全文获取类型
收费全文 | 235篇 |
免费 | 6篇 |
国内免费 | 4篇 |
专业分类
林业 | 15篇 |
农学 | 14篇 |
基础科学 | 5篇 |
56篇 | |
综合类 | 14篇 |
农作物 | 20篇 |
水产渔业 | 3篇 |
畜牧兽医 | 93篇 |
园艺 | 7篇 |
植物保护 | 18篇 |
出版年
2023年 | 6篇 |
2022年 | 6篇 |
2021年 | 20篇 |
2020年 | 8篇 |
2019年 | 8篇 |
2018年 | 8篇 |
2017年 | 10篇 |
2016年 | 12篇 |
2015年 | 8篇 |
2014年 | 8篇 |
2013年 | 23篇 |
2012年 | 20篇 |
2011年 | 12篇 |
2010年 | 8篇 |
2009年 | 4篇 |
2008年 | 13篇 |
2007年 | 10篇 |
2006年 | 10篇 |
2005年 | 6篇 |
2004年 | 11篇 |
2003年 | 3篇 |
2002年 | 6篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有245条查询结果,搜索用时 0 毫秒
61.
Linear measurements were made by computed tomography of the diameter of the femoral head, the width and depth of the acetabulum and the dorsal and ventral acetabular rim distances in 10 healthy German shepherd dogs, and angular measurements were made of the axial acetabular index, acetabular anteversion, and the dorsal and ventral centre-edge angles. There were no significant differences between the measurements made on the left and right sides. The width of the acetabulum was about twice its depth, and was a little larger than the diameter of the femoral head. The mean values of the axial acetabular index, acetabular anteversion, and ventral and dorsal centre-edge angles were 100.9 degrees, 25.1 degrees, 48.0 degrees and 12.2 degrees, respectively. 相似文献
62.
Nathaniel Kapaldo Rose McMurphy David Hodgson James Roush Kara Berke Emily Klocke 《Veterinary anaesthesia and analgesia》2021,48(4):493-500
ObjectiveTo assess laryngeal function in normal dogs administered isoflurane following partial clearance of alfaxalone or propofol.Study designRandomized experimental crossover study.AnimalsA group of 12 purpose-bred, male Beagle dogs.MethodsDogs were randomly assigned to one of two treatments: alfaxalone–isoflurane (ALF-ISO) or propofol–isoflurane (PRO-ISO) and anesthetized for three video laryngoscopy examinations. The alternate treatment occurred after ≥ 14 days interval. Examinations were performed after induction of anesthesia (LS-A), after 20 minutes of breathing isoflurane via a facemask (LS-B) and after a further 20 minutes of isoflurane (LS-C). Parameters of objective laryngeal function included inspiratory rima glottidis surface area (RGSA-I), expiratory rima glottidis surface area (RGSA-E) and % RGSA increase, calculated from three consecutive respiratory cycles in the final 15 seconds of each video laryngoscopy examination. The % RGSA increase was calculated using [(RGSA-I – RGSA-E)/RGSA-E] × 100. Subjective laryngeal function was evaluated independently by two experienced surgeons blinded to treatment.ResultsThe % RGSA increase within each treatment was greater for LS-B and LS-C than for LS-A (ALF-ISO: p = 0.03, PRO-ISO: p = < 0.001). There was no difference within each treatment from LS-B compared with LS-C. RGSA-I increased within each treatment from LS-A to both LS-B and LS-C (ALF-ISO: p = 0.002) and to LS-C (PRO-ISO: p = 0.006). Subjective laryngeal function scores improved from LS-A to LS-C.Conclusions and clinical relevanceLaryngeal function improved from postinduction examination following either 20 or 40 minutes of anesthesia with isoflurane via facemask. This study demonstrates that isoflurane may have a lesser effect on arytenoid abduction activity compared with more commonly used intravenous induction anesthetics (alfaxalone and propofol). 相似文献
63.
Sadiq Rehan Husain Tahir Al-Zahrani A. M. Sheikh Anwar Khalil Farooq Shaukat 《Water, air, and soil pollution》2003,143(1-4):41-63
The objective of this study is to examine the reuse of wastewaterfor beneficial purposes. To accomplish this objective, the efficiency of slow sand filters in removing total coliforms (TC) was studied using a probabilistic method. Three pilot scale slowsand filters were constructed at Alkhobar wastewater treatment plant, Dhahran, Saudi Arabia. The removal efficiency of filters was estimated under different operating control parameters, which included filtration rate (q), sand bed depth (d) and sand grain size (c). The Type III extreme value distribution best fitted theremoval efficiency data. A multiple linear regression analysis was performed to develop a relationship for mean removal efficiency as a function of control parameters. The predicted mean response and experimental results of previous studies werecompared to validate the empirical regression model. The controlparameters and influent concentrations of total coliform were used in Monte Carlo (MC) simulations for calculating the reliability index (β). The reliability index and corresponding risk were calculated for lognormally distributedsafety margins (SM). An effluent standard of 100 total coliform/100 mL was defined as capacity of the filter to ascertainthe risks of exceedence, which was approximately less than 50 for95% of the time. Pre and/or post disinfection would be necessaryto meet the stipulated effluent standards for unrestricted agriculture use. 相似文献
64.
