聚乙烯醇/海藻酸钙水凝胶的制备及其力学性能研究

采用冷冻-解冻交联聚乙烯醇(PVA),海藻酸钠(SA)交联Ca2+制备聚乙烯醇/海藻酸钙(PVA/Alg-Ca)互穿网络水凝胶。探究了影响混合水凝胶pH敏感性及平衡溶胀比的原因,考察了冷冻-解冻循环次数、Ca2+浓度、海藻酸钠含量对凝胶弹性模量(E)的影响。利用回归分析建立数学模型,实现对E定量控制,模拟细胞在体内生长的生物物理环境。数学模型模拟的相对误差不超过0.1,可实现对PVA/Alg-Ca互穿网格水凝胶力学性能的定量控制。     

聚乙烯醇/水性聚氨酯共混膜的制备

目的研究水性聚氨酯(WPU)对聚乙烯醇(PVA)的增韧效果。方法将固含量(质量分数)为35%的WPU按一定比例加入固含量为5%的PVA水溶液中,经混合、除泡、浇注、干燥后制成PVA/WPU共混膜。采用傅里叶红外光谱仪,扫描电子显微镜,差示扫描量热仪,动态热机械分析仪等对共混膜进行表征,并测试共混膜的力学性能、水接触角、吸水率。结果随着WPU含量的增加,与纯PVA相比,共混膜的羟基(—OH)的伸缩振动峰向高波数方向移动,结晶度下降,玻璃化转变温度(t_g)下降,拉伸强度降低,断裂伸长率增加,水接触角增大,吸水率降低,可见光透过率下降。结论 WPU的加入有利于提高PVA/WPU共混膜的韧性,在WPU质量分数为20%～30%时,得到了综合性能较佳的共混膜。     

ST/SA/AA超强吸水剂共混改性水性聚氨酯的制备及性能研究

采用可溶性淀粉(ST)、海藻酸钠(SA)与丙烯酸(AA)接枝共聚制备超强吸水剂溶液(SAP),并将其与水性聚氨酯溶液共混制备复合溶液(SP)及胶膜,重点研究了-NCO/-OH值(R值)和水性聚氨酯(WPU)质量分数对复合胶膜表观形貌、力学性能以及吸水性能的影响。结果表明,复合胶膜中生成大量氢键,且两相相容性良好;其成型质量随R值的增大而下降,且随WPU百分含量的增大而下降;吸水测试表明,其最大吸水率可达180.6%。     

高强度聚乙烯醇/氧化石墨烯复合水凝胶

采用冷冻-解冻方法制备了物理交联的聚乙烯醇/氧化石墨烯复合水凝胶。采用热失重、X射线衍射、差示扫描量热、扫描电镜、力学性能、溶胀性能及离子强度敏感性等分析对制备的复合水凝胶进行了表征,研究了氧化石墨烯(GO)含量、冷冻-解冻循环次数、聚乙烯醇(PVA)浓度对复合水凝胶性能的影响。研究结果表明,复合水凝胶呈现出三维多孔网络结构;随着GO含量的增加,水凝胶的热稳定性增强、熔融温度上升,拉伸强度和压缩强度也得到明显提高,说明GO在复合水凝胶中起到了物理交联剂的作用;复合水凝胶的平衡溶胀比随着GO含量的增加而增大,但当GO的质量分数超过0.4%时逐渐减小;增加冷冻-解冻循环次数或PVA浓度,水凝胶的拉伸强度和压缩强度增大,力学性能得到显著改善。     

表面功能化碳纳米管改性水性聚氨酯复合材料的制备与性能

以聚酯多元醇(PCDL)、异佛尔酮二异氰酸酯(IPDI)、二羟甲基丁酸(DMBA)、1,4-丁二醇(BDO)、双季戊四醇(DiPE)为原料,合成-NCO封端的水性聚氨酯预聚体(WPU);再以多巴胺(DOA)和γ-氨丙基三乙氧基硅烷(APTES)协同修饰碳纳米管(CNTs),得到A-DOA/CNTs,并与WPU进行共价连接、交联,制备了A-DOA/CNTs/WPU复合材料。通过红外光谱、X射线光电子能谱、透射电镜、扫描电镜、热重分析和拉伸性能等对材料结构和性能进行表征,探究了ADOA/CNTs的用量对胶膜耐水性、热性能、断面形貌及力学性能的影响。结果表明,当A-DOA/CNTs质量分数为0.75%时,能均匀分散在聚氨酯基体中,此时胶膜的综合性能最佳,水接触角为92.6°,吸水率5.7%,拉伸强度为29.6MPa,断裂伸长率为225%,质量损失T_(10%)时的热分解温度为267℃,与纯聚氨酯相比热分解温度提高了28℃,其耐热性、耐水性、力学性能均有显著提高。     

