养殖方式、光照强度对哲罗鱼稚鱼生长与存活的影响   总被引：1，自引：0，他引：1  

郭文学  尹家胜  佟广香  张永泉  白庆利 《海洋与湖沼》2014,45(2):264-273

采用生态学方法,研究了养殖方式、光照强度对哲罗鱼稚鱼生长与存活的影响。结果表明:在养殖方式实验中,哲罗鱼稚鱼体长、体质量均以室内静水组为最高,室内流水组其次,室外流水组最低。存活率以室内流水组为最高,室外流水组次之,室内静水组最低。统计分析表明养殖方式对哲罗鱼稚鱼终末体长、体质量、特定生长率、体长生长参数以及体长、体质量变异系数的影响均达到极显著水平(P0.01)。在光照实验中,哲罗鱼稚鱼的存活率、体长、体质量及特定生长率、体长生长参数均随光照强度的增加而增加,说明在哲罗鱼稚鱼室内培育阶段,适当地增加部分光照有利于其存活、摄食与生长。本研究结果为哲罗鱼高效养殖提供了科学依据。  相似文献   

多模式智能路灯控制系统     

张秀再  罗歆瑶  韦镇余  沈旭晖 《南京气象学院学报》2014,6(6):510-514

使用AT89S52单片机作为主控芯片,设计了一种多模式智能路灯控制系统,该系统能够根据道路、巷口或定时应用3种情况进行工作模式选择,并根据环境光亮度决定是否启动所设定的工作模式.巷口工作模式时,系统通过红外传感器检测道路上有汽车或行人通过时,将识别信号送入单片机,由单片机控制交通灯开启;道路工作模式时,路灯处于开启状态,以保障行人畅行;定时模式时,通过DS1302定时模块,可以设定路灯的开关时间.此外,该系统还具有自动故障检测功能,功能全面,有较强的实用价值.  相似文献   

光学显微镜成像方式及投影冷光源的分频合成探讨     

赵应权  沈忠民  王鹏 《岩矿测试》2014,33(5):674-680

传统显微镜光源主要包括卤素灯光源、纯水过滤热射线光源、LED光源等,由于卤素灯光源含有大量760~1400 nm区段的红外线,纯水过滤热射线光源滤除红外线不彻底且水会导致透射光线的部分散射,LED光源在500 nm波长附近的光照强度不足、波形存在缺陷,容易灼伤样品或使成像质量受限,都难以满足需要采用大功率冷光源进行无损、高质量显微观察成像和测试的要求。本文在总结光学显微镜的成像方式、光源类型及各类光源优缺点的基础上,提出了采用三棱镜-凸透镜组分频合成冷光源的新思路。该思路首先利用三棱镜将卤素灯光源光谱按频率顺序打开,然后选择可见光区域内的光谱,用凸透镜组校正可见光方向后,再由三棱镜将这些可见光合成不含热射线的冷光源。理论和砂岩荧光薄片实际测试效果表明,该方法既可完全排除热射线,从而使样品免遭受破坏,又保持了完整的可见光光谱,解决了大功率冷光源红外线生热和光谱存在缺陷的难题,这为采用大功率冷光源的光学显微镜投影高质量成像提供了新的方法及切实可行的依据。该套分频合成光源的装置主要配置为:玻璃材质的同规格的三棱镜与凸透镜各两个,卤素灯光源一个。结构简单,可在需使用大功率冷光源进行无损成像和测试等方面获得广泛的应用。  相似文献   

非球形轴对称粒子光散射的散射矩阵元素展开系数的数值计算     

丁继烈  许丽生 《成都信息工程学院学报》1999,(3)

扼要地介绍了非球形粒子光散射的散射矩阵元素按广义球函数展开的基本理论，以及球形粒子散射矩阵元素间的关系。在此基础上较详细地阐述了计算展开系数的方法以及在程序研制中所遇到的一些问题。最后，对非球形的Ｃｈｅｂｙｓｈｅｖ粒子光散射的散射矩阵元素的展开系数进行了计算，结果表明数值技术和计算的正确性。  相似文献   

The disappearance of eclipses in the central star of the planetary nebula NGC 2346     

Hao Xiang-liang 《Chinese Astronomy and Astrophysics》1991,15(4):431-438

This paper gives the result of photographic photography of the central star AGK3-0° 695 of the planetary nebula NGC 2346 made from 1981 through 1987. From it we see that after the large-amplitude eclipses which had started at the end of 1981 had continued for several years, the amplitude began to decrease rapidly in 1986 to ˜1.1 mag from ˜4 mag in 1984. In 1987, only irregular fluctuations with amplitudes ˜0.4 mag were present in the light curve and not longer any clear periodicity. A preliminary analysis of this phenomenon is carried out here.  相似文献   

