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491.
Lactation can have significant costs to individual and population-level productivity because of the high energetic demands it places on dams. Because the difference in condition between lactating and dry Rocky Mountain elk (Cervus elaphus nelsoni) cows tends to disappear as nutritional quality rises, the magnitude of that difference could be used to relate condition to habitat quality or the capability of habitats to support elk. We therefore compared nutritional condition of ≥ 2.5-yr-old lactating and dry cows from six free-ranging Rocky Mountain elk populations throughout the United States. Our goal was to quantify differential accrual of body fat (BF) reserves to determine whether the condition of dry and lactating cows could be used to define relevant management thresholds of habitat quality (i.e., relative carrying capacity) and consequently potential performance of elk populations. Levels of BF that lactating cows were able to accrue in autumn and the proportional difference in BF between dry and lactating cows in autumn were related (F1–2,10 ≥ 16.2, P < 0.001). Models indicated that elk experienced no negative effects of reproduction on condition when lactating cows were able to accrue ≥ 13.7% BF in autumn. When lactating cows are accruing ≤ 7.9% BF, elk are in a nutritionally stressed condition, which may be limiting population performance. Using the logistic model to predict relative proximity to ecological carrying capacity (ECC), our population-years ranged from 3–97% of ECC and proportion of the population lactating (an index of calf survival) was negatively related to proportion of ECC. Results indicate that the proportional difference in accrual of BF between lactating and dry cows can provide a sensitive index to where elk populations reside relative to the quality of their range. 相似文献
492.
Louis G. Licari DVM Jan P. Kovacic DVM DAVCECC 《Journal of Veterinary Emergency and Critical Care》2009,19(1):11-22
Objectives – To review the role of thrombin in physiology and clinical disease and to discuss the pharmacology of antithrombosis.
Data Sources – Original research articles, scientific reviews, textbooks.
Human Data Synthesis – Thrombin and thrombin receptors are involved in a variety of physiologic and pathologic processes resulting in a great deal of interest in thrombin-related pharmacologic intervention.
Veterinary Data Synthesis – Although there is little clinical research data available on thrombin specifically in veterinary patients, some of the original research on protease activated receptors was performed at veterinary institutions and many of the human molecular biology studies have been done on animals including dogs.
Conclusion – Thrombin plays a significant role in coagulation, anticoagulation, and fibrinolysis. Antithrombotic treatment is focused on preventing thrombosis while maintaining hemostasis. Pharmaceutical agents are selected for the specific component of the coagulation pathway associated with a specific disease process, for a proven prophylactic benefit with procedures that carry a risk of thromboembolism, for rapidity of onset and ease of reversibility, for limited monitoring requirements, and for oral formulation and bioavailablity. Recent insight into other aspects of thrombin physiology presents an opportunity for pharmacologic intervention in a variety of other processes such as inflammation and sepsis, peripheral blood cell activation and chemotaxis, vascular endothelial and smooth muscle activity, cellular development and tissue repair, mitogenesis, neoplasia, and the function of nervous tissue following injury. 相似文献
Data Sources – Original research articles, scientific reviews, textbooks.
Human Data Synthesis – Thrombin and thrombin receptors are involved in a variety of physiologic and pathologic processes resulting in a great deal of interest in thrombin-related pharmacologic intervention.
Veterinary Data Synthesis – Although there is little clinical research data available on thrombin specifically in veterinary patients, some of the original research on protease activated receptors was performed at veterinary institutions and many of the human molecular biology studies have been done on animals including dogs.
Conclusion – Thrombin plays a significant role in coagulation, anticoagulation, and fibrinolysis. Antithrombotic treatment is focused on preventing thrombosis while maintaining hemostasis. Pharmaceutical agents are selected for the specific component of the coagulation pathway associated with a specific disease process, for a proven prophylactic benefit with procedures that carry a risk of thromboembolism, for rapidity of onset and ease of reversibility, for limited monitoring requirements, and for oral formulation and bioavailablity. Recent insight into other aspects of thrombin physiology presents an opportunity for pharmacologic intervention in a variety of other processes such as inflammation and sepsis, peripheral blood cell activation and chemotaxis, vascular endothelial and smooth muscle activity, cellular development and tissue repair, mitogenesis, neoplasia, and the function of nervous tissue following injury. 相似文献
493.
