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941.
针对新疆通信盲区多、移动信号覆盖差,安全事故信息不能及时上报,应急救援指挥严重滞后的现状,提出了建设针对长途客货营运车辆、危险品运输车辆、应急运输车辆、野外工程车的基于我国自主建设、独立运行的北斗卫星导航系统的安全生产运输车辆监控管理系统,提供面向各行业需重点监控各型车辆及其主管调度部门的基于位置的综合信息服务。从而实现生产事故应急救援指挥,有序开展野外事故设备、人员的搜寻,有效提高安全生产信息化水平。  相似文献   
942.
Large amount of seawater is used in coastal industries, like power generating plants, desalination plants and aquatic culture farms. A similar requirement exists in Department of Atomic Energy campus at Kalpakkam, Tamil Nadu, India. Seawater in large quantities is required for its nuclear power stations and desalination plants erected on the east coast of Bay of Bengal situated in southern part of India. Such seawater systems have biofouling problems. Hence a seawater intake system has been designed, constructed and erected so that virgin seawater will be available for biofouling studies that was proposed to be carried in a once through flow test facility. A major criterion for the test facility was that continuous supply of seawater should be available at the rate of 160 m3/h. To meet this requirement, centrifugal pumps were installed at about 150 m away from the shoreline and connected to an intake structure using 600 m long, 355 mm OD, high density polyethylene pipeline laid on the seabed. Details of site selection, options of construction methods, materials selection, pressure drop calculations, sizing of pipes and anchor blocks, stability of intake pipeline, deployment criteria and project cost and planning have been discussed in this paper.  相似文献   
943.
Bacterial inorganic nitrogen control using carbon:nitrogen ratio (C:N) manipulation is a tool for aquaculture systems. The present study assessed the hatchery performance of Litopenaeus vannamei between the mysis 1 and postlarvae 5 stages in a zero-exchange biofloc system under different C:N fertilization levels (10:1, 12.5:1 and 15:1) with dextrose. Water quality, performance parameters and water microbiology were compared among treatments. The mean values of the evaluated water quality parameters were appropriate for this production stage. Fertilization with dextrose efficiently controlled ammonia levels, which did not reach the average concentrations considered toxic for the species. In the 10:1 C:N ratio treatment, the levels of ammonia started to increase early and showed significantly higher levels from the third to the last experimental day. There was no difference among groups in means of survival (>76%) and dry weight (0.26 mg) of L. vannamei production parameters and water quality were maintained without water exchange using a biofloc system supplemented with dextrose. Therefore, the use of biofloc systems without water exchange with dextrose as a carbon source in C:N ratios of 10:1, 12.5:1 and 15:1 results in both adequate production indexes and water quality during the misis 1 to post-larvae 5 hatchery phases of L. vannamei. However, the ratios of 12.5:1 and 15:1 keep lower levels of ammonia.  相似文献   
944.
为了满足多品种生产的需要,林海雅马哈摩托有限公司导入了雅马哈的PC-PYMAC生产管理系统。介绍了该系统的制造基础信息模块、计划模块、实绩管理模块和盘点模块;针对该系统在林海雅马哈摩托生产应用过程中产生的问题提出了相应的解决错施。  相似文献   
945.
为降低浅圆仓入库过程中产生的自动分级,减小破碎率的增加等现象,解决中心部位在通风过程中产生的通风死角,实现安全储粮,我库与河南工业大学及郑州筒仓公司合作开发研制了浅圆仓气浮式降分级、减破碎多功能中心系统。通过实仓试验发现,该系统在降低分级、减小破碎率方面效果明显,并实现了中心部位的径向通风,提高了储粮稳定性。  相似文献   
946.
水稻是我国60%以上人口的主食,在保障国家口粮安全中起着举足轻重的作用。近年来,随着人们生活水平的提高、城镇化进程的加快和消费习惯的改变,我国粳稻消费需求快速增长。但是,受耕地减少、生物与非生物因素胁迫日益严重的影响,粳稻增产的难度越来越大。基因工程技术的发展和应用为打破这一僵局提供了可能。回顾了粳稻转基因技术的发展,对粳稻转基因体系建立、体系优化、育种应用和安全转基因技术研发等方面进行了综述,并对目前粳稻转基因技术存在的问题和未来的发展进行了分析和展望。  相似文献   
947.
The concentration and balance of nutrients in both the hydroponic or soil solution has been evaluated with relevance to tomato productivity. Yields of 200 mt/ha have been produced in greenhouse, hydroponic culture in a 9 to 10 month period. Yields of more than 100 mt/ha of field grown tomatoes have been produced in Florida in a 4 to 5 month period. Within the limitations of either culture, it is possible per unit of time to provide the nutrients required to produce equivalent yields. It is most significant that field grown tomatoes in Florida can be grown with minimal management and at a fraction of the cost of those grown hydroponically. The validity of the Florida fresh market tomato industry is based on the production efficiency of the field culture. There are annually 16,000 ha of tomatoes grown in Florida, perhaps less than 40 ha grown in hydroponic cultures.  相似文献   
948.
Abstract

In feeding studies, red clover (RC) influenced positively the N utilization by ruminants. A relationship between polyphenol oxidase (PPO) activity and forage quality has not been established. Our objective was to investigate seasonal, site, genotype, and management effects on specific PPO activity in RC in three experiments under field conditions, and relate the activity to forage-quality parameters. In Experiment 1, six RC genotypes at two study sites were submitted to a 3-cut system. Specific PPO activity, forage quality, and vegetation stage were determined. PPO activity varied between harvest and study sites, with genotypes differing up to 3-fold in PPO activity within harvests. The specific PPO activity, forage quality, and vegetation stage in RC subjected to 5-cut system and grazing (Experiment 2) were determined. Additionally, in Experiment 3, cutting frequency in RC swards including mechanical stress (rolling) was investigated. The induction of PPO activity in RC by grazing or mechanical stress (Experiments 2 and 3) increased the activity up to 2.5-fold compared with RC at similar vegetation stage submitted to the 5-cut system. Mechanical stress induced by grazing or rolling, and seasonal differences, seem to have a larger influence on specific PPO activity than does the genotype effect observed in Experiment 1. For forage quality, an increased specific PPO activity explained 29–46% of the reduction in protein fraction ‘A’ content (non-protein N) in the cutting systems in Experiments 2 and 3. Other CP fractions achieved a lower relation. Furthermore, the precipitation-to-temperature ratio preceeding a harvest explained 63% of the variation in the specific PPO activity. In conclusion, the PPO activity in RC is induced by grazing and rolling. Whereas weather conditions preceeding a harvest showed a large influence, genotype influence had only minor relevance. These results may have implications for regional harvest management towards efficient N utilization by ruminants.  相似文献   
949.
高玉龙 《湖南农机》2013,(3):131-132
火灾是舰船主要危害之一,对舰船及船员的生命安全早场了严重的影响。确保舰船生命力的一项有力保证就是舰船消防措施。文章针对某型舰船的消防泵控制箱的改造进行了设计研究分析。  相似文献   
950.
Abstract

The root parasitic plants Orobanche spp. (broomrapes) seriously affect agricultural production. A visualization and quantitative analytical method for the interception of nutrients was established using a positron-emitting tracer imaging system and 13NO? 3. By using this analytical method that involves volume normalization with 18F? images, the nitrogen nutrient interception ratio of the Orobanche spp. was calculated to be 73.6 ± 3.9% in a host–parasite system of red clover (Trifolium pratense L.).  相似文献   
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