双组分水性聚氨酯胶黏剂的合成及表征

以聚酯二元醇、甲苯二异氰酸酯(TDI)、二羟甲基丙酸(DMPA)、1,4-丁二醇(BDO)和三羟甲基丙烷(TMP)等为原料合成了双组分水性聚氨酯(WPU)的多元醇组分.考虑到溶解性、反应活性、工业成本等因素,本研究从小分子二元醇(如乙二醇、丙二醇、丁二醇、一缩乙二醇等),小分子三元醇(甘油),小分子四元醇(季戊四醇),聚乙二醇(相对分子质量200~2 000),聚丙二醇(相对分子质量300~2 000)等数十种醇类化合物中,反复试验,再三筛选,最后确定以聚乙二醇-800和六亚甲基二异氰酸酯(HDI)三聚体为原料合成了亲水性多异氰酸酯固化剂组分.将多元醇组分和固化剂组分混合配制,得到了双组分WPU胶黏剂.通过红外光谱(FT-IR)、核磁共振(NMR)、黏度、吸水率、黏接强度、离心稳定性等性能测试,分别对多元醇组分和固化剂组分合成的关键步骤及影响产物性能的各种因素进行了探讨.结果表明,当DMPA、BDO、TMP的质量分数分别为6%、4%、3%时,多元醇组分的外观、稳定性、黏接强度等性能较好;选择聚乙二醇作为亲水组分对HDI三聚体进行改性,且当其添加的质量分数为11%及以上时,制备出的多异氰酸酯固化剂组分具有较好的水分散性.     

聚氨酯多元醇水分散体的合成

以异佛尔酮二异氰酸酯(IPDI),聚醚二元醇(N210),二羟甲基丙酸(DMPA),三羟甲基丙烷(TMP)为主要原料制备端-NCO聚氨酯预聚体,用二乙醇胺(DEA)封端引入羟基,合成了双组分水性聚氨酯的聚氨酯多元醇分散体组分.研究发现:DMPA,TMP的用量、羟基含量及分散体与固化剂组分的配比等因素显著影响分散体及涂膜...     

利用PA制备聚羧酸盐高效减水剂工艺

研究了利用活性大单体甲氧基聚乙二醇甲基丙烯酸酯(PA)、甲基丙烯酸(MAA)、甲基丙烯磺酸钠(MAS)制备聚羧酸盐高效减水剂的合成工艺.通过对反应物料的配比、反应温度、反应时间及搅拌速度等实验条件的研究,确定了最佳合成工艺条件为n(MAA):n(MAS):n(PA)=2.50:0.75:(0.75～1.00),过硫酸铵质量分数为1%、反应温度为90℃、反应时间为4～5h、搅拌速度为280～350r/min.对合成的产品和市售产品进行性能比较测试,表明合成产品的性能优于市售产品.     

阳离子型水性聚氨酯的研制

以聚乙二醇(PEG)、甲苯二异氰酸酯(TDI)、N-甲基二乙醇胺(MDEA)为主要原料,用自乳化法合成了阳离子型水性聚氨酯;探讨了合成反应工艺条件.研究表明,较佳的合成工艺条件为:制备预聚物时n(NCO)/n(OH)比值为3:1;以N—甲基二乙醇胺为扩链剂,采用“饥饿加料”方式,其用量为预聚物质量分数的5.0%~6.0%;预聚物合成反应温度为60℃,反应时间3 h;扩链反应的反应温度40℃,反应时间5 h;中和度为80%~100%.在此工艺条件下,合成的阳离子型水性聚氨酯具有良好的稳定性能.     

UV涂料用聚氨酯丙烯酸酯弹性预聚体

以甲苯-2,4-二异氰酸酯、SAN树脂、丙烯酸羟乙酯等原料合成聚氨酯丙烯酸酯预聚物,研究了反应温度、反应时间及催化剂浓度对树脂合成的影响.得出合成该预聚物的适宜条件:第1步反应温度为25~35℃,反应时间为2.5 h;第2步反应温度控制在75~80℃,反应时间为3 h,催化剂质量分数为0.4%.同时通过调节活性稀释剂三缩丙二醇二丙烯酸酯、三羟甲基丙烷三丙烯酸酯、1,6己二醇二丙烯酸酯的不同配比制备紫外光固化涂料,测试涂膜光泽、硬度、柔韧性、耐冲击强度、附着力等各项性能,找出涂膜具有良好弹性及柔韧性且符合光固化膜性能要求的涂料配方.     

