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排序方式: 共有63条查询结果,搜索用时 31 毫秒
1.
In the surface 5 cm of a clay soil in 2 successive years the microbial biomass, as measured by a fumigation-respiration technique, was constant. The biomasses in two clay soils were approximately ten times greater than that in a silt loam. When straw from a preceding crop was chopped and left on the soil surface the biomass after 8 months was greater by a factor of two than that in soil where the straw had been burnt. Where soil had been kept in grass for 9 yr, the biomass was greater by a factor of three than that in soil of the same kind that had been in arable cultivation for the previous 4 yr. As the fumigation-respiration technique measured only the microbial and microfaunal contribution to the biomass, the total biomass can only be assessed by measuring the root contribution separately; when this was done the total biomass in the grassland was found to be greater by a factor of about six. 相似文献
2.
Bruce TJ Hooper AM Ireland L Jones OT Martin JL Smart LE Oakley J Wadhams LJ 《Pest management science》2007,63(1):49-56
Field-trapping experiments with synthetic 2,7-nonadiyl dibutyrate, the female-produced sex pheromone of the orange wheat blossom midge, Sitodiplosis mosellana (Géhin), demonstrated that pheromone traps were highly attractive to males and caught very few non-target organisms. Different formulations of pheromone were tested to identify the optimum release rate and dispenser type for use in pheromone traps in the UK. Key findings were that racemic pheromone was as effective as enantiomerically pure (2S,7R)-2,7-nonadiyl dibutyrate, that release rates higher than 0.5 microg day(-1) were not necessary and that the optimal formulation was a 1 mg pheromone loading in a rubber septum. Pheromone traps gave a reliable indication of peak midge emergence, onset of flight and abundance of midges throughout the season. A strong correlation between maximum trap catch and crop infestation levels was obtained. 相似文献
3.
Cruz-Migoni A Hautbergue GM Artymiuk PJ Baker PJ Bokori-Brown M Chang CT Dickman MJ Essex-Lopresti A Harding SV Mahadi NM Marshall LE Mobbs GW Mohamed R Nathan S Ngugi SA Ong C Ooi WF Partridge LJ Phillips HL Raih MF Ruzheinikov S Sarkar-Tyson M Sedelnikova SE Smither SJ Tan P Titball RW Wilson SA Rice DW 《Science (New York, N.Y.)》2011,334(6057):821-824
The structure of BPSL1549, a protein of unknown function from Burkholderia pseudomallei, reveals a similarity to Escherichia coli cytotoxic necrotizing factor 1. We found that BPSL1549 acted as a potent cytotoxin against eukaryotic cells and was lethal when administered to mice. Expression levels of bpsl1549 correlate with conditions expected to promote or suppress pathogenicity. BPSL1549 promotes deamidation of glutamine-339 of the translation initiation factor eIF4A, abolishing its helicase activity and inhibiting translation. We propose to name BPSL1549 Burkholderia lethal factor 1. 相似文献
4.
5.
Kadar E Sykes JE Kass PH Bernsteen L Gregory CR Kyles AE 《Journal of the American Veterinary Medical Association》2005,227(6):948-953
OBJECTIVE: To determine the prevalence of infections developing postoperatively, document the contribution of infection to increased risk of death, and identify risk factors associated with the development of infectious complications in cats after renal transplantation. DESIGN: Retrospective study. ANIMALS: 169 cats that received renal allograft transplants. PROCEDURES: Medical records of cats receiving renal transplants at the University of California from January 1987 through December 2003 were reviewed. RESULTS: 47 infections developed in 43 of 169 cats. Bacterial infections were most common (25/47 cats), followed by viral (13/47), fungal (6/47), and protozoal (3/47) infections. The median duration from transplant surgery to development of infection was 2.5 months. Infection was the second most common cause of death after acute rejection of the transplant, accounting for 14% of deaths overall. Cats with concurrent diabetes mellitus had a significantly increased risk of developing an infection after renal transplantation. Sex, increasing age, concurrent neoplasia, and previous treatment for transplant rejection were not associated with development of infection. CONCLUSIONS AND CLINICAL RELEVANCE: Infection was a common complication and an important cause of death or euthanasia in cats after renal transplantation. Development of diabetes mellitus after transplantation significantly increased the risk of infection. 相似文献
6.
OBJECTIVE: To evaluate outcome of renal transplantation in dogs administered cyclosporine, azathioprine, and prednisolone immunosuppression. STUDY DESIGN: Prospective clinical study. ANIMALS: Fifteen dogs with chronic renal failure. RESULTS: Nine dogs died within 1 month of surgery; 5 died from complications associated with generalized thromboembolism. Three dogs survived for 6-25 months. Three dogs alive at the time of this report have survived 22-48 months; however, all 3 dogs have had bacterial infections that responded to antibiotic therapy. There was no biochemical evidence of acute allograft rejection in any dog. Perioperative use of enoxaparin may have prevented thromboembolism in 5 dogs. CONCLUSIONS: Triple drug immunosuppressive therapy used in this study prevented acute renal allograft rejection in 6 dogs that survived >4 weeks; however, immunosuppression was excessive, resulting in an unacceptable frequency of infection and other drug-related complications. Perioperative anticoagulation therapy seem to be warranted. CLINICAL RELEVANCE: Survival time and quality of life for this group of dogs was poor; however, there was no evidence of acute rejection in the dogs surviving >4 weeks. This protocol should only be used if the degree of immunosuppression is reduced, and early evidence of allograft rejection is monitored by renal biopsy or markers of lymphocyte activation. 相似文献
7.