Approach to modeling and virtual-reality-based simulation for plant canopy lighting     

Haopeng Wang  Kai Zhao  Fengbin Song 《中国地理科学(英文版)》2008,18(4):374-381

Over the past 20 years, significant progress has been made in virtual plant modeling corresponding to the rapid advances in information technology. Virtual plant research has broad applications in agronomy, forestry, ecology and remote sensing. As many biological processes are driven by light, it is the key for virtual plant to estimate the light absorbed by each organ. This paper presents the radiance equation suitable for calculating sun and sky light intercepted by plant organs based on the principles of the interaction between light and plant canopy firstly; analyzes the process principles of plant canopy primary lighting based on ray casting and projection secondly; describes the multiple scattering of plant lighting based on Monte Carlo ray tracing method and on the radiosity method thirdly; and confirms the research with 3D visualization based on Virtual Reality Modeling Language （VRML） finally. The research is the primary work of digital agriculture, and important for monitoring and estimating corn growth in Northeast China.  相似文献   

Light regime and components of turbidity in a Mediterranean coastal lagoon     

Biel Obrador  Joan Lluís Pretus 《Estuarine, Coastal and Shelf Science》2008

The underwater light regime of a Mediterranean coastal lagoon (Albufera des Grau, Balearic Islands) was studied during four years in order to characterise the spatial and temporal variations in the light attenuation coefficient (K) and to assess the relative contribution of the different water components to total light attenuation.  相似文献   

工厂化培养蒙古裸腹溞研究     

罗杰  刘楚吾  余坦健 《广东海洋大学学报》2004,24(3):14-18

采用充氧培养的方法 ,研究了不同饵料和不同盐度、光照下蒙古裸腹的生长情况。结果表明 :投喂小球藻、亚心形扁藻、等鞭金藻时蒙古裸腹的增殖率分别为 4 0 6 .6 %、377%、32 2 .2 % ,差异并不明显 ,而投喂酵母的增殖率达到 86 6 .7% ,效果显著 ;在 10～ 30的盐度范围内 ,盐度为 10时增殖最快 ,增殖率为 382 % ;自然光和遮光对蒙古裸腹的增殖率为 375 .2 %和 - 0 .6 8% ,差异显著 ,其生长和繁殖需一定的光照。  相似文献   

1991年10月24日白光耀斑的高时间分辨率多波段光谱分析     

周曦  方成  胡菊 《中国天文和天体物理学报》1996,(4)

本文分析了南京大学太阳塔1991年10月24日用多波段光谱仪观测到的高时间分辨率（5s）的一个2N／X2．1级白光耀斑光谱．对耀斑谱线轮廓、连续发射强度、X射线和射电爆发资料进行了综合对比，分析表明，该耀斑属Ⅰ类白光耀斑，具有如下特征：（1）在白光耀斑的脉冲相期间，各波段光谱线心强度、连续辐射、谱线半宽以及线翼红不对称性与硬X射线高能波段的爆发同时达到极大；（2）H_a谱线在连续发射极大时半宽达10A，且呈现强烈的线心反转，H_β和H_γ线心亦有反转；（3）所拍摄的5条谱线都有明显的红不对称性，持续时间约为1分钟，根据上述结果，本文用电子束轰击、色球蒸发和色球压缩区对该耀斑能量积聚和释放的动力学机制作了定性的分析和解释。  相似文献   

Changes in the Chemical Components of Light Crude Off During Simulated Short Term Weathering     

MA Qimin LUO Xia YU Zhigang 《中国海洋大学学报(英文版)》2007,6(3):231-236

To unambiguously identify spilled oils and to link them to the known sources are extremely important in settling questions of environmental impact and legal liability. The fate and behavior of spilled oils in the environment depend on a number of physicochemical and biological factors. This paper presents the results regarding changes in chemical composition of light crude oil during simulated short-term weathering based on natural environmental conditions. The results show that the saturated hydrocarbons of the light crude oil mainly distribute between n-C8 and n-C23 and the most abundant n-alkanes are found in the n-C10 to n-C16. The main chemical components of the light crude oil are n-alkanes and isoprenoids. The aromatic compounds are subordinate chemical components. Under the conditions of the weathering simulation experiment,n-alkanes less than n-C12,toluene and 1,3-dimethyl benzene are lost after 1 d weathering,the n-C13,n-C14,naphthalene and 2-methyl-naphthalene are lost on the fifth day of weathering,and n-C15 alkane components show certain weatherproof capability. The ratios n-C17/pristane and n-C18/phytane are unaltered and can be used to identify the source of the light crude oil during the first 8 d of weathering. After 21 d,the ratio pristine/phytane can not provide much information on the source of the spilled light crude oil. Triterpanes（m/z 191） as biomarker compounds of light crude oil are more valuable.  相似文献