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81.
本论文主要对分布式实时数据在输变电系统中各项事务管理和数据汇总处理等应用进行阐述.首先介绍了分布式实时数据库及其特点,接着,详细介绍了分布式实时数据库在输变电系统中的应用.分布式实时数据库的建立可以实现对国网山西省电力公司检修公司所有事务的处理和对所运营的各地区的变电站实时数据进行汇总和处理,同时为智能变电站网络管理系统的建立提供知识库数据和专家经验.为变电站的联网运行奠定基础.  相似文献   
82.
前辈梁思成先生在上世纪四十年代于清华大学教导学生:“建筑师的知识领域要很广,要有哲学家的头脑、社会学家的眼光、工程师的精确与实践、心理学家的敏感、文学家的洞察力……但是最本质的,他应当是一位有文化修养的综合艺术家”.  相似文献   
83.
The path of crack propagation in a graphene sheet is significant for graphene patterning via the tearing approach. In this study, we evaluate the fracture properties of pre-cracked graphene during the tearing process, with consideration of the effects of the aspect ratio, loading speed, loading direction, and ambient temperatures on the crack propagation in the monolayer sheet. Some remarkable conclusions are drawn based on the molecular dynamic simulation results, i.e., a higher loading speed may result in a complicated path of crack propagation, and the propagation of an armchair crack may be accompanied by sp carbon links at high temperatures. The reason for this is that the stronger thermal vibration reduces the load stress difference near the crack tip and, therefore, the crack tip can pass through the sp link. A crack propagates more easily along the zigzag direction than along the armchair direction. The out-of-plane tearing is more suitable than the in-plane tearing for graphene patterning. The path of crack propagation can be adjusted by changing the loading direction, e.g., a rectangular graphene ribbon can be produced by oblique tearing. This new understanding will benefit the application of graphene patterning via the tearing approach.  相似文献   
84.
Layered nickel oxides have been focused with intense research interests as high-performance lithium-ion batterie(LIB) anode.However,it is hard to obtain few layered nickel oxides material directly as it easily forms bulk material with the strong interaction between the interlayer.In this work,two-dimensional(2 D) nickel-based coordination polymers were successfully prepared according to aqueous phase copolymerization approach.And then uniform carbondoped NiO nanosheets were successfully obtained from facile solution assembly and post-thermal treatment.The detailed electrochemical testing shows that the uniform NiO nanocrystals encapsulated into porous N-doped carbon(NiO@NC) nanosheets present much higher rate capability with the discharge specific capacity of 782.7 mAh·g~(-1) at high current density of 2.0 A·g~(-1) than pure NiO(690 mAh·g~(-1)).It also shows long-term cycling performance with 91 % retention after 50 cycles at 1.0 A·g~(-1).The high rate capability,cycling stability and the easy synthesis make NiO@NC nanosheets as a promising candidate for LIB anode and build up new way for the fabrication of metal oxides anode materials.  相似文献   
85.
The effect of microstructures on strength, strain capacity and low temperature toughness of a micro-alloyed pipeline steel was elucidated. Five various dual-pha...  相似文献   
86.
摩擦改进剂对改善燃油经济性的影响研究   总被引:2,自引:0,他引:2  
李桂云  刘岚  陈刚  金理力  蔡继元 《润滑与密封》2007,32(4):140-141,144
采用四球机试验,考察了钼胺化合物、二烷基二硫代氨基甲酸钼、无灰型摩擦改进剂与摩擦因数的关系以及它们之间的复配作用。结果表明:摩擦改进剂(FM)降低摩擦因数的效果与其化学结构有关;加入量提高,摩擦因数的改善效果明显;不同化学结构的摩擦改进剂复配使用,可以减低整个温度区的摩擦因数。  相似文献   
87.
Litter size is an important indicator to measure the production capacity of commercial pigs. Spontaneous embryo loss is an essential factor in determining sow litter size. In early pregnancy, spontaneous embryo loss in porcine is as high as 20–30% during embryo implantation. However, the specific molecular mechanism underlying spontaneous embryo loss at the end of embryo implantation remains unknown. Therefore, we comprehensively used small RNA sequencing technology, bioinformatics analysis, and molecular experiments to determine the microRNA (miRNA) expression profile in the healthy and arresting embryo implantation site of porcine endometrium on day of gestation (DG) 28. A total of 464 miRNAs were identified in arresting endometrium (AE) and healthy endometrium (HE), and 139 differentially expressed miRNAs (DEMs) were screened. We combined the mRNA sequencing dataset from the SRA database to predict the target genes of these miRNAs. A quantitative real-time PCR assay identified the expression levels of miRNAs and mRNAs. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed on differentially expressed target genes of DEMs, mainly enriched in epithelial development and amino acids metabolism-related pathways. We performed fluorescence in situ hybridization (FISH) and the dual-luciferase report gene assay to confirm miRNA and predicted target gene binding. miR-205 may inhibit its expression by combining 3′-untranslated regions (3′ UTR) of tubulointerstitial nephritis antigen-like 1 (TINAGL1). The resulting inhibition of angiogenesis in the maternal endometrium ultimately leads to the formation of arresting embryos during the implantation period. This study provides a reference for the effect of miRNA on the successful implantation of pig embryos in early gestation.  相似文献   
88.
肿瘤细胞增殖与骨吸收之间的恶性循环加剧了骨肿瘤的进展和转移风险.为此,我们设计并制备了聚乙二醇-阿仑膦酸钠修饰的聚多巴胺(PPA)纳米粒子,并在其表面负载自噬抑制剂氯喹(CQ),期望利用该治疗载体(PPA/CQ)打破肿瘤细胞增殖与骨吸收之间的恶性循环,从而有效地治疗骨肿瘤.实验证明,PPA/CQ可以有效地富集到骨组织,...  相似文献   
89.
Sclerotinia head rot (HR), caused by Sclerotinia sclerotiorum, is an economically important disease of sunflower with known detrimental effects on yield and quality in humid climates worldwide. The objective of this study was to gain insight into the genetic architecture of HR resistance from a sunflower line HR21 harboring HR resistance introgressed from the wild perennial Helianthus maximiliani. An F2 population derived from the cross of HA 234 (susceptible-line)/HR21 (resistant-line) was evaluated for HR resistance at two locations during 2019–2020. Highly significant genetic variations (p < 0.001) were observed for HR disease incidence (DI) and disease severity (DS) in both individual and combined analyses. Broad sense heritability (H2) estimates across environments for DI and DS were 0.51 and 0.62, respectively. A high-density genetic map of 1420.287 cM was constructed with 6315 SNP/InDel markers developed using genotype-by-sequencing technology. A total of 16 genomic regions on eight sunflower chromosomes, 1, 2, 10, 12, 13, 14, 16 and 17 were associated with HR resistance, each explaining between 3.97 to 16.67% of the phenotypic variance for HR resistance. Eleven of these QTL had resistance alleles from the HR21 parent. Molecular markers flanking the QTL will facilitate marker-assisted selection breeding for HR resistance in sunflower.  相似文献   
90.
The spatiotemporal evolution of hairpin vortex structures in a fully developed turbulent boundary layer is investigated qualitatively and quantitatively by usin...  相似文献   
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