缺陷控制对胆甾相液晶材料双稳态性能的影响及其应用

通过弯曲分子的掺杂实现了胆甾相液晶平面态油丝缺陷的调控和焦锥形貌的稳定,研究了各因素对双稳态稳定性的影响,并展示了双稳态的潜在应用。偏光显微镜观察和透过率?电压曲线测试结果表明,弯曲分子的引入可以调控甚至消除平面态的油丝缺陷,实现透过率增加,同时调节焦锥态的形貌,使扇形畴更细小破碎,有利于增强焦锥态的散射和稳定性,实现双稳态效果。这是因为弯曲分子具有很小的弯曲弹性常数,进而对胆甾相液晶的弯曲弹性常数和扭曲弹性常数相对大小进行调节。平面取向层的锚定越强,对双稳态(主要是焦锥态)的稳定越不利,但锚定作用太弱,不利于平面态的完美排列。可以通过取向作用强弱调节、盒厚调整来达到较优的效果。少量聚合物的引入有利于实现双稳态的稳定。最后,基于缺陷调制后的双稳态特性制备了无色和彩色的调光膜,展示了双稳态的潜在应用。      

制备条件对反式聚合物稳定胆甾相织构膜电光性能的影响

选用1,4-双[4-(6-丙烯酰氧基己氧基)苯甲酰氧基]-2-甲苯(C6M)/(S)-4'-(2-甲基丁基)-4-联苯腈(CB15)/安息香二甲醚(IRG651)/SLC1717复合体系,通过紫外光聚合诱导相分离法制备了反式聚合物稳定胆甾相织构(R-PSCT)膜.研究了聚合温度和紫外光辐照度对所制备的R-PSCT膜电光性能的影响.随着聚合温度的升高或紫外光辐照度的减小,R-PSCT膜的驱动电压、对比度和开态响应时间减小,而关态响应时间增大.在聚合温度为293 K和紫外光辐照度为0.75 m W·cm^-2时,所制备的R-PSCT膜具有较佳的电光性能.     

AM/AMPS二元聚合物的合成及絮凝性能评价

以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)和丙烯酰胺(AM)为单体,制备了一种水溶性的AM/AMPS共聚物,对合成条件进行了分析,探讨了单体比例、引发剂、温度等因素对聚合物絮凝特性的影响,确立其最佳合成条件.研究发现合成反应温度45℃,反应时间7 h,AMPS与AM质量比3:7,引发剂过硫酸铵质量分数0.02%,溶液pH值6～8,该共聚物对污水的絮凝效果理想,显示出良好的耐盐抗温能力.     

对烯丙氧基苯甲酸胆固醇酯对聚合物分散液晶薄膜电—光性能的影响

选用对烯丙氧基苯甲酸胆固醇酯(ACB)/甲基丙烯酸β-羟乙酯(HEMA)/液晶(LC)/光引发剂(IRG-651)/玻璃微珠(SP-220)复合体系,在紫外光照射下制备了聚合物分散液晶(PDLC)薄膜.结果表明:虽然ACB没有参与聚合,但却明显地提高了PDLC薄膜的对比度.在紫外光(365.0 nm)辐照度为15.0 mW·cm^-2、照射温度为303.2 K、照射时间为10.0 min的条件下,ACB/HEMA/LC/IRG-651/SP-220的比例(质量分数)为6.2%/18.5%/74.0%/0.3%/1.0%时,所制备的PDLC薄膜具有高对比度和较佳的电-光性能.     

含取代茚基配体稀土金属有机化合物的合成、表征及催化性能

采用Schlenk技术,在干燥纯氩气保护下,用无水三氯化稀土LnCl3与2-苯基茚以1∶2的摩尔比在THF中反应,得到8种新配合物:(2-ph-Ind)2LnCl(A)[Ln=La(1),Pr(2),Nd(3),Sm(4),Gd(5),Dy(6),Yb(7),Y(8)]。再用(A)和LiN(TMS)2在THF中反应,得到两种新的二(2-苯基茚)稀土有机配合物:(2-ph-Ind)2LnN(TMS)2(B)[Ln=Y(1),Sm(2)]。所有配合物都经元素分析、红外和质谱鉴定。配合物(B)在甲基丙烯酸甲酯(MMA)的聚合反应中显示出一定的活性。     

