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31.
在野外地质考察、岩心观察和大量测试数据分析的基础上,对我国东北地区桦甸盆地始新统桦甸组和美国犹他盆地始新统绿河组油页岩中类异戊二烯烷烃、甾类和萜类等生物标志化合物特征进行了详细的对比研究,并探讨其对两地油页岩在有机质来源及古沉积环境上的差异指示意义。结果表明:在GC谱图上,桦甸油页岩Pr/Ph为1.47~2.03,具姥鲛烷优势;而绿河油页岩Pr/Ph为0.34~0.44,具植烷优势。GC-MS分析表明:桦甸油页岩规则甾烷C27-C28-C29呈反"L"型分布,∑(C27+C28)/∑C29为0.63~2.52;绿河油页岩规则甾烷C27-C28-C29呈钝角不对称"V"型分布,∑(C27+C28)/∑C29为0.96~1.20。桦甸油页岩萜类化合物中萜烯>ββ构型霍烷>αβ构型霍烷,以C29萜烯占优势;绿河油页岩中五环三萜烷>三环萜烷>四环萜烷,并检出丰富的γ-蜡烷和β-胡萝卜烷。两地油页岩生物标志化合物特征参数的对比分析揭示:桦甸油页岩为水生生物和高等植物双重生源,但细菌及藻类等水生生物的贡献较大,主要形成于弱还原淡水沉积环境;绿河油页岩有机质来源主要为细菌和藻类等水生生物,主要形成于强还原咸水沉积环境。  相似文献   
32.
卵形鲳鲹3个养殖群体的微卫星多态性分析   总被引:2,自引:0,他引:2  
运用6对微卫星引物分别对海南、深圳、福建3个地区的卵形鲳鲹Trachinotus ovatus养殖群体的遗传差异进行分析。结果表明,3个养殖群体的平均等位基因数(Na)为3.67—3.83,平均有效等位基因数(Ne)为2.43—3.03,平均观测杂合度(Ho)为0.48—0.66,平均期望杂合度(He)为0.56—0.64,平均多态信息含量(PIC)为0.49—0.55,可见3个养殖群体的遗传多样性较高。Hardy-weinberg平衡遗传偏离指数(d)显示海南和深圳养殖群体杂合子过剩(分别为0.10和0.12),而福建养殖群体则出现杂合子缺失(-0.08)。统计检验发现3个群体中各位点的遗传偏离并不显著(p>0.05)。3个养殖群体的遗传相似度及遗传距离信息聚类分析结果表明,福建与深圳养殖群体的亲缘关系较近,两者与海南养殖群体的亲缘关系较远。3个养殖群体的确切来源还有待进一步研究。  相似文献   
33.
国际地震学与地球内部物理学协会(LASPEI)第27届大会于1994年元月10-21日在新西兰首都惠灵顿的惠灵顿维多利亚大学举行。来自42个国家的483位科学家参加了这次大会。国家地震局派出了以副局长陈为团长的13人代表团出席会议。本届大会共安排了27个学术报告会和研讨会,会上宣读论文和报告399篇,张贴展示论文约160篇。本届IASPEI大会的学术报告会和研讨会涉及广泛的地震学和地球内部物理学研究的前沿问题,内容包括:波在非均匀介质中的传播;地震危险性与地震危害;亚太地区的沉积盆地及其构造背景;地球深部间断面的构造形态和动力学;地震预测;地震层析成像和地幔动力学;俯冲带和弧后盆地;地热在下地壳、岩石学与流变学等方面之作用;区域地震的定位和定量化;毫赫与毫微赫地震学;脊区的地震学详细研究;太平洋的地震和海啸危险性;大小尺度的各向异性;全球地震观测技术的改进;地震的震源模拟和断层力学;诱发地震;非线性地震学;地震运动的地面地质效应;空间大地测量学和实时构造地质学;热流和热液循环;宽频带地震学和震源,等等。  相似文献   
34.
We collected centric diatom Stephanopyxis palmeriana samples in coastal waters of Xiamen for characteristic red light/far red light (R/FR) phytochrome reactions to identify its photoreceptor in the course of sexual reproduction. The result showed that pre-illumination of 2-3h red light before darkness could induce sexualization of S.palmeriana, while the follow-up illumination of far red light could reverse the effect of red light, which is a featured reaction of phytochrome. The Southern Dot Blot was carried out to identify the type of phytochrome that induces the sexualization. The result also showed high homogeneity of DNA fragment of S. palmeriana with phyB, but phyA. This means the photoreceptor in the process of sexual reproduction of S. palmeriana is phytochrome B (phyB).  相似文献   
35.
I Introduction Many of the world’s commercially important fishstocks are overexploited and some are even depleted(FAO 1997, 2005). Overcapacity is considered to be amain factor leading to such a tragedy (FAO, 1999). Con-sequently, the existence of excess capacity has been sin-gled out by FAO (1995, 1998, 1999) as a matter of grow-ing concern over the last decades or so. This represents amajor shift in the fishery policy at the international level,from focusing almost exclusively on the is…  相似文献   
36.
