面包酵母悬浮液中添加脂溶性维生素对褶皱臂尾轮虫增殖率的影响     

刘东超  施军  邓超 《广东海洋大学学报》1996,(2)

采用批量培育法研究了在面包酵母悬浮液中添加不同浓度的脂溶性维生素对褶皱臂尾轮虫（Ｂｒａｃｂｉｏｎｕｓｐｌｉｃａｔｉｌｉｓ）增殖率的影响。结果表明：面包酵母对褶皱臂尾轮虫的生长繁殖是有营养缺陷的。在面包酵母悬浮液中．当添加维生素Ａ为０．０２～５．００μｇ／ｍｌ时，随着添加浓度的增大，轮虫的种群增殖率Ｒ值也增大。以添加５．００μｇ／ｍｌ为最佳，第４天的Ｒ值达０．７５，是对照组的５．６倍。添加维生素Ｄ０．００５～０．２０μｇ／ｍｌ对轮虫的增殖有一定促进作用，以添加０．０５μｇ／ｍｌ为最佳，第７天的Ｒ值为０．４０７，是对照组的２．７倍。添加维生素Ｅ０．００１～０．０１μｇ／ｍｌ和添加维生素Ｋ０．０１～０．１０μｇ／ｍｌ时，第４天的Ｒ值与对照组无差异。  相似文献   

德雷克海峡的扩张历史及其影响          下载免费PDF全文

吴水根  吕文正 《极地研究》1988,1(2):1-7

本文利用首次南大洋考察期间获得的德雷克海峡地球物理场资料,解释海峡海底板块扩张历史以及海峡扩张对南极环境形成的影响.  相似文献   

Study on respiratory electron transport system （ETS） of phytoplankton in Taiwan Strait and Xiamen Harbour   总被引：1，自引：0，他引：1  

黄邦钦洪华生  徐宪忠刘媛 《中国海洋湖沼学报》2005,23(2):176-182

Phytoplankton respiratory electron transport system (P-ETS) activities were studied in two cruises in Taiwan Strait (Aug. 1997 and Feb. -Mar.1998) and two cruises in Xiamen Harbour (Oct., 1997 and Apr.,1998). Results showed that P-ETS activity in the surface water of southern Yaiwan Strait in summer was homogeneous [mean value of 0.106 μ102/(L.h)], inhomogeneous in northern Yaiwan Strait in winter. Variation of P-ETS activity in middle part of the Strait was not obvious between summer and winter. Mean P-ETS activity of Xiamen Harbour in autumn was 0.255 μ102/(L.h) with a little higher value in Jiulong River estuary areas. In spring, P-ETS activity was more homogeneously distributed and the mean value was 1.076 μ102/(L.h). P-ETS activity in spring was obviously higher than in autumn in Xiamen Harbour. Vertical distribution of P-ETS in Taiwan Strait was homogeneous at some stations in winter and in summer. An obvious daily variation of P-ETS activity was recorded at Stn 9837, high at midnight and low in the early morning. Significant correlation between P-ETS activity and Chl-a was observed. Results also showed that the ratio of estimated respiratory rate to photosynthetic rate varied seasonally, high in winter (0.41) and low in summer (0.12).  相似文献   

最小水流能量损失率理论在河相关系中的应用   总被引：4，自引：0，他引：4  

黄克中  钟恩清 《地理学报》1991,(2)

本文介绍最小水流能量损失率理论的变分法基础。用该理论导出了航道整治工程前后的河相关系式,并将之用于预估东平水道航道整治工程后的河相。实测值与预估值的比较表明,该理论和该河相关系式是可信的。  相似文献   

Modern sedimentation rates and sedimentation feature in the Huanghe River estuary based on210Pb technique   总被引：1，自引：0，他引：1  

Li Fengye 《中国海洋湖沼学报》1993,11(4):333-342

Based on²¹⁰Pb technique, sedimentation rates of 11 cores collected from the Huanghe River estuary were determined. CaCO₃ distribution of 4 cores chosen from among these was measured. Profiles of²¹⁰Pb in the cores showed that the distribution of²¹⁰Pb activity decayed with depth, appeared in stages and in more than one segment. The sedimentation rates,²¹⁰Pb and CaCO₃ data have similar distribution trend in the 4 cores. The profiles of²¹⁰Pb and CaCO₃ were used to study sedimentation intensity, transportation trend of material and sedimentation features in the corring area. Contribution No. 2230 from the Institute of Oceanology, Academia Sinica. This research was supported by the National Natural Science Foundation of China.  相似文献   

几种抗菌药物对马氏珠母贝壳顶幼虫的毒性试验     

刘志刚  王本兴  沈汝寿 《广东海洋大学学报》1995,(1)