Leigh M. Holt Andrew E. Laursen Lynda H. McCarthy I. Vadim Bostan Alison L. Spongberg 《Biology and Fertility of Soils》2010,46(4):407-413
Effects of municipal biosolids on microbial N2-fixation in agricultural soil were assessed in a 3-month laboratory study which included analysis of metals, pharmaceuticals,
and personal care products. Reference agricultural soil was amended with organic manure or municipal biosolids from a southern
Ontario wastewater plant, with a biosolids-only treatment included to evaluate metabolic activity in this inoculum. Microbial
N2-fixation in reference and manure-amended soils were similar (p = 0.144) over 3 months and lower than in biosolids-amended soil (p = 0.001); however, differences among soil treatments decreased over time, with no significant difference at test termination.
In general, one-time application of biosolids caused short-term stimulation of N2-fixing activity with a return to reference conditions within 3 months. Although no residual effects were detected, biosolids
introduced elevated levels of metals, pharmaceuticals, personal care products (particularly analgesics), and viable bacteria;
long-term effects caused by repeat applications (as commonly practiced) requires further investigation. 相似文献
8.
Lynda Medjkouh Anabela Costa Abderezak Tamendjari Farid Bekdouche Khalida Bouarroudj M. Beatriz P. P. Oliveira 《Phytoparasitica》2018,46(5):595-605
The olive fruit fly, Bactrocera oleae (Rossi), is the major olive pest in the Mediterranean Basin, being responsible for high losses in olive production. The objective of this work was to study the influence of B. oleae infestation on the pomological parameters and nutritive value (lipids, proteins, carbohydrates and ash) of eight olive cultivars (Abani, Aellah, Blanquette de Guelma, Chemlal, Ferkani, Limli, Rougette de Mitidja and Souidi) from Algeria. The results displayed different degrees of susceptibility of the studied cultivars to this pest. Fruit size (weight) and the Fruit weight / stone weight ratio are significantly correlated with the attack. The statistical treatment of the results (PCA and HAC) highlighted different behaviors from the cultivars, concerning the attack. There are some cultivars more susceptible, being the nutritional value also affected. The lipid and protein contents were positively correlated with the attack and the carbohydrates negatively, suggesting a careful choice by the B. oleae. Ovipositional preference of olive fruit fly females and the success of larval development in different olive cultivars are crucial to establishing new approaches in Integrated Pest Management (IPM) against this pest. 相似文献
9.
Assessment of computed tomography derived cricoid cartilage and tracheal dimensions to evaluate degree of cricoid narrowing in brachycephalic dogs 下载免费PDF全文
Lynda Rutherford Lee Beever Mieghan Bruce Gert ter Haar 《Veterinary radiology & ultrasound》2017,58(6):634-646
The aims of this observational, analytical, retrospective study were to (i) obtain computed tomographic (CT) cricoid dimensions (height, width, and transverse‐sectional area), (ii) compare the cricoid dimensions between brachycephalic and mesaticephalic breeds, and (iii) compare cricoid cartilage dimensions between dogs without and affected with brachycephalic airway syndrome. The study is important to help to further evaluate and understand the anatomical components of brachycephalic airway syndrome. Measurements were performed in 147 brachycephalic and 59 mesaticephalic dogs. The cricoid cartilage was found to be significantly more oval in Pugs and French Bulldogs compared to mesaticephalic breeds. The cricoid cartilage transverse‐sectional area was smallest for the Pug and, after adjusting for weight, significantly smaller for Pugs (P < 0.001), Boston Terriers (P = 0.001), and French Bulldogs (P < 0.001) compared to Jack Russell Terriers. The tracheal transverse‐sectional area at C4 of English Bulldogs was significantly smaller than for Jack Russell Terriers (P = 0.005) and Labradors (P < 0.001). The cricoid cartilage transverse‐sectional area:weight ratio was significantly lower in brachycephalic breeds compared to mesaticephalic breeds (P < 0.001). The cricoid cartilage:trachea at C4 transverse‐sectional area for brachycephalic dogs was significantly larger than for mesaticephalic dogs (<0.001), demonstrating that the trachea was the narrowest part of the airway. No significant differences were found for cricoid dimensions between dogs affected with and without brachycephalic airway syndrome. However, large individual variation was found among the brachycephalic breeds and further studies investigating the relationship between cricoid cartilage size, laryngeal collapse, concurrent tracheal hypoplasia, and/or severity of brachycephalic airway syndrome are warranted. 相似文献
10.
A new technique is described which allows an estimation of the relative collection of insecticide on a crop, for three discrete droplet sizes simultaneously. Three droplet clouds, each consisting of a different chemical, were released along a line perpendicular to the wind. Subsequent chemical analysis of vegetation samples showed the relative efficiency of capture by any part of the plant as a function of the droplet size. The target vegetation and the micrometeorological conditions were the same for all three droplet clouds and thus did not mask the effects of droplet size. Initial results for a young crop of irrigated cotton are presented. The downwind distributions of chemical residues were in good agreement with a theoretical model published by Bache and Sayer. 相似文献