ON THE INTERFACE BETWEEN AUTOCAD AND THE ADVANCED LANGUAGE     

Lai Xinchang 《保鲜与加工》1988,(4)

This paper comprehensively discusses the interface between AutoCAD and the advanced language. It presents three main ways: by means of . DXF file, SCR file and AutoLISP language. The former two have been used by some people in China. This paper presents the method with its programs for its accomplishment. As to the last one, the author has developed its application with the method for its accomplishment, the problem and the handling method for deletion of library function. AutoCAD can be used as support software for microcomputer CAD. This paper provides some references for technical personnel concerned. The programs in this paper have been all verified by IBM PC/XT, GWO520-CH. The pictures are drawn by DMP-56A.  相似文献   

对两个玉米雄性不育系的细胞质分类研究   总被引：3，自引：0，他引：3  

李建生  徐尚忠 《作物学报》1993,19(2):156-164

本文从普通遗传学、植物病理学和分子生物学的水平对玉米雄花不育系—元徐cms—小黄和恩二激cms—大黄进行了综合性的分类研究。大田的育性反应表明，这两个不育系的育性恢复受一对显性基因控制。对花粉染色的观察发现F1可育花粉与败育花粉基本上呈1：1分离。用小斑病T小种接种，这两个不育系不表现专化感染。通过mtDNA的分析  相似文献   

中间砧对“茂谷橘橙”树体和果实品质的影响     

郑加协  赖正锋  余亚白  陈源 《中国农学通报》2005,21(11):273-273

以蕉柑、芦柑和改良橙作为茂谷橘橙的中间砧，对各中间砧组合的亲和性、树体及枝梢生长表现、产量和果实品质等进行比较研究，结果表明，3种中间砧与接穗的亲和性无显著差异，均表现为亲和力强；改良橙作中间砧的冠径，春梢、夏梢、秋梢的生长量和早期产量均显著地低于蕉柑、芦柑的。高接5年后，3种中间砧对产量的影响无显著差异。3种中间砧对茂谷橘橙果实外观品质和内部品质的影响都不明显。  相似文献   

单株幼龄苹果树修剪仿真研究     

杨丽丽  陈甲风  谢锐  华净  康孟珍  董乔雪 《农业机械学报》2015,46(S1):41-44

修剪是果树生产中重要的技术手段,要想研究更加合理的修剪技术体系,就必须保证能够对修剪反应有准确、直观和及时的判断,而仿真模拟技术提供了这种可能。以幼龄苹果树为研究对象,采用不同修剪处理对比的方法,在田间试验的基础上,总结修剪反应规律,构建苹果树结构和修剪模型。在此基础上基于Qt框架和OpenGL图形库,开发了单株苹果树修剪仿真软件平台。结合优化算法,通过仿真平台模拟了给定生产目标的修剪方案优化,优化结果对虚拟学习和实际生产提供了可视化指导。  相似文献   

Effect of soil matric potential on tomato yield and water use under drip irrigation condition     

Dan Wang  Yaohu Kang  Shuqin Wan 《Agricultural Water Management》2007

Field experiment was carried out to investigate the effect of soil matric potential (SMP) on tomato yield, evapotranspiration (ET), water use efficiency (WUE) and irrigation water use efficiency (IWUE) under drip irrigation condition in North China Plain. The experiment included five treatments, which controlled SMP at 0.2 m depth immediately under drip emitter higher than −10 (S1), −20 (S2), −30 (S3), −40 (S4) and −50 kPa (S5), respectively, after tomato plant establishment. The results showed that different SMP affected irrigation amount and tomato ET. Irrigation amount decreased from 185 mm (S1) to 83.6 mm (S5) in 2004, and from 165 mm (S1) to 109 mm (S5) in 2005, respectively. The ET decreased from 270 mm (S1) to 202 mm (S5) in both years. However, it was found that SMP did not affect the tomato yield significantly, for the range of SMP investigated. Both WUE and IWUE increased as SMP decreased. The maximum WUE (253 and 217 kg/ha mm) and IWUE (620 and 406 kg/ha mm) were for S5 in 2 years, whereas the minimum WUE (178 and 155 kg/ha mm) and IWUE 261 and 259 kg/ha mm) were for S1 in 2004 and 2005. Based on the above results, therefore, it is recommended that if the tomatoes are well irrigated (SMP is higher than −20 kPa) during establishment, controlling SMP higher than −50 kPa at 0.2 m depth immediately under drip emitter can be used as an indicator for drip irrigation scheduling during following period of tomato growth in North China Plain.  相似文献   

