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991.
992.
The FTIR method was used to study the melting behavior of poly(ethylene 2, 6-naphthalene-dicarboxylate) (PEN) samples of different thermal history of crystallization. With subtraction of the spectra of PEN samples of different crystallinities and amorphous PEN, the spectra of crystalline trans conformers, amorphous trans conformers, and amorphous gauche conformers were obtained. By following the changes in intensity of various gauche and crystalline bands during heating, the phenomenon of multiple melting endothermic peaks was shown to be due to the melting of imperfect crystalline conformation formed during crystallization. For two-step annealed samples, the crystalline conformational defects change into a more perfect one during annealing at higher temperatures. © 1996 John Wiley & Sons, Inc. 相似文献
993.
In order to develop a computer-based color consultation system, a quantitative evaluation of color harmony for interior images is constructed by using a linguistic-based image scale. Conventionally, color harmony from any engineering perspective has received limited attention, because its successful evaluation requires the development of pleasure-related features. In this study, a new pleasure-related function of color linguistic distribution (CLD) is proposed to quantitatively represent the mental color impression of interior images upon a designed one-dimensional linguistic-based image scale of EXCITING-CALM. Supported by a database that includes fashion trends, the distribution state of CLD is capable of indicating the fashion trends in Taiwan. Also, on the image scale, the grade of color harmony can be measured by its CLD similarity to a reference harmony distribution (RHD). Evaluated results demonstrate that interior design is primarily dominated by (low) saturation and (high) brightness. Also, results based on CIE1976 L*a*b* and CIE1976 L*u*v* color spaces are observed to be better than those based on the hue-dominated method of Moon-Spencer theory in corresponding with human's linguistic similarity, questionnaire-based harmony evaluation, and social trends. Moreover, our solution percentage has been investigated as 72.3%, which is better than those of the Moon-Spencer theory and of the “Law of Inverse Ratios of Areas.” For application purposes, the proposed system is suitable to analyze the mental impression of products from the perspective of the customer. © 1996 John Wiley & Sons, Inc. 相似文献
994.
本文介绍了一种超声波强化高速射流破岩新技术。高压水射流技术是上世纪70年代发展起来的一种清洗、切割、除垢、破岩新技术。用超声波来调制连续的高速射流使之产生脉动,可以使高速射流产生的作用力显著增强。本文介绍了这种新技术的原理、结构、应用等。 相似文献
995.
合理的景观设计抵制城市死角达到犯罪预防——以上海市徐家汇某高架公园环境分析为例 总被引:1,自引:0,他引:1
城市化进程不仅改变了传统土地组织结构与社会文化,也导致了日益严重的都市犯罪问题.特别是有些大城市随着城市发展出现了“城市死角”。该文主要探讨以合理的设计手法来倡导符合具体都市功能的环境设计,达到预防犯罪的目的,抵制城市死角。研究选取上海市典型的高架桥底舟固为模型,找出较为合理的设计通用手法来处理高架公园问题,旨在尽可能地使用城市集约空间,消除城市“死角”现象, 相似文献
996.
The high strength of boron carbide (B4C) is essential in its engineering applications such as wear-resistance and body armors. Here, by employing density functional theory simulations, we demonstrated that the strength of B4C can be enhanced by doping lithium to boron-rich boron carbide (B13C2) to form r-LiB13C2. The bonding analysis on r-LiB13C2 indicates that the electron counting rule (or Wade's rule) is satisfied in r-LiB13C2 whose formula can be written as r-Li+(B12)2-(CB+C). The shear deformation on r-LiB13C2 indicates that its ideal shear strength is larger than that of B4C because of the existing of Li dopant. The failure process of r-LiB13C2 under ideal shear deformation initiates from breaking the icosahedral-icosahedral B-B bonds. Then these B atoms react with the middle B in the C-B-C chain, resulting in the disintegration of icosahedral clusters and brittle failure. More interesting, the nanotwinned r-LiB13C2 is even stronger than r-LiB13C2 because of the directional nature of covalent bonding at the twin boundaries. This suggests that the nanotwinned r-LiB13C2 has a significant enhanced strength compared to B4C. Our simulation results illustrate the deformation mechanism of Li-doped boron carbide and its nanotwinned microstructure. We proposed to improve the strength of boron carbide by doping Li into B13C2 and increasing its twin densities. 相似文献
997.
WU Lin-tuo XU Xiang-dong SHEN Chong 《光电子快报》2006,2(2):145-147
Driverfatigueisoneofthemostimportantfactorsin manyvehicularaccidents.InU.S.A,theNationalHigh wayTransportationSafetyAdministrationhasestimated thatabout100,000police reportedcrashesarethedirect resultofdriverfatigueeachyear,representingmorethan1,550deaths… 相似文献
998.
Keng-Liang Ou Chiung-Fang Huang Wen-Chien Lan Bai-Hung Huang Hsu-An Pan Yung-Kang Shen Takashi Saito Hsin-Yu Tsai Yung-Chieh Cho Kuo-Sheng Hung Hsin-Hua Chou 《International journal of molecular sciences》2022,23(3)
The ability of Pluronic F127 (PF127) conjugated with tetrapeptide Gly-Arg-Gly-Asp (GRGD) as a sequence of Arg-Gly-Asp (RGD) peptide to form the investigated potential hydrogel (hereafter referred to as 3DG bioformer (3BE)) to produce spheroid, biocompatibility, and cell invasion ability, was assessed in this study. The fibroblast cell line (NIH 3T3), osteoblast cell line (MG-63), and human breast cancer cell line (MCF-7) were cultured in the 3BE hydrogel and commercial product (Matrigel) for comparison. The morphology of spheroid formation was evaluated via optical microscopy. The cell viability was observed through cell counting Kit-8 assay, and cell invasion was investigated via Boyden chamber assay. Analytical results indicated that 3BE exhibited lower spheroid formation than Matrigel. However, the 3BE appeared biocompatible to NIH 3T3, MG-63, and MCF-7 cells. Moreover, cell invasion ability and cell survival rate after invasion through the 3BE was displayed to be comparable to Matrigel. Thus, these findings demonstrate that the 3BE hydrogel has a great potential as an alternative to a three-dimensional cell culture for drug screening applications. 相似文献
999.
1000.
Haokun Shen Zitong Zhao Zengjue Zhao Yuyi Chen Linghua Zhang 《International journal of molecular sciences》2022,23(2)
Intestinal homeostasis is a dynamic balance involving the interaction between the host intestinal mucosa, immune barrier, intestinal microecology, nutrients, and metabolites. Once homeostasis is out of balance, it will increase the risk of intestinal diseases and is also closely associated with some systemic diseases. Probiotics (Escherichia coli Nissle 1917, Akkermansia muciniphila, Clostridium butyricum, lactic acid bacteria and Bifidobacterium spp.), maintaining the gut homeostasis through direct interaction with the intestine, can also exist as a specific agent to prevent, alleviate, or cure intestinal-related diseases. With genetic engineering technology advancing, probiotics can also show targeted therapeutic properties. The aims of this review are to summarize the roles of potential native and engineered probiotics in oncology, inflammatory bowel disease, and obesity, discussing the therapeutic applications of these probiotics. 相似文献