高效脱色絮凝剂MDF的合成

以双氰胺、甲醛为原料并引入改性剂氯化铵,在氯化铝的催化下合成了一种高效脱色絮凝剂MDF.以活性艳橙K-G模拟印染废水的脱色率为考核指标,考察了改性剂用量、反应物料配比、催化剂用量等因素对产品性能的影响.研究结果表明,脱色絮凝剂MDF最佳的合成条件为反应温度75℃,反应时间4 h,反应物配比为n(甲醛)∶n(双氰胺)∶n(氯化铵)∶n(氯化铝)=2.5∶1∶0.75∶0.05.脱色絮凝剂MDF对活性艳橙K-G模拟印染废水的脱色率可达98.5%,最佳药剂投加量为100 mg/L.     

新型改性水性聚苯胺-环氧树脂涂料的制备

通过化学结构改性法分别在环氧树脂E-44的一端引入双键,另一端引入羟基,用不饱和有机酸中和,得到水性环氧树脂.研究了单体配比、反应温度对反应转化率的影响,确定了水性环氧树脂制备的最佳条件为:n(N-甲基烯丙基胺):n(二乙醇胺):n(E-44)=1.00:1.05:1.00;反应温度60℃;反应时间 4 h.同时研究了水性环氧树脂及固化剂不同配比对涂层性能的影响,确定了水性环氧树脂乳液和固化剂的最佳质量比为2:1.     

Ymer N120改性非离子型水性环氧乳液的制备与性能研究

为克服当前水性环氧乳液的环氧基团含量和固含量低导致的涂料和涂膜性能差的缺点，本文从分子结构设计的角度出发，首先以聚乙二醇400（PEG400）为软段，制备了非离子型水性环氧（WEP）乳液；然后以侧基亲水扩链剂（Ymer N120）对其进行改性，合成了改性非离子型水性环氧（YWEP）乳液，研究了Ymer N120的用量对YWEP乳液和涂膜性能的影响.结果表明，WEP乳液的环氧基团含量（以环氧值表示）最高可达0.36,引入侧基亲水基团后YWEP乳液可在保持较高环氧值的条件下进一步将固含量由30%提高至52%,提高了73.3%.固化后涂膜的拉伸强度由57.3 MPa增大至64.8 MPa.腐蚀电流密度由7.97×10^-8 mA·cm^-2减小至9.99×10^-9 mA·cm^-2.综上所述，亲水基团由主链转移至侧基后可有效提高水性环氧乳液、涂料和涂膜的性能.     

无溶剂有机硅浸渍树脂合成及性能研究

以混合烷氧基硅烷和三甲基氯硅烷为原料,以盐酸为催化剂,采用水解-缩聚法制备了三甲基硅基封端同时包含乙烯基、氢、苯基的体型聚硅氧烷(无溶剂有机硅浸渍树脂),配合氯铂酸-乙烯基硅氧烷催化剂和抑制剂,配制无溶剂有机硅浸渍漆.研究了无溶剂有机硅浸渍树脂合成工艺中反应温度、反应时间、酸的浓度、水/烷氧基配比等因素对聚合物制备的影响规律.研究了硅乙烯基、苯基含量和硅氢/硅乙烯基配比对无溶剂有机硅浸渍树脂性能的影响规律.研究结果表明,最佳的制备工艺:水解温度为60℃,反应时间4 h,盐酸的质量分数为14%,水/烷氧基配比为0.5∶1.当硅乙烯基摩尔分数为7.8%,苯基摩尔分数为45%,硅氢/硅乙烯基配比为1.26∶1时,拉伸及弯曲性能最佳.采用红外、核磁、TGA等手段对无溶剂有机硅浸渍树脂进行结构表征和分析,并测试其机械、耐热和绝缘等性能.     

新型磷腈阻燃剂对环氧树脂的阻燃应用研究

以三乙烯四胺(TETA)、环氧树脂(E-51)、单环氧化合物(AGE)为原料,在物料摩尔比(TETA:E-51:AGE)为1∶0.5∶1,反应温度为60℃,反应时间为4h的工艺条件下制备的水性环氧固化剂,与环氧乳液均匀混合,合成了一种新型环氧树脂涂料。分别将5%(wt,质量分数,同下),10%,15%,20%的磷腈阻燃剂添加到制备的环氧树脂涂料混合,并通过耐盐雾、耐水、极限氧指数、热重分析等测试研究阻燃涂料的综合涂膜性能、阻燃性能及热性能。结果表明:水性环氧固化剂与自制环氧乳液和添加10%磷腈阻燃剂混合涂膜,极限氧指数值从19.8提高至28,改善了环氧树脂的阻燃性能。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to