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排序方式: 共有176条查询结果,搜索用时 109 毫秒
101.
Pamela Paparu Thomas Dubois Danny Coyne Altus Viljoen 《Physiological and Molecular Plant Pathology》2007,71(4-6):149-157
102.
Sandra Wenger Wayne Boardman Peter Buss Danny Govender Chris Foggin 《Journal of zoo and wildlife medicine》2007,38(3):380-387
White rhinoceroses (Ceratotherium simum) anesthetized with etorphine combinations develop severe pathophysiologic changes, including hypoventilation, hypoxemia and metabolic acidosis. The aim of this study was to evaluate the addition of butorphanol to the immobilizing mixture on the cardiopulmonary effects in free-ranging white rhinoceroses darted from the helicopter. In the control group (n=15), the rhinoceroses were anesthetized with etorphine, azaperone, detomidine, and hyaluronidase administered intramuscularly. In the treatment group (n=16), 10-20 mg of butorphanol was added to the combination. Within 10 min of becoming immobile, vital parameters (heart rate, respiratory rate, and temperature) and blood gas analyses were taken, and measurements were repeated after 10 (treatment group) and 20 min (control group). Both groups showed respiratory and metabolic acidosis, hypoxemia, and hypercapnia. In the control group, the arterial partial pressure of oxygen was significantly higher and the alveolar-to-arterial oxygen pressure gradients were significantly lower in all body positions compared with the butorphanol group. Oxygen hemoglobin saturation in the control group was higher than in the butorphanol group only in the lateral position. Improvements in arterial oxygen levels were observed in all animals when placed in sternal recumbency. There were no significant differences in the mean induction times between groups, but the distance the butorphanol group ran was significantly less after darting than in the control group. By adding butorphanol to the immobilizing mixture, no benefits in ventilation were seen; although, size differences make comparisons difficult. Running for a shorter distance during induction could be beneficial in the prevention of severe acid-base imbalances and capture myopathy. 相似文献
103.
Scott L. Stephens Danny L. Fry Ernesto Franco-Vizcaíno Brandon M. Collins Jason M. Moghaddas 《Forest Ecology and Management》2007,240(1-3):87-95
The cultural practices associated with Euro-American settlement in the United States have altered forest structure and ultimately changed fundamental ecosystem processes. Coarse woody debris (CWD) and canopy cover are recognized as having great importance for many wildlife species and ecological processes. Little information is available from forests on historical levels of canopy cover and CWD before European settlement. A great deal of uncertainty exists concerning the long-term role of fire and the dynamics of CWD, especially in forests that once experienced frequent, low-moderate intensity fire regimes. The objective of this study was to quantify CWD and forest canopy cover in an area where harvesting has never occurred and limited fire suppression began in the 1970s. This study was done in Jeffrey pine-mixed conifer forests in the Sierra San Pedro Martir (SSPM) in northwestern Mexico. Canopy cover, canopy closure, and CWD were sampled on a grid of plots. Average canopy cover was 26.8%, average canopy closure was 40.1%. A total of 102 CWD pieces were measured, and nearly half of the plots (45.7%) had no CWD present. Average CWD density, percent cover, volume, and weight were 108 pieces ha−1, 1.5%, 47.5 m3 ha−1, and 15.7 tonnes ha−1, respectively. All of the CWD sampled were in the later stages of decay. Less than average values for CWD density, percent cover, volume, and weight were recorded in 57%, 64%, 67%, and 69% of the plots, respectively. CWD dynamics in forests that experience frequent, low-moderate intensity fires are fundamentally different than those having long-interval, high-severity fires. There was a large amount of variability in all CWD and forest canopy cover measurements taken from Jeffrey pine-mixed conifer forests in the SSPM. Spatial heterogeneity in forest structure should be included in the desired conditions of xeric, pine-dominated forests in the United States that once experienced frequent, low-moderate intensity fire regimes. It should be noted that heterogeneity by itself may not lead to sustainable forests unless that heterogeneity includes stand structures that are resistant/resilient to high-severity fire, drought, insects, and disease. 相似文献
104.
