钢管混凝土粘结滑移本构关系理论研究

钢管混凝土中钢管与混凝土之间的粘结强度和粘结滑移备受关注.国内外对钢管混凝土粘结滑移的研究较多,但主要侧重于粘结强度的研究,而对粘结滑移本构关系的研究相对较少;而且目前钢材和混凝土的本构关系均已经比较明确,钢管混凝土粘结滑移的本构方程尚无定论.从理论上推导了钢管与混凝土粘结滑移的本构关系,讨论了钢管混凝土粘结滑移本构关系的建立方法.为进一步研究钢管混凝土的粘结滑移本构关系提供了理论依据.     

基于CiteSpace的医用防护服研究可视化分析

为了解医用防护服研究进展,对医用防护服的时空关系、合作关系、共现关系和共被引进行了研究.以文献计量和知识图谱法为研究方法,CiteSpace为分析工具,对2006年1月1日—2020年10月30日在Web of Science上发表的380条文献进行可视化分析.研究发现:在时间线上有关医用防护服的发展呈现螺旋上升的趋势...     

溶聚丁苯橡胶的序列结构及玻璃化温度与力学性能关系的研究

采用DSC和~(13)C-NMR等方法,将玻璃化温度(T_g)和溶聚丁苯橡胶(S-SBR)的序列结构关联起来,并以此为判据,将具有不同序列结构的S-SBR分为无规,短嵌段和长嵌段三种类型。T_g和序列分布对S-SBR性能的影响基本相似,硬度、拉伸强度、300％定伸应力和永久变形基本恒定,分别为72±2度、22±1.5MPa,11.0—13.0MPa和<12％;伸长率λ=-5627-15.8×T_g,弹性E=27.9-0.197T_g;分别求得无规型和短嵌段型S-SBR的λ、E与序列分布的线性关联式。     

渭北油田延长组储层四性关系的研究

储层"四性"关系是指储层的岩性、物性、电性和含油气性之间的关系。本文通过结合测井、录井、岩心、分析化验和岩电资料对渭北油田延长组储层四性关系进行了综合分析研究,明确了其储层四性之间的关系,进而为油层解释和储层评价奠定了基础。     

基于SNA的公租房项目核心利益相关者识别

在文献分析法识别公租房项目建设过程中利益相关者的基础上,借助问卷调查得到公租房项目利益相关者之间的关系强度,并运用UCINET6.0软件构建公租房项目利益相关者的社会网络模型。然后,基于社会网络分析法(SNA)定性和定量地识别出公租房项目核心利益相关者。     

用广义拟压力法确定产液气井流入动态

单相气体产能方程有其自身的局限性。广泛使用的压力和压力平方法是对气井在不同的压力区间通过简化而得到的;尽管单相气体拟压力产能方程采用了更严格的处理方法,但也不再适用于油、气、水多相渗流。为此,提出了广义的拟压力函数,从而导出适用于气井多相渗流的产能方程。通过实例计算证明该方法是正确、可行的。     

确定合成地震记录子波主频的方法研究

针对目前合成地震记录质量不高导致层位标定解释、构造解释、储层反演精度低的问题．基于模型正演研究认为合成地震记录质量不高的原因主要是地震子波主频与实际地震子波主频不一致造成的;研究据此提出了基于模型建立地震子波主频与实际地震记录主频两者的差异之间的关系,在实际的应用过程中根据已建立的差异关系和实际地震记录主频可以获得比较准确的地震子波主频,利用这样的主频子波进行合成可获得较好的合成地震记录质量。     

12C6+离子辐照诱发人类肝L02细胞hprt基因突变的研究

本文研究12C6 离子辐照人类肝细胞系L02细胞诱发hprt基因突变与剂量的效应关系,为正确评价重离子对人体正常组织细胞的辐射风险及危害提供基础数据和依据.分别用12C6 离子束(LET为30 keV/μm)和X射线(LET为0.2 keV/μm)对L02细胞进行0～6Gy照射后,用克隆形成法检测细胞的存活分数,另外在含有6-TG的培养基中克隆、筛选hprt突变细胞株,测定突变频率.结果表明:12C6 离子辐照后L02细胞的存活分数明显小于X射线照后.两种射线照射后,每106个存活细胞中突变克隆的个数随照射剂量增大而增大,受照细胞的突变频率也都在1Gy处最大.但相对于X射线,人类肝细胞系L02细胞对高LET重离子辐射更敏感,而且12C6 离子束诱发更多的存活细胞hprt基因突变.     

Genetic evaluation of test-day milk yields from smallholder dairy production systems in Kenya using genomic relationships

Efforts to improve dairy production in smallholder farming systems of East Africa over the past decade have had limited impact because of the lack of records on performance to guide targeted breeding programs. Estimates of genetic parameters in these systems are lacking. Using data generated through a project (“Germplasm for Dairy Development in East Africa”) in Kenya and a genomic relationship matrix from genotypic records, we examined the potential impact of different models handling contemporary groups or herd effects on estimates of genetic parameters using a fixed regression model (FRM) for test-day (TD) milk yields, and the covariance structure for TD milk yield at various stages of lactation for animals using a random regression model (RRM). Models in which herd groups were defined using production levels derived from the data fitted the data better than those in which herds were grouped depending on management practices or were random. Lactation curves obtained for animals under different production categories did not display the typical peak yield characteristic of improved dairy systems in developed countries. Heritability estimates for TD milk yields using the FRM varied greatly with the definition of contemporary herd groups, ranging from 0.05 ± 0.03 to 0.27 ± 0.05 (mean ± standard error). The analysis using the RRM fitted the data better than the FRM. The heritability estimates for specific TD yields obtained by the RRM were higher than those obtained by the FRM. Genetic correlations between TD yields were high and positive for measures within short consecutive intervals but decreased as the intervals between TD increased beyond 60 d and became negative with intervals of more than 5 mo. The magnitude of the genetic correlation estimates among TD records indicates that using TD milk records beyond a 60-d interval as repeated measures of the same trait for genetic evaluation of animals on smallholder farms would not be optimal. Although each individual smallholder farmer retains only a few animals, using the genomic relationship between animals to link the large number of farmers operating under specified environments provides a sufficiently large herd-group for which a breeding program could be developed.     

基于制造特征的加工链模糊推理研究

研究了运用增量式制造特征识别技术,基于零件几何结构、拓扑关系对设计模型中单一设计特征和相交设计特征进行分析,在分析结果的基础上实现对应制造特征识别;深入研究制造特征工艺属性与对应加工方案之间存在的模糊映射关系,运用多因素模糊推理技术形成机加工特征合理的加工链,从而有力地支持设计的可制造性评价及工艺规划的生成。