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121.
Molecular characteristics of granulosa and cumulus cells and oocyte competence in Nelore cows with low and high numbers of antral follicles 下载免费PDF全文
122.
The effect of waterborne selenite levels on selenium accumulated by different developmental stages of rainbow trout (Salmo gairdneri) was studied using75SeO
3
=
as a tracer. All stages readily accumulated selenium at both high and low concentrations, but the rate of accumulation increased
as the trout developed from the egg to the juvenile feeding stage. The low rate of selenium accumulation by embryos seemed
to be related more to a lack of gills than to the presence of a chorion. The bioconcentration factor (the ratio of tissue-to-water
concentrations) declined in all groups with increased waterborne selenium levels; accumulation rates appeared limited by cell
permeability. At low levels of waterborne selenium (0.4μg/l), the total accumulated was small relative to existing body burdens and unlikely to contribute significantly to the nutritional
requirement for selenium. High levels (45.6μg/l), however, caused considerable selenium accumulation and may be sufficient to overcome the effects of low dietary selenium. 相似文献
123.
Brucellosis in Moose (Alces alces). A Serological Survey in an Open Range Cattle Area of North Central British Columbia Recently Infected with Bovine Brucellosis 下载免费PDF全文
M. Hudson K. N. Child D. F. Hatler K. K. Fujino K. A. Hodson 《The Canadian veterinary journal. La revue veterinaire canadienne》1980,21(2):47-49
A serological survey for Brucella abortus antibodies in mature cow moose (Alces alces) was made in an area of northcentral British Columbia which recently had been heavily infected with bovine brucellosis and in which there was considerable intermixing of moose and range cattle. No evidence of Brucella infection was found in the moose tested and it was concluded that they were probably not of great significance in the epidemiology of bovine brucellosis in the study area and were therefore unlikely to have hindered attempts to eradicate brucellosis from the cattle in that area. 相似文献
124.
Yong Yu Arnico Panday Elke Hodson Bo Galle Ronald Prinn 《Water, air, and soil pollution》2008,191(1-4):71-81
Mixing ratios of seven monocyclic aromatic hydrocarbons, as well as NO2, SO2 and O3, were measured by long path differential optical absorption spectroscopy (DOAS) at a suburban site in Kathmandu, Nepal, during Jan.–Feb. 2003. The results showed average benzene (3.9?±?1.8 ppbv), toluene (13.3?±?7.1 ppbv), and sum of xylene isomers (42.2?±?15.7 ppbv) mixing ratios in Kathmandu. The xylenes concentrations were higher than in the large cities that have been studied. The observed ratio of toluene to benzene (2.9?±?1.8) reflected the small fraction of vehicles with catalytic converters in the Kathamndu. Analysis of the late afternoon time series of aromatics, NO x , and wind data indicated that road traffic was one of the main sources of aromatics in the urban air. In addition, the correlations between aromatics, SO2, NO x , and PM10 during the night strongly suggested that fossil and biomass fuel burning made an important contribution to air pollution in the Kathmandu valley. Aromatic pollution was further strengthened by daily recurring stable meteorological conditions and the surrounding topography. The chemical reaction of aromatics with free radicals during the daytime could also be deduced. High ratios of phenol/benzene and para-cresol/toluene could not be explained by chemical processes, and suggested direct emission of phenol and para-cresol in the Kathmandu atmosphere. 相似文献
125.
126.
Previous studies have demonstrated that fish inhabiting polluted waterways often have an impaired stress response at the organismal
level. Given the possible link between the organismal (i.e. cortisol) and cellular (i.e. heat shock proteins; hsp) stress
responses, we conducted this study to examine the ability of rainbow trout to respond to a 2 h, +14 °C heat stress (HS) challenge
following a 28 d, sub-chronic exposure to increased concentrations of cortisol (5 mg kg−1 b.w.), β-napthoflavone (bnf; 50 mg kg−1 b.w.), and a combination of both (mixture), through the diet (1.5% b.w. every 48 h). While control fish responded to the
HS by significantly increasing components of their organismal (cortisol, glucose, and lactate) and cellular (hepatic hsp70
protein) stress responses 6 and 24 h post HS, cortisol-, bnf-, and mixture-fed fish had impaired stress responses at both
levels of organization. Additionally, hepatic hsp70 levels were significantly reduced 6 h post HS in cortisol-fed fish. While
bnf-fed fish had significantly higher EROD activity, cortisol potentiated EROD activity in the mixture-fed fish. Similarly,
plasma cortisol concentrations in the mixture-fed fish were significantly lower relative to cortisol-fed fish. These data
are the first to indicate that sub-chronically stressed fish can have impaired stress responses at both the organismal and
cellular levels. These findings raise questions regarding: (a) the universal and simple applicability of biological indicators
of stress in fish; (b) the possible functional relationship between these two levels of stress responses; and (c) the importance
of hsps in the generalized stress response of the whole organism.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
127.
Robert Park Tom Fetch Dave Hodson Yue Jin Kumarse Nazari Mohinder Prashar Zacharias Pretorius 《Euphytica》2011,179(1):109-117
Surveillance of wheat rust pathogens, including assessments of rust incidence and virulence characterization via either trap
plots or race (pathotype) surveys, has provided information fundamental in formulating and adopting appropriate national and
international policies, investments and strategies in plant protection, plant breeding, seed systems, and in rust pathogen
research. Despite many successes from national and regional co-ordination of rust surveillance, few attempts were made to
extend rust surveillance to international or even global levels. The Global Cereal Rust Monitoring System was established
to address this deficiency. It is underpinned by an information platform that includes standardized protocols for methods
and systems used in surveys, preliminary virulence testing, data, sample transmission and management at the field and national
and global levels, and includes two web-based visualization tools. While considerable progress has been made towards a global
system for monitoring variability in the wheat stem rust pathogen, and linking this to the threat posed by this pathogen to
regional wheat production, some challenges remain, including ongoing commitment to support rust surveillance, and the ability
to share and compare surveillance data. 相似文献