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51.
氨对长毛对虾幼体的毒性   总被引:4,自引:0,他引:4  
邹栋梁  高淑英 《台湾海峡》1994,13(2):133-137
氨对长对虾各期幼体的毒性试验表明:蚤状幼体对氨最每天敏感,而仔虾幼体对氨的耐受性最强,在盐度32,PH8.20,水温29.0℃时,无节幼体Ⅱ期,蚤状幼体Ⅰ期,仔虾第五天24h的LC50值分别为13.20(1.15)、9.97(0.87)、26.99(2.35)和60.81mg/dm^3ΣNH^+4(NH3)-N^1(5.30gm/dm^3NH3-N).Z1,M1,P5的48h的LC50值分别为5.  相似文献   
52.
杂交鲷和黑鲷幼鱼的代谢率及排泄率比较   总被引:1,自引:0,他引:1  
杂交鲷是以真鲷为母本,黑鲷为父本的杂交F1代品种,为了比较杂交鲷与黑鲷的代谢特征,采用静水密闭式呼吸仪测定了13、18、23、28、33℃(32℃)5个温度下杂交鲷和黑鲷幼鱼的代谢率及排泄率.结果表明:13~28℃温度下,杂交鲷和黑鲷幼鱼的代谢率、排泄率均随温度的升高而升高,28℃时杂交鲷和黑鲷幼鱼的代谢率、排泄率分别为14.22±0.95、0.39±0.02 J/(g.h)和17.47±0.14、0.43±0.02 J/(.gh),分别是其13℃时的5.69、4.05倍和4.01、3.73倍;且各温度下黑鲷的代谢率始终高于杂交鲷,前者是后者的1.23~1.73倍;杂交鲷和黑鲷幼鱼分别在32℃和33℃时代谢率比28℃下跌了22.23%和3.83%,证明该温度已分别超出了这2种幼鱼的最高适温;杂交鲷和黑鲷幼鱼28℃时的窒息点溶解氧含量分别为1.94、1.40 mg/dm3,低于真鲷21℃时的窒息点溶解氧含量(2.30 mg/dm3);O∶N原子比值结果显示,28℃时蛋白质供能比最低,生长积累速度最快,是2种幼鱼的最适温度.综合分析认为,杂交鲷幼鱼具有代谢率显著低于亲本的优点,也继承了父本耐低温的特点,但同时失去了亲本耐高温、耐低氧的特点,并出现了应激反应大等不良性状.  相似文献   
53.
为探讨河西走廊地下水“三氮”的污染现状和个人健康风险。本文以酒泉东盆地为例,通过数据统计、空间分布趋势、污染源和影响因素分析的手段,从“三氮”分布、迁移和影响因素及其健康风险评价进行研究。结果表明:在其独特的地形地貌、氧化还原环境、包气带和含水层岩性、潜水的埋深、酸碱环境和地下径流条件等自然因素以及生态环境的破坏和城市化的发展等人为因素影响下,研究区地下水“三氮”总体含量较低,污染相对较轻,仅有一处NO3--N含量超过标准限值;区域分布上,“三氮”含量具有明显的北高南低的规律,NO3--N和NO2--N含量东、西两侧高,中间低,NH4+-N含量由西北向东南逐渐减少。“三氮”个人年健康风险的整体分布趋势基本一致,由西部人口密集区域向东部人口非密集区域逐渐递减。  相似文献   
54.
