对苯酚和己内酰胺制备的新型离子液体的研究

对弱酸苯酚与弱碱己内酰胺以不同配比制备的离子液体进行了研究,考察了其物理化学性质(熔点、密度、电导率、溶解性等).结果表明,合成的离子液体的熔点随二者物质的量比的不同而变化,当物质的量比为3.5 : 1时熔点最低,为-22℃.离子液体的密度比水的密度大,且随温度的升高,密度增大.离子液体的电导率为10-4S/m数量级,且随温度的升高,电导率增大,电导率与温度符合Arrhenius方程.溶解性试验表明,离子液体具有较强的溶解能力,能与水、醇类、酯类等一般溶剂互溶.IR测试结果显示,所合成的离子液体具有苯酚和己内酰胺的特征峰.     

基于低共熔溶剂聚合物电解质染料敏化太阳能电池研究

以琼脂糖聚合物为基质, 1-甲基-2-吡咯烷酮(NMP)为溶剂, 由尿素、氯化胆碱合成的低共熔溶剂(DES)作为添加剂制备聚合物电解质用于制备准固态染料敏化太阳能电池(DSSC)。研究了尿素/氯化胆碱配比、低共熔溶剂添加量对聚合物电解质电化学性能及其DSSC光电性能的影响。研究结果表明: 随着尿素/氯化胆碱配比增加, 准固态电解质的导电性能增加, 尿素、氯化胆碱的配比为2:1时可获得最佳电导率7.24 mS/cm。对不同低共熔溶剂含量电解质进行离子电导率测试研究发现: 添加量为20wt%时, 电解质获得最佳电导率6.21 mS/cm。染料敏化太阳能电池的光电效率随低共熔溶剂含量的增加先增加后降低, 低共熔溶剂添加量为20wt%时, 获得最佳光电效率η=3.18%, 短路电流密度J_sc=10.28 mA/cm², 开路电压V_oc=0.59 V, 填充因子FF=0.51。     

癸酸与棕榈酸低共熔混合物的制备与热特性分析

在实验测得单一物质熔点和熔化潜热的基础上,利用低共熔混合物配比计算公式对癸酸和棕榈酸低共熔混合物的配比、熔点和熔化潜热进行了理论预测,以指导DSC测试,并对低共熔混合物进行了红外光谱试验,以判断是否有新相生成.实验结果表明,癸酸的熔点和熔化潜热分别为29.85℃和150.32J/g,棕榈酸的熔点和熔化潜热分别为62.13℃和210.13J/g.低共熔混合物的理论配比为85.7:14.3(质量比),相变温度为26.74℃,相变潜热为152.74J/g.低共熔混合物的配比为86.1:13.9(质量比),相变温度为25.39℃,相变潜热为153.58J/g,与理论计算结果较吻合.红外光谱试验结果表明,癸酸和棕榈酸混合物中没有新相生成.     

柠檬酸交联纤维素气凝胶的制备及其网络结构的表征

以柠檬酸作为交联剂,在氯化锂/N,N-二甲基乙酰胺(LiCl/DMAc)的纤维素溶解体系中,通过溶剂置换、酯化交联反应和超临界干燥工艺制备了纤维素气凝胶。通过电子显微镜、傅里叶红外光谱分析仪、差示扫描量热仪以及密度、吸水率和力学性能测试对纤维素气凝胶的结构和性能进行了表征。结果表明:柠檬酸的改性或纤维素初始浓度的增大均能使纤维素气凝胶的网络结构变得更加紧密,改性获得的气凝胶网络结构能够获得更加稳定的化学交联点且具有更小的孔隙和更好的形变恢复能力;柠檬酸与纤维素结构单元的物质的量比为1∶1时纤维素气凝胶具有更好的热、力稳定性能;在25~120℃温度范围内反应温度越高交联反应程度越大。讨论了使用柠檬酸作为交联剂以及改变交联反应条件对纤维素气凝胶网络结构的影响。     

高DP竹溶解浆在NaOH/添加剂水溶液中的溶解行为

低温溶解纤维素的NaOH/添加剂水溶液溶剂体系因其价廉环保、溶解快速的特点引起了广泛的关注,但因为溶解能力的限制使其难于工业化。因此本文以较高聚合度(DP740)的商业竹溶解浆为实验原料,通过正交偏光显微镜观察了其在7%NaOH/12%尿素、9.5%NaOH/4.5%硫脲和8%NaOH/8%尿素/6.5%硫脲等NaOH/添加剂水溶液溶剂体系中低温溶解的行为。通过生成的透明纤维素溶液的粘度测试、溶解率的测定,UV-Vis光谱分析、动态光散射(DLS)测试和未溶残渣的XRD分析比较了3种NaOH/添加剂水溶液溶剂体系对高聚合度竹溶解浆的溶解能力。实验结果表明,8%NaOH/8%尿素/6.5%硫脲水溶液对竹溶解浆表现出最佳的溶解能力,约达到60%的浆纤维溶解。即不同于纯纤维素和其它低聚合度的化学木浆,纤维刚硬的高聚合度竹溶解浆在低温需要较高浓度的碱液和复配强氢键破坏能力的添加剂的溶剂体系才能获得较好的溶解效果。     

