PowerBuilder下旅游管理系统的设计与实现

文章阐述了用PowerBuilder开发旅游管理系统的设计方法与实现方案.并对其设计时的关键技术作了较为详细的分析。     

GIS technologies for aquatic macrophyte studies: I. Database development and changes in the aquatic environment

Geographic information system (GIS) and digital database technologies provide a link between landscape-scale ecological studies and resource management applications. A case study involves the development of an extensive GIS database for upper Lake Marion, South Carolina that includes macrophyte distributions for 1972–1988, bathymetry, sedimentation and water chemistry. This database was utilized to assess changes in the aquatic environment related to management practices such as herbicide applications for aquatic plant control. Although the herbicides were found to be very effective, spraying must be repeated annually to maintain open water areas clear of aquatic vegetation. Without herbicides macrophytes quickly reinvade and proceed in normal successional patterns to establish submergent and emergent aquatic plant beds. The PC-based procedures developed in this study can be utilized by local resource managers to assess the impact of management practices on the aquatic environment.     

微生物拮抗检测方法的优化及其在秸秆发酵用菌株的应用

在利用复合菌添加剂提高青贮品质和营养价值的研究中, 首先需要确定菌株间的拮抗特性, 以便获得最佳组合效果。利用传统的1/2组合菌饼法和牛津杯法检测了6种微生物间的拮抗特性。结果显示, 仅产朊假丝酵母菌和黑曲霉菌之间存在弱拮抗现象。在后续全组合液滴法检测中不仅观察到了以上拮抗现象, 还检测到了枯草芽孢杆菌与产朊假丝酵母菌, 以及绿色木霉菌与黑曲霉菌之间的拮抗现象。通过显微镜观察绿色木霉菌与黑曲霉菌之间的接触区域, 进一步证实了拮抗现象的存在。在所用的6种微生物中, 乳酸菌与其他受试菌无明显拮抗, 能够与其他微生物进行复配。产朊假丝酵母菌与枯草芽孢杆菌和黑曲霉菌存在拮抗, 因此, 可与乳酸菌和绿色木霉菌进行组合发酵。同样, 枯草芽孢杆菌和黑曲霉菌可单独与乳酸菌进行组合使用。综上表明, 与传统的1/2组合菌饼法和牛津杯法相比, 全组合液滴法具有操作简便、接触充分、不易污染和结果全面等优点。     

Shading decreases the growth rate of young apple fruit by reducing their phloem import

This study investigates the effects of shading on the biophysical mechanisms of apple (Malus Domestica Bork.) fruit growth by assessing how vascular and transpiration flows to/from the fruit are affected by shading. At 30 days after full bloom, a 90% neutral shading net was applied to four trees of the cv. Gala, for seven days, while four more trees, chemically thinned, were used as control. Fruit vascular and transpiration flows were assessed from two days before, to the end of shading. The daily patterns of fruit relative growth rate (RGR) and of phloem, xylem and transpiration flows were determined by continuous monitoring of fruit diameter by automatic fruit gauges. Before shading application, no differences between the two groups of trees selected were found for any of the parameters measured. Despite shading induced an immediate drop in canopy photosynthesis, both fruit daily RGR and phloem flow decreased gradually, until reaching 20% of the before treatment values after 7 days of shading. Differences in RGR and phloem flow appeared especially during the afternoon and night, i.e. post carbon assimilation by the tree, and fruit growth rates were higher in control trees. In the same period no, or very small differences were found between treatments for transpiration rates, while xylem flow was affected later than phloem and only at specific times during the day. These results suggest that the decrease in fruit growth rate under shading should be attributed to the reduction of canopy photosynthesis, rather than to a direct effect of shading on fruit sink strength.     

Sucrose synthase dominates carbohydrate metabolism and relative growth rate in growing kiwifruit (Actinidia deliciosa, cv Hayward)

Changes in fruit growth rate, carbohydrate content (glucose, fructose, sucrose and starch) and enzyme activity (sucrose synthase, UDPglucose pyrophosphorylase, fructokinase, glucokinase, sucrose phosphate synthase, ADPglucose pyrophosphorylase and invertases), in the external pericarp of kiwifruit, were measured throughout the growing season. Sucrose synthase showed the highest activity among the sucrose cleaving enzymes during large part of the growing season. The activity of invertases were much lower than that of sucrose synthase until ripening started. Sucrose synthase showed a tight although not linear relationship with the fruit RGR. Furthermore, sucrose synthase showed linear and significant correlations with the activities of both fructokinase and UDPglucose pyrophosphorylase indicating a strong co-regulation of the activities of these three enzymes involved in sucrose cleavage and sink strength, in kiwifruit. Sucrose synthase is suggested to be the dominating enzyme in the cleavage of imported carbon in kiwifruit, in tight coordination with fructokinase and UDPglucose pyrophosphorylase.     

高校文库数据库建设的实践与思考

分析了国内外文库建设的现况,从建设目标、系统设计和最终实现3方面介绍了西安交通大学图书馆文库建设实践,并提出了完善文库建设的建议。     

Ovid系统生物、农业数据库使用探讨

笔者详细的介绍了Ovid发展、特点 ,并且对基于Ovid平台的生物、农业数据库主要检索方法、检索工具、检索技巧等作了详尽的阐述     

膳食营养素计算与评价系统的设计与实现

采用Microsoft的Visual Basic和Access开发环境,将各种最新的营养信息数据组织起来,编制成相应的应用程序,实现用计算机对膳食营养素进行计算和评价,为膳食调查、营养监测及咨询、膳食结构的自我调整等提供有力而科学的技术支持.     

自制低压微型喷头

分析比较了国产和进口“全光雾插自动喷雾装置”喷头的优缺点,提出了自制低压喷头的必要性,通过对自制喷头的实际使用验证,证明了该喷头的实用可靠.     

工程造价领域分布式数据库加锁与刷新机制研究

本文根据工程预算领域的实际情况，特别是结合中小型建筑企业的特点，运用数据库理论与技术以及构件技术，阐述了分布式数据库加锁与刷新构件的实现原理与实现机制，并将其应用到“造价工程师2004网络版”的研制开发中，取得了满意的结果。该分布式数据库加锁与刷新构件可以应用到系统中的各个模块中，具有复用性强、安全可靠、简单易用等特点，并在一定范围内推动了工程造价领域自动化、数字化的进程。