The effect of denitrification on the behavior of nitrate in saturated sandy soil was studied in the laboratory and the results were compared with the temporal and spatial concentration of nitrate in nonreactive (without denitrification) and reactive (with denitrification) cases. A laboratory model was fabricated to study steady one-dimensional flow and to transport nitrate with or without denitrification. Denitrification at various rates has been simulated with varied C∶N ratios and detention time. Retardation constant, dispersivity, and degradation constants have been computed using existing analytical models supporting adsorption and zero and/or first order production or decay. It was found that such analytical models can be used to fit the concentration of nitrate in saturated porous media for a C∶N ratio between 2 and 5. 相似文献
65.
The synergistic effect of cold treatment and protein synthesis inhibition was investigated in cut spikes of Consolida ajacis cv. Violet blue to determine the effective postharvest storage and transportation protocol, and to improve the postharvest performance. The 35 cm cut spikes were cool wet stored at 5 °C for 72 h before or after pulse treatment with protein synthesis inhibitor, cycloheximide, at 0.01 mM concentration. A set of unpulsed spikes wet stored at 5 °C represented control. The treatment effects were evaluated by placing the spikes in holding solutions containing distilled water (DW) or sucrose 0.2 M + 8-HQS 100 mg/l (SUC + HQS) at room temperature under laboratory conditions. The spikes pretreated with CHI before 72 h wet storage at 5 °C showed an enhancement of vase life besides maintaining higher fresh and dry mass of flowers, soluble protein content in sepals and sustained rate of blooming as compared to controls. The present study recommends that pulse treating the spikes of C. ajacis with 0.01 mM CHI before wet storage at 5 °C for 72 h, followed by transfer to holding solution containing SUC + HQS can be used as an effective postharvest storage treatment to bring out their transportation within 72 h without affecting their vase life. 相似文献
66.
67.
Youssouf MS Kaiser P Tahir M Singh GD Singh S Sharma VK Satti NK Haque SE Johri RK 《Fitoterapia》2007,78(7-8):535-539
The Euphorbia hirta ethanolic extract (EH A001) was found to possess a prominent anti-anaphylactic activity. A preventive effect of EH-A001 given by oral route at dose from 100 to 1000 mg/kg was observed against compound 48/80-induced systemic anaphylaxis. At the same range of dose, EH-A001 inhibited passive cutaneous anaphylaxis (PCA) in rat and active paw anaphylaxis in mice. A suppressive effect of EH-A001 was observed on the release of TNF-alpha and IL-6 from anti-DNP-HSA activated rat peritoneal mast cells. 相似文献
68.
Tahir Hussain Awan Pompe C. Sta Cruz Bhagirath Singh Chauhan 《Journal of pest science》2015,88(2):427-438
69.
Allelopathic behaviour of three medicinal herbs viz. Rheum emodi, Saussaurea lappa and Potentilla fulgens, on some traditional food crops was examined. Germination of all the traditional food crops was reduced significantly under
aqueous extracts of S. lappa and P. fulgens but radicle and plumule growth of Amaranthus
caudatus and Eleusine coracana was reduced significantly under aqueous extracts of all three medicinal species. For marginal farmers sole medicinal plants
cultivation is not possible, therefore, medicinal plants based agroforestry is being propagated. 相似文献
70.
Effects of juniper essential oil on growth performance,some rumen protozoa,rumen fermentation and antioxidant blood enzyme parameters of growing Saanen kids 下载免费PDF全文
D. Yesilbag H. Biricik I. Cetin C. Kara Y. Meral S. S. Cengiz A. Orman D. Udum 《Journal of animal physiology and animal nutrition》2017,101(5):e67-e76
This study aimed to evaluate the effects of juniper essential oil on the growth performance, rumen fermentation parameters, rumen protozoa population, blood antioxidant enzyme parameters and faecal content in growing Saanen kids. Thirty‐six male Saanen kids (36 ± 14 days of age) were used in the study. Each group consisted of 9 kids. The control group (G1) was fed with a diet that consisted of the above concentrated feed and oat hay, whereas the experimental groups consumed the same diet but with the concentrated feed uniformly sprayed with juniper essential oil 0.4 ml/kg (G2), 0.8 ml/kg (G3) or 2 ml/kg (G4). There were no differences (p > 0.05) in live weight, live weight gain or feed consumption between the control and experimental groups. There was a significant improvement (p < 0.05) in feed efficiency in the G3 group. There were no differences in the rumen pH, rumen volatile fatty acid (VFA) profile or faecal pH of the control and experimental groups. The rumen NH3N values were similar at the middle and end of the experiment, but at the start of the experiment, the rumen NH3N values differed between the control and experimental groups (p < 0.05). The faecal score value was significantly (p < 0.05) decreased in the experimental groups. The addition of juniper essential oil supplementation to the rations caused significant effects on the kids’ antioxidant blood parameters. Although the superoxide dismutase (SOD) activity, total antioxidant capacity (TAC) and catalase values were significantly (p < 0.05) increased in the experimental groups (G2, G3 and G4), especially group G4, the blood glutathione peroxidase (GPX) value significantly decreased in the experimental groups. The results of this study suggest that supplementation of juniper oil is more effective on antioxidant parameters than on performance parameters and may be used as a natural antioxidant product. 相似文献