全文获取类型
收费全文 | 4019篇 |
免费 | 331篇 |
国内免费 | 1篇 |
专业分类
林业 | 122篇 |
农学 | 63篇 |
基础科学 | 13篇 |
236篇 | |
综合类 | 275篇 |
农作物 | 65篇 |
水产渔业 | 216篇 |
畜牧兽医 | 3185篇 |
园艺 | 59篇 |
植物保护 | 117篇 |
出版年
2024年 | 5篇 |
2023年 | 66篇 |
2022年 | 10篇 |
2021年 | 36篇 |
2020年 | 140篇 |
2019年 | 50篇 |
2018年 | 115篇 |
2017年 | 113篇 |
2016年 | 80篇 |
2015年 | 106篇 |
2014年 | 155篇 |
2013年 | 183篇 |
2012年 | 165篇 |
2011年 | 214篇 |
2010年 | 146篇 |
2009年 | 140篇 |
2008年 | 171篇 |
2007年 | 146篇 |
2006年 | 126篇 |
2005年 | 119篇 |
2004年 | 157篇 |
2003年 | 157篇 |
2002年 | 142篇 |
2001年 | 82篇 |
2000年 | 64篇 |
1999年 | 76篇 |
1998年 | 114篇 |
1997年 | 117篇 |
1996年 | 86篇 |
1995年 | 93篇 |
1994年 | 84篇 |
1993年 | 93篇 |
1992年 | 109篇 |
1991年 | 84篇 |
1990年 | 99篇 |
1989年 | 82篇 |
1988年 | 73篇 |
1987年 | 81篇 |
1986年 | 38篇 |
1985年 | 50篇 |
1984年 | 39篇 |
1983年 | 51篇 |
1982年 | 23篇 |
1981年 | 7篇 |
1980年 | 8篇 |
1978年 | 9篇 |
1977年 | 9篇 |
1975年 | 5篇 |
1973年 | 6篇 |
1970年 | 4篇 |
排序方式: 共有4351条查询结果,搜索用时 15 毫秒
11.
Epidural Morphine in Goats after Hindlimb Orthopedic Surgery 总被引:1,自引:0,他引:1
Morphine (0.1 mg/kg) diluted with 0.9% saline to a volume of 0.13 mL/kg was administered into the epidural space at the lumbosacral junction in 10 halothane-anesthetized goats immediately before discontinuation of halothane. The same volume of 0.9% saline was given to control group of eight anesthetized goats. Both groups had undergone an orthopedic procedure that replaced the anterior cruciate ligament with a patellar tendon autograft. The appearance and unprovoked behavior of goats in the morphine group were significantly different (p < .05) from the saline groups. The goats in the morphine group were more sedate and struggled less during recovery. Epidural morphine did not produce respiratory depression or bloat during a 9 hour observation period. Heart rate, respiratory rate, and blood pressure (mean, systolic, and diastolic) of the morphine group did not differ from those of the control group. 相似文献
12.
KAREN J. FRISCHMEYER dvm PAUL E. MILLER dvm diplomate acvo YVONNE BELLAY dvm MS STEPHANIE L. SMEDES DVM Diplomate ACVO DAVID B. BRUNSON dvm MS Diplomate ACVA 《Veterinary surgery : VS》1993,22(3):230-234
Dogs given parenteral anticholinergic drugs have been thought to be at risk for development or exacerbation of elevated intraocular pressure (IOP). In a randomized, blinded, placebo-controlled study, we evaluated the effect of intramuscular glycopyrrolate (0.01 mg/kg) on pupil diameter and IOP in unanesthetized normal dogs. Treatment with glycopyrrolate did not change pupil diameter or IOP from baseline, nor were there differences between glycopyrrolate and saline-treated (control) dogs. In addition, the authors retrospectively reviewed the medical records of 2,828 dogs undergoing general anesthesia between April 1987 and September 1990 to determine if there was an association between parenteral anticholinergic medication and postanesthetic elevation in IOP. The authors also determined the frequency of bradycardia requiring anticholinergic therapy during anesthesia in dogs with glaucoma. Of the 2,828 cases reviewed, the records of 46 dogs coded for glaucoma were examined in detail. The 46 dogs underwent 62 episodes of anesthesia, with 23 episodes including exposure to an anticholinergic drug. An increase in IOP from preanesthetic to postanesthetic measurement occurred in three dogs. One of these dogs received anticholinergic medication for bradycardia during anesthesia. The postanesthetic elevation in IOP in this dog was probably not drug related. Preanesthetic anticholinergic administration did not affect the incidence of anticholinergic administration for bradycardia during the anesthetic episode. Anticholinergic therapy during anesthesia was more frequent when the preanesthetic medication included an opiate drug. These studies do not indicate an association between parenteral anticholinergic administration and elevations in IOP. 相似文献
13.
