功能奇特的透温性纤维衣料

控温混纺衣料 它是由日本一家运动衣料厂与美国航天管理局的科学家共同研制成功的。其材料的制作方法是,在聚酯、再生纤维的混纺面料上真空蒸镀一层在高温下能熔化的铝。因而,它对太阳光中的红外线的反射,比一般棉布服装强50％。 调温聚醇衣料 美国开发了一种对温度反应特别敏感的调温型防寒材料,实质上是利用聚乙醇等的热贮存和释放性。实现了化学能与热能的相互转化。采用这种可随温度改变而自动调节的热反应纤维制成的衣服。

苎麻织物透湿性评价研究

本文用蒸发法测试了五种苎麻织物的透湿性能,并用灰色理论建立了相应织物的GM(1,1)灰色模型,运用该模型,预测了该五种织物在五小时内透湿性能的总体趋态,继而全面、客观地评价了该五种苎麻织物的透湿性能。

Seepage characteristics of a fractured silty mudstone under different confining pressures and temperatures

To investigate the influence of confining pressures and temperatures on the seepage characteristics of fractured rocks, seepage tests were conducted on a fractured silty mudstone using a self-developed experimental system, and the effects of different factors on coefficient of permeability were discussed. The results showed that the increasing confining pressure will gradually decrease the coefficient of permeability, and this process is divided into two stages: 1) the fast decrease stage, which corresponds to a confining pressure less than 30 kPa, and 2) the slow decrease stage, which corresponds to a confining pressure larger than 30 kPa. Unlike confining pressure, an increase in temperature will increase the coefficient of permeability. It is noted that fracture surface roughness will also affect the variation of coefficient of permeability to a certain extent. Among the three examined factors, the effect of confining pressure increases is dominant on fracture permeability coefficient. The relationship between the confining pressure and coefficient of permeability can be quantified by an exponential function.

Preparation of high-permeability NiCuZn ferrite

Appropriate addition of CuO/V2O5 and the reduction of the granularity of the raw materials particle decrease the sintering temperature of NiZn ferrite from 1200 °C to 930 °C. Furthermore, the magnetic properties of the NiZn ferrite prepared at low temperature of 930 °C is superior to that of the NiZn ferrite prepared by sintering at high temperature of 1200 °C because the microstructure of the NiZn ferrite sintered at 930 °C is more uniform and compact than that of the NiZn ferrite sintered at 1200 °C. The high permeability of 1700 and relative loss coefficient tanδ/μi of 9.0×10?6 at 100 kHz was achieved in the (Ni0.17Zn0.63Cu0.20)Fe1.915O4 ferrite.

Calculation of gas content in coal seam influenced by in-situ stress grads and ground temperature

On the basis of the analysis of coal bed gas pressure in deep mine, and the coal bed permeability ( k ) and the characteristic of adsorption parameter ( b ) changing with temperature, the author puts forward a new calculating method of gas content in coal seam influenced by in situ stress grads and ground temperature. At the same time, the contrast of the measuring results of coal bed gas pressure with the computing results of coal bed gas pressure and gas content in coal seam in theory indicate that the computing method can well reflect the authenticity of gas content in coal seam,and will further perfect the computing method of gas content in coal seam in theory,and have important value in theory on analyzing gas content in coal seam and forecasting distribution law of gas content in coal seam in deep mine.

Mathematical Modeling of Non-Isothermal Flow of Thin Layer of Two-Phase Medium Permeable Surface

Processes of filtering two-phase media in filtration devices play an important role in various industries. Significant role in the process of filtering is the initial section of flow, which defines the basic parameters： the profile and value of the velocity, pressure gradients, concentration and dispersion of sediment particles, etc.. The problem is solved by the method of surfaces of equal cost, the results enabled to establish the influence of the input section on the filtering process.

