重庆市南岸区发展城郊型农业的对策探讨

依据重庆市南岸区独特的区位优势、地理优势、自然资源和生物资源条件,以及农业发展现状,提出了南岸区大力发展城郊型特色农业,应坚持品种多样性、产品时新性、市场竞争性、经济高效性、多种经营、复种指数高、生长周期短、可持续发展、扩大开放和交流合作、品牌带动以及科教兴农等原则,并针对性较强地提出了发展＂绿色食品工程＂、发展休闲观光农业、大力调整农业结构、优选发展模式、优化生态环境、提高产品质量、实施良好的运作机制和完善相关配套政策等8方面的发展对策和措施,为促进资源优势向经济优势转变提供有价值的参考意见和建议,对重庆市都市发达经济圈农业发展具有一定借鉴作用.     

Dietary magnesium requirement and physiological responses of marine shrimp Litopenaeus vannamei reared in low salinity water

An 8‐week feeding experiment was conducted to determine the dietary magnesium (Mg) requirement and physiological responses of Litopenaeus vannamei in low salinity water of 2 g L^?1. Casein–gelatin‐based diets supplemented with seven levels of Mg (0, 0.4, 0.8, 1.6, 3.2, 6.4 and 8.0 g kg^?1) were fed to juvenile shrimp. Prior to the experiment, the postlarvae were gradually acclimated to the low salinity media and fed with a basal diet (0.5 g Mg kg^?1) for 2 weeks. After 8 weeks of feeding, survival ranged from 80.11% to 85.65% with no significant difference among the treatments. Hepatopancreas Mg²⁺‐ATPase and Na⁺/K⁺‐ATPase activities and muscle content of lipid and protein were not significantly affected by graded levels of Mg. The weight gain and mineral (calcium, potassium, sodium and total phosphorus) content of different tissues were significantly affected by dietary Mg levels, while there were no significant differences in ash and zinc content in tissues. The Mg content in tissues except hepatopancreas was maintained relatively constant regardless of dietary treatments. The dietary Mg requirement for optimal growth was 2.60–3.46 g Mg kg^?1 by using the polynomial regression analysis based on growth.     

Numerical simulation of NO and N2O emission in fluidized bed reactor

Both NO and N2O emission in fluidized bed reactor are studied by numerical simulation. The effects of excess air ratio, coal composition and co combustion of coal and biomass are researched. The results show that NO and N2O are the main products of the NOx in the fluidized bed reactor combustion, and the emission of NO and N2O increases with the excess air ratio increasing. The NOx production has strong relationship with coal composition. The nitrogen content of the coal plays an important role in the production of NO and N2O, as well as oxygen to nitrogen mass ratio and hydrogen to nitrogen mass ratio. In the co combustion process of coal and biomass, carboxyl group have remarkable effect on HCN production, which reduces the content of NO and NO2. The co combustion of coal and biomass can reduce the emission of NO and N2O.     

阜新地区玉米生产中值得重视的问题

阜新地区位于辽宁省西部,耕地面积约26．67万hm2,其中玉米种植面积就有20万hm2。由于阜新地区位于玉米黄金带．阜新的玉米技术是东北地区的缩影。了解阜新的玉米市场与生产中问题,可以了解整个东北地区玉米存在的问题。     

法国家具业下一个目标:扩大出口

法国现在是世界上第四经济大国,法国家具生产在欧洲名列第三位,仅次于意大利和德国。法国有13000家家具制造公司,其中只有76家公司职工人数在200人以上,其余绝大部分是10人以下的小型企业,从事家具行业的人数已达10多万人。     

重庆市农机购置补贴政策实施现状与成效分析

重庆市是我国典型的丘陵山区,研究其农机购置补贴政策实施现状和成效对促进重庆市农机化发展,进而辐射、带动全国丘陵山区农机化发展具有重要意义。为此,首先从财政投入、补贴机具种类、补贴区域、补贴对象和补贴方式5方面总结重庆市农机购置补贴政策实施现状。分析实施该政策取得的成效:增加了农机装备总量,改善了农机装备结构;提高了农机化作业水平;提升了农机社会化服务水平,促进了农机服务组织发展;带动了农民增加个人投入;扩大了农村需求,推动了本市农机工业发展;提高了劳动生产率,加快了农村劳动力转移;促进了农民增收。