几种抗菌药物对壳顶幼虫的毒性试验结果表明：（１）以９６ｈ平均日生长率作为药物对幼虫毒性的观察指标，求出日生长率仅为对照组一半时的药物浓度（９６ＴＬＭ）及安全浓度（ＳＤ）如下：氯霉素６９×１０－６、６．９×１０－６；呋喃西林７２×１０－６、７．２×１０－６；百炎净７７×１０－６、７．７×１０－６；红霉素９７×１０－６、９．７×１０－６；硫酸链霉素４８×１０－６、４．８×１０－６；青霉素钠大于１００×１０－６、１０×１０－６。（２）１３×１０－６的呋喃西林、１３×１０－６的红霉素、１３×１０－６的青霉素钠对幼虫生长均有促进作用。（３）各试验组随药物浓度递增，幼虫活动逐渐被抑制；摄食率及眼点率逐渐下降。高浓度红霉素对摄食的抑制作用最强。  相似文献   

Kinetics of the reactions of hydroxyl radicals with aliphatic ethers studied under simulated atmospheric conditions: Temperature dependences of the rate coefficients     

Paul J. Bennett  J. Alistair Kerr 《Journal of Atmospheric Chemistry》1990,10(1):27-38

Rate coefficients have been measured for the reactions of hydroxyl radicals with five aliphatic ethers over the temperature range 242–328 K. Competitive studies were carried out in an atmospheric flow reactor in which the hydroxyl radicals were generated by the photolysis of methyl nitrite in the presence of air containing nitric oxide. The reaction of OH with 2,3-dimethyl-butane was used as the reference reaction and the following Arrhenius parameters have been obtained for the reactions: OH+RORproducts:

ROR	E/kJ mol–1	1012 A/cm3 molecule–1 s–1
dethyl ether	–2.8±0.4	3.5±0.6
di-n-propyl ether	–1.2±0.6	11.5±2.7
methylt-butyl ether	0.85±0.59	4.0±1.3
ethyln-butyl ether	–1.3±0.5	8.7±1.7
ethylt-butyl ether	–1.2±0.6	3.0±0.8

  相似文献   

改进的矿山地温类型划分          下载免费PDF全文

邓孝 《地质科学》1990,(1):81-86

本文基于对地壳浅部地温场形成特征及控制因素的分析及对我国东部几十个矿区的地温测量和对若干典型热矿山的研究成果,提出改进的矿山地温类型划分,对原分类加以修订。新的划分系统分为两级,第一级为“类”,按矿区平均地温梯度值分为低地温(梯度)类、中常地温(梯度)类和高地温(梯度)类。第二级为“型”,按引起地温场显著变化的主要控制及致热因素,将低地温类型分为深源低热型、地下水循环冷却型;高地温类分为深源高热型、局部聚热型和附加热源型。这一新的划分基于广厚的资料基础,采取统一的划分原则,具有大的蓄容能力,较之原划分更符合我国矿山地温场的实际,因而对矿山地热研究实用意义更强。  相似文献   

MapReduce在气象数据传输时效统计中的应用     

赵文芳  刘旭林  桑雪竹  王鳞春 《南京气象学院学报》2018,10(2):238-243

气象数据的传输时效保障已成为探测和信息部门的重要工作之一,快速统计各类数据到报率和及时率成为一项迫切需求.基于MapReduce编程模型设计了各类数据到报率和及时率的算法,在Hadoop平台上利用该算法实现了各类数据的逐日到报率和及时率的统计,选择文本方式和Sequence File方式作为MapReduce计算模型的输入数据源进行对比试验.试验结果表明,Sequence File作为数据源能更好地提升MapReduce并行运算的性能.  相似文献   

气候变化背景下山东大气自净能力特征分析          下载免费PDF全文

董旭光  刘焕彬  汤子东  曹洁  邱粲 《山东气象》2018,38(4):93-102

利用山东22个基本（准）气象站小时气象观测资料,采用A值法计算了山东1961—2017年逐日大气自净能力指数（the atmospheric self-purification capacity index,ASPC）,分析了其气候空间分布特征和时间演变规律,利用MK检验（Mann-Kendall检验）和MT检验（Moving-t,滑动t检验）方法对历年ASPC进行了突变检验。结果表明：平均ASPC气候倾向率减小趋势极显著(P<0.01),除章丘和威海外,其他各地ASPC减小趋势均极显著(P<0.01);春季各月ASPC较大,历年各月ASPC随时间明显减小;年和四季ASPC空间分布基本一致,半岛地区较大,鲁南等内陆地区相对较小;年和春、夏、秋、冬季ASPC突变年份分别出现在2003年和2006年、2003年、2003年、2005年。济南、青岛地区ASPC分别从1999年、1993年开始显著减小,低ASPC日数历年变化大致与ASPC变化相反;济南和青岛历年各月ASPC变化差异明显。  相似文献