全文获取类型
收费全文 | 1029篇 |
免费 | 45篇 |
专业分类
林业 | 120篇 |
农学 | 39篇 |
基础科学 | 6篇 |
221篇 | |
综合类 | 153篇 |
农作物 | 49篇 |
水产渔业 | 88篇 |
畜牧兽医 | 308篇 |
园艺 | 33篇 |
植物保护 | 57篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 16篇 |
2021年 | 31篇 |
2020年 | 33篇 |
2019年 | 27篇 |
2018年 | 24篇 |
2017年 | 26篇 |
2016年 | 28篇 |
2015年 | 27篇 |
2014年 | 26篇 |
2013年 | 38篇 |
2012年 | 89篇 |
2011年 | 85篇 |
2010年 | 35篇 |
2009年 | 39篇 |
2008年 | 94篇 |
2007年 | 73篇 |
2006年 | 68篇 |
2005年 | 72篇 |
2004年 | 64篇 |
2003年 | 50篇 |
2002年 | 40篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 6篇 |
1998年 | 8篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 7篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1978年 | 1篇 |
1955年 | 1篇 |
1940年 | 1篇 |
排序方式: 共有1074条查询结果,搜索用时 15 毫秒
991.
Causes of color changes in wood during drying 总被引:3,自引:0,他引:3
The forest industry operates in a dynamic and global market where change and competition are the rule rather than the 相似文献
992.
Valentina Spanic Marc Lemmens Georg Drezner 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(4):511-516
Fusarium head blight (FHB) is an important fungal disease of wheat. The aim of this research was to determine the diversity
of Fusarium species infecting winter wheat ears in East Croatia. In 2008 wheat kernels were obtained from three locations in the eastern
part of Croatia (Tovarnik, Osijek, Pozega), and in 2009 from two additional locations (Slavonski Brod, Nova Gradiska). In
total, 498 visually diseased kernels were selected for morphological identification of Fusarium spp. The identity of 226 selected isolates was further investigated by molecular techniques. The predominant species on wheat
kernels in East Croatia in 2008 were F. graminearum, isolated and confirmed from more than 80% of sampled wheat kernels, followed by F. avenaceum (8%) and F. culmorum (7%). Incidence of F. poae was less than 2%. The most common species identified in 2009 were F. graminearum (50%), F. culmorum (13%), F. avenaceum (12%) and F. poae (7%). This is the first report on the identification of Fusarium species isolated from naturally infected wheat ears in Croatia. 相似文献
993.
994.
995.
Marc Papageorges DMV PhD Patrick R. Gavin DVM PhD David D. Barbee DVM MS Donald P. Knowles DVM PhD William P. Cheevers PhD Ronald D. Sande DVM PhD 《Veterinary radiology & ultrasound》1992,33(1):55-61
During a study designed to investigate the potential of radioimmunodetection to detect lentiviral antigens in vivo , it was found that technetium-99m-labeled antibodies (Tc-99m-Abs) accumulated nonspecifically in arthritic joints of goats infected with the caprine arthritis-encephalitis virus. The uptake of Tc-99m-Abs was significantly higher in both chronic and acute arthritis compared to normal joints, but similar to the uptake of Tc-99m-labeled human serum albumin (Tc-99m-HSA). Tc-99m-Abs could be used to detect synovitis but did not show any advantage over Tc-99m-HSA. 相似文献
996.
Pasmans F Martel A Boyen F Vandekerchove D Wybo I Immerseel FV Heyndrickx M Collard JM Ducatelle R Haesebrouck F 《Veterinary microbiology》2005,110(3-4):285-291
Reptile-associated salmonellosis in humans is an increasing public health issue. This study aimed at characterizing Salmonella isolates from captive lizards and to compare them to human isolates. Salmonella was isolated from 25 of 33 cloacal and 47 of 79 faecal samples from captive lizards (75.8 and 59.5%, respectively). The strains belonged to 44 serotypes of subspecies I (27 serotypes), II (9), IIIb (3) and IV (5). Two strains, one of serotype Enteritidis and one of serotype Amsterdam, were resistant to nitrofurantoin. Invasion assays in Caco-2 cells were performed with 40 saurian isolates of subspecies I, 15 isolates of subspecies II, 4 strains of subspecies IIIb, 6 subspecies IV isolates and 17 human isolates of corresponding serotypes of subspecies I. Saurian isolates belonging to subspecies I invaded the Caco-2 cells to a higher extent than those from the other subspecies. The human isolates invaded the Caco-2 cells to a lesser degree compared to their saurian counterparts. In the same strains, the presence of virulence genes agfA, shdA, spvR, pefA and sopE was determined using PCR. Whereas agfA was detected in all strains, pefA was only detected in one saurian and in the human serotype Enteritidis strains. The spvR gene was detected in the same serotype Enteritidis strains and in 33% of the subspecies IV strains. The shdA gene was present in all the human isolates and in 86% of subspecies I saurian isolates. SopE was found in 17% of the human isolates, in 24% of the saurian subspecies I strains and in all of the subspecies IV strains. 相似文献
997.
998.
Chemical interaction of Earth's mantle with the liquid outer core should influence the mantle's iron content. Osmium isotope ratios in Hawaiian lavas indicate a mass flux of =1% core to the mantle, which is the immediate source of these lavas. We present precise measurements of the Fe/Mn ratio for Hawaiian lavas, revealing an increase of 1 to 2% in the mole fraction of iron in the mantle beneath Hawaii. This corresponds to a density anomaly of about 0.5%, about the same magnitude observed in seismic tomography models of the Pacific superswell region. These data also rule out a role for Mn-rich sediments as the source of the Hawaiian Os isotope signal. 相似文献
999.
1000.
Hamaide AJ Verstegen JP Snaps FR Onclin K Balligand MH 《American journal of veterinary research》2003,64(5):574-579
OBJECTIVES: To compare retrograde filling cystometry at infusion rates of 5, 10, and 20 mL/min with diuresis cystometry for determination of an appropriate infusion rate and to confirm the reproducibility of measurements obtained by urethral pressure profilometry (UPP) and cystometry in female Beagles. ANIMALS: Adult female Beagles. PROCEDURE: Successive UPP and cystometry were performed by use of a water perfusion catheter on dogs anesthetized with propofol. Dogs randomly underwent each of the following at 1-week intervals: retrograde filling cystometry at 5, 10, and 20 mL/min, and diuresis cystometry. The maximum urethral pressure and closure pressure, functional and anatomic profile lengths, threshold pressure, threshold volume, and compliance were measured. RESULTS: For each UPP variable, significant differences were found among dogs, but no significant differences were found in intra- or interstudy measurements for individual dogs. For retrograde filling cystometry, threshold pressure was not significantly different between a 5 and 10 mL/min infusion rate. Threshold pressure was significantly higher during retrograde filling cystometry at 20 mL/min, compared with 5 and 10 mL/min, and was associated with bladder wall damages. Threshold pressure was significantly lower during diuresis cystometry, compared with retrograde filling cystometries. Threshold volume and compliance were not significantly different among retrograde filling cystometries but were significantly higher during diuresis cystometry. CONCLUSIONS AND CLINICAL RELEVANCE: Retrograde filling cystometry at 20 mL/min leads to unacceptable sudden increase in threshold bladder pressure. Retrograde filling cystometry at 10 mL/min can be recommended in a clinical setting, shortening the anesthesia time. However, diuresis cystometry approximates physiologic bladder filling most accurately. 相似文献