一种室温相变乳状液的制备及表征

以正十八烷作为室温相变材料，通过乳化剂的优选，将OP乳化剂、Span乳化剂及Tween乳化剂按照一定的比例配制成复合型乳化剂，并在一定的乳化工艺下，制备出了稳定性优良的O／W型室温相变乳状液。当复合型乳化剂HLB值为9．6时，所制备的相变乳状液呈浓牛奶状，内相粒径为1．09μm，在自然条件下贮存半年未出现分层现象。     

粒径与掺杂对ZrO2纳米粉相结构的影响

用Ｘ射线衍射仪和透射电镜研究了粒径和Ｙ，Ｃｅ掺杂元素对ＺｒＯｗ纳米粉相结构的影响。结果表明，在室温下平均粒径为￣１０ｎｍ的ＺｒＯ２粉单斜相不足２０ｖ．％，而加入２ｍｏｌ％Ｙ２Ｏ３或２ｍｏｌ％ＣｅＯ２可使单斜相更少，试验测得纯ＺｒＯ２，ＺｒＯ２－２ｍｏｌ％ＣｅＯ２，ＺｒＯ２－２ｍｏｌ％Ｙ２Ｏ３纳米粉在室温下单斜相和四方相保持平衡共存的临界粒径分别为１７．５，２１．０和３２．５ｎｍ。     

相变微胶囊单体熔化过程的数值模拟研究

该文研究了相变微胶囊的熔化过程,采用热焓法进行了数值模拟,分析了粒径大小、壁材厚度以及壁材的导热系数对相变过程的影响,预测了不同时刻微胶囊内部的物相分布。研究结果表明,在单个相变微胶囊中,熔化初始时刻,热量传递率较大,随着熔化进程的推移,热量传递减小。相变微胶囊完全熔化时间随壁材的导热系数及厚度的增加而缩短,随粒径的增大而延长。该研究对提高相变微胶囊的储热能量和速率具有一定的理论指导意义。     

云母衬底上W掺杂VO_2薄膜的光学和变色性能研究

在云母衬底上采用溶胶-凝胶法制备了掺钨VO2薄膜,采用XRD、SEM、FT-IR和色差等检测手段,对掺杂薄膜物相、表面形貌、相变温度和热致变色性能进行分析。结果表明,掺钨后其相变温度降低到室温以下,并保持良好的红外透过率随温度变化性能;相变前后颜色发生了改变,色差最大值为5.9。     

珍珠粉与蚌壳粉的鉴别

利用XRD比较研究了珍珠粉与蚌壳粉热相变过程,结果表明,随温度的升高,珍珠粉与蚌壳粉的文石相向方解石相转变,蚌壳粉的相变速率快于珍珠粉。在室温至200℃温区,珍珠粉与蚌壳粉的相结构基本保持不变;在200-360℃温区,二者均发生相转变,相变速率随温度升高逐渐增大;珍珠粉与蚌壳粉的相转化快速过程分别发生在380-480℃和360-450℃温区。这种热相变速率的明显差异,能准确地鉴别珍珠粉与蚌壳粉。     

非晶CIGS前驱膜无硒退火的相变历程

采用一步射频磁控溅射法在室温获得了CIGS薄膜,研究了不同的真空无硒退火温度(150～350℃)对CIGS薄膜相变历程的影响。薄膜相变历程中的结构和性能采用XRD、SEM、EDS、紫外-可见光吸收和四探针等测试手段进行测试表征。结果表明,室温下制备的CIGS薄膜为非晶态,随退火温度升高发生非晶CIGS→CuSe→CIGS的相变。150℃退火形成的CuSe薄膜的电阻率最低,光透过性能最差。退火温度超过200℃便生成CIGS相,CIGS相的结晶质量随退火温度升高而改善,薄膜的电阻率和光透过率也随退火温度的提高而增加。     

反铁电晶体PbTaO3的对称性和序参量

根据室温下X射线衍射结果，仔细研究了反铁电晶体PbTaOa的晶体结构。确定PbTaO3在973K发生顺电一反铁电相变，反铁电相对称性所属点群是P2／m（C2i）。用轴矢量R作为序参量来描述反铁电相便是对称性的变化，对于已得到的晶体相变前后的对称点群，应用居里原理，得到了理想结果。     

EFFECTS OF HYDROGEN ON THE α_2 /βTRANSUS TEMPERATURE AND LATTICE CONSTANT IN SUPER-α_2 ALLOY

用膨胀仪测定了含氢Ｓｕｐｅｒ－α２／β相变点；用Ｘ射线衍射仪探讨了氢对α２和β相晶格常数的影响。结果表明，随氢含量增加，Ｓｕｐｅｒ－α２的α／β相变点显著降低，β相晶格常数显著增大，α２相的晶格常数α增大，而Ｃ变化不大。     

Ar工作压强对磁控溅射Ni-Mn-Ga铁磁形状记忆薄膜成分的影响

采用直流磁控溅射技术在单晶硅衬底上沉积Ni-Mn-Ga铁磁性形状记忆薄膜.试验结果表明,Ar工作压强对Ni-Mn-Ga薄膜化学成分有显著影响.Ni含量随Ar工作压强的升高呈先增加后减少的趋势,Mn含量呈先减少后增加的趋势,Ga含量几乎呈线性减少的趋势.随Ar工作压强的升高,薄膜的e/a值逐渐增大,薄膜的相变温度逐渐升高,室温下可以获得具有四方结构马氏体相的Ni-Mn-Ga薄膜.     

TiO2纳米粒子热处理过程相变原因研究

通过差热 热重分析(TG DTA)和 X射线衍射分析(XRD)对热处理过程中 TiO2 纳米粒子相变过程进行了研究。结果表明,在热处理过程中, 纯锐钛矿相TiO2 纳米粒子的相变温度与粉体粒径的大小有关,当粉体粒径<21nm时,金红石相的标准自由能大于锐钛矿相,粉体不会发生相变。当粉体粒径增大到21nm以上时,情况相反,粉体可能发生相变,表现出明显的尺寸效应。     

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.     

Effect of Permeable Crystalline Material on Steel Reinforcement Corrosion of Concrete

Permeable crystalline materialcan permeate into pores and cracks of concrete and catalyze the reaction between Ca(OH) 2and unhydrated cement to generate a great quantity needle non-soluble crystals, which can stop up the pores and cracks of concrete, and increase the impermeability of concrete. This paper reported the results of a study conducted to evaluate steel reinforcement corrosion of concrete specimens uncoated and coated with permeable crystalline material as well as mixed with the permeable crystalline material. The properties evaluated for corrosion test were water impermeability, water absorption, compressive strength and potential. The results of water impermeability, water absorption, compressive strength clearly showed that the permeable crystalline material could prohibit water, any soluble salts and moisture from penetrating the concrete to cause corrosion, leaking, and other problems, and it did increase the compressive strength, which was favorable for protection of corrosion of reinforcing steel. Moreover, it was concluded from the potential-time curve that the steel reinforcement of uncoated specimen was in the state of activation whereas that of other specimens coated and mixed with the permeable crystalline material was in the state of inactivation. Above all, it was indicated that the permeable crystalline materialis very effective to protect the steel reinforcement of concrete from corrosion.