Prediction of the Economic Development for the Circumjacent Reservoir Region of the Longtan Hydropower Project Using Grey Quantitative Analog     

Duan Yurong Zhu Jinming Liu Size Hong Guiyu 《保鲜与加工》1996,(5):95-99

In order to overcome some technical difficulties,we adopt ingenously the grey models combined with the quantitative analog method,and select the Dan Jiangkou Project which has accumulated practical operation data for a long time as the analog project to predict the economic influence for the circumjacent reservoir region of the Longtan hydropower project.On the basis of analog we have built various industrial economic grey models,and compare them with the corresponding predictions for the unconstructed reservoir case.The predictions of the former are greatly larger than the later ones.and hence provides a certain scientific basis for the central leaders to make a decision for constructing the huge hydropower project ultimateiy.  相似文献   

Region Study on Sciences of Human Settlements in China     

Yang YuZhe 《保鲜与加工》2005,(3):5

By review of region study in recent development of history science, geography and Sciences of Human Settlements, this paper points out that material collecting without interrelated analyzing as well as focusing on main question and assumption without enough argumentation are main problems in this field now. The method renovation & combination with related subjects are discussed, this paper concludes that strengthen interdisciplinary study with Geography is a key issue in the future development of region study in Sciences of Human Settlements and possible approach to "technical development' and "humanity concern'.  相似文献   

Around Body Flow Computation with Vortex-Flow-streamFunction in Boundary Fitted Coordinates     

GAN Zi 《保鲜与加工》2003,(6):58

In this paper, partial differential equations of vortex flow-stream function in boundary fitted coordinates and related ADI equations were listed. The flow around a cylinder in quadrilateral area by auto control boundary was computed. The diagram of distribution of speed arrow, constant lines of flow-stream function, vortex, two speed parts and pressure were studied.  相似文献   

TRUST REGION METHOD FOR UNCONSTRAINED OPTIMIZATION     

Tang Jian Duan Yurong 《保鲜与加工》1991,(1):33-41

A new trust region algorithm is proposed for solving unconstrained optimization problems. According to the quadratic approximate model of the original optimization problem,the trust region algorithm uses directions,a convex combination of the quasi-newton direction and the steepest descent direction. This algorithm with new strategy is analyzed and the global and local quadratic convergent theorems are proved. At last,the implementation and computational results of the algorithm are demonstrated.  相似文献   

酿酒葡萄延迟栽培方式的研究   总被引：2，自引：0，他引：2  

房玉林  陈书霞  李华 《中国农学通报》2005,21(5):304-304

利用西昌地区丰富的光热资源，以3年生真芳德和梅尔诺为试材，2000年在西昌正大葡萄试验园进行了酿酒葡萄延迟栽培的研究。摘除一次花序，对新梢分别在花后20、40、60、80d进行中梢修剪，逼迫冬芽萌发结果。结果表明：真芳德具有较强的冬芽副梢结果能力。在延迟栽培条件下，两品种的果实成熟期可推迟到11月上中旬。单株产量、果实可溶性固形物含量和总糖的最大值均出现在花后60d的处理中；各处理滴定酸均高于对照；出汁率随处理时间延迟而降低。两品种花后40、60和80d处理的果实黑痘病和白腐病的发生均低于对照。冬芽副梢成熟度良好。结果表明，延迟栽培能够有效调节葡萄成熟期并改善原料质量，但同时也造成产量的下降和生产周期的加长。  相似文献   

井灌区地下管道输水灌溉工程设计的研究     

张玉池 《节水灌溉》1993,(4)

近几年来,井灌区地下管道输水灌溉(以下简称“管灌”)工程发展很快。保证“管灌”工程质量,发挥其应有效益,提高“管灌”工程设计水平非常必要。本文就井灌区地下硬塑管、混凝土管输水灌溉工程设计的依据、方法,水力计算,管径选择,设计灌溉面积等方面,从实际应用角度提出研究意见。  相似文献   

加快洞庭湖区农机化发展 促进社会主义新农村建设     

江波  黄瑞英  汤楚宙 《湖南农机》2006,(7)

