Lattice matching of D023 and D022 phases in Al-6at.%(Ti,V,Zr) systems

Composite quaternary alloys with 21–22 vol.% of Al₃M (M = Ti,V,Zr) were made by vacuum arc melting. Two inlermetallic phases were found in alloys: one is V rich D0₂₂-Al₃(Ti,V,Zr) and the other is Zr rich D0₂₃-Al₃(Ti,V,Zr). Measured lattice constants of precipitate phases were strongly dependent on the composition of transition elements in precipitates and generally obeyed Vegard's rule. The lattice misfits between Al₃M phases and the matrix did not change much in alloys while the lattice misfit between D0₂₂ and D0₂₃ Al₃M phases was found to decrease with an increase in Ti content implying that the interface between both phases became more smooth, hard to distinguish and separate. A geometrical model was made for the lattice matching between two, D0₂₂ and D0₂₃ Al₃M phases. Titanium has been found to act as a retarding element to separation into D0₂₃ and D0₂₂ phases and the pre-existing phase may have been L₁₂ or D0₂₃ phase.     

黄土隧道衬砌断面优化设计与研究

结合神延铁路黄土地层的工程特性 ,进行了衬砌断面的优化设计、结构检算等工作 ,并辅以相应的结构分析 ,进一步检验优化设计方案或修正支护参数 ,从而提出黄土隧道优化设计后的稳定性综合评价指标。     

离层注浆技术的应用与效果

对覆岩离层注浆减缓地表沉降技术在抚顺矿区３个采区，６年时间的应用情况进行了阶段性总结，并对实际应用效果进行了分析。     

Thermal Conductivities of Ⅲ-Ⅴ Antimonides

Thermal parameters of various Ⅲ-Ⅴ antimonides, especially the quaternary lattice matched to GaSb or InAs substrates as well as some strained ternaries, have been investigated theoretically. Results show that at most composition region many ternary and quaternary antimonides exhibit rather lower thermal conductivity compared to related binaries,and the reason has beendiscussed. The thermal designing rule of the lasers and other power devices using those antimonides also has been discussed.     

Measurement of total water and bound water contents in human stratum corneum by in vitro proton nuclear magnetic resonance spectroscopy

The reliability of in vitro proton nuclear magnetic resonance (NMR) spectroscopy to specifically measure the water content of rehydrated human stratum corneum samples was assessed by comparison with the previously validated thermal desorption-mass spectrometry technique. The interest of proton NMR is that it can determine, in the same sample, both the amount of total water by recording the spectra at ambient temperature, and that of bound water (non-freezing water) by recording the spectra below 0 degrees C. Provided that enough samples of stratum corneum are analysed to average out the observed and well-known sample-to-sample variation, proton NMR may be of value in the evaluation of hygroscopic properties of raw materials for moisturizer formulations.     

长安东大热水井成井工艺探讨

分析了西安市长安区东大乡南石村热水井钻探施工中,由于水井孔径大、含砂层多、地层松散、胶结性差等原因使得井壁容易垮塌,因而中断正常钻进,对水井施工造成危害,影响工程质量的问题。提出在该地层中施工,如何平衡地层侧力不使其垮塌的解决思路。     

明代麻葛纺织服饰探析

明代是棉织物崛起,麻葛服饰走向回落的节点。文章基于文献与文物的视角,追溯明代麻葛服饰演变的历程,考证其服饰形制特征。研究认为:明代初期,朝廷政令大力推广棉植业,加之棉织物功能性和经济价值同麻葛织物具有比较优势,使其在棉与麻的产业博弈中胜出。明代中晚期,市民阶层僭越逾矩,竞尚奢华之风盛行,在放弃麻葛布衣作为平民视觉符号的同时,加速了麻葛业的衰落。仅从有限的明代麻葛服饰实物考证来看,明代初期麻葛服饰品类广泛,明中晚期其仅局限于单衣夏服或赐服的范畴。     

Novel Mg-Zr-A-H (A = Li, Na) hydrides synthesized by a high pressure technique and their hydrogen storage properties

It is important to develop the hydrogen storage technology by creating novel metal hydrides. In the present study, the powder mixtures of 6MgH₂ + ZrH₂ + nAH (A = Li, Na; n = 0, 0.3, 0.7, 1.0) were reacted to synthesize quaternary hydrides by use of a high pressure technique. The crystal structures of the new hydrides were refined by the Rietveld method based on the synchrotron XRD data. By reacting 6MgH₂ + ZrH₂ + nLiH, the quaternary hydrides with simple FCC-type structure were formed. In the case of 6MgH₂ + ZrH₂ + nNaH, novel quaternary hydrides with Ca₇Ge type structure were formed as well as the hydrides with simple FCC structure. The hydrogen storage capacities were around 6 wt.% according to the pressure-composition isotherm measurements. The formation enthalpies of the quaternary hydrides with simple FCC structure were proved to be lower while the enthalpies of the Mg-Zr-Na-H hydrides with Ca₇Ge type structure were higher, than that of the ternary Mg-Zr-H hydride obtained by reacting the basic system 6MgH₂ + ZrH₂. The hydrogen releasing temperatures of the quaternary Mg-Zr-A-H hydrides were slightly lower than that of the ternary Mg-Zr-H hydride.     

Topical proteolytic enzymes affect epidermal and dermal properties

Although proteolytic enzymes have a history of use in skin care products it is not known whether they simply induce superficial exfoliation or with continued use can alter epidermal and dermal skin properties. We examined herein whether enhanced exfoliation resulting from treatment with an aspartyl dependent acid protease produces appearance improvements and over time, changes in the epidermis and dermis. Test participants applied 15% enzyme containing serum and a simple moisturizer twice daily for 3 months; a matched control group applied the same serum (without enzyme) and moisturizer. Changes in skin smoothness and texture, the depth and number of lines and wrinkles, and epidermal and dermal firmness and thickness were examined in a double-blind fashion. Treatment with 15% enzyme product(s) resulted in significant improvement in epidermal properties after 1 month and both epidermal and dermal properties after 3 months. The control group showed modest improvements in surface properties only. These results demonstrate that significant appearance benefits can be derived from use of exfoliative proteolytic enzymes. Such improvements are the result of changes to the epidermis and dermis and are strikingly similar to results observed with higher concentrations of AHAs (alpha hydroxy acids).     

Infrared and Raman imaging spectroscopy of ex vivo skin

This primer describes and illustrates experimental protocols for both Fourier transform infrared (FTIR) spectroscopic imaging and confocal Raman mapping of ex vivo skin and thereby acquaints the reader with these measurement techniques, including the temporal and spatial limitations associated with each technique. The experimental conditions by which the unique ‘molecular histology’ information obtained from confocal Raman mapping and infrared spectroscopic mapping of ex vivo skin is generated will be described. Raman and FTIR spectra of tissue, when collected in spatially resolved arrays, permit the generation of ‘molecular images’ of tissue components and tissue organization without the use of fluorescent labels or chemical stains. To illustrate the molecular information from ex vivo skin that can be spectroscopically imaged with confocal Raman and infrared microspectroscopy, we have collected new data using both techniques and generated spectral images which illustrate the capacity of each technique to provide unique insights into skin histology, biochemistry and biophysics. Understanding the measurement possibilities and specific constraints of both approaches is a prerequisite to their meaningful use as powerful research tools in skin research.