共查询到19条相似文献，搜索用时 156 毫秒
1.
根据夫琅禾费单缝衍射的基本原理,利用MATLABR2008a的图形用户界面(Graphical User Interfaces,GUI)设计了单缝衍射的仿真交互界面,给出了单缝衍射仿真结果.该仿真能使单缝衍射理论和实验很好地结合起来,具有一定的应用价值. 相似文献
2.
海城市大豆光能利用率分布特征 总被引：1，自引：0，他引：1
利用海城市近50年的大豆产量,采用数学模拟方法,分析其光能利用率的分布特征.研究表明,海城50年光能利用率呈增长趋势,可以发现在大豆各个环节提高其生长环境,光能利用率仍有提升的空间. 相似文献
3.
提高二代目光温室光能利用率，可有效地改善温室内作物的光合作用，提高各类蔬菜的产量和品质。节能二代目光温室光能利用率的提高主要从增加温室采光量和改善光照分布余缺均匀性两个方面入手。其主要技术措施如下。 相似文献
4.
张益才 《湖南农业大学学报(自然科学版)》1982,9(4)
本文对玻尔、海森堡关于电子单缝衍射实验的解释,以及他们对不确定关系物理根源的看法进行了分析,澄清了他们的误解,论证了电子单缝衍射图样和不确定关系都是微观粒子二象性的直接表露。 相似文献
5.
马子华 《内蒙古农业大学学报(自然科学版)》1986,(2)
在内蒙古农牧鱼业厅的组织领导下,于1983年到1984年就蛮汉山,大青山一带的野生果树资源,包括树种,分布及生态条件进行了实地调查。野生果树与天然次生林混杂,分布于大青山南侧和前山山区之中。这一带属温带半干旱区,大陆性季风气候。其特征如下: (一)光能充足:地势高,水气少,晴天多。按低云量标准,全年晴天日数220—260天,大气透明度好,辐射强度大,日照时间长,全年在3000小时以上。光能充足, 相似文献
6.
果粮间作生态系统光能分布规律的研究 总被引：1，自引：0，他引：1
对内蒙古巴盟地区果粮间作生态系统的光能分布研究表明：果粮间作生态系统有其特殊的光照分布规律;果粮间作生态系统可更好地利用光能;根据果粮间作生态系统的光照分布规律可以确定合理的栽植方式和合理的树形、树高、冠幅等指标。 相似文献
7.
板栗树冠光能分布特征对叶片和座果的影响 总被引：6，自引：0，他引：6
以玉屏大板栗为材料，探索了树冠内光能分布特征，以及光能分布对叶片形态，结构和座果的影响。结果表明，太阳能爱时幕层时，光强消减规律合符Ｂｅｅｒ－Ｌａｍｂｅｒｔ公式，８年生植株的关系式为Ｉ＝Ｉ０Ｅ＾－０．４４５９Ｆ，而１５年生植株的关系式为Ｉ＝Ｉ０ｅ＾０．４４２８Ｆ。叶幕内的光能分布主要受累计叶面积指数和自然光强的影响。 相似文献
8.
文章通过建立一简单的电偶极子模型，从理论上研究和探讨红皮云杉冠层表面光的散射分布以及表面的光能分布。引入表面空隙度这一新概念，描述在冠层表面中介质（枝叶）分布状况。理论结果表明，冠层表面散射光强的影响很小，它的强度近似于原入射光强的０５％。因此，在单木冠层表面的各个侧面，每个侧面表面光能分布近似均匀的，并且各个侧面的光能分布不同，其中与光入射方向垂直的哪个侧面分布最强。 相似文献
9.
通过推广大豆平作窄行密植栽培技术既可适应我省大豆平作的栽培习惯,又可克服其密度不足的缺点,实现高产。一、窄行密植的增产机理1.增加了叶面积。在开花期和结荚期,大豆叶面积指数随密度增加而增加,达到显著相关水平。增加了叶面积,使之持续较长时期的绿色面积是提高光能利用率的重要条件,也是大豆高产的关键。2.改善了光的分布。由于窄行使植株分布的更均匀,克服了宽行的大行距、小株距植株分布不匀的不足,因此单株受光更均匀,为提高光能利用率创造了条件。 相似文献
10.
对内蒙古巴盟地区果粮间作生态系统的光能分布研究表明；果粮间作生态系统有其特殊的光照分布规律；果粮间作生态系统可更好地利用光能；根据果粮间作生态系统的光照分布规律可以确定合理的栽植方式和合理的树形、树主、冠幅等指标。 相似文献
11.
MATLAB在光学教学中的应用 总被引：1，自引：0，他引：1
符运良 《华南热带农业大学学报》2004,10(3):55-57
探讨在基础物理光学教学中,应用MATLAB软件模拟光的双缝干涉、单缝衍射和光栅衍射,以获得良好的课堂教学效果。 相似文献
12.
分析夫琅禾费双矩孔衍射及其特例的光强分布,以日光为光源,基于Matlab软件实现日光夫琅禾费双矩孔衍射及其特例的计算机仿真。结果表明,夫琅禾费双矩孔衍射的光强分布为2个矩孔衍射的相干叠加结果,仿真图像色彩细腻而逼真,可应用于与日光相关的研究和教学等领域。 相似文献
13.
