纳他霉素产业发展现状及前景分析

综述了目前国内外纳他霉素的应用领域、行业发展及市场需求状况,并对国内纳他霉素产业发展的前景和存在的问题进行了分析.     

Study on constant current control of inductive power transfer with parameter identification

Aiminy at magnetic exciting current (resonant current) control, a constant current control method based on dynamic parameter identification is put forward. With energy conversion analysis, the energy storage, supply and dissipation functions of the system resonant network are constructed. The reflecting impedance identification functions are obtained by constructing the energy equilibrium relations in a period and among several periods. Furthermore, a constant current control strategy by regulating the system input voltage with Buck converter is presented. Combining the relations among system input voltage, the envelope of resonant current and the input of Buck converter, the constant current control law is proposed. The control law is verified with experiments. For the proposed method, in parameter identification, only the data of zero crossing point of resonant voltage and current are required, which reduces the complexity and costs of sampling system. Also, the constant current control law does not need complex computation and is easy to implement.     

Intercepted radiation by apple canopy can be used as a basis for irrigation scheduling

Improved approaches for irrigation scheduling require specific protocols for adaptation to different growing conditions. We assessed crop intercepted radiation as the main factor for decision on irrigation scheduling. Over two growing seasons (2007-2008), apple trees growing in a large weighing lysimeter were used to measure daily canopy transpiration (T_d). Seasonal patterns of daily canopy intercepted photosynthetically active radiation (IPAR_d) and midday stem water potential were also measured. In 2007, irrigation was withheld in two different times to study T_d responses to midday stem water potential. Before harvest, under full irrigation, T_d increased linearly with IPAR_d (R² = 0.81 in 2007 and 0.84 in 2008). With the two year data combined, R² increased from 0.74 to 0.80 when VPD was considered as a second variable. When irrigation was withheld in 2007 the ratio between T_d and IPAR_d, which is defined here as transpiratory radiation use efficiency (TRUE), decreased linearly (R² = 0.49) as midday stem water potential decreased. Due to the highly significant effect of IPAR_d and VPD on T_d, TRUE showed potential applications in estimating the amount of irrigation water.     

多相流管道输量突增的瞬态效应试验研究

在大型多相流环道上进行了液量增加的瞬态试验，讨论了试验中的瞬态效应。当液相流量快速增加后，压力波首先传播到管道各点，压力发生扰动，一般时间后空隙传播到各点，压力快速上升。压力快速变化向下游的传播速度等于空隙波的波速。在段塞流时，空隙波波速等于液塞运动速度，在分层流时，空隙波波速等于液体实际流速；在气团流时，空隙波波速等于气液混合物的速度。差压的变化较为复杂，在不同流型和液量下的变化不同。     

重庆市胭脂鱼资源及保护现状

收集整理了重庆渔政网2007～2009年的胭脂鱼误捕信息,以及1997～2009年的《长江三峡生态环境公报》中有关胭脂鱼的资料,着重分析了胭脂鱼在重庆的分布区域、资源现状与保护现状等,提出了加强增殖放流效果研究、规范误捕记录、进行产卵场调查、增设保护区等建议。     

我国油菜科技创新体系现状及发展建议

通过分析我国油菜科研布局、科研队伍、科研经费、研发基地、仪器设备、成果产出等方面的现状，指出我国油菜科技创新体系目前存在的主要问题，并就今后我国油菜科研体系的建设提出了相关建议。     

山西旱地小麦栽培技术体系的形成及其发展战略

系统论述了山西旱地小麦在山西小麦生产中的地位、现状及其与降雨的相关性，回顾了山西旱地小麦栽培技术体系的形成与发展，提出了山西旱地小麦再上新台阶的5项战略性意见。     

黄土区农田作物降水利用效率影响因素及提高途径分析

降水资源高效转化利用对于提高早地农业和灌溉农业生产综合效益均具有重要意义。通过对黄土区农田作物降水利用效率的概念及其影响因素、农田降水生产潜力等相关研究成果的分析，从实现土壤水库扩蓄增容、增加农田地面覆盖、促进作物根系生长、减少作物无效蒸腾、持续增加土壤肥力等5个方面，提出了提高黄土区农田降水利用效率的方法和途径，并结合降水资源转化利用技术发展需求，提出了近中期提高降水资源利用效率技术的发展方向和研发的若干重点。     

机动水稻插秧机送秧机构的计算机辅助设计

滚动直插式水稻插秧机在栽插拔取苗时通常采用对准式送秧机构,这种机构结构简单,但送秧轨迹不够理想.现先设想送秧叉的运动轨迹为一连杆曲线,根据曲柄连杆机构各杆件的几何关系列出轨迹的方程,然后采用有约束条件的直接搜索法中的随机方向搜索法求得轨迹的实现机构,最终改善插秧机的送秧能力。     

加入WTO陕西苹果产业化发展的几个战略性问题

分析了我国尤其是陕西省的苹果产业化发展现状及潜在危机 ,提出了陕西苹果产业化发展的几个战略问题 :1以生态为核心 ,以资源为基点 ,以特色为内涵 ,以全球化为目标 ,科学规范化、地域特色化的苹果资源配置是生态型绿色苹果产业链的基础。 2生态型绿色无公害果业的建设是陕西生态型绿色苹果产业链的强生长点。 3以分子态认识陕西特色苹果资源的内涵成分为基础 ,以全球市场需求为背景 ,以多学科高技术集成化为手段 ,开发生产生物活性成分富集化、营养保健功能化的生态型绿色多元化产品 ,是陕西生态型绿色苹果产业链链接的核心点。 4苹果及系列加工产品安全性的评价、监测、预警及整体性、系统化、立体型产业化控制技术 ,是生态型绿色苹果产业链建设的强支撑点。 5生物、化学、机、光、电集成化 ,产学研一体化 ,加速陕西地区性优势苹果资源精深加工产业化 ,尽快形成陕西生态型绿色苹果产业链的梯度型、阶梯式龙头企业集团群