首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
This paper suggests the formula about sky luminance distribution on pseudoovercast sky. After testing and verifying,it is a fact that this formula and actual measure about pseudo-overcast sky luminance distribution are nearly identical. This paper also suggests unified fornula expressing four types of sky luminance distributions(CIE clear sky,pseudo-clear sky,pseudoovercast sky and CIE orercast sky). As a result,it is of great advantage to the calculation of vertical illuminance.  相似文献   

2.
Starting from the optical factors of Climate and on the basis of CIE formulasof brightness distribution for clear and overcast sky,this paper suggests a kindof formula which can be used to compute brightness distribution on average skybrightness.Besides,it proposes a simple method by which it is easy to carryout the design of natural lighting under the condition of average sky brightnessmodel.  相似文献   

3.
According to the daily change law from curves for percentage insolation,this paper presents a new formula of the average insolation in the zones where the insolation is more than 70%. By means of the hourly observing data during two years for solar direct ratiation, cloudage and sunshine condition in seven zones different lighting climate,considering the vaper pressure and the altitude present the function of percentage insolation and the probability of four sky brightness classification,this formula has a certain precision to be proved by observation.  相似文献   

4.
Under the condition of average sky model,this paper studies the luminous flux arriving at the window and suggests the modified daylightingcoefficient method for estimating the area of the window.The method is simpleand easy to be carried out.And according to average sky luminance model,this paper has carried out the calculation of average sky lighting with a computer.The method described above is verified reasonable and applicable in engineering.  相似文献   

5.
This paper suggests a new method to determine a sky luminance value, and it has the advantage of instantaneity. It also is a good method to study sky luminance distribution.  相似文献   

6.
The products and kinetics of intermediate transfo atien early stlage in Fe-C-Mo alleys are studied with optical micrography and electron transmision mierography. it has been found that the bainite transformation carried out through formation of bainitic 1 asic unit.and its growth evolution. The overall kinetics and structural morphology showedthc diffusion charactcraslic of the process.  相似文献   

7.
Zenith luminance converting factor is the characteristic parameter of sky luminance distribution,which is not related to regions.The fractal dimension value of the change process of zenith luminance converting factor shows that the sky can be divided into four types as CIE standard clear sky,pseudo- clear sky,pseudo- overcast sky and CIEstandard overcast sky.This is more suitable for the study of sky lumimance distribution with the exception of a few particular weather conditions.  相似文献   

8.
This paper introduces the new reappear technique of Sky Luminauce distributionwith the help of the computer figure and numerica system. Using this program, we can obtain theluantitative figure of Sky Luminance distribtion much conveniently and accurately so that studyingabout Sky luminauce distribtuion goes a step further;  相似文献   

9.
The problems that the bump of coal and methame in the mine is contraled by the stress of longwall and that the coal and methane bump in the mine is affected by the physical properties of the coal are analysed and discussed through some specific bump cases. It is shown that the compressive stress, the content of the methane of the coal, and the bump of coal and methane are directly affected by the content of the ash and the volatile of the coal.  相似文献   

10.
FFT(Fast Fourier Transform)is the basis of spectrum analysis. This paper gives out a method which can improve the speed and accuracy of FFT. The spectrum analysis based on the proposed method is of a high level: the amplitude error of spectrum is less then 1 % , the time of completing 1024 compler points FFT and 32 segments spectrum analysis is less then 250ms and only 5 seconds respectively.  相似文献   

11.
研究表明,香料烟株内结晶细胞是一类特化的含晶细胞,细胞内充满晶体,晶体形状似角锥状,质体等被挤到细胞边缘。叶片成熟过程中,结晶细胞超微结构发生变化,质体逐渐退化,胞基质逐渐干缩。结晶细胞与普通细胞相比有较高的钙含量,因此推测细胞内结晶体可能是一种钙盐结晶,但不排除结晶体可能含有尚未证实的有机物成分。同时,在试验中,初步摸索出了结晶细胞的分离方法。  相似文献   

12.
The Chinese philosophical dialectical thought was in the period times of the early years. In which, the Ying and Yang was deeply influenced the Chinese culture. Architecture as a body of culture is expressed all round. According to pursure the nature environment of mountains and rivers, the architectural mass height is arranged up and down; the statics and movement is changed; the emotional is osmosed between them and they can incorporate each other. They reflect the nature, order, dynamic state, opening and incorporation of architecture themselves. This paper analyses the system of the Chinese architectural laws for develpment.  相似文献   

13.
喷雾对小麦光合作用与籽粒产量的影响   总被引:2,自引:0,他引:2  
本文报道了在小麦籽粒灌浆期用水喷雾提高叶片光合速率与单位面积产量的结果.光合速率的提高与叶片气孔阻力降低有关.研究进一步证实了华北地区小麦灌浆期光合作用有明显的“午睡”现象,这种现象与中午前后颇低的空气湿度和较高的空气温度引起的大气饱和差增加有很大关系,并且表明用少量喷水可以改善田间小气候和作物水分状况,减轻光合作用“午睡”现象,提高光合速率,进而增加作物产量.  相似文献   