一种手性Zn(Ⅱ)配位聚合物的水热合成及晶体结构

通过水热技术制备了1种新的手性配位聚合物[Zn(Tar)(bipy)·5H2O](聚合物1,Tar为L-酒石酸根,bipy为2,2'-联吡啶),其结构经X射线单晶衍射鉴定.在水热反应过程中,酒石酸衍生物缩酮保护基发生水解.该聚合物属正交晶系,P2(1)2(1)2(1)空间群,晶胞参数a=0.664 61(13)nm,b=1.431 3(3)nm,c=1.912 8(4)nm,α=β=r=90°,V=1.819 6(6)nm3,Z=4,μ=1.414 mm-1,dcalc=1.678 g/cm3,F(000)=952,R1=0.045 7,ωR2=0.093 0.结构分析表明,酒石酸根桥连Zn(Ⅱ)形成一维配位聚合物手性链;2条平行一维链上的吡啶环以面对面的方式相互嵌入(质心距离为0.358 nm)形成新颖的梯状双链结构,5个结晶水之间存在氢键作用,通过共用边5聚环形成一维水链,而水链上的2个O又与未配位的羧酸根O通过氢键作用相连接形成三维超分子结构.     

铜离子印迹聚合物的制备、性能与应用研究

以Cu2＋为印迹离子,Cu2＋、AM和EGDMA的摩尔比为1：4：30,合成了一种具有高选择性和分离富集能力的金属离子印迹聚合物（ⅡP2）。其在40μg／mL的cu2＋水溶液中对Cu2＋的吸附量为12．80mg／g,印迹因子为1．94。以优化工艺下合成的印迹聚合物（ⅡP2）制备了印迹固相萃取柱,优化了固相萃取条件,并在此条件下对两个污水样品进行分析,cu2＋的萃取率分别达到93．5％和90．7％。该印迹聚合物有作为cu（Ⅱ）分离富集材料的应用前景。     

粘结相对原位合成TiC钢结硬质合金组织结构和性能的影响

以钛铁粉、铬铁粉、铁粉、胶体石墨和镍粉等为原料,原位合成了TiC/Cr18Ni8、TiC/Cr19Al3和TiC/Ni40钢结硬质合金,并用扫描电镜、X射线衍射仪和洛氏硬度计、拉力试验机等对不同粘结相所制备的试样进行了组织结构分析和物理力学性能检测.结果表明:钢结硬质合金主要相组成为TiC、Fe-Cr-Ni和Fe-Cr固溶体,TiC晶粒细小,形状较为规则;粘结相对原位反应合成的钢结硬质合金的密度、硬度和所合成的TiC晶粒有较大影响,在相同烧结条件下TiC/Ni40钢结硬质合金的密度和硬度比TiC/Cr18Ni8和TiC/Cr19Al3钢结硬质合金的高,但TiC/Ni40钢结硬质合金中所合成的TiC晶粒比TiC/Cr18Ni8和TiC/Cr19Al3钢结硬质合金中合成的TiC晶粒偏聚现象严重.TiC/Ni40钢结硬质合金的硬度为60～70.5HRC,TiC/Cr18Ni8和TiC/Cr19Al3钢结硬质合金的硬度多在20～50HRC之间.三者的抗弯强度为960～1452MPa.     

手性Eu(Ⅲ)配合物的合成和作为ct-DNA荧光探针的研究

通过制备拆分剂氯化(8S,9R)-(-)-N-苄基辛可尼定,拆分了外消旋联萘酚得到其两种对映异构体,以手性联萘酚为原料分别合成了配体(R)-L和(S)-L及其相应的Eu(Ⅲ)配合物(R or S)-L-Eu(NO3)3,并测定了旋光度。分别研究了配合物(R or S)-L-Eu(NO3)3与ct-DNA的作用方式及键合常数,发现配合物与小牛胸腺DNA(ct-DNA)存在插入作用,且(R)-L-Eu3+配合物与ct-DNA的键合能力较强。由于ct-DNA对(R)-L-Eu3+配合物荧光的增敏作用,选择(R)-L-Eu3+配合物作为ct-DNA的手性荧光探针,在最佳实验条件下,其线性范围为0.11×10-5～0.55×10-5 mol·L-1,0.55×10-5～7.8×10-5 mol·L-1,检出限为5.85×10-7 mol·L-1。     

新型双尾疏水缔合三元共聚物的合成及流变性能评价

通过丙烯酰胺(AM)与N-苄基-N-十二烷基丙烯酰胺(BDAM)反应,采用自由基胶束共聚后加减水解法合成了双尾疏水缔合三元共聚物(AM-NaA-BDAM).用FTIR红外光谱表征了聚合物的结构,并研究了共聚物溶液的流变性能及影响因素.实验结果表明:随着共聚物浓度的增加,在临界缔合浓度以上,表观黏度迅速增加,表现出明显的疏水缔合行为;共聚物溶液具有良好的黏弹性,G'(储能模量)＞G"(损耗模量),且共聚物具有较强的耐温抗盐能力.     