Small-angle neutron diffraction (wavelength 4.05 angstroms) of human and rabbit sciatic nerve has been carried out by means of the Brookhaven high flux beam reactor with an automated slit camera. Most of the free water of the nerves was substituted in order to minimize incoherent scatter of hydrogen atoms. The differences in amplitude and phase shifts between neutrons and x-rays resulted in a neutron diffraction pattern that was completely different from the x-ray pattern. The neutron pattern consisted of a single peak of about 89-angstrom spacing in the region examined (up to 6-angstrom spacing). The strong third, fourth, and fifth order reflections (about 60, 45, and 36 angstroms) seen in the x-ray pattern were suppressed. The neutron data indicated a strong scattering from one portion of the membrane. 相似文献
14.
为南方小面积田块棉秆切碎还田机设计了棉秆切碎还田装置。该装置由切割装置、扶秆装置、除茬装置组成,棉秆由扶秆装置喂入,从上至下依次被切断、除茬。将该装置挂接在土槽试验机上,对影响棉秆切割长度合格率、功耗和除茬率的主要因素,即机具前进速度、锯盘转速和导向槽口宽度进行了单因素试验和回归正交试验。结果表明:影响合格率与除茬率的因素大小依次为机具前进速度、锯盘转速、导向槽口宽度;影响功耗的因素大小依次是锯盘转速、机具前进速度、导向槽口宽度。利用规划求解进行参数优化,在棉杆长度合格率与除茬率分别不低于85%和90%的情况下,锯盘转速为860 r/min,机具前进速度为0.65 m/s,导向槽口宽度为60 mm时,功耗为5.91 k W。 相似文献
15.
Akoury D Kreidi K Jahnke T Weber T Staudte A Schöffler M Neumann N Titze J Schmidt LP Czasch A Jagutzki O Costa Fraga RA Grisenti RE Díez Muiño R Cherepkov NA Semenov SK Ranitovic P Cocke CL Osipov T Adaniya H Thompson JC Prior MH Belkacem A Landers AL Schmidt-Böcking H Dörner R 《Science (New York, N.Y.)》2007,318(5852):949-952
The wave nature of particles is rarely observed, in part because of their very short de Broglie wavelengths in most situations. However, even with wavelengths close to the size of their surroundings, the particles couple to their environment (for example, by gravity, Coulomb interaction, or thermal radiation). These couplings shift the wave phases, often in an uncontrolled way, and the resulting decoherence, or loss of phase integrity, is thought to be a main cause of the transition from quantum to classical behavior. How much interaction is needed to induce this transition? Here we show that a photoelectron and two protons form a minimum particle/slit system and that a single additional electron constitutes a minimum environment. Interference fringes observed in the angular distribution of a single electron are lost through its Coulomb interaction with a second electron, though the correlated momenta of the entangled electron pair continue to exhibit quantum interference. 相似文献
16.
The room temperature dynamics of single sulforhodamine 101 molecules dispersed on a glass surface are investigated on two different time scales with near-field optics. On the 10(-2)- to 10(2)-second time scale, intensity fluctuations in the emission from single molecules are examined with polarization measurements, providing insight into their spectroscopic properties. On the nanosecond time scale, the fluorescence lifetimes of single molecules are measured, and their excited-state energy transfer to the aluminum coating of the near-field probe is characterized. A movie of the time-resolved emission demonstrates the feasibility of fluorescence lifetime imaging with single molecule sensitivity, picosecond temporal resolution, and a spatial resolving power beyond the diffraction limit. 相似文献
17.
It has long been postulated that gas-surface chemical reactions can occur by means of two distinct mechanisms: direct reaction on a single gas-surface encounter or reaction between two adsorbed species. It is shown here that these mechanisms have distinct dynamical signatures, as illustrated by the reaction of hydrogen with chlorine on gold(111). The direct reaction product leaves the surface with a high kinetic energy in a narrow angular distribution that displays a "memory" of the direction and energy of the incident hydrogen atom. The indirect reaction product has a near-thermal energy distribution and an angular distribution that is close to that of a cosine function. 相似文献
18.
本文介绍了国产喷雾器喷头的几个主要性能参数与国外著名喷头公司产品的对比结果、并提出了改进我国喷头产品的若干建议。如:1.影响侧向进液式喷头喷量变异的因素。2.缝隙式扇雾喷头药液沉积横向分布中的牛角、对喷杆式喷雾器药液沉积分布均匀性有着极坏的影响。 相似文献
19.
Site occupancy numbers for ferrous iron, magnesium, and calcium at the Ml and M2 sites in lunar clinopyroxenes are estimated from nuclear gamma-ray resonant absorption spectra of (57)Fe. The cation distribution is ordered; calcium and magnesium prefer M2 and Ml, respectively. The distribution corresponds to an equilibrium at a temperature lower than 680 degrees C. Crystals cleaved and sectioned by diamond-knife ultramicrotomy were examined by high-voltage (200 kv) electron microscopy and diffraction. Uniform 300-to 600-A-wide bands that correspond to single crystal domains were found. Correlation of the bands with magnetic ordering at low temperatures is considered. 相似文献