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101.
根据南方和北方海带夏苗培育采用苗帘苗绳差异,在山东烟台国家级海带良种场海带育苗基地进行两种夏苗培育工艺的实验研究。在同一个育苗车间内,利用种海带采集游孢子并附苗,跟踪观测维尼纶苗帘和棕绳苗帘对海带育苗期间配子体发育、孢子体(幼苗)生长的影响,并比较两种不同苗帘育苗成本差异。结果显示:相同育苗条件下,维尼纶苗帘采苗后,配子体发育速度、孢子体形成速度显著优于棕绳苗帘上的配子体和孢子体;转化孢子体后,在育苗第15~31天时间内,维尼纶苗帘海带幼苗相对生长速率(RGR)显著大于棕绳苗帘幼苗(P0.05);维尼纶苗帘幼苗经55天培育,幼苗平均长度长至1.53 cm±0.13 cm,达到出库下海暂养规格,此时棕绳帘幼苗平均长度约0.47 cm±0.03cm。至70天,棕绳苗帘幼苗平均长度约1.78 cm±0.19 cm,维尼纶绳苗帘幼苗平均长度达7.87 cm±1.35cm,显著大于棕绳苗帘幼苗。采用维尼纶苗帘育苗,每1m3育苗水体育苗量约为60万株,综合育苗成本约为23元/万株,采用棕绳苗帘育苗,每1m~3育苗水体育苗量约40万株,综合育苗成本约为31元/万株。综上所述,北方采用维尼纶帘进行海带育苗在生产上具有可行性,并且可降低生产成本约25.8%。 相似文献
102.
淡水有核珍珠大面积养殖技术研究 总被引:1,自引:0,他引:1
谢绍河 《广东海洋大学学报》2010,30(1):55-58
在33.3hm2的育珠水体中,选择2龄三角帆蚌作手术贝,采用外套膜错位排列的方法,每只母蚌植入直径6~7mm珠核10粒进行育珠试验。结果表明,经2~3a的育珠,育珠蚌成活率75%,留核率45%~75%,优质珠率40%,经济效益是普通无核珍珠的3倍以上,并且收珠后的育珠蚌可以再次植核育珠。1991-2001年,试验结果以广东绍河珍珠有限公司建立的养殖基地在福建、江西、安徽、浙江和江苏等地进行示范和推广,推广面积2000hm2,取得良好的经济效益和社会效益。 相似文献
103.
中国老挝跨境生物多样性保护区的林地变化(英文) 总被引:2,自引:1,他引:1
This paper analyzed forest land use change in Trans-Boundary Laos-China Biodiversity Conservation Area which is called Namha
National Biodiversity Conservation Areas (Namha NBCAs), with 1992 and 2002 TM (ETM). Based on GIS and statistical methods,
the intensity, state index of land use change and transfer matrix were used to study spatiotemporal land use change in the
region. The results showed that the area of forest land decreased greatly, also the area of bamboo and grassland decreased.
The other way round, the area of unstocked forest, slash and burn and rice paddy land increased. As a whole, the intensity
of forest land change was higher, but others were lower. From the transfer matrix, most of the forest land changed into unstocked
forest and urban area, some to slash and burn. The grassland and bamboo were mainly transferred to forest and unstocked forest.
The unstocked forest land mostly came from forest land and grassland. It was showed there were three main causes of the land
use change namely: opium poppy cultivation, rubber plantation and also ecotourism activities and finally some policies were
developed in order to address the land use change in the study areas. 相似文献
104.
城郊部分菜地土壤重金属污染简述 总被引:13,自引:2,他引:11
介绍了中国城郊部分菜地土壤重金属污染现状,系统地分析了部分菜地土壤重金属污染元素、污染趋势、污染城市分布、污染来源及污染原因,同时,着重探讨了重金属在土壤中的分布、向上迁移、向下迁移、转化等行为特征.结果表明,城郊部分菜地土壤重金属污染与农业生产活动有密切关系,其中重金属在土壤中的行为特征与土壤环境和重金属形态有关. 相似文献
105.
