共查询到20条相似文献，搜索用时 705 毫秒
1.
所谓高分子,可以粗略地分为天然高分子与合成(人工)高分子。自古以来天然高分子对于人类的生活始终是密切相关的。无论是作为食物的蛋白质与淀粉还是作为织物的棉、毛与蚕丝都是天然高分子,此外,利用竹、棉、麻等纤维造纸是我国古代的天然高分子加工技术,再如,利用桐油与大漆作为油漆、涂料乃至漆制品又是我国古代的传统技术。 相似文献
2.
高分子材料是新材料领域的重要组成部分．由于其具有优良的物理、化学性能和优异的加工特性．被广泛应用于信息产业、航空航天、生物医药、交通运输、建筑和能源等国民经济重要领域。随着新型高分子合成、改性与加工等高技术的发展．高性能高分子材料迅速崛起．新产品、新技术不断涌现。新型高分子材料的开发和广泛应用．对于推动传统产业的升级换代、新兴产业的发展壮大起到积极的作用。 相似文献
3.
王玮 《科技成果管理与研究》2016,(5):1-2
蹇锡高,中国工程院院士,大连理工大学教授.主要从事聚合改性和耐热高分子材料研究.从分子结构设计结构出发,研制新单体和新聚合物,研究合成反应路线、合成工艺、反应动力学和机理,研究聚合物的结构/性能关系,开发综合性能优异的新型耐热高分子材料,并开展新型高分子材料的加工、应用研究.2003年,其主持完成的"含二氮杂萘酮联苯结构新型聚醚砜酮及其制备法"获技术发明二等奖;2012年,主持完成的"杂萘联苯聚醚腈砜系列高性能树脂及其应用新技术"获得国家技术发明二等奖.为发展我国高性能工程塑料作出了重要贡献. 相似文献
4.
在工业生产领域中,高分子材料成型加工属于热门研究课题。本文围绕高分子材料成型加工技术进行研究,首先概述了高分子材料及其成型加工技术,其次介绍了几种常见的高分子材料成型加工技术（挤出成型技术、注射成型技术、吹塑成型技术）,最后讨论了高分子材料成型加工技术发展趋势,以期为业内人士提供有益参考。 相似文献
5.
近年来,随着高分子材料成型加工技术在工业上取得了飞速发展,我国航空工业、国防工业等领域的发展对聚合物材料的性能提出了更高的要求。现着重探讨一下高分子材料成型加工技术的发展前景。 相似文献
6.
加工过程中高分子材料形态控制的研究进展 总被引：2，自引：0，他引：2
高分子材料的性能不仅依赖于大分子的化学结构和链结构，而且在
很大程度上依
赖于结晶、取向形态及多相体系的相形态。开展高分子材料在加工过程中的热、应力场作用
下形态形成、演化、调控及“定构”研究对发展高分子成型加工基础理论、开发高性能化、
复
合化、多功能化、低成本化及清洁化高分子材料有重要意义。本文简述了加工过程中高分子
材料形态控制的研究进展，包括国内外研究现状、存在的问题和我国的差距及未来研究的重
要科学问题。 相似文献
7.
8.
9.
我国反应注射成型研究新进展 总被引：5，自引：0，他引：5
材料、能源、信息是当代科学技术的三大支柱。高分子材料是材料科学领域的后起之秀,现已获得广泛的应用,并具有广阔的发展前景。传统的高分子材料制造工艺,一般首先需要经历单体聚合成为高聚物,再通过特殊的成型手段将高聚物加工成为特定形状制品的过程。注射成型是高聚物的主要成型手段之一,传统的注射成型是将颗粒状的高聚物粒料通过加热熔融注射到模具中,再冷却制作成特定形状的制品,其工艺过程一般不涉及聚合反应。 相似文献
10.
11.
单相有源电力滤波器谐波无功检测方法的研究 总被引：1，自引：0，他引：1
有源电力滤波器(APF)的谐波无功电流检测是关键。本文提出了基于瞬时无功功率理论与基于神经网络的单相谐波无功电流检测法,Matlab仿真研究表明这两种检测法均能达到检测要求,且后者具有更高的检测速度,有着广泛的应用前景。 相似文献
12.
本文从10KV供电线路进行无功补偿的必要性出发.介绍了无功补偿的原理和意义,详述了LHGW10KV无功自动补偿系统的原理、结构性能、安装调试及常见故障的排除方法. 相似文献
13.
针对农村中压配电网无功损失较为严重的现象,研究了农村中压电网无功补偿优化问题,寻找满足电压质量要求和线损最小条件下农村中压电网无功补偿装置的最佳安装位置和最佳补偿容量。在研究农村中压电网结构特点的基础上,提出了简便、有效的优化算法。算法以无功补偿的最佳位置和最佳容量为目标,考虑了网损最小、电压质量和综合经济性等多目标优化约束条件。 相似文献
14.
利用LDW-PSO算法解决了输配电网的无功优化补偿问题。阐述了无功优化补偿的数学模型以及LDW-PSO算法优化步骤。工程实例验证表明,该方法降低了网损,且所有节点电压都满足要求,在节能降耗方面具有较大优势。 相似文献
15.
