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1.
An efficient, reproducible and rapid fused silica capillary column gas chromatographic method, in splitless mode, for analysing of the three chloroanthracene isomers is described. The method affords efficient separation and good linearity for each isomer in the range of 0.2 -200 μg/ml. The method can also be used in separation and determination of another thirty three aromatic and their halosubstituted compounds. This paper also presents the applications of the method in analysing of complex products mixture from reaction of the selected aromatic compounds with hydrogen chloride on fly ash surface from municipal incinerator. 相似文献
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雷州半岛地区磷肥高效利用技术及其应用 总被引:5,自引:0,他引:5
在研究雷州半岛土壤特殊的强固磷机理基础上,以改性的工农业废弃物作为活化剂,活化磷矿粉制得高效磷肥,不仅利用了废弃物资源,变废为宝,而且节省了硫酸资源,降低了肥料成本。在雷州半岛不同地区,以西瓜、甘蔗、辣椒、水稻为供试作物,以过磷酸钙为对照,在等质量(低成本)条件下进行了大量的田间试验,结果表明,除水稻产量持平外,其他作物均表现出明显的增产效果,增产幅度在3%-22%之间,且产品品质改善。因此,高效磷肥在雷州半岛地区有广阔的应用前景。 相似文献
3.
Setting of larvae of the oyster Crassostrea virginica was monitored in the James River, Virginia, USA from 1963 to 1980. Setting patterns were similar in two ways to those described prior to 1960 (before the onset of the oyster pathogen Haplosporidium nelsoni (MSX) in Chesapeake Bay): (1) setting intensity (average number of spat per shell) was greater at stations in the lower than upper estuary, and (2) on the average, 60 to 80% of the total annual set at each station occurred during a 6-week period from mid-August through September. However, annual setting intensity from 1963–1980 was lower than previously recorded, and annual sets occurred as a series of discrete pulses rather than continuously throughout the season. Pulses were each approximately 1 to 2 weeks in duration and separated by a period of diminished or no setting. Cross-correlation analysis of annual setting patterns among stations revealed three zones in the James River: the upper estuary and entire southwest side, the lower estuary, and a mid-estuary transition zone. Setting pulses tended to be synchronous at stations within each zone, but occurred 1 to 2 weeks later at stations in downriver than in upriver zones. The location of zones is related to known aspects of water circulation in the James River estuary. Moreover, pulse setting itself may be related to the absence of strong vertical salinity gradients accompanying the fortnightly stratification-destratification process.Contribution No. 1213 from the Virginia Institute of Marine Science, School of Marine Science, The College of William and Mary 相似文献
4.
N. Haven 《Marine Biology》1977,42(2):177-184
Records of Nautilus pompilius trapped in the Tañon Strait, Negros Oriental, Philippines were kept for a 1 year period from August 1971 through August 1972, and ovaries of mature females collected from August 1971 through March 1972. Females averaged only 8% of the catch during the year of study, but were more abundant in catches from January through May. The male:female ratio was not markedly altered at any depth in the trapping range (61 to 300 m). During the 8 month period, there was no trend apparent in the changes in average size of the ovaries collected; however, oocytes within varied markedly in their maximum weight. Encapsulated spermatophores are stored above the buccal cone on the male, and are attached unencapsulated below the ventral cirri of the female. N. pompilius pairs kept at 80 m remained healthy but laid no eggs from September 1971 through May 1972. 相似文献
5.
基于黄土高原1961—2008年月平均气温、最高气温、最低气温、相对湿度、降水量、风速和日照百分率等气候要素资料,应用修订的Penman-Monteith(P-M)模型计算了最大可能蒸散量,分析其时空分布、异常分布特征和次区域时间演变特征。结果表明:1961—2008年间,黄土高原最大可能蒸散量多年平均在400~800 mm之间,大部分区域650~750 mm之间。一致性异常分布是黄土高原最大可能蒸散量的最主要空间模态。黄土高原最大可能蒸散量的异常空间分布可分为以下3个关键区:高原西北部区、高原东北部区和高原东南部区。高原西北部区域最大可能蒸散量呈显著增加趋势,且发生了突变现象;高原东北部区域最大可能蒸散量呈显著下降的趋势,也发生了突变;而高原东南部区域下降趋势不显著,未发生突变。黄土高原最大可能蒸散量的3个空间分区中,3 a的周期振荡表现得比较显著。 相似文献
6.