母乳中p,p’-DDE浓度是监测母体短期内p,p’-DDE的“静态”蓄积水平,估算婴幼儿每日摄入量的重要技术手段。本文旨在通过监测北京女性两个相邻哺乳期内母乳中p,p’-DDE浓度及变化,估算两次分娩间隔期母体内p,p’-DDE的“动态”富集速度,并根据每日摄入量掌握人体p,p’-DDE的长期变化趋势。在2009年至2019年期间,收集了43名女性首次分娩后六个月内和18名女性第二次分娩后六个月内的母乳样本,并采用气相色谱法检测了母乳中p,p’-DDE的浓度。实验结果表明,母乳中p,p’-DDE浓度在哺乳期持续下降。年龄和分娩次数是母乳中p,p’-DDE浓度的影响因素,p,p’-DDE浓度随母亲年龄增大而升高,随分娩次数增多而降低。18名母亲两个哺乳期内母乳中p,p’-DDE平均排泄速度计算结果表明,排泄速度从18.9μg/kg lipid/month降低到16.8μg/kg lipids/month。而母体两次分娩隔期内p,p’-DDE年富集速度估算值为正,分布在10.9~14.9μg/kg lipids/year之间,每日摄入量分布在29.8~40.8ng/day/kg.b.w.之间。因此北京女性哺乳期母体内p,p’-DDE月排泄速度与母体年富集速度数值相当,母体p,p’-DDE每日摄入量远低于世界卫生组织(WHO)建议值,北京女性是低风险暴露人群。  相似文献   
55.
There are more than 2000 species of brittle stars in the world. For most of them, many scientific questions including basic characteristics of eco-physiology are still unknown. In the present study, Ophiopholis sarsii vadicola acclimated at 15℃, salinity 31, were assessed for temperature and salinity tolerance. Its oxygen consumption and ammonia excretion were studied at different temperatures(5, 10, 15, 20, 25℃) and salinities(25, 30, 35). O. sarsii vadicola could tolerate 0–24℃ and no brittle star was dead in the salinity range of 19–48 in the experimental situation. Two-way ANOVA showed that the oxygen consumption and ammonia excretion normalized with both dry mass and wet mass, Q10, which is used to describe the temperature sensitivity of respiration, and moisture content were significantly affected by temperature and salinity, and the combined effects of the two factors were significant. Stepwise multiple regression analysis revealed that logarithmic oxygen consumption and ammonia excretion showed a significant positive relationship with logarithmic temperature and salinity. The logarithmic moisture content of the brittle stars showed an inverse relationship with logarithmic salinity, but a positive relationship with logarithmic temperature. This suggests that the tolerance of temperature and salinity of brittle stars is closely related to their living environment, and that the effects of temperature on oxygen consumption are more significant at higher salinity, and that the ammonia excretion is less affected by salinity at lower temperatures.  相似文献   
56.
Polychaete Neanthes japonica is a species geographically specific in China and Japan with important scientific implication and commercial value. In this study, the relations of body weight, salinity and temperature to oxygen consumption and ammonia excretion of N. japonica were determined. Three different groups in body weight (large: 2.34±0.36 g, middle: 1.50±0.21 g and small: 0.62±0.12 g) were set for all experiments. Results show that the body weight is negatively related to the rates of oxygen consumption and ammonia excretion; and the relationship is significant. The oxygen consumption and ammonia excretion at 24°C decreased at salinity from 5 to 30 and increased above 30, indicating that both lower and higher salinity are adverse and certain degree of salinity stress is necessary for enhancing the energy demand. At salinity 30, rising temperature from 18°C to 30°C, the oxygen consumption increased before 27°C and then decreased. However, the relation of ammonia excretion and temperature seems more complex. Two-way ANOVA shows that salinity, temperature and body weight all have a significant effect on the oxygen consumption and ammonia excretion of the worm. Moreover, interaction between salinity/temperature and body weight is also significant. O:N (oxygen/nitrogen) ratio varies greatly in this case from 5.97 to 463.22, indicating that N. japonica can regulate the type of metabolic substrate against environment changes. Supported by the National Natural Science Foundation of China (No. 30490233) and the Three-Gorge Project and the Estuarine Environment (No. SX2004-018) from the Three Gorges Project Construction Committee  相似文献   
57.