建设社会主义新农村是我党今后很长一段时期的重大历史任务。新农村建设使洞庭湖区农机化获得了发展良机,而农机化在新农村建设中的地位和作用显著,本文从湖南洞庭湖区新农村建设的要求出发,提出了大力推广水稻生产全程机械化技术,以促进洞庭湖区农村生产发展、农民生活宽裕;坚持依法行政,保障农机安全生产,以促进农村社会和谐,乡风文明;抓好农机部门自身建设,以适应社会主义新农村建设的需求等几项措施。  相似文献   

利用Radon变换计算粮仓害虫图像的倾斜角度     

卢军  谭佐军  陈海清  陈建军 《农机化研究》2007,(5):39-41

针对无明显的直线特征的仓储害虫图像,提出了一种基于Radon变换算法定位图像区域和检测图像倾斜角度的方法.实验结果表明,该算法能快速、准确地测量出仓储害虫图像的倾斜角度,并具有很强的抗干扰性、应用适应性和抗随机噪声的特性.  相似文献   

Incorporation of ridge and furrow method of rainfall harvesting with mulching for crop production under semiarid conditions   总被引：31，自引：0，他引：31  

Xiao-Yan Li  Jia-Dong Gong  Qian-Zhao Gao  Feng-Rui Li 《Agricultural Water Management》2001,50(3):173-183

A plastic-covered ridge and furrow rainfall harvesting (PRFRH) system combined with mulches was designed to increase water availability to crops for improving and stabilizing agricultural production in the semiarid Loess region of northwest China. The system was built by shaping the soil surface with alternate ridges and furrows along the contour. The plastic-covered ridges served as a rainfall harvesting zone and furrows as a planting zone. Some materials were also used to mulch the furrows to increase the effectiveness of the harvested water. This system can make better utilization of light rain by harvesting rainwater through the plastic-covered ridge. The field experiment (using corn as an indicator crop) showed that grain yields in the PRFRH system with mulches in 1998 and 1999 were significantly higher than the controls, with an increase of 4010–5297 kg per ha (108–143%). In most treatments, the water use efficiencies (WUE) were in excess of 2.0 kg m⁻³. The WUE values of corn in this system were 1.9 times greater than the controls in 1998 and 1.4 times greater than the controls in 1999. The plastic-covered ridge led to a yield increase of 3430 kg per ha (92%) in 1998 and of 1126 kg per ha (21%) in 1999 compared with the uncovered ridge. On average, the additional mulches in the furrow brought about a yield increase of 8–25%. Based on the results of this study and other researches, this technique can increase corn grain yield by 60–95% in drought and average years, 70–90% in wet years, and 20–30% in very wet years. The PRFRH system had the potential to increase crop yield and produced greater economic benefit, therefore it could be used in regions dominated by light rainfall of low intensity where crops generally fail due to water stress.  相似文献   

玉米籽粒内部组分低对比度透射图像精确分割研究     

王金星  李玉风  江浩  张宏建  张春庆  刘双喜 《农业机械学报》2020,51(6):238-247

为解决玉米籽粒透射图像由于对比度较低造成内部组分提取不精确的问题,提出一种基于色彩通道非线性变换的多通道重叠区域分割方法,对玉米籽粒图像在灰度、R通道及b通道下得到的二值图像使用重叠区域原理,实现玉米籽粒组分的精确分割。首先,采集不同玉米品种的籽粒透射图像,提取单粒玉米籽粒;其次,采用多通道重叠区域法分割单粒籽粒图像,得到玉米籽粒胚部、角质胚乳和粉质胚乳3部分的图像;最后,以查全率和查准率评价多通道重叠区域法与传统图像分割方法对不同品种玉米籽粒的分割效果。不同品种玉米籽粒的分割试验表明:多通道重叠区域分割方法的查全率、查准率及综合评价指标均达到98%以上,分割效果优于传统的图像分割方法,能够实现不同品种透明角质玉米籽粒透射图像的精确组分分割。  相似文献