The distribution of hexachlorocyclohexanes(HCHs) and dichlorodiphenyltrichloroethanes(DDTs) in the surface seawater and sediment of Jincheng Bay mariculture area were investigated in the present study. The concentration of total HCHs and DDTs ranged from 2.98 to 14.87 ng L-1 and were 0.032 ng L-1, respectively, in surface seawater, and ranged from 5.52 to 9.43 and from 4.11 to 6.72 ng g-1, respectively, in surface sediment. It was deduced from the composition profile of HCH isomers and DDT congeners that HCH residues derived from a mixture of technical-grade HCH and lindane whereas the DDT residues derived from technical-grade DDT and dicofol. Moreover, both HCH and DDT residues may mainly originate from historical inputs. The hazard quotient of α-HCH, β-HCH, γ-HCH and δ-HCH to marine species was 0.030, 0.157, 3.008 and 0.008, respectively. It was estimated that the overall probability of adverse biological effect from HCHs was less than 5%, indicating that its risk to seawater column species was low. The threshold effect concentration exceeding frequency of γ-HCH, p,p'-DDD, p,p'-DDE and p,p'-DDT in sediment ranged from 8.3% to 100%, and the relative concentration of the HCH and DDT mixture exceeded their probable effect level in sediment. These findings indicated that the risk to marine benthos was high and potentially detrimental to the safety of aquatic products, e.g., sea cucumber and benthic shellfish.  相似文献   
37.
Amphioxus, a cephalochordate, is an important model fish for studies in evolution and comparative biology. A successful cell culture from amphioxus tissues in vitro would help understanding some basic issues. To determine the optimal culture conditions for proliferation of amphioxus cells, primary cultures were initiated from buccal cirri, tail, gill, gut and metapleural fold of amphioxus Branchiostoma belcheri tsingtauense. The media tested were L-15, F-12, M 199, MEM, DMEM, PRMI 1640 and LDF, each was supplemented with 20% fetal bovine serum. The optimal conditions include tail tissue cultured in L-15 or F-12 with supplement of 20% FBS and 1.5% NaCl at about 25°C.  相似文献   
38.
坛紫菜叶状体体细胞对抗生素敏感性的研究   总被引:2,自引:0,他引:2  
坛紫菜(Porphyrahaitanensis)叶状体体细胞对氨苄青霉素有很强的耐受性,但氨苄青霉素对体细胞分裂、分化具有明显的抑制作用,导致更多的体细胞分化形成细胞团,并能抑制叶状体假根的形成.坛紫菜叶状体体细胞对氯霉素敏感,100μg/cm3和800μg/cm3组的体细胞分别于培养的12、10d全部死亡.本试验结果初步表明,氯霉素可作为坛紫菜基因工程的有效选择压力.  相似文献   
39.
国际地震学与地球内部物理学协会(IASPEI)第29届大会于1997年8月18~28日在希腊塞萨洛尼基举行。来自62个国家和地区的1051位科学家参加了这次大会。国家地震局有近20位科学家出席了会议。本届大会共安排了46个学术专题报告会和研讨会,会上宣读论文716篇,张贴展示论文695篇。本届IASPEI大会的学术报告涉及广泛的地震学和地球内部物理学研究的问题,内容包括:地震预测;地球内部构造和地球动力学;不同构造区的强地面运动;地震孕育过程:定量模型和假设检验;岩石圈结构、动力学过程和各向异性;火山地震学;地震早期预警系统;地震危险性与地震危害;地震危险性和地震危害评估中的新的地学信息技术;触发/诱发地震;与构造过程有关的电磁信号;岩石圈结构的长周期研究和工程地震学;估计地震大小的新方法;地球的结构和演化:地球物理观测、实验约束和模似;地震成核、动力破裂及其终止:观测和物理模拟;今后的地震仪器的发展;地震灾害与危害的公众教育,等等。  相似文献   
40.
A major heavy-oil spill from the Russian tanker Nakhodka occurred in the Sea of Japan on 2 January 1997. We investigated the impacts of this spill on a rocky intertidal ecosystem along the southern coast of the Sea of Japan. We selected Imago-Ura Cove as our study site to observe temporal changes along the oiled shore, because minimal cleaning effort was made in this area. Field surveys were conducted every autumn and spring from 1997 to 2000. We measured coverage by macroalgae in 1 x 1-m(2) quadrats and counted the animals in 5 x 5-m(2) quadrats along the intertidal zone. Changes in the ecosystem caused by the oil spill were analyzed by applying a geographical information system (GIS) to the Sea of Japan for the first time. The GIS showed that following the accident there were heavily oiled areas in sheltered regions, but these decreased over the three years. It also showed that coverage by macroalgae and the number of animals increased, although some species of algae with microscopic sporophyte generations, and some populations of perennial shellfish, remained stable or decreased during the study period. GIS was able to trace temporal changes in intertidal communities resulting from the impacts of heavy oil on flora and fauna at a spatial scale of 10-100 m. GIS is thus a practical tool for visualizing, analyzing, and monitoring changes in an ecosystem polluted by oil, taking into account topographic differences along the coastline.  相似文献   
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