Guy Smagghe Tarlochan S. Dhadialla Stefaan Derycke Luc Tirry Danny Degheele 《Pest management science》1998,54(1):27-34
Toxicity assays with tebufenozide, the first commercial non-steroidal ecdysteroid agonist, against a laboratory strain of the beet armyworm, Spodoptera exigua (Hübner), demonstrated the promise of this new compound for the control of this important pest. Experiments to select insects artificially from the laboratory strain by continuous exposure of larval instars to corresponding LC25 doses of tebufenozide for over 12 generations (G0→G12: 14–15 months), revealed no loss in susceptibility to the insecticide for up to five generations. Moreover, retention and fate of 14C-labelled tebufenozide were investigated using G6 larvae from the selection experiments and the results compared with those for the susceptible (G0) larvae. In addition, piperonyl butoxide, an inhibitor of monooxygenases, when ingested by larvae along with tebufenozide, increased the susceptibility of intoxicated larvae to this ecdysteroid agonist, indicating its oxidative metabolism in Spodoptera larvae. © 1998 Society of Chemical Industry. 相似文献
105.
The essential oil obtained from the leaves of Chamaecyparis obtusa was analyzed by GC and GC-MS. alpha-Terpinyl acetate, sabinene, isobornyl acetate and limonene were found to be the major components. The oil showed relatively strong antibacterial activities against Gram (+) bacteria and some fungi. 相似文献
106.
Danny Marks Michelle Ann Miller Sujitra Vassanadumrongdee 《Asia Pacific viewpoint》2020,61(2):266-282
Currently approximately 9 million tons of plastic enter the world's oceans annually. This is a major transboundary problem on a global scale that threatens marine wildlife, coastal ecologies, human health and livelihoods. Our concern in this paper is with the environmental governance of marine plastic pollution that emanates from Thailand, the sixth biggest contributor globally. By zooming in on land‐based polluters in Thailand, we highlight both the systemic nature of the marine plastic problem and the relative impunity with which drivers of transboundary environmental harm function at all levels of governance. Drawing from 19 interviews conducted with actors from the public, private and non‐profit sectors, we examine three stages of the problem: production, consumption and waste management. We found that three major barriers prevent Thailand's government, private sector and citizens from engaging in the sort collective action needed to reduce marine plastic pollution. They are: (i) insufficient incentives to enact political change; (ii) scalar disconnects in waste management; and (iii) inadequate public and private sector ownership over plastic waste reduction. As the state alone cannot change corporate and consumer behaviour, we argue that multi‐stakeholder efforts across organisational scales of governance and administrative boundaries are needed to address the barriers. 相似文献
107.
Washington Gapare Warren Conaty Qian-Hao Zhu Shiming Liu Warwick Stiller Danny Llewellyn Iain Wilson 《Euphytica》2017,213(3):66
A genome-wide association study (GWAS) was conducted on a diversity panel of 103 cotton accessions over three seasons to determine genetic contributions to a range of cotton yield components including fibre quality, plant architecture and stomatal conductance traits. The accessions covered breeding lines, released cultivars and some obsolete cultivars that contributed significantly to modern breeding pools. They were genotyped with Illumina’s CottonSNP63 K single nucleotide polymorphism (SNP) assay. Broad-sense heritability was low for yield component traits (\(h_{B}^{2}\) = 0.14–0.43), except for gin turnout and boll weight (\(h_{B}^{2}\)) = 0.74 and 0.59, respectively), and low to high for fibre quality traits (\(h_{B}^{2}\) = 0.26–0.89). Population structure analysis revealed extensive admixture and cryptic relatedness amongst the accessions. Genome-wide linkage disequilibrium (LD) analyses showed LD decayed, on average, within a physical distance of 5 Mbp and reduced to 2 Mbp at r 2 ≥ 0.2, suggesting that few markers are necessary for association mapping in cotton. A mixed linear model accounting for population structure and cryptic relatedness identified 17 and 50 significant SNP associations for fibre length and micronaire, respectively. GWAS failed to detect significant associations in other traits, with the contribution of any single SNP to the phenotypic falling below 5%. This may be due to the low level of DNA polymorphism in cotton and/or insufficient resolution provided by the cotton SNP chip. Whole genome sequencing combined with whole genomic selection approaches that do not require prior knowledge about the effect or function of individual SNPs may be better suited than GWAS for trait dissection and prediction in cotton breeding. 相似文献
108.