Synthesis and Electrocatalytic Properties of Complex Oxides Containing Lanthanum

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Synthesis and Photophysical Properties of Dy^3＋ and Gd^3＋ Polymeric Complexes with Functionalized Polybenzimidazole Containing β-Diketone Side Group

The polymeric ligand PBIa （functionalized polybenzimidazole containing β-diketone side group） was successfully synthesized via the reaction of polybenzimidazole （PBI） with 3-Br-acetylacetone in DM SO solvent using Nail as the deprotonation reagent. Its corresponding polymeric complexes of Dy^3＋ and Gd^3＋ were prepared and characterized by FT-IR, ^1H NMR, molar conductance measurements, and thermal analysis. The photoluminescence properties and the probable mechanism of the Dy and Gd complexes were studied. The measurement and analysis of the thermal properties showed that these were thermal stable.     

Long-Term Properties and Transfer Length of Fiber-Reinforced Polymers

This paper discusses the experimental results on properties and transfer length of the common types of fiber-reinforced polymer (FRP) tendons. Based on the experimental results, an equation is proposed for predicting the creep coefficient of aramid-based FRP (AFRP) tendons. The results show that the creep of carbon-based FRP (CFRP) is less than 0.2%. The test results show that the transfer length of CFRP is in the range of 300–800 mm and the concrete strength at transfer is one of the major factors affecting the transfer length of CFRP. A new factor accounting for the concrete strength is proposed for estimating the transfer length of CFRP tendons, and the verification is made for this equation. The transfer length was found to vary from 170 to 270 mm, which was 20–30 times the tendon diameter for these AFRP tendons. Despite the creep and shrinkage of concrete and the relaxation of the tendon itself, the range for transfer length did not vary with time.     

Interaction Between Liquid Steel and AlN Substrate Containing Al-Y-Oxides

Metallurgical and Materials Transactions B - Reactions between molten iron, molten silicon steel, and ceramic materials are of great importance from the perspective of the corrosion of refractory...     

氧化锌晶体的制备与表征

利用聚乙二醇-10000（PEG-10000）为添加剂,改变锌盐种类,在水热条件下反应10 h,经洗涤、干燥处理后,得到ZnO微晶粉体.产物通过全自动X射线衍射仪（XRD）进行物相分析,扫描电子显微镜（SEM）,透射电子显微镜（TEM）观测形貌和大小.结果表明,生成的产物是六方晶相,形貌为花状、纺锤状的氧化锌晶体.花状ZnO大小约3 μm,分枝呈极性生长趋势,末端为针尖状,纺锤状氧化锌晶体长径比约为5左右,纺锤体尖端处不平滑,有明显螺旋位错.简单分析了锌盐种类在氧化锌晶体生长过程的辅助作用.     

Thermophysical Properties of Liquid Aluminum

Ohmic pulse-heating with sub-microsecond time resolution is used to obtain thermophysical properties for aluminum in the liquid phase. Measurement of current through the sample, voltage drop across the sample, surface radiation, and volume expansion allow the calculation of specific heat capacity and the temperature dependencies of electrical resistivity, enthalpy, and density of the sample at melting and in the liquid phase. Thermal conductivity and thermal diffusivity as a function of temperature are estimated from resistivity data using the Wiedemann–Franz law. Data for liquid aluminum obtained by pulse-heating are quite rare because of the low melting temperature of aluminum with 933.47 K (660.32 °C), as the fast operating pyrometers used for the pulse-heating technique with rise times of about 100 ns generally might not be able to resolve the melting plateau of aluminum because they are not sensitive enough for such low temperature ranges. To overcome this obstacle, we constructed a new, fast pyrometer sensitive in this temperature region. Electromagnetic levitation, as the second experimental approach used, delivers data for surface tension (this quantity is not available by means of the pulse-heating technique) and for density of aluminum as a function of temperature. Data obtained will be extensively compared to existing literature data.