纤维素在1-烯丙基-3-甲基咪唑氯盐中溶解机理

通过分析纤维素/1-烯丙基-3-甲基咪唑氯盐(AmimCl)溶液在不同温度下浊度的变化和红外谱图变化,研究了纤维素在AmimCl中的溶解机理。温度升高,浊度变大,红外谱图羟基特征峰向高波数移动,说明纤维素与AmimCl的相互作用是氢键,而且温度升高会破坏纤维素/AmimCl溶液中的氢键,从而导致纤维素在AmimCl中析出。向纤维素/AmimCl溶液加入尿素、LiCl、KH_2PO_2、K_2SO_4和KPF_6等不同的氢键受体,用核磁共振方法研究了这些氢键受体与AmimCl的相互作用,核磁研究表明,氢键受体与AmimCl相容性越好,溶解纤维素能力越大,进一步说明了纤维素与AmimCl间的氢键作用。根据这一结论,指导合成了3种新型离子液体,并考察了这些溶剂体系对于纤维素的溶解性。     

微晶纤维素/CdS纳米复合材料的原位复合反应

以微晶纤维素(MCC)为模板,采用原位复合法制备MCC/CdS纳米复合材料。研究了超声波预处理以及镉离子、硫离子物质的量比对复合效果的影响,用扫描电镜(SEM),原子力显微镜(AFM),X射线衍射,荧光光谱(PL)以及激光共聚焦显微镜(CLSM)对复合材料的结构及性能进行表征。研究表明,超声波预处理后的纤维素对镉离子吸附能力更强,粒径为30 nm~100nm的CdS粒子均匀分布于纤维素表面,所得CdS为立方型晶体,复合材料体现出一定强度的光致发光性,较佳Cd2+∶S2-(物质的量比)为3∶1。     

脂肪酸二元低共熔混合物相变温度和潜热的理论预测

对低共熔混合物相变温度和潜热的理论预测公式进行了选择和验证,对脂肪酸类二元低共熔混合物的配比、熔点和熔化潜热进行了理论计算。从实际的计算过程来看,计算值与实验值吻合得很好,可以用来计算脂肪酸类低共熔混合物的热特性参数。在15种脂肪酸类低共熔混合物中,熔点最低为10.2℃,最高为51.5℃;熔化潜热最低为138.6J/g,最高为187.5J/g。从工程实际应用来看,脂肪酸类低共熔混合物适用于低温采暖、生活热水、相变墙体、温控混凝土、相变服装等领域。     

混合溶剂中聚丙烯腈纺丝原液的可纺性

以二甲基亚砜/二甲基乙酰胺(DMSO/DMAc)为混合溶剂,选择高黏均分子量(Mη)聚丙烯腈(PAN)为研究对象,系统研究了温度、溶剂比例、分子量、固含量对混合溶剂纺丝原液流变性的影响。结果表明,纺丝原液的表观黏度随分子量、固含量的增大而增加,随温度升高而降低,随溶剂比例先增加后减小,在V(DMSO)∶V(DMAc)=1.25∶1处出现最小值,随后逐渐增加。PAN的结晶度随溶剂体积比增大而升高,在1.25∶1时结晶性能最优。最终实验确定PAN纺丝原液可纺性最佳条件为:纺丝温度60℃～70℃,溶剂体积比1.25:1,固含量14%～16%。     

磷酸铬铝粘结剂的制备及其热处理中的相变

以Al(OH)3、H3PO4、CrO3和CH3OH为原料制备磷酸铬铝,通过对反应体系粘度及其吸潮率、热失重率的监测,确定反应的物质的量比、温度及反应时间。采用DTA-TG、IR和XRD分析研究了体系的固化特性和耐热性能。结果表明,反应的最佳条件为:反应温度80℃,n(Al(OH)3)∶n(H3PO4)∶n(CrO3)=3∶9∶1,反应时间为1h。磷酸铬铝粘结剂在300～1000℃时是非晶相,1100℃时是Cr(PO3)3和AlPO4两种晶型,1200℃时是Cr4(P2O7)3和AlPO4两种晶型。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.