甲基丙烯酸缩水甘油酯交联壳聚糖/聚乙烯醇水凝胶薄膜的制备及性能

以甲基丙烯酸缩水甘油酯(GMA)为交联剂制备了一系列壳聚糖(CS)/聚乙烯醇(PVA)水凝胶薄膜,研究了GMA用量对水凝胶样品溶胀性能、力学性能、热失重、生物相容性以及降解性能等方面的影响。实验表明,制备出的水凝胶薄膜韧性由未加交联剂时的14%增加到300%左右。耐溶剂性能和溶胀能力随交联剂用量增加而先减小后增大,在GMA用量为5%时最优。另外,MTT分析和溶菌酶降解实验表明水凝胶薄膜具有良好的生物相容性和降解性。     

PNIPAAm/WPU半互穿网络温敏水凝胶的合成与热性能表征

采用过硫酸铵(APS)和亚硫酸氢钠(SBS)作为引发剂,N,N’-亚甲基双丙烯酰胺(MBA)作为交联剂,在水性聚氨酯(WPU)水溶液中引发N-异丙基丙烯酰胺(NIPAAm)单体聚合,获得聚N-异丙基丙烯酰胺/水性聚氨酯半互穿网络(Semi IPNPNIPAAm/WPU)温敏水凝胶。采用红外光谱法(FT-IR)进行结构分析;采用差示扫描量热法(DSC)、热重法(TG)进行热性能分析。结果表明,成功合成了PNIPAAm/WPU半互穿网络水凝胶,该半互穿网络水凝胶的具有温敏特性与良好的热稳定性,其低临界转变温度(LCST)约为31℃,比PNIPAAm的LCST低3℃。PNIPAAm/WPU半互穿网络水凝胶结合了PNIPAAm和WPU各自的优势,因而在纺织、生物、医学、等领域有较大的应用前景。     

透明隔热SiO2气凝胶/水性聚氨酯复合涂料的制备及性能研究

以水性聚氨酯乳液(WPU)为基体，引入SiO₂气凝胶(SA),制备了一种隔热性能优良的SA/WPU复合涂料，并探讨了SA用量对SA/WPU复合涂料性能的影响。结果表明，随着SA的加入，在保持透明度良好的条件下，复合涂料的隔热性能、附着力及硬度都得到提高。当复合涂料中SA含量为WPU基体固含量的20%时，复合涂料的隔热性能、附着力以及硬度相对最佳，可以获得综合性能优良的复合透明隔热水性聚氨酯涂料。     

磷氮水性聚氨酯胶粘剂阻燃性能研究

研究三聚氰胺(ME)、磷酸三(2-氯丙基)酯(TCPP)和三聚氰胺焦磷酸盐(MPP)3种阻燃剂通过单独添加、两两复配添加和3种共同添加对制得的新型水性阻燃聚氨酯(WPU)胶粘剂的阻燃性能及力学性能的影响,进行了阻燃和力学性能测试。实验结果表明:3种阻燃剂复配制得的新型水性阻燃WPU胶粘剂性能最佳,ME、TCPP和MPP添加量分别为15%(wt,质量分数,下同)、15%、25%制得的新型水性阻燃WPU胶粘剂的续燃时间为0s、阴燃时间为0s、断裂伸长率为15.1%、拉伸强度为13.7MPa。     

