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41.
  • 1. Maintaining ecological processes that underpin the functioning of marine ecosystems requires planning and management of marine resources at an appropriate spatial scale.
  • 2. The Great Barrier Reef World Heritage Area (GBR) is the world's largest World Heritage Area (approximately 348 000 km2) and second largest marine protected area. It is difficult to inform the planning and management of marine ecosystems at that scale because of the high cost associated with collecting data. To address this and to inform the management of coastal (approximately 15 m below mean sea level) habitats at the scale of the GBR, this study determined the presence and distribution of seagrass by generating a Geographic Information System (GIS)‐based habitat suitability model.
  • 3. A Bayesian belief network was used to quantify the relationship (dependencies) between seagrass and eight environmental drivers: relative wave exposure, bathymetry, spatial extent of flood plumes, season, substrate, region, tidal range and sea surface temperature. The analysis showed at the scale of the entire coastal GBR that the main drivers of seagrass presence were tidal range and relative wave exposure. Outputs of the model include probabilistic GIS‐surfaces of seagrass habitat suitability in two seasons and at a planning unit of cell size 2 km×2 km.
  • 4. The habitat suitability maps developed in this study extend along the entire GBR coast, and can inform the management of coastal seagrasses at an ecosystem scale. The predictive modelling approach addresses the problems associated with delineating habitats at the scale appropriate for the management of ecosystems and the cost of collecting field data. Copyright © 2010 John Wiley & Sons, Ltd.
  相似文献   
42.
Common carp (Cyprinus carpio) is a very important fish species for warm-water aquaculture in Croatia. All Croatian carp farms are subjected to a surveillance programme for the presence of koi herpesvirus (KHV), causing a deadly disease called koi herpesvirus disease (KHVD). However, there is no surveillance for other viral pathogens of importance like carp edema virus (CEV), a causative agent of koi sleepy disease (KSD). During regular testing within the KHVD surveillance programme, we tested samples for CEV simultaneously. The screening indicated possible outbreaks of KHVD and KSD. During 2016, KHVD broke out in an isolated area and soon thereafter a KHV eradication programme was successfully performed. However, during 2018 and 2019, two additional mortality events occurred in lakes in the southern part of Croatia during the spring. Samples from both events tested positive for CEV. An epidemiological investigation confirmed the introduction of infected carps from an infected farm to one of the lakes. To prevent the spreading of CEV into open waters, it is of utmost importance to introduce CEV testing before fish movement or to perform regular testing of all carp farms in the country to determine CEV prevalence for the purpose of implementation of control measures.  相似文献   
43.
对松浦镜鲤(SP)和德国镜鲤选育系(F4)(DJ)的可量性状及体表鳞片数进行比较,SP与DJ的可量性状与体表鳞被存在差异。SP的体长/体高(2.44±0.15)、头长/眼间距(2.24±0.08)明显小于DJ,体长/头长(3.86±0.20)、头长/吻长(2.99±0.23)明显大于DJ,SP体表的鳞片数明显少于DJ。结果表明,从DJ到SP遗传选育过程中,体型和鳞片的变化已达到了选育目的。  相似文献   
44.
[目的] 探究水电开发对局地气候的影响,是预防和减轻水电开发可能带来的负面效应,实现能源的可持续发展与环境保护的重要保障。[方法] 选取金沙江中游的龙开口、观音岩及下游的溪洛渡、向家坝4个典型水电站,运用气候倾向率、M-K趋势检验和小波分析等方法,定量分析了中下游水电局地气温、降水在蓄水前后的月、季、年变化及在水电开发中的突变情况和周期性特征。[结果] (1)蓄水后,水电站对河谷内最高温起抑制作用,最低温起抬升作用;夏季和秋季,下游水电站发挥了降温作用,月平均气温2,6,7,9,10,11月下降显著,而中游水电站调温作用不明显,仅7月平均气温略有下降。(2)蓄水后,各季节降水量均有增加,在4,8,9月增加显著,增幅为0.71~27.95 mm。(3)气温、降水与水电开发相关,中下游水电站的气温、降水在开发中和蓄水后发生不同时间的突变。(4)气温和降水在小波变化周期上呈现相似的特征,蓄水后,局地降水呈现出更显著的周期性,并且具有一定稳定性。[结论] 不同时间尺度上,水电开发在不同河段上影响局地气温和降水的程度不同,受到地理位置、周边环境及蓄水时长的多重因素制约。  相似文献   
45.
使用中国气象资源共享平台四川省1951-2016年的夏季(6-8月)降水资料,并采用GIS技术分析了四川省夏季年代平均和夏季多年平均降水空间分布,然后利用小波分析法,线性趋势系数法分析了四川省不同地貌单元下(高山高原地带(甘孜)、山地向盆地过渡地带(广元)、中低山丘地带(宜宾)、盆地中部丘陵低山地带(遂宁)及高原向盆地边缘过渡地带(雅安)夏季总降水的周期性和趋势性特征。结果表明:近66年四川省夏季年代平均降水空间分布不均,夏季多年平均降水量等值线走向基本上与地形高低相对,基本上处于地形越高降水越少;四川省不同地貌单元近66年夏季总降水存在3个尺度周期:主周期为20~47 a尺度,次周期为2~13 a和10~27 a尺度,四川省不同地貌单元夏季总降水在2008年开始整体进入丰水期且2016年后仍然处于丰水期状态。  相似文献   
46.
