Materials Literature
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The role of initiator and activator concentrations on the whole process of ε -caprolactam anionic polymerization has been explored, with the aim of selecting the most suitable experimental conditions for the RIM process. The effects of the active species on high polymer yield, residual monomer content, higher oligomer…
The successful utilization of Reaction Injection Molding (RIM) to fabricate complex polyurethane shapes in a single step from relatively low viscosity streams has led to a search for other chemical systems which can be fabricated by the RIM process. The rapid polymerization of molten caprolactam by anionic catalysis h…
Optical second-harmonic generation has been applied to the study of clean Si(111) 2\ifmmode\times\else\texttimes\fi{}1 and 7\ifmmode\times\else\texttimes\fi{}7 surfaces. By an analysis of polarization dependences of the two reconstructions, the symmetry properties of the surfaces have been determined. The 2\ifmmode\ti…
A comparison of infrared spectra from individual teeth along the radula of a chiton (Polyplacophora, Mollusca) shows that the first-formed calcium phosphate mineral is amorphous. Over a period of weeks the mineral transforms to dahllite. The c axes of the dahllite crystals are aligned approximately perpendicular to th…
Analogous to mechanical strength, electric strength in insulation systems is a particularly important property. If the electric stress exceeds the electric strength, the insulation either partially or completely loses its insulating capacity. Such a loss can be transient or permanent in nature, correspondingly one dif…
窒素ガス流通下 (150-200ml/min), 500°-1100℃の温度範囲でMg還元によってZrO2からのZrN粉末の合成を試みた. ZrNは600℃以上で生成し, 試料混合比Mg/ZrO2=2-4 (モル比) において中間生成物γ-Zr2ON2が生成したが, Mg/ZrO2=5 (モル比) ではγ-Zr2ON2は生成しなかった. Mg/ZrO2=5 (モル比), 600°-1100℃, 1h反応で得られた生成物を1N HNO3及びアルコールで洗浄し, 真空乾燥 (10-3Torr) させた精製粉末は, X線回折試験によればZrN単相であった. このZrN粉末の結晶子径及び比表面積は, 1000℃以下でほぼ一定で, 結晶子径…
Preparation de poudre ultrafine de nitrure de zirconium par nitruration de ZrO 2 en presence de Mg dans un courant d'azote a 1000°C pendant une heure. Etude microstructurale de la poudre
The purpose of this study is to research into the thermal condition and the weight of clothes suitable for the officers engagged in light works in an air-conditioned room in summer. The Major findings are as follows: 1. Thermal conditions of the working environment are (Dry bulb temp.), (Relative humidity) and 2.6m/se…
リチウム金属の表面を窒化することによりLi3N膜の作製を試みた. 生成反応過程の観察を行い, 生成反応に対する雰囲気の影響について調べた. 更に生成した膜のリチウム固体電池への利用について検討した. 膜厚を制御するための反応は室温で行い, 反応時間90分で約1mmの膜厚を得た. 膜の生成速度は, 反応に用いた窒素ガスの純度が高くなるに従って遅くなることが分った. TiS2を正極とした電流では1μA程度の電流を約1時間取り出した. しかし一般的に電池の内部抵抗が高く, また長時間にわたる放電はできなかった. 比較のために窒化リチウムの圧粉体及び焼結体についても導電度の測定を行い, 窒化リチウムの化学的及び電気化学的な安定性を検討した.
Binding of aspartate and glutamate residues with the lanthanide cation Yb3+ has been studied in D2O, involving two kinds of peptide backbones: N-acetylamino acid methyl esters and cyclic dipeptides. A method is described for the quantitative analysis of the lanthanide-induced shifts (LIS) from which the best model of…
An attempt is made to illustrate the continuous change that occurs in the solidification behavior of undercooled melts, as cooling rates increase from 0.0001 K/sec to about 1000 K/sec. At the higher cooling rates, more significant changes occur as the dendrite tip temperature begins to drop from the equilibrium liquid…
The dimethoxy-substituted Cookson's cage diketone (1a) underwent competitive rearrangement and cycloreversion reactions under treatment with Lewis acid, where two types of electron push-pull interaction are operative.
The influence of an electric field on a blue phase system containing a nematic component with negative dielectric anisotropy is investigated. For BP2, a shift of the maximum of selectively reflected light to shorter wavelengths is observed for the first time. For BP1, the maxima are shifted towards each other and addi…
Thermodynamic properties of Y2O3·Cr2O3 were determined by means of electromotive force (emf) measurements using stabilized zirconia as a solid electrolyte at 1182 -1386 K. The constructions of oxygen concentration cell was Mo|Cr, Y2O3, Y2O3·Cr2O3|ZrO2(+MgO)|Cr, Cr2O3|Mo Using the emf values and its temperature depende…
Ultrastructural changes in the silk gland after an ethanol treatment and the encapsulation of the abnormal regions of silk glands by hemocytes were studied. Abnormalities induced by low doses of ethanol are restricted to several cells located in the most anterior region of the middle silk gland, and to the duct cells…
Virtually every manufacturer of AISI Type 316L stainless steel surgical implants uses electropolishing as a surface finishing procedure, but little research has been devoted to the basic chemistry, techniques, and possible benefits of the process. The electrochemical reactions that take place in the electropolishing c…
In this work, the Lagrangian-Eularian code MMALE was applied to numerically simulate the penetration of a high speed copper jet into a metal-explosive-metal sandwich. The numerical simulation of the reactive flow induced in the explosive uses the Forest Fire model. Both normal and 45/sup 0/ oblique impact were conside…
The carbon deposition on iron has been studied by means of metallography and thermogravimetry, in order to investigate the carbon depositing behavior and the rate-determining step of the reacion. Two types of carbon, laminar carbon and filamentous carbon, are observed to deposit on iron. The deposition of laminar carb…
The purpose of this paper is to examine not only qualitatively but also quantitatively the influence of a rise time of longitudinal impact on the propagation of elastic waves in a bar. The adequacy of application of Love's theory for the propagation of longitudinal elastic waves to this problem is discussed by means o…
Abstract Thermal behavior of unfractionated poly(2‐methoxy)‐Cyanurate, PMCBC‐ film has been reported. The degradation of the polymer involved two steps. The glass transition temperature, T g , from DSC and DMA studies is ∼ 200°C. TMA study shows that the glass‐rubber transition region is in the range of 157 to 199°C.…