解决关中地区水荒的对策和建议

关中属资源性缺水地区,供需水问题将是长期困扰关中经济发展的问题。随着经济的发展,今后缺水将由农业用水转向工业、城市用水。解决关中水荒问题应从节水和开源两方面进行,文中对此提出了建议和措施对策。     

电磁耦合叠层矩形贴片天线的研究

介绍了由同轴探针馈电的电磁耦合多层重叠贴片天线的分析方法。分析以电场积分方程为基础，为解此方程，在频谱落款畴内采用加略金法。该分析方法用于研究一个两层重叠矩形片天线的特性。同时介绍了衬底材料，贴片尺寸，贴片移动以及天线罩对输入阻抗或者辐射方向图的影响。     

Midrex直接还原工艺——直接生产洁净钢的方法（Ⅰ）

直接还原铁（ＤＲＩ）为电弧炉炼钢厂提供了生产优质钢丝制品、棒材、管材和扁材的能力。ＤＲＩ除了是一种低残余元素的炉料资源外．ＣＯ的产生和泡沫渣可使钢材具有优良的屈服强度、延伸率、应变时效等机械性能。还可改善电炉的操作。     

Surface properties of muscle protein extracts

The interfacial properties of proteins extracted from muscle using salt solutions of different concentration and for different extraction times were determined by the drop volume method. At a bulk phase concentration of 10(-2) wt%, it appears that the sarcoplasmic-rich fraction of muscle is more surface active than the salt-soluble fraction. The average equilibrium surface pressure at the air-liquid interface was 21·5 mN m(-1) for an aqueous extract and 20·1 mN m(-1) for a 1m KCl-extract. The equilibrium surface pressure decreased from 21·7 mN m(-1) to 19·50mN m(-1) as the extraction time with Weber-Edsall solution increased from 15 min to 48 h.     

Effect of zeranol on bull muscle fibre composition

Two trials are reported in which bulls were implanted with zeranol and slaughtered at 18 months. There was no significant change in carcass weight due to zeranol in either trial. Samples of the longissimus dorsi (LD) and splenius (Sp) were cross-cryosectioned, stained for myofibrillar ATPase and examined by conventional light microscopy. The stain resolved three fibre types: I, slow contracting with an oxidative metabolism, IIA, fast-oxidative-glycolytic and IIB, fast-glycolytic. In the LD from treated bulls, the occurrence of IIB fibres was increased, apparently at the expense of IIA fibres, as the occurrence of I fibres was unchanged. These occurrence changes parallelled previously reported effects of castration. Changes in Sp were less dramatic. In one trial IIB fibres were absent from all Sp muscles, but, in the other, some of the Sp muscles from treated animals contained these fibres whereas they were absent from the Sp of the control group. If the changes in fibre type occurrence due to zeranol extend to skeletal muscles other than LD and Sp, there is likely to be a subtle change in the musculature's metabolism. Fibre areas were largely unaffected by zeranol. In this respect zeranol did not mimic castration.