.经MD和MM平板筛选、酶活性测定,获得了阳性转化子,并进行了诱导表达.SDS-PAGE分析表明:表达产物分子量为42.01KD,表达量占细胞可溶性总蛋白的24%,并具有植酸酶的生物学活性.酶学性质分析结果显示:胞内表达的植酸酶酶促反应最适pH值为7.5;最适反应温度为70℃;经90℃处理10min,残留酶活性42% 均优于出发菌株天然植酸酶的相应性质. 相似文献
995.
Production of bacterial blight resistant lines from somatic hybridization between Oryza sativa L. and Oryza meyeriana L 总被引:1,自引:0,他引:1
Novel bacterial blight (BB) resistance gene(s) for rice was (were) introduced into a cultivated japonica rice variety Oryza sativa (cv. 8411), via somatic hybridization using the wild rice Oryza meyeriana as the donor of the resistance gene(s). Twenty-nine progenies of somatically hybridized plants were obtained. Seven somatically hybridized plants and their parents were used for AFLP (amplified fragment length polymorphism) analysis using 8 primer pairs. Results confirmed that these plants were somatic hybrids containing the characteristic bands of both parents. The morphology of the regenerated rice showed characters of both O.sativa and O.meyeriana. Two somatic hybrids showed highest BB resistance and the other 8 plants showed moderate resistance. The new germplasms with highest resistance have been used in the rice breeding program for the improvement of bacterial blight resistance. 相似文献
996.
Two-component genes are kinds of genetic elements involved in regulation of antibiotic production in Streptomyces coelicolor. DNA microarray analysis revealed that ecrA1/A2, which mapped at distant sites from red locus and encode respectively the kinase and regulator, expressed coordinately with genes of Red specific biosynthetic pathway, ecrA1 and ecrA2 gene-disruptive mutants were constructed using homogenotisation by reciprocal double crossover. Fermentation data showed that the undecylprodigiosin (Red) level of production was lower than that of wild-type strain. However, the change of the actinorhodin (Act) production level was not significant compared with wild type. Thus, these experiment results confirmed that the two-component system ecrA 1/A2 was positive regulatory element for red gene cluster. 相似文献
997.
以“哲学是什么”为核心的元哲学问题是马克思早期理论活动的轴心,马克思是通过对元哲学问题的探索而进入哲学殿堂并登上理论的峰顶的。马克思力求通过对哲学自身的追问与反思、通过揭示哲学的实然形态和应然形态的巨大反差。借助于揭示“哲学不是什么”来界定“哲学应该是什么”。马克思有关元哲学问题深刻而精辟的阐述。对于我们今天认识哲学和哲学问题,对于我们理解和掌握马克思主义哲学的精神实质,具有重要的理论价值和指导意义。 相似文献
998.
本文以"N+Ad.+的+不+V"讨论表示否定的"N+Adj.+的+否定词+V/VP"句式.首先考察了"N+Adj.+的"的论元角色与谓语动词论旨结构的关系,指出当动词是二元动词或三元动词时,"N+Adj.+的+否定词+V/VP"句式和"否定词+V/VP+N+Adj.+的"句式在论旨结构上具有平行性联系,认为"N+Adj+的+否定词+V/VP"句式实际上是由"否定词+V/VP+N+Adj.+的"中的焦点成分"N+Adj.+的"前置形成的焦点突显句式."N+Adj+的"作为论元,其所指与动词的论元属性及语义密切相关. 相似文献
999.
β葡聚糖酶杂合基因bglHAM的克隆及在P.pastoris中的表达 总被引:2,自引:0,他引:2
采用PCR的方法,以Bacillus macerans总DNA为模板,构建出β-1,3-1,4葡聚糖酶杂合基因bglHAM,与巴斯德毕赤酵母表达载体pPIC9K重组,得到重组质粒pPIC9K-HAM,电脉冲转化法转化酵母菌GS115,KM71,在MM,MD平板上筛选表型,YPD-G418平板上筛选多拷贝重组子,重组菌株经甲醇诱导后,刚果红平板染色法检测到β-葡聚糖酶活性,SDS-PAGE证明表达产物的分子量约为24kD,摇瓶诱导培养筛选到的重组菌株,胞外每mL发酵液最高酶活达240U。 相似文献
1000.