PEGDA/SA复合水凝胶的制备及性能研究

通过SLA 3D打印和离子交联的方法制备出聚乙二醇二丙烯酸酯(PEGDA)/海藻酸钠(SA)复合水凝胶。探究了PEGDA和SA不同含量对复合水凝胶溶胀性能、力学性能和热动态分析的影响。溶胀测试结果表明,PEGDA含量的降低或SA含量的上升的均能有效提高水凝胶的吸水速率和平衡溶胀率;压缩性能测试结果表明,SA网络的引入有助于提高凝胶的极限压缩应变和能量耗散性能,PEGDA/SA含量为50/2.5的复合水凝胶极限压缩应变达到30.4%,比相同PEGDA含量的单网络水凝胶提升了45.4%;数字散斑分析结果表明,复合水凝胶的泊松比复合水凝胶的泊松比在0.35~0.5之间;DMA结果标明,复合水凝胶在-20~100℃之间拥有相同的物质结构,SA的加入并没有影响到材料的玻璃化转变温度。     

Study on Shanghai Water Management Information Standard and its application

In Shanghai, three trades including water conservancy, water supply and water drainage are managed integratively by Shanghai Water Authority. However, trade division is apparent among them, and information sharing needs to be strengthened. Therefore, lack of information standard is becoming an urgent problem to be solved. According to the strategic objectives of "Golden Water Project" in China and "Digital City" in Shanghai, "Shanghai Water Management Information Standard" is made for normalizing information classifications, codes, terms, GIS symbols and attributed data structures. It not only coincides with national standards, ministerial standards and Shanghai local standards, but also embodies the characteristic of integrated water management in Shanghai. It provides "traffic rule" for resources integrating and information sharing. Some good research ideas such as omni-direction, multi-levels and facing application can be popularized in other provinces and municipalities of China.     

Fully automatic container terminals of Shanghai Yangshan Port phase IV

Engineering Owner: Construction Headquarters of Yangshan Deep-water Port Phase IV Project of Shanghai International Shipping CenterDesigner: CCCC Third Harbor Consultants Co., Ltd. Civil Constructer: China State Construction Harbor Construction Co., Ltd.;CCCC Third Harbor Engineering Co., Ltd.Equipment Manufacturer: Shanghai Zhenhua Port Machinery Co., Ltd.Software Developer and System Integrator: Shanghai Harbor e-Logistics Software Co., Ltd. of Shanghai International Port (Group) Co., Ltd.Supervisor: Shanghai Far East Waterway Engineering Construction Supervision and Consultation Co., Ltd.;Shanghai Donghua Construction Management Co., Ltd.;Jinghua Engineering Supervision Co., Ltd. under CCCC Water Transportation Consultants Co., Ltd. Operator: Shangdong Branch, Shanghai International Port (Group) Co., Ltd.     

第十一届中国·上海国际摄影器材和数码影像展览展品点击

2009年7月在上海举办的第十一届中国·上海国际摄影器材和数码影像展览会,是国内重要的摄影器材展,许多国内外著名的影像器材制造商参加展出,展出了新产品、新技术。本文介绍一些主要新产品的新技术、规格和性能,供读者了解目前的技术水平。     

Regional development and interregional collaboration in the growth of nanotechnology research in China

China is becoming a leading nation in terms of its share of the world??s publications in the emerging nanotechnology domain. This paper demonstrates that the international rise of China??s position in nanotechnology has been underwritten by the emergence of a series of regional hubs of nanotechnology R&D activity within the country. We develop a unique database of Chinese nanotechnology articles covering the period 1990 to mid-2006 to identify the regional distribution of nanotechnology research in China. To build this database, a new approach was developed to clean and standardize the geographical allocation of Chinese publication records. We then analyze the data to understand the regional development of nanotechnology research in China over our study period and to map interregional and international research collaboration linkages. We find that the geographical distribution of China??s domestic nanotechnology research is characterized by regional imbalance, with most of the leading regions located in eastern China, including not only Beijing and Shanghai but also a series of other new regional hubs. There is much less development of nanotechnology research in central and western China. Beijing, Shanghai, and Hong Kong are among the leading Chinese regions for international nanotechnology research collaboration. Other Chinese nanotechnology regions are less focused on international collaboration, although they have developed domestic interregional collaborations. Although new regional research hubs have emerged in the nanotechnology domain, the paper notes that their concentration in eastern China reinforces existing imbalances in science and technology capabilities in China, and in turn this may further reinforce the dominant position of eastern China in the commercialization of new technologies such as nanotechnology.     