Our field experiments showed that the cultivation of pearl mussels formed a new biocoene composed of filamentous algae, protozoa, porifera and coelenterate. It effectively reduced nitrogen, phosphorus,chemical oxygen demand and biochemical oxygen demand in the water by 67.3%, 73.2%, 38.1% and 15.5%,respectively, during May to September 1998 when the water eutrophication was developing. This could control water eutrophication and produce pearls, shellfish meat and shells. This is an economical and effective way to control water eutrophication by using the ultra strong filtering capability of freshwater pearl mussels. 相似文献
106.
“项目导向”的测绘高技能人才培养途径探讨 总被引:2,自引:0,他引:2
通过校企合作,以区域典型测绘工程项目为导向,将测绘工程项目引入人才培养方案中,深化“项目导向”的人才培养模式改革,构建以项目工作任务为载体的课程体系,改革教学内容、教学方法和教学手段,探索测绘高技能人才培养途径。 相似文献
107.
Effects of land management practices on labile organic carbon fractions in rice cultivation 总被引:1,自引:1,他引:0
SHAO Jing'an LI Yangbing WEI Chaofu XIE Deti 《中国地理科学(英文版)》2009,19(3):241-248
A research trial with four land management practices, i.e., traditional tillage-fallow (TTF), traditional tillage-wheat (TTW),
conservation tillage-fallow (CTF) and conservation tillage-wheat (CTW), was sampled in the 15th year after its establishment
to assess the effects of different management practices on labile organic carbon fractions (LOCFs), such as easily oxidizable
organic carbon (EOC), dissolved organic carbon (DOC), particulate organic carbon (POC) and microbial biomass carbon (MBC)
in a typical paddy soil, Chongqing, Southwest China. The results indicated that LOCFs were significantly influenced by the
combination of no-tillage, ridge culture and crop rotation. And, different combination patterns showed different effectiveness
on soil LOCFs. The effects of no-tillage, ridge culture and wheat cultivation on EOC, DOC, POC and MBC mainly happened at
0–10cm. At this depth, soil under CTW had higher EOC, DOC, POC and MBC contents, compared to TTF, TTW and CTF, respectively.
Moreover, the contents of LOCFs for different practices generally decreased when the soil depth increased. Our findings suggest
that the paddy soil in Southwest China could be managed to concentrate greater quantities of EOC, DOC, POC and MBC.
Foundation item: Under the auspices of Key Project of National Natural Science Foundation of China (No. 40231016) 相似文献
108.
西施舌人工育苗及幼虫、稚贝生长研究 总被引:3,自引:0,他引:3
对西施舌 (Coelomactraantiquata)室内人工育苗进行了研究。结果表明 ,西施舌在广东的繁殖高峰期为 5~ 6月 ,用阴干加流水刺激的方法诱导亲贝排放精卵 ,其受精率和孵化率可达 98%左右。 1997年和 1999年两次育苗试验结果 :在盐度为 2 6 .0 0~ 32 .0 0、水温为 2 3~ 2 6℃条件下 ,幼虫在培育密度为 1~ 2mL- 1时生长较好 ,经 9~ 10d培育 ,可进入附着变态期 ,其壳长生长速度为14 .1μm·d- 1。稚贝阶段在日流水量为育苗水体的 1.5~ 2 .0倍时取得较好效果 ,其壳长生长速度为 112 .4 μm·d- 1。 相似文献
109.
110.
JIA Qinxian Elena ANUFRIIEVA LIU Shash LIU Xifang KONG Fanjing ZHENG Mianping Nickolai SHADRIN 《《地质学报》英文版》2014,88(Z1):74-76
正1 Introduction The human population is projected to reach 9200million by 2050.A fundamental question for science is whether it is possible to increase food production to meet the demands of a human population of that magnitude.It’s possible only to increase an aquaculture production.Cultivation of fish/shrimp larvae is a bottleneck in a cultivation of the different organisms.Live food 相似文献