视频图像编码的现状与发展

本文介绍了静态和运动图像压缩编码国际标准的发展过程中出现的一系列标准,特别是JPEG2000、MPEG-4以及H.264,总结了这些国际标准的压缩效果、应用场合及相应的压缩编码算法,分析讨论了这些新标准的特点和优越性。     

Evaluation of Water–Nitrogen Schemes for Rice in Iran,Using ORYZA2000 Model

The model ORYZA2000 simulates the growth and development of rice under conditions of potential production and water and nitrogen (N) limitations. Crop simulation models could provide an alternative, less time-consuming, and inexpensive means of determining the optimum crop N and irrigation requirements under varied irrigation and nitrogen conditions. Water productivity (WP) is a concept of partial productivity and denotes the amount or value of product over volume or value of water used. For the evaluated ORYZA2000 model in Iran, a study was carried out in a randomized complete block design between 2005 and 2007, with three replications at the Rice Research Institute of Iran, Rasht. Irrigation management (three regimes) was the main plot and N application (four levels) was the subplot. In this study, simulation modeling was used to quantify water productivity and water balance components of water and nitrogen interactions in rice. Evaluation simulated and measured total aboveground biomass and yield, by adjusted coefficient of correlation, T test of means, and absolute and normalized root mean square errors (RMSE). Results showed that with normalized root mean square errors (RMSE_n) of 5–28%, ORYZA2000 satisfactorily simulated crop biomass and yield that strongly varied among irrigation and nitrogen fertilizer conditions. Yield was simulated with an RMSE of 237–443 kg ha^?1 and a normalized RMSE of 5–11%. Results showed that the significant (28–56%) share of evaporation into evapotranspiration, using the actual yield (measured) and simulated water balance (ORYZA2000), the calculated average WP_ET was significantly lower than the average WP_T: 37%. The average WP_I, WP_I+R, WP_ET, WP_T, and WP_ETQ were 1.4, 1.07, 1.07, 1.57, and 0.82 kg m^?3. Results also showed that irrigation with 8-day intervals and 60 kg N ha^?1, nitrogen level was the optimum irrigation regime and nitrogen level.     

基于局域网的数据库文件备份

Oracle、SQL Server、MySQL是中小型企事业单位常用的三种数据库,数据库的备份和恢复至关重要;数据库文件的备份有很多种方法,本文主要介绍了如何将它们的数据库文件导出并自动备份到局域网内其它计算机上,同时介绍了Ghost、WinRAR等软件在数据库文件备份中的应用.     

论过程方法在生产企业内外部审核中的应用

本文介绍了过程方法及在生产企业内外部审核的具体应用,中国企业在做ISO9001内外部审核时基本上是以部门为主线,但在建立体系及审核时如用过程方法效果会更好。本文从过程方法介绍,企业的内外部审核概述,过程方法在内外部审核中的应用展开详细阐述了怎么去应用过程方法。     

Using ecological trajectories to track long-term taxonomic and functional changes in benthic shallow soft-bottom communities (Bay of Saint-Brieuc,English Channel)

1. Taxonomic and functional trajectories of benthic assemblages were studied in shallow soft-bottom sediments in the bay of Saint-Brieuc (Western English Channel). Changes were assessed at different spatial and temporal scales using a macrobenthic dataset based on 38 stations sampled in 1987 and 2019, coupled with data from one station sampled annually between 2005 and 2019 as part of the European Water Framework Directive monitoring programme.
2. Taxonomic trajectories indicated 1) changes in the structure and distribution of benthic assemblages, 2) an homogenization of the assemblages, and 3) significant functional shifts.
3. Fishing activities and nutrient enrichment are probably strong drivers of the observed changes, as suggested by the higher mortality rate of fragile, flexible, tubiculous and burrowing species, and the increase in the abundance of opportunistic species in the assemblages. Certain populations of macroinvertebrates seem jointly controlled by climate change and by the aforementioned local factors of disturbance.
4. The Community Trajectory Analysis framework appears as a new and interesting method to track ecological changes in marine ecosystems by measuring change with respect to a baseline state, to help define ecological recovery (station returning to the initial ecological state) and departure (station presenting increased changes over time), and to analyse trajectory similarity.
5. According to the degradation of habitat over time, we identify the need for the implementation of knowledge-based conservation strategies, especially within Natura 2000 sites.

     

苏云金芽孢杆菌YJ-2000菌株对家蚕安全性和杀虫活性的评价

应用时间-剂量-死亡率模型就苏云金芽孢杆菌(Bacillus thuringiensis)YJ-2000菌株对6种鳞翅目昆虫的杀虫活性作了初步评价。该菌株对家蚕基本无毒性,而对蔬菜害虫小菜蛾、菜粉蝶,水稻害虫三化螟、二化螟,桑树害虫桑螟幼虫均有不同程度的毒性,其中对小菜蛾和菜粉蝶的毒性最强;幼虫死亡率可高达100％。该菌株是对家蚕安全而对其它鳞翅目害虫具杀虫活性的特异性菌株,有望用于养蚕地区桑园及其邻近作物的鳞翅目害虫防治。     

一种高效低功耗JPEG2000小波变换器的设计

提出了一种高效低功耗的JPEG2000小波变换器的硬件结构,减小了二维离散小波变换器(2-D DWT)中暂存器的大小,降低了存储器的平均访问带宽,有效减小了芯片的面积和功耗.整个设计通过了FPGA验证,并采用HJTC 0.18μm工艺库进行了芯片设计.试验结果表明,片内暂存器的面积和功耗比普通方法分别减小了54.5%和61.4%.     

化学分析实验室的质量管理特点与LIMS的运用

介绍了化学分析实验室的业务特点,对照GB/T 15481-2000 idt ISO/IEC 17025:1999标准《检测和校准实验室能力的通用要求》,指出了在不同环节中进行质量管理应注意的事项.评述了实验室信息管理系统(LIMS)应具备的功能层次和与环境检测实验室的业务相对应的功能模块.     

应用ORYZA2000模型制定北京地区旱稻优化灌溉制度

通过优化灌溉提高水分利用效率,使有限的水资源发挥最大的效益,是推行节水农业的一个重要方面.在模型验证的基础上,利用ORYZA2000模型和多年气象资料,分析了北京地区不同降水年型条件下早稻产量和水分利用效率与灌溉定额之间的关系,在此基础上制定不同降水年型和产量水平的北京地区旱稻优化灌溉制度.结果表明:当灌溉定额达到一定水平后,最高产量趋于不变.干旱和平水年型条件下旱稻均有较大的增产潜力,灌溉定额为300～500 mm可增产约3000 kg/hm2;丰水年型灌溉定额为250 mm时可增产1000 kg/hm2.70%、80%和90%产量潜力3个产量水平的最优灌溉制度分别需要保持根层土壤相对含水率在67%、73%和83%左右,灌水定额不宜过高,以50～60 mm为宜.灌溉次数和灌溉定额随产量水平的提高而增加,并取决于实际的降水情况:干旱年型3个产量水平的灌溉次数为3～8次;平水年型为2～5次;丰水年型为1～5次.水分利用效率变化范围为0.92～1.28 g/kg,受各年型降水量影响灌溉水水分利用效率变化在1.61～7.76 g/kg之间,丰水年型的灌溉水水分利用效率高于平水年型和干旱年型.80%产量潜力水平时的水分利用效率最高,不同年型灌溉定额在98～239 mm之间,灌溉次数为2～5次.