Anisotropy of Critical Fields in MgB_2: Two-Band Ginzburg-Landau Theory for Layered Superconductors

The temperature dependence of the anisotropy parameter of upper critical field γHe2 （T） = Hc2^‖ （T） /Hc2^⊥ （T） and London penetration depth γλ （T） = λ‖（T）/λ⊥ （T） are calculated using two-band Ginzburg-Landau theory for layered superconductors. It is shown that, with decreasing temperature the anisotropy parameter γHc2 （T） is increased, while the London penetration depth anisotropy γλ（T） reveals an opposite behavior. Results of our calculations are in agreement with experimental data for single crystal MgB2 and with other calculations..Results of an analysis of magnetic field Hc1 in a single vortex between superconducting layers are also presented.

Effect of low temperature thermo-mechanical treatment on microstructures and mechanical properties of TC4 alloy

The effects of low temperature thermo-mechanical treatment （LTTMT） on microstructures and mechanical properties of Ti-6Al-4V （TC4） alloy were studied by optical microscopy （OM）, tensile test, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The experimental results confirm that the strength of TC4 alloy can be improved obviously by LTTMT processing, which combines strain strengthening with aging strengthening. The effect of LTTMT on the alloy depends on the microstructure of the refined and dispersed a＋fl phase on the basis of high dislocation density by pre-deformation below recrystallization temperature. The tensile strength decreases with the increase of pre-deformation reduction. The optimal processing parameters of LTTMT for TC4 alloy are as follows： solution treatment at 900 ℃ for 15 min, pre-deformation in the range of 600-700 ℃ with a reduction of 35%, finally aging at 540 ℃ for 4 h followed by air-cooling.

Synthesis and room-temperature ferromagnetism in FeCo-and FeCu-codoped ZnO nanoparticles

Nanosized FeCo- and FeCu-codoped ZnO particles were synthesized by rheological phase reaction-precursor method and the thermal decomposition of oxalate precursors was studied by thermogravimetry and differential thermal analysis in air atmosphere. X-ray analysis revealed that the FeCo- and FeCu-codoped ZnO crystallize in a wurtzite structure. Further characterization by HRTEM showed that no FeCo, FeCu clusters and other secondary phases were found in the samples. X-ray photoelectron spectroscopy and absorption spectra results indicated that Fe and Cu were mainly likely to have nominal Fe3＋ and Cu＋ and Co successfully incorporated into the wurtzite configurations, 2＋ lattice at the Zn2＋ sites. Curie temperature above room temperatures was observed from the FeCo- and FeCu-codoped ZnO nanoparticles. The origin of the observed ferromagnetism in the FeCo- and FeCu-codoped ZnO nanoparticles can be explained by Ruderman-Kittel-Kasuya-Yosida-type exchange mediated under the conduction carriers and the double-exchange-like interaction, respectively.

Treatment of 30 patients with intractable facial paralysis by warming-needle moxibustion at B?ihuì(百会 GV 20)combined with penetration needling

Objective To observe the clinical efficacy of moxibustion at B ihuì（百会 GV 20） combined with penetration needling in treatment of intractable facial paralysis. Methods Sixty patients with intractable facial paralysis included in the study were divided into two groups according to the random number table, with 30 patients in observation group（group A）, and 30 patients in control group（group B）. Moxibustion at GV 20 combined with penetration needling were adopted in group A, and simple penetration needling was applied in group B. Once daily, thirty days of treatment were required. The House Brackmann（H-B） facial nerve function grading and improvement of clinical symptoms were observed. Results The H-B function grading and improvement of clinical symptoms in group A were superior to group B, and the difference was statistically significant（P〈0.05）. Conclusion The clinical efficacy of moxibustion at GV 20 combined with penetration needling in treatment of intractable facial paralysis is definite, and the treatment method is deserving of clinical promotion.

High Temperature Stability of Platinum Nanoparticles on Few-Layer Graphene Investigated by In Situ High Resolution Transmission Electron Microscopy

Heterogeneous catalytic reactions involve the use of highly dispersed active phases such as metal, metal oxide, or metal sulphide nanoparticIes on thermally stable supports. Fluctuations of the reaction temperature during the reactions can induce sintering of the particles. The stability of such small particles represents a crucial parameter in the development of new families of catalysts with high activity in many fields. Here we report the stability of platinum nanoparticles （2-3 nm） on a few-layer graphene （FLG） surface as studied by in situ high temperature transmission electron microscopy.