[目的]明确苏州市土壤养分及有机质含量在不同空间尺度下的变化规律。[方法]以2010年苏州市耕地质量监测点数据为基础,分析了土壤养分及有机质含量与空间尺度的关系。[结果]土壤养分及有机质含量的变异程度与空间尺度变化存在一定关系,其中土壤养分及有机质含量的组内变异程度随着空间尺度的增大而增加,而其组间变异程度则表现出相反趋势,土壤养分及有机质含量的组间变异程度普遍大于其组内变异程度。[结论]为准确确定土壤养分及有机质含量的空间区域划分方法提供了科学依据。  相似文献   
47.
 以紫皮大蒜品种‘G075’为试材,研究了鳞茎发育过程中鳞茎外皮花青苷的积累规律及与其生物合成相关的苯丙氨酸解氨酶(PAL)、查儿酮异构酶(CHI)和二氢黄酮醇还原酶(DFR)活性的关系,分析了不同设施栽培方式、基质pH值、基质氮素水平和磷素水平对花青苷生物合成的影响。研究结果表明:随着大蒜鳞茎的发育,鳞茎外皮花青苷含量逐步提高,CHI活性与鳞茎外皮花青苷积累关系密切,其活性变化与花青苷积累趋势吻合;露地栽培温度相对较低的紫皮大蒜花青苷积累高于保护地温度相对较高的栽培大蒜,基质pH 6.5和1/2氮素水平(7.5 mmol · L-1)时对花青苷合成有利,花青苷积累随磷素水平提高呈现先升后降的变化趋势。  相似文献   
48.
Transferrin partial complementary DNAs were cloned from the livers of five species in four genera of Indian carps (Indian major carp species: Labeo rohita, Catla catla and Cirrhinus mrigala; medium carp: Puntius sarana; minor carp: Labeo bata) subsequent to polymerase chain reaction amplification with published heterologous primers or self-designed primers derived from conserved regions of transferrin cDNA sequences. The partial transferrin cDNAs of the five species of carps had sizes from 624 to 633 bp (487 bp for L. rohita) and encoded an open reading frame consisting of 206–211 (162 for L. rohita) amino acids. The alignments of carp cDNA sequences showed 85–97% homology and 71–93% homology in deduced amino acid sequences. A phylogenetic tree of amino acid sequences of transferrin cDNAs from carps showed that the relationship among the four genera of Indian carps is well correlated with that derived from classic morphologic analyses. The hypothesized cleavage site and interdomain bridge of transferrin molecule were predicted for the above carp species and interestingly the cleavage site amino acid sequence was found to be conserved among all the carps. To study the tissue-specific expression of the transferrin gene, various tissues (liver, kidney, spleen, brain, muscle, testis, heart, intestine, gill and fin) from apparently healthy (control), moribund and survived C. mrigala experimentally infected with Aeromonas hydrophila infection were analyzed. Transferrin mRNA was detected only in liver RNA and to lesser extent in brain tissue out of the 10 tissues analyzed irrespective of bacterial infection.  相似文献   
49.
以东方百合索蚌(Sorbonne)的鳞片为试材,采用Hoaglang与Amon 1938年提出的营养液配方Y1(N:P:K=15:1:6)和对照(CK)去离子水处理,研究了小子球分生、新根和新叶产生动态.结果表明,小子球分生大多在鳞片愈伤组织腹内侧1~2 mm处,呈线状规律排列,愈伤组织(伤口)与腹背产生较少,仅占1%左右;营养液和对照两种培养方法,子球的分化期都集中在破球扦插后的3~4周,以后子球的数量不再增加;营养液无土扦插较对照去离子水培养,子球产生高46.74%,差异极显著;新根的分化集中在破球前1~4周,但破球后的生长期内仍有新根产生;新根产生较对照高35.69%,差异极显著.营养液培养下,子球分生较新根早,而对照根的发生则先于小子球,但新叶产生较早,比对照提早2周,差异显著.  相似文献   
50.
To assess strain related differences in growth performance and growth patterns under the same culture environment, four strains of common carp, two each of the scale carp, Cyprinus carpio var. communis (Chinese big-belly carp and long bodied carp) and mirror carp, C. carpio var. specularis (scattered carp and linear carp) were communally stocked in three fertilized earthen ponds of 0.14 ha each at 5,000 fish ha?1 in the ratio of 1:1:1:1 during an 11-month (February to December) culture cycle. Chinese big-belly carp grew larger than other groups, among which there were no significant differences. Scale carp strains performed relatively better than mirror carp at higher temperatures and then essentially stopped growing as temperatures declined into winter. The strains of mirror carp, on the other hand continued growing well later into the cold season.  相似文献   
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