14.
板栗空棚严重影响燕山板票的产量.产生原因与土壤中缺硼有关.通过早春施硼肥可使空棚率由85.53%下降到2.43%,产量提高7.7倍.但花期喷硼效果不稳定;人工辅助授粉和增施氮、磷、钾肥料及浇水对降低空棚率均无明显效果.  相似文献   

15.
光对稻苗根系生长及其生理活性的影响   总被引:11,自引:0,他引:11  
倪文 《作物学报》1983,9(3):199-204
强光或蓝光照射培育的稻苗可以促进稻苗根系的生长发育,根系活性高,且能提高根系对NH_4~+的吸收速率,根系的蛋白质氮和总氮量以及蛋白质氮/总氮含量比值都比较高。  相似文献   

16.
土壤供磷水平与冬小麦合理施肥   总被引:1,自引:0,他引:1  
因土施肥的关键在于如何确定土壤肥力水平.根据我们按统一方案进行的多年多点田间肥料试验结果认为,土壤诸养分中速效磷含量的高低与产量有较好的相关关系:y=8.25+62.46logP r=0.8618~(**)(y为产量百分数,p为土壤速效磷测试值),所以用土壤速效磷含量做为土壤肥力指标之一在河北是可行的.根据不同土壤供磷水平配置了三个肥效方程,算出不同供磷水平土壤的经济最佳施肥量和氮磷肥施用比例,也可预测产量幅度.本试验结果从宏观上提出了河北省冬小麦施肥配方,对指导小麦科学施肥有重要意义,同时为国家安排生产和调配化肥提供了科学依据.  相似文献   

17.
糙米储藏过程的品质变化与米粒图像颜色特征参数的关联   总被引:1,自引:0,他引:1  
通过测定不同储藏温度条件下的糙米脂肪酸值,同时用扫描仪采集糙米图像并基于计算机图像处理方法提取图像颜色特征,考察了储藏过程糙米的表面颜色特征参数的变化及其与脂肪酸值的关联.结果表明:用图像处理方法可以检测出糙米储藏过程米粒表面颜色的变化;糙米表面的亮度值随着储藏时间延长和储藏温度提高而增大的趋势最明显;糙米储藏过程的亮度值变化与脂肪酸值增加的趋势基本一致,全部糙米试样两者的相关系数为r=0.81,具有较强的关联性,提示了用图像处理方法及用米粒颜色特征参数表征糙米储藏过程品质变化的有效性和可能性.  相似文献   

18.
根据湖南省多年多点的棉花苗情定点观察与气象观测资料,采用相关及多种回归分析方法,研究棉花产量与苗情性状及气候条件相互间的内在联系和定量关系,找出影响棉花生长发育及产量形成的主导因素,并根据所建立的回归方程进行苗情预测预报,从而提出有效的促控指标,为指挥棉花生产,作出宏观决策提供科学依据。  相似文献   

19.
GIS支持下的区域中低产耕地评价与改良利用对策   总被引:2,自引:0,他引:2  
黄河 《中国农学通报》2004,20(1):168-168
借助GIS和数学模型集成技术,评价荔城区中低产耕地及其障碍因素,结果表明全区中、低产耕地面积分别为2293.39公顷和1594.97公顷, 分别占保护区耕地总面积的25.49%和17.72%; 中产耕地主要分布于北高和新度镇,而低产耕地则主要分布于北高镇; 中产耕地主要限制因素为旱限制、缺钙限制、瘠瘦限制、缺钾限制、缺磷限制和酸限制,分别占中产耕地总面积的88.76%、18.26%、15.48%、8.18%、7.91%和6.53%,低产耕地主要限制因素为旱限制、缺钙限制、瘠瘦限制、障碍层限制、渍涝限制、盐碱限制和酸限制,分别占低产耕地总面积的96.98%、58.31%、54.89%、18.90%、18.47%、18.47%和16.28%。在中低产耕地及其障碍因素评价的基础上,提出了区域中低产耕地的改良利用对策。  相似文献   

20.
小麦温光发育模型的研究   总被引:3,自引:0,他引:3  
1981~1984年,选用代表不同生态类型的25个小麦品种,在大田进行分期播种.通过分析温光等主要生态因子与小麦生长发育的关系,建立了各品种主要发育阶段的温光模型:播种至出苗为G=104.4751/(T-1.1032),出苗至二棱、出苗至拔节为V=a+bG+cP_(t1),二棱至抽穗、拔节至抽穗为V=a+bT+cL.文中认为,播种至出苗的日数(G)既能反映当时的温度条件,又可表示萌发时的“田间春化效应”;温光积(Ptl)则给“温度与光照之间存在明显的互补作用”找到了量的表达基础;因此,建模时采用这两个变量,是很有意义的.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号