LaNiO3底电极上的BiFeO3薄膜的铁电性能

用溶胶一凝胶方法在LaNiO3底电极上制备了500℃退火的BiFeO3薄膜.研究了室温下薄膜的结构,介电与铁电性质和漏电流性质.XRD研究表明薄膜呈R3m结构,没有观察到不纯相.铁电性研究表明,薄膜具有大的剩余极化强度,在600 kV/cm的测试电场下,薄膜的剩余极化强度为20uC/cm2,矫顽场为440 kV/cm.介电性质研究表明,在整个测试频率范围内,薄膜具有小的介电损耗.而漏电流特性测试表明,通过工艺的改进,有效的限制了BiFeO3薄膜的漏电流.     

La0.5Sr0.5CoO3底电极上的BiNdFeO3薄膜的电性质。

用溶胶．凝胶方法在La0.5Sr0.5CoO3底电极上制备了纯的和10％A位Nd替代的BiFeO3薄膜。对薄膜的结构、形貌和电性质进行了研究。XRD研究表明两薄膜呈随机取向。而SEM测试结果表明，通过Nd替代，构成薄膜的晶粒显著减小，表面出现了针孔。铁电性研究表明，通过Nd替代，薄膜的铁电性得到显著增强，剩余极化强度由1．87μC/cm^2。增加到3．11μC/cm^2。而漏电流特性测试表明，Nd替代有效地限制了BiFeO3薄膜在正向偏压下的漏电流。     

BixLa1-xFeO3薄膜的介电和铁电性质的研究

用溶胶-凝胶法制备了纯的和5%La掺杂的BiFeO3薄膜,研究了室温下薄膜的介电和铁电性质.介质性质研究表明,在6.8MHz和7.8MHz附近,BiFeO3薄膜和Bi0.95Ia0.05FeO3薄膜分别出现了介电损耗极大和介电常数的正负转变,归结为薄膜的介电性质由容性向感性的转化.而铁电测试表明,通过La掺杂,增强了薄膜的铁电性,同时有效地减少了BiFeO3薄膜的漏导.     

BixLa1-xFeO3薄膜的介电和铁电性质的研究

用溶胶-凝胶法制备了纯的和5%La掺杂的BiFeO3薄膜,研究了室温下薄膜的介电和铁电性质.介质性质研究表明,在6.8MHz和7.8MHz附近,BiFeO3薄膜和Bi0.95Ia0.05FeO3薄膜分别出现了介电损耗极大和介电常数的正负转变,归结为薄膜的介电性质由容性向感性的转化.而铁电测试表明,通过La掺杂,增强了薄膜的铁电性,同时有效地减少了BiFeO3薄膜的漏导.     

BixLa1-xFeO3薄膜的介电和铁电性质的研究

用溶胶-凝胶法制备了纯的和5％La掺杂的BiFeO3薄膜，研究了室温下薄膜的介电和铁电性质。介质性质研究表明，在6．8MHz和7．8MHz附近，BiFeO3薄膜和Bi0．95La0．05FeO3薄膜分别出现了介电损耗极大和介电常数的正负转变，归结为薄膜的介电性质由容性向感性的转化。而铁电测试表明，通过La掺杂，增强了薄膜的铁电性，同时有效地减少了BiFeO3薄膜的漏导。     

PbTiO_3/BiFeO_3多层薄膜的铁电性质

用溶胶一凝胶方法在LaNiO3底电极上制备了BiFeO3/PbTiO3多层薄膜.研究了室温下薄膜的结构,铁电性质和漏电流性质,并将其与纯的BiFeO3薄膜的性质进行了比较.从薄膜的XRD模式中可以观察到共存的BiFe3O相和PbTiO3相.通过电滞回线测量发现,在较低的测试电场下,BiFeO3/PbqTiO3多层薄膜表现出反铁电性;而在较强的测试电场下表现出铁电性.相对于纯的BiFeO3薄膜,BiFeO3/PbTiO3多层薄膜能够承受更高的测试电场而获得充分极化,从而表现出较强的铁电性.漏电流特性测试表明,相对于纯的BiFeO3薄膜,BiFeO3/PbTiO3多层薄膜具有更低的漏电流.     

Pt电极上BiFeO3薄膜的淬火效应

用溶胶-凝胶法采用快速退火方法在Pt/Ti/SiO2/Si衬底上制备了BiFeO3(BFO)薄膜.通过淬火冷却与自然冷却的对比,研究了淬火冷却对BiFeO3(BFO)薄膜的结构、形貌及电性能的影响.XRD研究表明淬火未对薄膜的结晶产生显著的影响.扫描电镜研究表明淬火导致薄膜表面粗糙度增加并出现了裂纹.铁电性测试表明淬火冷却得到的薄膜,其铁电性得到了增强,同时,淬火使BiFeO3薄膜的漏电流增加.     

Sol-gel方法制备BiFeO_3/Bi_4Ti_3O_(12)多层薄膜及其电性能

采用溶胶-凝胶方法在FTO/glass底电极上制备了BiFeO3/Bi4Ti3O12和Bi4Ti3O12/BiFeO3多层薄膜。研究了室温下薄膜的结构,铁电性质和介电性质,并将其与纯的BiFeO3薄膜的性质进行了比较。从薄膜的XRD模式中可以观察到共存的BiFeO3相和Bi4Ti3O12相。通过电滞回线测量可以看出,相对于纯的BiFeO3薄膜,BiFeO3/Bi4Ti3O12和Bi4Ti3O12/BiFeO3多层薄膜能够承受更高的测试电场而获得充分极化,从而表现出较强的铁电性,在450kV/cm测试电场下,薄膜的剩余极化强度分别为37μC/cm2和23μC/cm2。     

退火温度对Sol-gel法制备的BiFeO_3薄膜结构及电性能的影响

采用溶胶-凝胶法在ITO/glass衬底上制备了BiFeO3薄膜,退火温度分别为500℃和550℃.实验结果表明,550℃退火的薄膜晶粒较大且不均匀,并有杂相产生,薄膜的漏电流较大,没有得到饱和的电滞回线;而在500℃退火的薄膜晶粒较小且均匀,没有杂相产生,相对于550℃退火的薄膜,其漏电流密度降低了约2个数量级,铁电性得到明显增强,剩余极化强度约为40μC/cm2,矫顽场约为75kV/cm,最大的测试电场为130kV/cm.     

淬火对BiFeO3薄膜电效应的影响

采用溶胶．凝胶法和快速退火方法在LaNiO3/Si（100）衬底上制备了BiFeO3（BFO）薄膜。研究了淬火冷却与随炉冷却两种不同的冷却方式对BiFeO3薄膜的结构、形貌与电性能的影响。XRD研究表明淬火未对薄膜的结晶产生显著的影响。扫描电镜研究表明，淬火导致薄膜表面出现了裂纹，同时粗糙度增加。铁电性测试表明，淬火冷却的薄膜的铁电性得到了增强。通过对薄膜漏电流的观察发现，淬火的薄膜的漏电流相对自然冷却的薄膜减少。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

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 Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

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.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

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.