Shao S Hernandez M Kramer JK Rinker DL Tsao R 《Journal of agricultural and food chemistry》2010,58(22):11616-11625
This article investigated the mycochemical profiles and the antioxidant activities of the lipophilic extracts of the white and brown button mushrooms. We found that only free ergosterols were present in both mushrooms at 2.04-4.82 mg/g dry matter (DM). Ergosterol concentration was higher in early growth stages but decreased as the mushrooms grew, and it distributed evenly between the caps and stems during early developmental stages but accumulated more in the caps after maturation. The photochemiluminescence (PCL) values of the two mushrooms were 5.49-10.48 nmol trolox equivalent/mg DM, and the EC50 values of 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay ranged 20.19-41.49 mg DM/μg DPPH. The ergosterol content positively correlated with the antioxidant activities (r2>0.89). The total fatty acid content was 8.7 mg/g DM in the white and 5.1 mg/g DM in the brown button mushroom and contained mainly linoleic, palmitic, and stearic acids. Our data provide guidance for optimized harvesting time of mushrooms and maximized health benefits. 相似文献
109.
Hasnip S Crews C Potter N Christy J Chan D Bondu T Matthews W Walters B Patel K 《Journal of agricultural and food chemistry》2007,55(7):2755-2759
Results are presented of a survey of fermented foods and beverages sold in the United Kingdom for levels of ethyl carbamate (urethane) carried out to expand the range of food types sold in the United Kingdom for which data regarding ethyl carbamate are available. Samples were analyzed by in-house validated methods, which included measurement uncertainty estimates. The samples comprised 75 fermented liquids (beers, wines, fortified wines, spirits, liqueurs, soy sauces, and vinegars) and 25 fermented solid foods (cheeses, yogurts, soybean products, sauerkraut, yeast extract, olives, and Christmas pudding). Ethyl carbamate was not detected in the beers or the cider. Wines contained between 11 and 24 microg/kg and sake between 81 and 164 microg/kg. Fortified wines contained ethyl carbamate at levels between 14 and 60 microg/kg. Only two of five liqueurs contained ethyl carbamate. Most soy sauces and vinegars did not contain ethyl carbamate. No ethyl carbamate was detected in cheeses, yogurts, olives, or soybean-based products. Single samples of sauerkraut, yeast extract, and Christmas pudding contained low levels (29, 41, and 20 microg/kg ethyl carbamate, respectively). 相似文献
110.
Kalua CM Bedgood DR Bishop AG Prenzler PD 《Journal of agricultural and food chemistry》2006,54(19):7144-7151
Virgin olive oil samples stored in the light at ambient temperature, in the dark at ambient temperature, and at low temperature in the dark for 12 months both with and without headspace were separated into recognizable patterns with stepwise linear discriminant analysis. The discrimination with variables volatile and phenolic compounds, free fatty acid (FFA), peroxide values, K232, and K270 revealed a departure of stored oil from freshness and showed significant (p < 0.01) differences between storage conditions. Virgin olive oil stored at low temperature had characteristics closest to fresh oil while oil stored in the light showed the largest departure from freshness. Parameters that exclusively and significantly (p < 0.01) discriminated storage conditions were identified as potential markers of the storage condition. In the presence of oxygen, hexanal was a marker of storage in the light, FFA was a marker for dark storage, and markers of low-temperature storage were acetic acid and pentanal. In the absence of oxygen, octane was the marker for storage in the light whereas tyrosol and hexanol were markers of virgin olive oil stored in the dark, with no marker indicative of low-temperature storage. E-2-Hexenal, K232, and K270 were identified as markers of virgin olive oil freshness. 相似文献