全文获取类型
收费全文 | 585篇 |
免费 | 49篇 |
国内免费 | 23篇 |
专业分类
林业 | 59篇 |
农学 | 32篇 |
基础科学 | 8篇 |
114篇 | |
综合类 | 90篇 |
农作物 | 45篇 |
水产渔业 | 37篇 |
畜牧兽医 | 196篇 |
园艺 | 18篇 |
植物保护 | 58篇 |
出版年
2023年 | 1篇 |
2022年 | 9篇 |
2021年 | 23篇 |
2020年 | 19篇 |
2019年 | 18篇 |
2018年 | 28篇 |
2017年 | 27篇 |
2016年 | 24篇 |
2015年 | 22篇 |
2014年 | 24篇 |
2013年 | 39篇 |
2012年 | 42篇 |
2011年 | 37篇 |
2010年 | 17篇 |
2009年 | 17篇 |
2008年 | 41篇 |
2007年 | 28篇 |
2006年 | 25篇 |
2005年 | 21篇 |
2004年 | 18篇 |
2003年 | 23篇 |
2002年 | 36篇 |
2001年 | 31篇 |
2000年 | 18篇 |
1999年 | 14篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 6篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1968年 | 2篇 |
1965年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有657条查询结果,搜索用时 15 毫秒
121.
122.
工业人工林发展研究——解决我国木材供需矛盾途径分析之一 总被引:12,自引:2,他引:10
从我国工业人工林的发展背景出发 ,论述我国工业人工林发展的意义 ;重点分析我国南方工业人工林经营的技术经济效益、发展中存在的问题以及工业人工林在我国的发展前景 ;找出影响我国工业人工林发展的关键因素 ,在此基础上提出进行制度创新和技术创新为我国工业人工林的发展提供必要的条件和相应技术支持的对策建议 相似文献
123.
124.
应用间接血凝试验(IHA)对采自杨陵区食品公司屠宰点、西北农业大学实验农场种猪场,西北农林科技大学兽医院的214份猪血样进行弓形虫抗体的定性检测,包括血清检测法(176份),滤纸干血滴法(38份)两种方法。结果检出阳性血样5份,阳性率为2.34%。其中来自杨陵区食品公司屠宰点猪血样136份,全部用血清检测法测定结果,阳性5份,阳性率为3.68%,来自西北农林科技大学农场种猪场血样76份,38份血清 相似文献
125.
"黑麦草-水稻”草田轮作系统的研究V.稻田冬种黑麦草的优质高产栽培技术 总被引:29,自引:4,他引:29
黑麦草(IRG)的栽培方式、播种量、施肥种类和施肥量是影响IRG优质高产的主要因素。研究结果表明,高播量(22.5kg/hm^2)稻底撒播方式可以获得优质高产的IRG,干物质产量9183.45kg/hm^2,粗蛋白质产量达1668.00kg/hm^2,因其节省劳力,且可以有效利用稻田水分,因此可作为稻田冬种IRG的主要方式。中等播量(15.0km/hm^2)育苗移栽方式也获得了较高的产量(9765 相似文献
126.
127.
Roman Gancarz Witold Wielkopolski Elbieta Jaskuska Pawel Kafarski Barbara Lejczak Przemyslaw Mastalerz Jan Sylwester Wieczorek 《Pest management science》1985,16(3):234-238
9-Aminofluoren-9-ylphosphine oxides and the corresponding 9-hydroxy analogues were synthesised and evaluated for herbicidal activity using Spirodela oligorrhiza (Kurz.) Hegelm. All the test compounds were highly active at concentrations of about 10 μM and were comparable with the corresponding phosphonic esters. 相似文献
128.
Barbara Lejczak Pawel Kafarski Roman Gancarz Elzbieta Jaskulska Przemyslaw Mastalerz Jan Sylwester Wieczorek Marta Krl 《Pest management science》1985,16(3):227-233
Peptides of 9-aminofluoren-9-ylphosphonic or 1-aminocyclohexylphosphonic acids were synthesised and found to have typical morphactin activity when tested on Lepidium sativum and Triticum vulgare. The observed effects included root elongation with simultaneous stem shortening. The results obtained indicate that these phosphonic acid derivatives of cyclohexylamine and fluoren-9-ylamine may have a similar mechanism of action. 相似文献
129.
Hubert Wojtasek Piotr Wieczorek Barbara Lejczak Bogdan Boduszek Roman Gancarz Pawel Kafarski 《Pest management science》1991,32(2):245-252
A series of derivatives of 9-aminofluoren-9-ylphosphonic acid (phosphonic analogues of morphactins) were synthesized and screened for herbicidal activity against Lepidium sativum, Cucumis sativus and Lycopersicon esculentum. Ethyl 9-(N-alkylamino)fluoren-9-yl(phenyl)phosphinates appeared to be equipotent with glyphosate and thus may be recognized as new lead compounds for further structural modifications. 相似文献
130.
TOLERABILITY AND TUMOR RESPONSE OF A NOVEL LOW‐DOSE PALLIATIVE RADIATION THERAPY PROTOCOL IN DOGS WITH TRANSITIONAL CELL CARCINOMA OF THE BLADDER AND URETHRA
下载免费PDF全文
![点击此处可从《Veterinary radiology & ultrasound》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Previously reported radiation protocols for transitional cell carcinoma of the canine lower urinary tract have been ineffective or associated with increased side effects. Objectives of this retrospective, cross‐sectional study were to describe safety of and tumor responses for a novel palliative radiation protocol for transitional cell carcinoma in dogs. Included dogs had cytologically or histologically confirmed transitional cell carcinoma of the bladder or urethra, and were treated with 10 once‐daily fractions (Monday–Friday) of 2.7 Gy. Thirteen dogs were sampled, with six treated using radiation as first‐line (induction) therapy and seven treated using radiation as rescue therapy after failing previous chemotherapy. Within 6 weeks of radiation, 7.6% (1/13) dogs had a complete response, 53.8% (7/13) partial response, 38.5% (5/13) stable disease, and none had progressive disease. Three patients presenting with urethral obstruction had spontaneous micturition restored during the treatment protocol. A single patient with unilateral ureteral obstruction was patent at recheck examination. Median survival time from time of initial diagnosis was 179 days. Median survival time from start of radiation was 150 days. Acute radiation side effects occurred in 31% (4/13) patients and were classified as grade 1 or 2. No significant late side radiation side effects were reported. No variables examined were identified as prognostic factors. Findings indicated that the reported radiation protocol was safe in this sample of dogs with bladder and urethral transitional cell carcinoma. Future prospective studies are needed to determine utility of this treatment as a rescue therapy in patients with complete urinary tract obstruction. 相似文献