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101.
吴志强 《林产工业》2020,57(3):96-98
随着我国对环保的日益重视,以人造板为主要原料的板式家具适应绿色健康发展理念。介绍了板式家具主要材料以及板式家具主要原材料分类,分析了板式家具设计与制造中的减碳技术,为板式家具设计及制造企业能获得更好的社会和经济效益提供参考。  相似文献   
102.
为了更加全面地了解产地对普洱生茶品质与化学成分的影响,本研究选取来自临沧市、普洱市、西双版纳州三大产区12个茶山(自然村)的普洱生茶样品,采用超高效液相色谱-四级杆-飞行时间质谱(UHPLC-Q-TOF/MS)对不同产地普洱生茶的非挥发性代谢物表型进行了研究。结果表明:不同产地普洱生茶的化学成分在含量上具有较大差异,且具有明显的产地特征。采用主成分分析,可以对来自西双版纳自治州(包括勐腊县、勐海县、景洪市)、普洱市、临沧市3个地级行政区的普洱生茶进行有效区分,也可以对来自普洱茶产区的东南、西南、西北3个区域的普洱生茶进行有效区分。进一步鉴定了普洱生茶中79种主要成分,并对其在12个茶山(自然村)的普洱生茶中的含量分布,以及与不同产地普洱生茶滋味品质的关系进行了分析。本研究表明,基于UHPLC-Q-TOF/MS的茶叶非挥发性化学成分轮廓可以作为普洱生茶产地判别的依据。  相似文献   
103.
  1. The study of Argopecten purpuratus reproduction, post‐larval settlement, stock size, and population size structure and shell growth was undertaken in the 2000s in the Rinconada marine reserve (Chile) to evaluate the effectiveness of scallop recruitment and self‐sustainability.
  2. The results highlight strong seasonal and inter‐annual variations of environmental conditions and scallop gonadosomatic index, spat collection, benthic distribution, total abundance and population size structure.
  3. The Von Bertalanffy growth parameters were L = 120.12 mm and K = 0.9681; commercial size would be reached in about 17.2 months in the bay. Substrate availability, meteorological conditions, hydrodynamics and illegal harvesting explain spatial and temporal variations in scallop distribution and abundance.
  4. Recruitment strength depends on one main cohort from year to year. While recruitment made up 81% and 94% of total abundances in May 2002 and May 2003, respectively, there were no overall density‐dependent relationships between stock size and recruitment. Spawning asynchrony in the bay supports the hypothesis that multiple gamete releases form part of a reproductive strategy in response to environmental variability.
  5. The massive disappearance of large‐sized scallops during the study periods was direct evidence of overfishing owing to clandestine harvesting within the marine reserve. The failure of current legislation, strategies and policies for scallop conservation requires new regulations to restore scallop stock size, maintain its reproductive performance and limit illegal harvesting in the Rinconada.
  6. A scenario allowing harvesting regulated by stock‐dependent fishing quotas would more efficiently ensure stock recovery and self‐sustainability. The modalities of this new policy are discussed.
  相似文献   
104.
  1. The purpose of this study was to investigate the effects of a circle hook ring on catch rates of target fish species and bycatch rates of sea turtles, elasmobranchs, and non‐commercial fish in a shallow‐set Italian swordfish longline fishery.
  2. Results were compared from 65 sets from six commercial fishing vessels totalling 50 800 hooks in which ringed and non‐ringed 16/0 circle hooks with a 10° offset were alternated along the length of the longline. In total, 464 individuals were caught in the 4 years of experiment, with swordfish (Xiphias gladius) comprising 83% of the total number of animals captured. Catch rates of targeted swordfish were significantly higher on ringed hooks (CPUEringed hooks = 8.465, CPUEnon‐ringed hooks = 6.654).
  3. Results indicate that ringed circle hooks captured significantly more small‐sized swordfish than non‐ringed circle hooks (27.7% vs. 19.5%, respectively).
  4. For species with sufficient sample sizes, the odds ratio (OR) of a capture was in favour of ringed hooks; significantly for swordfish (OR = 1.27 95%CI 1.04–1.57), and not significantly for bluefin tuna (Thunnus thynnus) (OR = 1.50, 95%CI 0.68–3.42) nor for pelagic stingray (Pteroplatytrigon violacea) (OR = 1.13, 95%CI 0.54–2.36). All six loggerhead turtles (Caretta caretta) and three of the four blue sharks (Prionace glauca) were captured on ringed hooks, however, the small sample sizes prevented meaningful statistical analysis.
  5. In summary, results from this study suggest that the addition of a ring to 16/0 circle hooks confers higher catchability for small‐sized commercial swordfish, and does not significantly reduce catch rate of bycatch species and protected species in a Mediterranean shallow pelagic longline fishery.
