净耕地系数,net arable land coefficient
1)net arable land coefficient净耕地系数
1.thenet arable land coefficients estimated using the remote sensing image and those derived from the field sample survey,are similar,and the similarities are all higher than 90%,which reveals that the method of using remote sensing image to derive the arable land coefficients is feasible,and the reliability ofnet arable land coefficient is high.利用CBERS遥感影像数据进行目视解译,扣除各种细小地物,获得基于遥感影像的净耕地系数。
2.The measurement ofnet arable land coefficient is of great importance in investigating the status of land-use,aiming at improving accuracy of the area survey.净耕地系数测算是土地利用现状调查中一项极其重要的工作,其目的是提高耕地面积调查的精度。
英文短句/例句
1.Arable Land in the Manas River Basin Based on CBERS Data利用CBERS数据测算净耕地系数的可行性分析
2.A net Arable Land Coefficient Study of Manas River Basin based on Remote Sensing基于遥感的净耕地系数实验研究——以玛纳斯河流域为例
3.Study on Conversion Coefficient of Supplementary Cultivated Land in Hubei Province;湖北省补充耕地按等级折算系数研究
4.Temporal and spatial distribution of cropland-population-grain system and pressure index on cropland in Jinghe watershed;泾河流域耕地-人口-粮食系统与耕地压力指数时空分布
5.The Different Degree of Arable Land Quality in Hunan Province Based on Gini Coefficient Analysis;基于基尼系数的湖南省耕地质量差异程度分析
6.Management and Realization of Spatial Data of Cultivated Land Resource Information System;耕地资源信息系统中空间数据的管理与实现
7.STUDIES ON THE RELATION BETWEEN ARABLE LAND QUANTITY IN GUANGZHOU AND INDUSTRY STRUCTURE CHANGE;广州市耕地数量与产业结构变化的关系研究
8.Econometric Analysis of Relationship between Cultivated Land Quantity and Economic Development;耕地资源数量与经济发展关系的计量分析
9.A Study on Correlation of Dynamic Change of Cultivated Land and Economic Development in Hunan Province;湖南省耕地数量动态变化与经济发展关系研究
10.Research on the Relation of Food Security and Cultivated Land s Quantity and Quality in China;我国粮食安全与耕地的数量和质量关系研究
11.Empirical Study on the Relationships between Cultivated Land Occupation Quantity by Construction and Population Growth in China中国建设占用耕地数量与人口增长关系实证
12.The discussion of calculation method based on multi-object oriented cropland ridge coefficient面向多对象的耕地田坎系数测算方法探讨
13.Dynamic Changes of Net Primary Productivity of Cultivated Land in Wind-drift Sand Region--A Case of Yuyang Area of Northern Shaanxi Province;风沙过渡区耕地生态系统净第一性生产力动态变化研究——以陕西榆阳区为例
14.Analyzing the Differences of the Regional Cultivated Land Quality based on Gini Coefficient Analysis:A Case Study in Guangdong Province;基于基尼系数的耕地质量差异程度分析——以广东省南方稻田耕地地力结果为例
15.Treatment of Rural Domestic Sewage by Land Natural Purification Technology under Cultivation Layer耕作层下土地自然净化技术处理村镇生活污水
16.In order to save power and use fuel more efficiently, the relationship between the rotator"s traction power coefficient and the rotator width was studied in this article.为节省动力和更有效地利用燃料,对旋耕机的牵引功率利用系数与旋耕进距的关系进行了研究。
17.The Design and Development of B/S Mode System Which Manage the Soil Fertility Monitoring Data of Arable LandB/S模式耕地地力监测数据管理系统的设计与开发
18.Land Fiscalization and Cultivated Land Protection:Causal Relationship Based on Provincial Panel Data Analysis土地财政与耕地保护——基于省际面板数据的因果关系分析
相关短句/例句
Cultivation land coefficient耕地系数
3)non-effective coefficient of cultivated land无效耕地系数
1.Results show that thenon-effective coefficient of cultivated land is 6.结果表明:县内平耕地的无效耕地系数平均为6。
4)standard coefficient of cultivated land耕地标准系数
5)The cultivated land Gini Coefficient耕地基尼系数
6)Quantity of cultivated land耕地数量
1.In this article,by analyzing the structural changes of economic growth in Huainan city,we conclude that the non-agricultural rate is an important factor which affects economic growth;by elucidating the relationship between the changes in the quantity of cultivated land and th.通过分析淮南市经济增长的结构性变化,发现非农化产值率是影响经济增长的重要因子,并进一步阐述耕地数量变化与经济增长结构性变化之间的关系,指出经济发展与耕地保护具有一定的协同性,还针对经济增长过程中耕地资源面临的问题提出一些对策和建议。
2.There are many complicated factors influencing the quantity of cultivated land,so a simple regression analysis can not achieve a satisfactory model.影响耕地数量变化的因素错综复杂,简单的回归分析不易得到满意的模型结果。
3.The factors influencing the quantity of cultivated land are many and c omplex,so a satisfactory model is hard to make by adopting the common regression method.影响耕地数量变化的因素错综复杂,用单一的回归分析法不易得到一个满意的模型。
延伸阅读
阀门技术注重流量系数和气蚀系数阀门的流量系数和气蚀系数是阀的重要参数,这在先进工业国家生产的阀门资料中一般均能提供。我国生产的阀门基本上没有这方面资料,因为取得这方面的资料需要做实验才能提出,这是我国和世界先进水平的阀门差距的重要表现之一。3.1、阀门的流量系数
阀门的流量系数是衡量阀门流通能力的指标,流量系数值越大,说明流体流过阀门时的压力损失越小。
按KV值计算式
式中:KV—流量系数
Q—体积流量m3/h
ΔP—阀门的压力损失bar
P—流体密度kg/m3
3.2、阀门的气蚀系数
用气蚀系数δ值,来选定用作控制流量时,选择什么样的阀门结构型式。
式中:H1—阀后(出口)压
H2—大气压与其温度相对应的饱和蒸气压力之差m
ΔP—阀门前后的压差m
各种阀门由于构造不同,因此,允许的气蚀系数δ也不同。如图所示。如计算的气蚀系数大于容许气蚀系数,则说明可用,不会发生气蚀。如蝶阀容许气蚀系数为2.5,则:
如δ>2.5,则不会发生气蚀。
当2.5>δ>1.5时,会发生轻微气蚀。
δ<1.5时,产生振动。
δ<0.5的情况继续使用时,则会损伤阀门和下游配管。
阀门的基本特性曲线和操作特性曲线,对阀门在什么时候发生气蚀是看不出来的,更指不出来在那个点上达到操作极限。通过上述计算则一目了然。所以产生气蚀,是因为液体加速流动过程中通过一段渐缩断面时,部分液体气化,产生的气泡随后在阀后开阔断面炸裂,其表现有三:
(1)发生噪声
(2)振动(严重时可造成基础和相关构筑物的破坏,产生疲劳断裂)
(3)对材料的破坏(对阀体和管道产生侵蚀)
再从上述计算中,不难看出产生气蚀和阀后压强H1有极大关系,加大H1显然会使情况改变,改善方法:
a.把阀门安装在管道较低点。
b.在阀门后管道上装孔板增加阻力。
c.阀门出口开放,直接蓄水池,使气泡炸裂的空间增大,气蚀减小。
综合上述四个方面的分析、探讨,归纳起来对闸阀、蝶阀主要特点和参数列表便于选用。两个重要参数在阀门运用中 。