P. Faizal B. Satheeshan Milindkumar A.K. Adarsh R. Shilpa P. Roshni T. Remya K.T. Augusti 《Indian journal of clinical biochemistry : IJCB》2013,28(4):426-428
Extensive research has demonstrated the protective properties of antioxidants, which scavenge reactive oxygen species and their precursors, as well as up-regulate enzymes involved in the repair of cellular damage. Several case–control studies have showed higher blood levels of antioxidants and decreased oxidative stress in younger individuals when compared with older ones. Cell damage caused by free radicals appears to be a major contributor in aging and degenerative diseases of aging such as cancer, cardiovascular disease, cataracts, compromised immune system, rheumatoid arthritis and brain dysfunction. The objective of this study was to determine the variation of Circulating levels of selected antioxidants (enzymic and non enzymic) and oxidative stress marker in younger and older humans. The results showed that a majority of the younger age group participants showed a significant increase in enzymic and nonenzymic antioxidant status and a decrease in oxidative stress when compared with the older age group. 相似文献
16.
研究职称差异对科研成果的影响机制不仅有利于充分调动科研人员的积极性,而且对于优化职称结构具有重要意义,但相关领域的研究比较薄弱。本文在分析不同职称科研人员对科研成果影响机制的基础上,采用联立方程模型研究不同职称科研人员对不同科研成果的贡献,并且研究高职称科研人员与低职称科研人员的协调效应,最后采用BP人工神经网络进行稳健性检验。研究结果表明：不同职称科研人员对科研成果的作用机制不同;高级职称科研人员对科研成果的贡献大于初中级职称科研人员;研发经费对科研成果的贡献要小于研发人员;高级职称科研人员与初中级职称科研人员协调不佳。最后从优化职称结构和科研经费分配方面提出了相关政策建议。 相似文献
17.
基于激发型信息处理的视角,探讨了合作目标互依性、知识共享和团队反思与科研团队创造力之间的关系,构建了相应的概念模型。运用结构方程模型和225个有效科研团队样本对所提出的假设进行检验。实证研究结果表明,合作目标互依性对科研团队创造力有积极影响;知识共享与团队反思在合作目标互依性与科研团队创造力之间具有完全中介效应,而知识共享对团队反思有正向促进作用。研究结果打开了合作目标影响科研团队创造力的信息处理黑箱,扩展了激发型信息处理视角在团队创造力研究领域中的应用。 相似文献
18.
Reactive oxygen species and other free radicals are known to be the mediators of phenotypic and genotypic changes that lead
from mutation to neoplasia. There are some primary antioxidants such as glutathione peroxidase (GPx), glutathione S-transferases
(GSTs) and reduced glutathione, which protect against callular and molecular damage caused by the reactive oxygen metabolites
(ROMs). The present study was conducted to determine the level of malondialdehyde (MDA), as an index of lipid peroxidation,
along with the GPx, GSTs activities and level of reduced glutathione in 45 prostate cancer (PC) patients, 55 benign prostate
hyperplasia (BPH) patients as compared to the controls. Significant higher levels of MDA and GSTs activities in the serum,
(P<0.005) and significant lower levels of reduced GSH concentration and GPx activity in blood haemolysates (P<0.05) of PC and BPH patients were observed as compared to the controls. The relatively higher GSTs activity and low level
of reduced GSH may be due to the response of increased reactive oxygen metabolites production in the blood. The higher MDA
and lower GPx activities may be inadequate to detoxify high levels of H2O2 into H2O leading to the formation of the*OH radical followed by MDA. This result hypothesizes that oxidant-antioxidant imbalance may be one of the major factor responsible
for the development of prostate cancer and benign prostate hyperplasia. 相似文献
19.
Piotr Tarka 《Information processing & management》2019,56(3):541-553
The main purpose of this paper is to investigate the relationships between three theoretical constructs developed in the course of the study measuring: (a) managers' memory capacity, (b) information processing, as a part of general system of cognitive capabilities, and (c) their perception of market research usefulness. In particular, we diagnose managers' natural limitations associated with cognition which determine their capabilities to deal with the market research information storage and retrieval as well as research information processing. With this intention and theoretical assumption, we designed and implemented a two-phase process of research. In the first phase, based on the literature review; face-to-face in-depth interviews and a pilot study (a pretest) we developed measurement models for the proposed theoretical constructs. Next, we conducted quantitative research among 213 highly experienced managers working in multinational companies in a European country (Poland), where the sample included individuals who were responsible for planning strategic and tactical marketing activities. Based on the structural equation modeling as the analytical strategy, the empirical research results revealed that managers in business organizations due to limited cognitive capabilities such as lower-than-average memory capacity and poor information processing, develop wrong perceptions of the usefulness of market research. Managers, when faced with difficulties regarding information storage and retrieval, as well as information processing, react negatively towards that research. Finally, we explained the reasons as to why managers in companies perceive market research in a negative light, as well as presented the most important theoretical and managerial implications. 相似文献
20.
为了实现变电站内无功电压优化控制,提出了采用禁忌搜索算法进行无功电压优化控制问题的求解。以最大限度地降低功率损耗、提高电压质量和减少变压器的调节次数及电容器组的投切次数为目标,建立了相应的数学模型,并考虑系统潮流、控制变量、状态变量、器件动作次数的约束条件。采用数值仿真的方法进行了验证,仿真结果表明提出的方法可以得到最优解,解的质量较高。 相似文献