面向应用发展炭材料——记世界碳科学年度大会( Carbon2011)

世界碳科学年度大会( Carbon2011)于2011年7月24日-29日在华东理工大学校园内举行.这是我国继2002年之后第二次承办世界碳科学年度大会.本次会议由华东理工大学、上海理工大学和中国科学院山西煤炭化学研究所共同主办,并得到了教育部、中国科学院、国家自然科学基金委的大力支持.     

Low temperature education and research in China

University education and scientific research in China are briefly discussed with particular emphasis on and examples from low temperature physics. The report is based on its author's recent visit to Peking, Shanghai, Hangchow, and Nanking at the invitation of Academia Sinica     

Measuring the knowledge-based economy of China in terms of synergy among technological,organizational, and geographic attributes of firms

Using the possible synergy among geographic, size, and technological distributions of firms in the Orbis database, we find the greatest reduction of uncertainty at the level of the 31 provinces of China, and an additional 18.0 % at the national level. Some of the coastal provinces stand out as expected, but the metropolitan areas of Beijing and Shanghai are (with Tianjin and Chongqing) most pronounced at the next-lower administrative level of (339) prefectures, since these four “municipalities” are administratively defined at both levels. Focusing on high- and medium-tech manufacturing, a shift toward Beijing, Shanghai, and Tianjin (near Beijing) is indicated, but the synergy is on average not enhanced. High- and medium-tech manufacturing is less embedded in China than in Western Europe. Knowledge-intensive services “uncouple” the knowledge base from the regional economies mostly in Chongqing and Beijing. Unfortunately, the Orbis data is incomplete since it was collected for commercial and not for administrative or governmental purposes. However, we provide a methodology that can be used by others who may have access to higher-quality statistical data for the measurement.     

Characteristics of research on bioinformatics in China assessed with Science Citation Index Expanded

A bibliometric research based on the Science Citation Index Expanded was carried out to provide insights into research activities on bioinformatics in China. Annual publication output has been on continuous increase both worldwide and for China from 1998 to 2012. In recent years, China showed faster growth rates than world average. As the second productive country in the field of bioinformatics, China did not do equally well in terms of citation counts and h-index. Chinese Academy of Sciences and Shanghai Jiao Tong University were among the ten most productive institutes in the world, and their basic metrics and collaboration patterns were compared with other institutes, especially two institutes from Japan. The journal PLoS One was found to have published the most papers from China. In addition, this paper compared the most active categories in Web of Science worldwide with those of China. Personal perspectives of bioinformatics research in China were also presented.     

Corridor-level signalized intersection safety analysis in Shanghai,China using Bayesian hierarchical models

Most traffic crashes in Chinese cities occur at signalized intersections. Research on the intersection safety problem in China is still in its early stage. The recent development of an advanced traffic information system in Shanghai enables in-depth intersection safety analyses using road design, traffic operation, and crash data. In Shanghai, the road network density is relatively high and the distance between signalized intersections is small, averaging about 200 m. Adjacent signalized intersections located along the same corridor share similar traffic flows, and signals are usually coordinated. Therefore, when studying intersection safety in Shanghai, it is essential to account for intersection correlations within corridors. In this study, data for 195 signalized intersections along 22 corridors in the urban areas of Shanghai were collected. Mean speeds and speed variances of corridors were acquired from taxis equipped with Global Positioning Systems (GPS). Bayesian hierarchical models were applied to identify crash risk factors at both the intersection and the corridor levels. Results showed that intersections along corridors with lower mean speeds were associated with fewer crashes than those with higher speeds, and those intersections along two-way roads, under elevated roads, and in close proximity to each other, tended to have higher crash frequencies.     

提升上海国际航运中心综合竞争力的策略研究

在分析东亚各主要港口的竞争态势与我国的实际国情和国际物流发展趋势的基础上,从资源、组织、运行等方面提出了富有建设意义和前瞻性的建议和对策措施：以“轴辐”式立体网络发挥我国的腹地优势,积聚上海周边各港口资源以整合各方力量,以新型组织体系实现港口的一体化管理,以灵活的政策平台快速形成比较竞争优势,以兼容稳定的信息平台提升基于时间的竞争优势,以智能型运行机制赢得持续竞争优势等。除此之外,还必须强化人力资源管理、建立一体化现场监控调度系统,最终形成上海国际航运中心的特色,真正成为世界枢纽港。