Electrical properties and hydrogen flux performance of Sr(Ce0.6Zr0.4)1−xYxO3−δ ceramic proton conductors

In this study, Sr(Ce_0.6Zr_0.4)_1?xY_xO_3?δ (x = 0.1, 0.15, 0.2, 0.25, 0.3, SCZY) perovskite proton-conducting ceramics were synthesized using the citrate-ethylenediaminetetraacetic acid complexing method. The effect of the Y concentration on the crystal structure, electrochemical performance and hydrogen flux of the SCZY samples in air and a H₂ atmosphere were investigated. The sintered SCZY samples showed a main perovskite crystal structure with several SrY₂O₄ impurity phases when x ≥ 0.20. The grain size of SCZY samples when x = 0.25 and 0.30 was smaller than that of other samples. The conductivity of all samples increased as the temperature increased in both air and H₂; however, the conductivity of SCZY in H₂ was lower than that in air. The results of AC impedance, demonstrated that resistance mainly derived from the charge transfer, which was apparently higher than the bulk and grain boundary resistance. Sr(Ce_0.6Zr_0.4)_0.85Y_0.15O_3-δ exhibited low charge transfer resistance in both air and the H₂ atmosphere and had a high hydrogen flux of 0.34 ml min^?1 cm^?2 μm^?1 at 800 °C. The structures of all SCZY samples were stable in 80 °C water.     

发动机可控进气状况装置的研制

标志发动机性能的主要参数：功率、扭距、燃油消耗率三大指标，在发动机试验台架上的测量结果，受当时的环境大气状况(大气压力、温度、湿度)的影响，这给我们客观评价、调试发动机带来了很多困难。本文介绍的可按进气状况装置使我们在任何时间、地点，都可以得到我们希望的大气状况，并在此状况下对发动机进行测试、评价与研究，本文介绍了研究可控进气状况装置的主要设计思路与试验结果。     

水冷前烟箱常压卧式中心回焰燃油燃气锅炉的设计

简要介绍了目前常用的常压卧式中心回焰燃泊、燃气锅炉的优缺点，针对锅炉使用过程中出现的前烟箱易过热烧损的问题，充分利用常压锅炉结构灵活的特点，对锅炉的结构在原有基础上进行了改变，摒弃了一贯采用的用耐火材料填充前烟箱的方法，将前烟箱设计成水夹套的形式，并与锅筒联成一体，用锅筒内的循环水对前烟箱进行冷却，整个结构设计简单明了，安全性高，制造工艺简单，解决了前烟箱存在的问题。     

Estimating the irradiance spectrum from measurements in a limited number of spectral bands

Accurate measurement and characterisation of fluctuations in the irradiance environment is important for many areas of optical remote sensing. This paper describes a method of estimating spectral irradiance over the region 400-1000 nm from the radiance of a calibrated reference panel, measured in four narrow spectral bands (FWHM approx. 10 nm). The reproducibility of the method was found to have an average root-mean-squared error of approximately 30 mW m^− 2 nm^− 1 over the region 400-1000 nm when applied to spectra covering a range of clear-sky conditions typical of mid-latitude temperate regions. This was approximately twice as precise as the sequential method, even when the interval between target and reference panel measurements was very short (median interval 23 s). The method provides an alternative to linear interpolation between successive reference panel measurements and is particularly appropriate for conditions when irradiance is varying in a non-systematic way, for example, during the passage of sub-visual clouds.     

The effect of environment pressure on high temperature stability of silicon oxycarbide glasses derived from polysiloxane

Silicon oxycarbide glasses (SiOC) have been produced by siloxane resin under flowing argon atmosphere at 1000 °C. Those glasses were further annealed at 1200, 1300, 1400, and 1500 °C under the pressure of 0.01 KPa and 101 KPa, respectively, to investigate the effect of environment pressure on their high temperature stability. The two series of glasses were characterized by X-ray diffraction, ²⁹SiMASNMR, and chemical element analysis. The environment pressure plays a crucial role on high temperature stability of SiOC glasses by promoting or hindering bonds redistribution and carbothermal reductions. It can be found that SiOC glasses exhibit enhanced thermal stability in high pressure environment.     

镁合金消失模铸造的优势及关键

对常见镁合金铸造工艺作了分析和总结，对镁合金消失模工艺的优缺点作了客观分析；提出了可控气氛、可控压力镁合金消失模铸造新工艺；认为该工艺是一种非常适合镁合金液态成形的新的精密铸造方法，具有设备投资小、铸件成本低、内在质量好、精度高、生产率高的优势，同时可以较好地解决镁合金液态成形过程中易氧化燃烧的问题。     

中国古典园林理水的现代启思

中国古典园林理水有着丰富的文化内涵和独特的构思手法,它所塑造的如诗如画的水环境,让世人叹为观止.从介绍中国古典园林理水的历史入手,分析其理水手法、文化意境的塑造,并结合创作实践,阐述中国古典园林理水的继承和发展问题,以期探索既符合当代可持续发展观念,又具有中国传统文化底蕴的水环境设计手法.     

某云母型含钒石煤氧压与常压酸浸提钒比较

湖北某地云母型含钒石煤中85%以上的钒赋存于云母类矿物中,V3+、V4+分别占总钒的70.83%、29.17%,V3+以类质同象取代云母晶格中的Al3+离子,常压酸浸极难释放出晶格中的钒。为了确定该矿石的高效、低耗、环保浸钒工艺及参数,以常压酸浸效果为参照,对氧压酸浸工艺条件进行了研究。结果表明,浸出温度、硫酸浓度以及氧分压的升高可显著提高钒浸出率,压力场的引入可大幅度提高钒浸出率、缩短反应时间、降低酸耗;在硫酸体积浓度为20%、浸出时间为5 h、反应温度为160℃、氧分压为0.5 MPa情况下的氧压酸浸,钒浸出率可达75.98%,较硫酸体积浓度为20%、浸出时间为5 h、反应温度为98℃情况下的常压酸浸钒浸出率高45.12个百分点。     

动力学在草霉MA保鲜中的应用

从酶动力学方程出发,建立了草霉的呼吸强度Ro2和Rco2、与O2浓度、CO2浓度之间的动力学模型,并测定了其中的系数。通过建立的模型分析草霉MA保鲜,为草霉等果蔬MA保鲜的参数选择提供了理论依据。     

筑境·山水间 访中联筑境建筑设计有限公司

＂筑境·山水问＂展览展示了建筑大师程泰宁和中联筑境十年来完成的建筑设计项目,呈现了程泰宁的三个＂立足＂、三个＂合一＂的建筑设计思想以及＂抽象继承＂的设计手法,并回顾了筑境建筑十年的发展历程与未来发展目标。