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排序方式: 共有162条查询结果,搜索用时 31 毫秒
91.
Isolation and sequence of L3T4 complementary DNA clones: expression in T cells and brain 总被引:15,自引:0,他引:15
B Tourvieille S D Gorman E H Field T Hunkapiller J R Parnes 《Science (New York, N.Y.)》1986,234(4776):610-614
92.
Mortality rates of larval walleye pollock Theragra chakogramma were estimated from larval survey data from 1988 to 1991. Mortality estimates were based on cohort-specific losses between occupations of survey grids. Interannually, estimates of early feeding stage larval mortality rates ranged over an order of magnitude, from 0.045–0.43 day-1 , and declined sharply with age. There is some evidence that mortality rates of early feeding larvae tend to be negatively correlated with temperature and postively correlated with wind mixing. 相似文献
93.
The deposition onto grass stalks of two distinct, strong-smelling substances produced in the anal scent pouch, is the most common form of scent marking in the brown hyaena (Hyaena brunnea). It is called pasting. The behaviour associated with pasting is described, as is the related functional anatomy of the scent pouch. The dispersion pattern of pastings within a group territory and the rate of marking in different parts of the territory were ascertained by direct observations on radio collared hyaenas. The data were analysed by the computer programs SYMAP and SYMVU which graphically display the data as a three dimensional map. Brown hyaenas leave most pastings in those areas in which they spend most time. This is in the central part of the territory. When they visit the boundaries, however, the frequency of pasting increases. GLC analyses of the pastings from two known individuals show distinct differences in the relative concentrations of the many compounds in the pastings of each. Behavioural observations show that the hyaenas are able to recognize different individuals' pastings. Pasting could function to inform group members of each other's movements as well as to inform outsiders that the territory is occupied. 相似文献
94.
Dispersion of invasive biotypes of the tobacco whitefly, Bemisia tabaci, has led to protracted crop protection constraints in numerous countries over recent decades. These polyphagous, highly efficient vectors of plant viruses present an intractable problem as they frequently carry a diverse suite of insecticide resistance mechanisms. In many areas of China, native biotypes have been supplanted by the invasive and globally widespread biotype B since the 1990s. More recently, biotype Q has established, posing a new and more potent threat to agricultural production systems throughout the country. Insecticide resistance profiles for a range of Chinese B. tabaci strains covering biotypes B and Q were examined, to establish the potential for insecticides to play a pivotal role in biotype competition and ultimate displacement. Commonly used compounds including pyrethroids, neonicotinoids, abamectin and pyriproxyfen were targeted as widespread use is pre-requisite to drivers of population dynamics on a national scale. 相似文献
95.
The natural products kahalalide F, halichondrin B, and discodermolide are relatively large structures that were originally harvested from marine organisms. They are oxygen rich structures that, to varying degrees, should have the ability to bind iron (II or III) by Fe-O and/or Fe-N bonds. In this semi empirical study, the binding of these natural products to iron (II) is studied and the aqueous stability factor (ASF) is used to determine which bonding configuration is most stable. The energy, the complex charge (+1), the average Fe-O (or Fe-N) bond distances and the dipole moments are used to calculate the ASF. The ASF provides insight to which complex will be the most stable and water soluble, important for a medicinal application. The ability of a molecule with a more than six oxygen and/or nitrogen atoms to bind iron (hexavalent, octahedral) by shifting which six atoms (O/N) are bound to the iron qualifies it as a polarity adaptive molecule. 相似文献
96.
Nikos Karatolos Ian Denholm Martin Williamson Ralf Nauen Kevin Gorman 《Pest management science》2010,66(12):1304-1307
BACKGROUND: Trialeurodes vaporariorum (Westwood), also known as the greenhouse whitefly, is a serious pest of protected vegetable and ornamental crops in most temperate regions of the world. Neonicotinoid insecticides are used widely to control this species, although resistance has been reported and may be becoming widespread. RESULTS: Mortality rates of UK and European strains of T. vaporariorum to a range of neonicotinoids and pymetrozine, a compound with a different mode of action, were calculated, and significant resistance was found in some of those strains. A strong association was found between neonicotinoids and pymetrozine, and reciprocal selection experiments confirmed this finding. Expression of resistance to the neonicotinoid imidacloprid and pymetrozine was age specific, and resistance in nymphs did not compromise recommended application rates. CONCLUSION: This study indicates strong parallels in the phenotypic characteristics of neonicotinoid resistance in T. vaporariorum and the tobacco whitefly Bemisia tabaci Gennadius, suggesting possible parallels in the underlying mechanisms. Copyright © 2010 Society of Chemical Industry 相似文献
97.