呼吸和排泄是鱼类代谢活动的重要特征,是鱼类生物能量学研究的重要内容之一,对于评估鱼类在水生态系统中的作用、物质循环、能量流动以及养殖容量等具有十分重要的意义。通过了解耗氧率和排氨率与各种因素的相互关系及变化规律可以了解鱼体的代谢水平和活动规律等,可为鱼类的养殖生产、新品种培育、移植驯化、养殖水体水质调控和活体运输等提供科学依据。有关鱼类耗氧率的研究,国内已有许多文献[1-11],但关于排氨率的研究相对较少,目前已见有牙鲆、犬齿牙鲆、大西洋鲆等种类的报道[12-14]。  相似文献   
58.
鲢、鳙放养使微型生态系统的水柱氮、磷浓度和磷的分布发生了明显的变化。至实验结束时,各实验组的水柱颗粒磷、总磷和氨氮浓度都比对照组高,而正磷酸盐浓度和沉积物磷的量均低于对照组。这种变化以鳙单养系统为最大,其次是鲢、鳙混养系统,鲢单养系统的变化最小。微型生态系统中正磷酸盐浓度同浮游动、植物密度和初级生产力显著相关,氨氮浓度同所述变量之间的相关关系则多半与正磷酸盐相反。实验观测期间浮游植物密度与总磷浓度之间存在营养级联假说所预见的下行影响,实验结束时二者之间却有上行影响的趋向。根据实验观测结果认为,微型生态系统营养物(尤其是磷)水平的变动,主要是鲢、鳙的摄食改变了系统的群属结构和代谢强度的结果,同时反映了实验鱼对系统中营养物再生的影响。  相似文献   
59.
A simple sample treatment method for the accurate and precise determination of iodine in soil, sediment and biological samples by inductively coupled plasma-mass spectrometry (ICP-MS) is described. Iodine in samples was extracted in screw top PTFE-lined stainless steel bombs using a 10% v/v ammonia solution at 185 C for 18 hours (overnight), after which the extract was introduced into the ICP-MS for direct measurement. 126Te was employed as the internal standard to compensate for matrix effects and instrument drift. The limit of detection (LOD, three times the standard deviation of the procedural blank solution, expressed as the concentration in the sample solution) was 0.003 ng ml--1. The limit of quantitation (LOQ, ten times the standard deviation of the procedural blank solution, expressed as the concentration in the solid samples, dilution factor DF = 100) was 0.01 μg g--1 (dry mass). The accuracy and precision of the method were demonstrated by analysing different Chinese geological certified reference materials (soils, stream sediments and a hair sample). The measured concentrations were in a good agreement with the certified values indicating that bias in the method was not significant. The precision (n = 10) for different concentrations ranged from 1.82% to 4.32% RSD. Comparison of the ammonia extraction procedure with a "sintering" method indicated that there was no significant difference in results obtained with the two methods for geological soil and stream sediment samples. However, for biological samples, such as hair, kelp, tea etc., the results obtained by the sintering method were far below those of the ammonia extraction method. The ammonia extraction has advantages, as it is simpler than the "sintering" method, and has a lower procedural blank, better detection limits and reproducibility. Due to the simplicity of the method, a high rate of sample throughput is possible.  相似文献   
60.
活化沸石除铵及其动力学过程研究   总被引:1,自引:1,他引:1  
丁磊  王萍 《矿物学报》2006,26(1):107-112
对新型水处理材料活化沸石去除水中氨氮的各项性能进行了研究。单因素影响试验表明,沸石用量、粒径、溶液温度、浓度、pH值及吸附时间对去除效果有重要影响。据此确定了最佳静态试验条件,在该条件下,活化沸石对水中的氨氮有较好的去除效果,可将生活污水中的120 mg/L氨氮降到40 mg/L。动态小试确定了小试设备的工艺参数,该处理设备在实际运行过程中,吸附周期为64 h,处理效果良好。动力学研究表明,活化沸石除铵是离子交换与吸附两种行为共同作用的结果,该过程符合Freundlich等温式,动力学方程可用一级反应来描述。  相似文献   
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