Design of an Electromagnetic Frequency Tunned Antenna for Mobile Communications

Wireless Personal Communications - Current mobile communications technology relies heavily on efficient design of antennas, where the operational characteristics of the wireless communication...     

Anchoring single Pt atoms on hollow Ag3VO4 spheres for improved activity towards photocatalytic H2 evolution reaction

The high cost of noble metal catalysts has been a great bottleneck for the catalyst industry. Using the noble metal at a single-atom level for catalytic applications could dramatically decrease the cost. The impacts of single Pt atoms on the photocatalytic performance of Ag₃VO₄ have been investigated and reported. In this report, single Pt atoms were anchored on the surface of Ag₃VO₄ (AVO) as a cocatalyst, and the resultant composite photocatalyst has been studied for photocatalytic H₂ production from water driven by visible light. The as-prepared AVO particles are hollow nanospheres in the monoclinic phase with a bandgap of 2.20 eV. The light absorption edge of AVO/Pt is slightly red-shifted compared to that of the pristine AVO, indicating more visible light absorption of AVO/Pt. The XPS peaks of Ag, V, and Pt exhibit a significant shift after AVO and Pt get into contact, suggesting the strong interaction between the surface Ag and V atoms, and single Pt atoms. After 3-h illumination, the photocatalytic H₂ evolution amount from AVO/Pt is improved up to 1400 μmol, which is 2.8 times that on the bare AVO. Such efficient photocatalytic H₂ evolution on AVO/Pt is still maintained after five reaction cycles. The better photocatalytic performance of AVO/Pt has been attributed to the more efficient visible light utilization and the lower interfacial charge transfer resistance, as demonstrated in the DRS and EIS spectra. The presence of the surface Pt atoms also leads to a higher amount of reactive radicals, which could efficiently promote the surface redox reactions.     

柯克亚油气田混合来源天然气的地球化学特征

柯克亚油气田是我国开发比较早的一个油气田,但由于受混源和其他因素的影响,对气源的认识众说纷纭。通过对天然气的地球化学特征的分析,并参照国内外关于甲烷、乙烷、丙烷碳同位素关系方面的资料,提出了如下看法:柯克亚天然气碳同位素相对较重,与塔里木盆地下古生界海相天然气的碳同位素组成区别较大;根据天然气40Ar/36Ar组成,柯克亚油气田的气源不是单一来源;柯克亚油气田绝大多数天然气的甲烷和乙烷碳同位素值关系符合Faber推断的 型有机质方程直线关系,说明有机质属于较好的有机质类型,或者是由原油裂解形成的天然气;除了K2井和K18井天然气成熟度较低以外,绝大多数天然气的成熟度大约在1.8%～2.2%之间,属于高过成熟气,但也混有一些成熟度在0.9%～1.2%的源岩形成的天然气;推测天然气主要来源于石炭系―二叠系源岩,而混有成熟度低的源岩形成的天然气则有可能来自侏罗系源岩。     

现代电子工业Cpk评价中的特殊问题

现代电子工业生产具有许多新的特点，如果不针对具体情况，均采用传统工业生产中广泛使用的常规方法计算其工序能力指数，评价生产工艺水平，将可能导致错误的结论。总结了电子工业生产中工艺参数的典型特点，并讨论了工序能力指数的正确计算方法。     

水溶性油墨用富马酸改性松香树脂的研制

介绍了一种水溶性富马酸改性松香树脂的制备方法 ,选取了较佳的工艺条件 ,本产品经国内几家油墨厂使用 ,结果表明适合水溶性油墨的应用要求     

对编写《水轮机》新教材的建议

提出适应新的中等职业《水轮机》教材和课程教学大纲的修改建议。     

石油焦原料性质及炭化工艺对活性炭性能的影响

从分析石油焦原料着手，考察了其热解特性、孔隙率和石墨化程度。由于石油焦结构致密，属易石墨化碳，因此用水蒸气法直接活化得到的炭质材料吸附性能差，其碘吸附值小于350mg/g。不同来源的石油焦由于组成不同，其活化性能也有差异。通过成型法，以金山石油焦为原料轻预炭化、预氧化和炭化，得到炭化料，再用水蒸气活化得到的活性炭的碘吸附值达800.40mg/g、亚甲蓝值达120.40mg/g。以独山子石油焦为主要原料制得的活性炭的碘吸附值与亚甲蓝值分别达871．58mg/g、100..67mg/g。     

土壤因子对植物缺铁失绿的影响

本文主要从土壤 pH ,重碳酸盐 ,和氮素形态等几方面综述了各种土壤因子对土壤缺铁失绿的影响 ,并提出了进一步加强研究的方向     

鱼雷罐喷粉预处理过程水模研究

在鱼罐喷粉预处理水模实验数据的基础上，进一步利用线性回归确定各工艺操作参数对喷吹基本参数（均混时间、粉剂穿透比和粉剂停留时间）的影响，得出各传输动力学基本参数的函数关系式。