BACKGROUND: Rice brown planthopper, Nilaparvata lugens Stål, is a primary insect pest of cultivated rice, and effective control is essential for economical crop production. Resistance to neonicotinoid insecticides, in particular imidacloprid, has been reported as an increasing constraint in recent years. In order to investigate the extent of resistance, 24 samples of N. lugens were collected from China, India, Indonesia, Malaysia, Thailand and Vietnam during 2005 and 2006. Their responses to two diagnostic doses of imidacloprid (corresponding approximately to the LC95 and 5 × LC95 of a susceptible strain) were examined. RESULTS: Ten of the 12 samples collected during 2005 were found to be susceptible to imidacloprid, but two late‐season samples from India showed reduced mortality at both diagnostic doses. All 13 strains collected in 2006 showed reduced mortality at both doses when compared with the susceptible strain. Dose–response lines showed resistance in one of the most resistant field strains to be approximately 100‐fold compared with the susceptible standard. CONCLUSION: The data demonstrate the development and spread of neonicotinoid resistance in N. lugens in Asia and support reports of reduced field efficacy of imidacloprid. Copyright © 2008 Society of Chemical Industry 相似文献
98.
Stephen T. Buckland Robin E. Russell Brett G. Dickson Victoria A. Saab Donal N. Gorman William M. Block 《Journal of Agricultural, Biological & Environmental Statistics》2009,14(4):432-442
Distance sampling is a survey technique for estimating the abundance or density of wild animal populations. Detection probabilities
of animals inherently differ by species, age class, habitats, or sex. By incorporating the change in an observer’s ability
to detect a particular class of animals as a function of distance, distance sampling leads to density estimates that are comparable
across different species, ages, habitats, sexes, and so on. Increasing interest in evaluating the effects of management practices
on animal populations in an experimental context has led to a need for suitable methods of analyzing distance sampling data.
We outline a two-stage approach for analyzing distance sampling data from designed experiments, in which a two-step bootstrap
is used to quantify precision and identify treatment effects. We illustrate this approach using data from a before—after control-impact
experiment designed to assess the effects of large-scale prescribed fire treatments on bird densities in ponderosa pine forests
of the southwestern United States. 相似文献
99.
N T Gorman 《Veterinary immunology and immunopathology》1984,7(3-4):213-225
The ability of lymphocytes isolated from cases of canine thymic lymphomas to activate the alternative complement pathway has been studied. In a series of 14 thymic lymphomas 5 were found to activate the alternative pathway. This ability to activate was not abrograted by trypsinisation of the cells. It was found that normal canine thymic lymphocytes did not activate the alternative pathway. 相似文献
100.
Haney DR Levy JK Newell SM Graham JP Gorman SP 《Journal of the American Veterinary Medical Association》2003,223(11):1614-1616
OBJECTIVE: To determine the relationship between parturition date and fetal skeletal mineralization detected radiographically in cats. DESIGN: Prospective clinical trial. ANIMALS: 31 queens and their 49 pregnancies. PROCEDURE: Seventeen pregnant queens were radiographed with a computed radiography system every 2 to 3 days from 1 week after pregnancy was identified by abdominal palpation until parturition. Radiographs were evaluated to determine the first identifiable mineralization of 16 bony structures and teeth during each pregnancy. This information was used to establish a table of expected parturition dates on the basis of fetal mineralization. Single radiographs from an additional 32 pregnant cats were evaluated, and predictions of parturition dates were made on the basis of the mineralization table. RESULTS: Mineralization was first detected 25 to 29 days prior to parturition (dpp). Mineralization was determined for the spinal column (22 to 27 dpp), skull (21 to 27 dpp), ribs (20 to 25 dpp), scapula (17 to 24 dpp), humerus (20 to 24 dpp), femur (19 to 23 dpp), radius (15 to 22 dpp), tibia (15 to 21 dpp), ulna (5 to 21 dpp), pelvis (8 to 20 dpp), fibula (0 to 17 dpp), tail (8 to 16 dpp), metacarpals and metatarsals (3 to 14 dpp), phalanges (0 to 11 dpp), calcaneus (0 to 10 dpp), and teeth (1 to 6 dpp). Date of parturition was predictable within 3 days in 75% of cats. CONCLUSIONS AND CLINICAL RELEVANCE: Identification of bony structures in the fetus is useful in estimating the time to parturition in queens. 相似文献