Abi S. dos A. Marques Roselyne Corbière Louis Gardan Catherine Tourte Charles Manceau John D. Taylor Régine Samson 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(8):715-734
The relationships between strains of Pseudomonas savastanoi pv. phaseolicola (P. sav. phaseolicola), P. syringae pv. tabaci (P. syr. tabaci) and P. syr. syringae which all cause disease on bean; the related species P. sav. glycinea and P. syr. actinidiae, and reference bacteria, were evaluated by studying the phenotypic and genetic diversity of a collection of 62 strains. All the P. sav. phaseolicola strains tested produced characteristic watersoaked lesions on bean pods. Other pathovars produced varying combinations of symptoms including necrotic lesions, with or without watersoaked centres and sunken tissue collapse of the lesion (P. syr. tabaci) and necrotic lesions with or without sunken collapse (P. syr. syringae). At the genomospecies level, all the strains of P. sav. phaseolicola, P. sav. glycinea and P. syr. tabaci, belonging to genomospecies 2, could be separated from P. syr. syringae strains (genomospecies 1) and P. syr. actinidiae strains (unknown genomospecies) by BOX-PCR and DNA/DNA hybridisation. To distinguish P. sav. phaseolicola, within genomospecies 2, from P. sav. glycinea and P. syr. tabaci, it was necessary to perform nutritional characterisations myo-inositol negative and p-hydroxy benzoate positive for P. sav. phaseolicola strains), PCR with specific primers designed from the tox region (positive for all of the P. sav. phaseolicola strains) and serotyping, as 71% of the P. sav. phaseolicola strains reacted as O-serogroup PHA1. Important intrapathovar variation was seen by genomic fingerprinting with REP and ERIC primers, as well as with RAPD primers (AE7 and AE10) and esterase profilings. While RAPD fingerprinting detected variability correlated with two race-associated evolutionary lines, REP, ERIC and esterase profiles revealed intrapathovar variation linked to some host origins, that separated the kudzu isolates, and the mungbean isolates, from the other P. sav. phaseolicola strains. 相似文献
494.
Mohamed Kerkoud Charles Manceau Louis Gardan Regine Samson Jean-Pierre Paulin 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(5):481-485
Pseudomonas syringae pv. papulans (PSP) the causal agent of blister spot, on the apple cultivar Mutsu in the USA, Canada and Italy, has not been described in France. A study on epiphytic populations of P. syringae isolated from French apple orchards revealed two isolates called KA54 and E121, whose biochemical characterisation showed high similarities with PSP strains. Identical symptoms were obtained with KA54, E121 and PSP strains, after vacuum inoculation of detached immature fruits of the cultivar Fuji, and young leaves of the cultivars Fuji, Mutsu, Gala and Golden Delicious. Koch's postulate was verified. These results indicate the presence of PSP in France. Differential characterisation criteria including serological, molecular and pathogenicity tests are proposed. 相似文献
495.
An ethyl acetate extract of bark from Evodia elleryana produced significant growth inhibition of Mycobacterium tuberculosis at concentrations only minimally inhibitory to human T cells. The crude extract yielded 95% inhibition of TB at 50 microg/ml. The crude extract yielded 29% growth inhibition of human T-cells in culture at that concentration. 相似文献
496.
取美洲黑杨(母本)和青杨(父本)杂交获得的F2群体样本80株,应用RAPD标记检测与F2群体3个数量性状(苗高、地径和封顶期)有关的QTLs。在F2九体中,一年生苗高、地径和封顶期性状表现显著分离,基本符合正态分布。单因子方差分析检测出与苗高、地径和封顶期性状相关的7个、6个和3个标记座位。并计算了各标记对相关性状变异的贡献率。与数量性状相关的标记有不同的亲本来源。t检查结果各标记显带型和不显带型 相似文献
497.
Louis M. McDonald Jr V. P. Evangelou Paul M. Bertsch 《Water, air, and soil pollution》1998,104(1-2):41-55
An understanding of the controls on aluminum solubility is essential because Al can reach toxic levels in waters that are affected by acidic precipitation or acid mine drainage. One factor which has received little attention is the role of in-lake sinks for Al. We hypothesized that a chloritization mechanism was capable of removing large amounts of Al from solution when sediments contained 2:1 minerals without well-developed Al-hydroxy interlayers. The objective of this investigation was to evaluate the potential role of lake sediments in regulating Al equilibria in the overlying waters. Water chemistry data, sediment mineralogy and exchange phase composition, and Al sorption isotherms were used. Sediments with well developed Al-hydroxy interlayers sorbed less total Al, accumulated more Al on the readily reversible exchange phase, and had less pH buffering capacity than sediments without Al-hydroxy interlayers. We conclude that the mineralogy of lake sediments needs to be considered when evaluating Al equilibria in lakes. 相似文献