罗湾水电站引水系统过渡过程研究   总被引：1，自引：1，他引：1  

赖旭  朱渊岳 《中国农村水利水电》2003,(5):70-71

为了对罗湾水电站增容前后的引水系统过渡过程和机组增容改造对引水系统建筑物的影响进行研究，应用水击计算方法中的电算法进行计算，得出了调压室最低、最高涌浪水位，蜗壳处最大压力水头和机组转速最大升高。结果表明，电站增容后引水系统完全能满足有关规范和设计的要求。  相似文献   

Effect of water deficit in different growth stages on stem sap flux of greenhouse grown pear-jujube tree     

Fusheng Ma  Shaozhong Kang  Fusheng Li  Jianhua Zhang  Taisheng Du  Xiaotao Hu  Mixia Wang 《Agricultural Water Management》2007,90(3):190-196

The effects of water deficit in different fruit growth stages on the variation of stem sap flux of 6-year old greenhouse-grown pear-jujube trees were investigated. Treatments included sufficient water supply during the whole fruit-growing period (T₁), mild water deficit during the flowering–fruit setting stage (T₂), moderate water deficit during the fruit rapid growth stage (T₃) and severe water deficit during the fruit maturing stage (T₄). Results showed that significant compensation effect on stem sap flux after re-watering was observed in T₂, but not in T₃ and T₄ stages. At the end of rapid growth stage, the diurnal variation of stomatal conductance generally had a similar trend as that of stem sap flux, but with a distinct midday depression from 12:00 to 14:00 p.m. In addition, a linear relationship between the relative available soil water content (RAWC) and the ratio of daily stem sap flux to that of sufficient water treatment was observed (R² = 0.4489).  相似文献   

Drip irrigation scheduling for tomatoes in unheated greenhouses   总被引：5，自引：0，他引：5  

Bao-Zhong Yuan  Yaohu Kang  Soichi Nishiyama 《Irrigation Science》2001,20(3):149-154

During the last two decades, energy-saving solar greenhouses without heating systems, about 150-800 m² (width: 5-10 m, length: 30-80 m) in size, have been widely used in the North of China for vegetable production during cold seasons. The greenhouse is also suitable for use in other countries located in the temperate or warm-temperate zones, especially in the developing countries, because it is inexpensive with a simple structure, and does not need any additional energy for heating in winter. Drip irrigation has been recognized as a sensible method of supplying water inside the greenhouses, and a simple method for drip irrigation scheduling at low cost is urgently required. Using the water-balance method, the authors studied the water consumption of tomato (Lycopersicon esculentum Mill.) and the relationship between evapotranspiration and water surface evaporation measured with 20 cm pan. Research results show that there is no significant water flux at 0.75 m depth when soil water potential is kept higher than -20 kPa at 15 cm depth, and around -20 kPa at 60 cm depth. The accumulative value of evapotranspiration is approximately equal to the accumulative value of water surface evaporation measured using 20 cm pan. Further analysis found that 20 cm pan can be used to determine the water requirement of tomato drip irrigation scheduling in this type of greenhouse.  相似文献   

保种群体遗传结构变化的模拟研究     

芒来 《内蒙古农业大学学报(自然科学版)》1991,(2)

本文运用电子计算机模拟的方法,分析了影响畜禽保种的主要因素,并通过不同参数组合(包括起始基因频率、群体有效含量和世代数等)的模拟试验得出三个主要结论: 1 在有性繁殖的有限群体中,原封不动地保存群体基因库中的每个基因(包括频率很低的基因)是根本不可能的。 2 在完全实行随机交配的情况下,长期保存频率较高的基因也需要相当大的群体才有可能。 3 频率较高基因的保存也不能单纯依靠群体大小,还需借助于选择。只有这样才能在小群体内长期保存频率较高的基因。  相似文献   

黑胫突眼隐翅虫捕食功能的初步研究   总被引：2，自引：0，他引：2  

雷朝亮  宗良炳 《华中农业大学学报》1990,9(2):155-157

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