  6. These findings should motivate fisheries managers to consider factors in addition to hook shape when aiming to promote sustainable fishing practices. The presence of a ring has the potential to negate some conservation benefits.
Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
105.
  1. Aerial surveys have detected alarming declines in counts of harbour seals in several regions across Scotland.
  2. Demographic data and simple models were used to examine the recent decline in the numbers of harbour seals counted in one population within a Special Area of Conservation (SAC) on the east coast of Scotland. The models suggest that the continuation of current trends would result in the species effectively disappearing from this area within the next 20 years.
  3. While the cause of the decline is unknown, it must be reducing adult survival because the high rate of decline cannot be wholly accounted for by changes in other demographic parameters.
  4. Recovery of the population to the abundance recorded at the time the SAC was designated (2005) is likely to take at least 40 years, even if the cause of the decline is immediately identified and removed.
  5. The models suggest that partial removal of the cause can have only limited benefits to population recovery, and there are unlikely to be any long‐term benefits from introducing or reintroducing additional individuals while the underlying problem persists. Therefore, if the population of harbour seals in this area is to recover it is essential that the sources of the increased mortality are identified and measures are put in place to manage these.
Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
106.
为研究目前渤海主要渔业生物的时空关系,文章依据2014年~2015年渤海双船底拖网4个季度调查数据,初步分析了渤海三类主要渔获物(鱼类、甲壳类和头足类)的水平空间分布特点、空间距离及四季变化特征。结果显示,三类生物的主要分布区水平方向上存在空间分化现象,且随着三类生物集中分布区聚集程度的提高,空间分化现象越来越明显。三类生物的水平空间分布距离在季节上表现出夏、秋季(平均欧氏距离,夏季为75.91;秋季为44.76)较远,冬、春季(冬季为8.55;春季为11.81)较近的特点。三类生物间,头足类与甲壳类的距离相对较近(平均欧氏距离,24.44),而头足类与鱼类(40.07)、鱼类与甲壳类(38.27)的距离相对较远。  相似文献   
107.
为了解我国秸秆资源利用情况,通过实地考察、问卷、走访等形式,对我国部分省份的秸秆品种、产量及其利用情况进行了调查。结果表明:在调查的省份内,农民因为受到时间、经济等因素的影响,焚烧和废弃是处理秸秆的首选方法。农民愿意接受新能源,促进秸秆再利用。我国秸秆利用途径不多,方法陈旧。受调查人员中有96.6%对秸秆新能源利用持支持态度,80%受调查人员希望能综合利用秸秆,减少环境污染。最后综合调查结果提出合理利用秸秆的建议。  相似文献   
108.
为了明确海南山区耕地土壤养分空间分布特征,为热带山区耕地土壤养分管理提供思路。以海南五指山市耕地为研究对象,采用野外调查、采样和室内分析相结合的方法,阐述土壤养分现状,探讨其土壤养分分布规律。结果表明:五指山耕地土壤总体呈酸性,其pH值为5.1;土壤有机质、有效磷、速效钾和中量元素(钙、镁、硫)含量均为中等或偏下水平,土壤有效铜和有效锌含量较为丰富。五指山耕地土壤酸化和养分含量分布不均主要与气候、母质分布和施肥不平衡有关。  相似文献   
109.
通过对六堡茶种质资源进行调查,发现六堡茶品种资源在苍梧全县、藤县金鸡镇、岑溪市南渡镇等地均有分布,以苍梧县六堡镇、狮寨镇为主要分布地。这些茶原料的水浸出物含量为46.6%~56.4%,茶多酚含量为32.2%~49.7%,氨基酸含量为2.7%~5.2%,咖啡碱含量为2.7%~6.6%,儿茶素含量为17.5%~24.6%,适制六堡茶和红茶。  相似文献   
110.
基于2016年黑龙江省重点国有林区348户家庭的微观调查数据,实证分析黑龙江省国有林区脆弱异质性家庭对停伐政策的态度及影响因素。采用因子分析与综合评价法将348户职工家庭分为脆弱性家庭和非脆弱性家庭,描述性分析2组样本家庭对停伐政策的态度及认知情况,利用多元有序logit模型分析脆弱性与非脆弱性家庭对停伐政策态度的影响因素。结果表明:非脆弱性家庭对停伐政策的了解程度及执行情况的评价均高于脆弱性家庭,脆弱性家庭相对非脆弱性家庭对停伐政策的认可度较高,但是应对风险冲击的能力相对较低。脆弱性家庭和非脆弱性家庭对停伐政策的态度受户主特征、家庭特征以及政策认知特征变量的显著影响,但脆弱性家庭变量参数估计绝对值相对更大,因而停伐政策对脆弱性家庭有着更为敏感和强烈的冲击。  相似文献   
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