Zhuang Yahui Zhang Hongxun Wang Xiaoke & Li Changsheng Research Center for Eco-Environmental Sciences Chinese Academy of Sciences PO Box Beijing China Institute for the Study of Earth Oceans and Space University of New Hampshire Durham NH U.S.A. 《中国人口.资源与环境(英文版)》2004,(3)
The report summarizes surveys on carbon inventories and initiatives on sustainable carbon cycling taken by the Research Center for Eco-Environmental Sciences, where the authors work/worked. The first part of the report, which appeared in the preceding issue of this journal, deals with the concept of sustainable carbon cycling, the historic evolution of carbon cycling processes in China, carbon pool enhancement, value addition, carbon sequestration and carbon balance. This very paper, as the second part of the report, covers the results of carbon dynamics modeling, emission inventories of various carbon-containing greenhouse gases and their potential abatement measures. 相似文献
7.
The use of genetic markers to estimate the frequency of successful alternative reproductive tactics 总被引:4,自引:0,他引:4
David F. Westneat Peter C. Frederick R. Haven Wiley 《Behavioral ecology and sociobiology》1987,21(1):35-45
Summary This paper outlines a method for estimating rates of successful alternative reproductive tactics from parental exclusions known through the use of genetic markers. We review a method for calculating the probability of excluding a putative father when he is not the actual father. We adapt this method to model two mating tactics of concern to sociobiologists: extrapair copulations (EPCs) and intra-specific egg parasitism (egg-dumping). Four different types of parental exclusions are possible (both male and female, male only, female only, and ambiguous). The two models predict different proportions of each type of exclusion. Models are also generated for the case when the putative mother's or father's genotypes are not available.We used parental exclusions from an electrophoretic study of indigo buntings (Westneat 1987b) to demonstrate these methods. The distribution of parental exclusions in the buntings departed significantly from the predictions of the egg-dumping model, but agreed well with those of the EPC model. The probability of detection for the EPC model (0.401) was then used to estimate the actual rate of extra-pair fertilizations (0.421 of all the young sampled). We present a method for calculating a confidence interval on this estimate, which ranged from 0.247 to 0.659. We concluded that these methods will allow the quantitative study of the success of alternative reproductive tactics in a wide variety of species. 相似文献
8.
The effects of fluctuating salinities on the survival and activity of Urosalpinx cinerea (Say) from the James River, Virginia, USA, were observed and compared to results of similar studies at constant salinities. All experiments were conducted at summer temperatures. The lower extremes of salinity fluctuations, especially values below 9, had the greatest effect on mortality; the upper extremes may have delayed, but did not reduce, mortality. There was a characteristic 10-day mortality-free period at the start of the fluctuating salinity experiments. Mortality patterns were much different in constant salinities, where the first 2 weeks of exposure were characterized by highest mortalities. In both types of experiments, drill activity, measured by attachment, feeding, and oviposition, increased as salinities increased above lethal levels (greater than a minimum of 9). Fluctuating salinities, which approximated field conditions, affected drills differently from constant salinities and were, therefore, more realistic for study of these estuarine organisms.Contribution No. 543, Virginia Institute of Marine Science, submitted by the senior author to the School of Marine Science of the College of Williams and Mary, in partial fulfillment of the requirements for the Master of Arts degree. 相似文献
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10.
Philip New Alastair Brown Andrew Oliphant Philip Burchell Adam Smith Sven Thatje 《Marine Biology》2014,161(3):697-709
Anthropogenic effects on marine ecosystems (e.g. hypoxia, warming) at and beyond continental margins are assumed to affect physiological and biochemical boundaries to species’ distributions, potentially leading to habitat contraction across depth. Whether or not shallow-water benthic invertebrates are capable of undergoing depth-related migrations in response to such perturbations remains largely unknown. The few studies available have focused solely on whether colonisation of deep waters may be ongoing and on the ability of shallow-water species to tolerate low temperatures and high hydrostatic pressures: two physical parameters, which are thought to limit the depth range of a species. Those studies did not consider the effects of acclimation to low temperature and, especially, acclimation to high hydrostatic pressure on pressure tolerance. We demonstrate that acclimation to both low temperature (5 °C) and to high hydrostatic pressure (10 MPa) increases the pressure tolerance within the shallow-water shrimp Palaemonetes varians. Previous studies have demonstrated the impressive temperature and pressure tolerance of this shallow-water shrimp. Here, we provide evidence that a shallow-water species may acclimate to low temperature and high pressure and show greater pressure tolerance, suggesting that shallow-water organisms may be able to rapidly—and potentially stepwise—acclimate to the low temperature and high pressure conditions typical of the deep sea. These findings are of importance for understanding phylogenetic development from shallow- to deep-water species and the processes behind past, present and future bathymetric range shifts in species. 相似文献