Benny J. Woody DVM MS Michael J. Murphy DVM PhD AIlen C. Ray PhD Robert A. Green DVM PhD 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1992,6(1):23-28
The clinical signs and laboratory changes of brodifacoum (BDF) intoxicated dogs and their response to vitamin K1 treatment were examined. Brodifacoum, a second-generation anticoagulant rodenticide, was fed to four dogs for 3 consecutive days producing a cumulative dose of 1.1 mg BDF/kg body weight. Clinical observations of the animals were made daily throughout the study. Monitored laboratory parameters included: one-stage prothrombin time (OSPT), activated partial thromboplastin time (APTT), activated coagulation time (ACT), complete blood counts, thrombocyte counts, and serum chemistry values. Response to vitamin K1 therapy was evaluated clinically and by laboratory tests. Serum BDF concentrations were monitored. Inappetence and hemorrhagic tendencies were exhibited by day 5 postrodenticide exposure. One-stage prothrombin time, APTT, and ACT were 25% greater than time zero values at 24, 24, and 72 hours postdosing, respectively. All laboratory parameters returned to normal within 48 hours of initiating vitamin K1 therapy (0.83 mg/kg orally, TID for 5 days). Serum brodifacoum concentrations were highest (1065-1215 ng/mL) during the 3 days after BDF dosing and were detectable (3.0-7.5 ng/mL) until day 24 postexposure. A mean BDF elimination half-life of 6 +/- 4 days was observed. 相似文献
14.
SHARON L. ULLMAN DVM MS MICHAEL M. PAVLETIC DVM Dipiomate ACVS GEOFFREY N. CLARK DVM 《Veterinary surgery : VS》1991,20(6):385-391
Surgical stapling equipment was used to perform open antiperistaltic side-to-side ("functional end-to-end") entero-anastomoses in 20 dogs and 4 cats. Twenty-one anastomoses healed uneventfully. Seven animals with severe bacterial peritonitis required open peritoneal drainage and delayed abdominal closure. There was postoperative leakage at the anastomotic site in two dogs and a localized abscess at the staple line in one cat. No long-term complications occurred in follow-up periods of 3 to 29 months. 相似文献
15.
Kevin Kline PhD Leonard P. Frey PhD Jonathan H. Foreman DVM MS Joseph T. Lyman DVM MS 《Journal of Equine Veterinary Science》2005,25(8):349-354
Changes in blood gases, pH, and plasma electrolyte concentrations in response to intravenously infused sodium bicarbonate (NaHCO3) and sodium acetate (NaCH3CO2) solutions (1.34 mEq/mL) in 5 light breed mares were investigated. Jugular venous blood samples were collected before and after completion of the infusions in 20-minute intervals for 200 minutes. Infusion of sodium bicarbonate and sodium acetate caused significant (P < .00l) increases in blood pH and bicarbonate ion concentration that persisted throughout the collection period. The elevation in blood pH and bicarbonate ion concentrations was greater (P < .01) for sodium bicarbonate than for sodium acetate immediately after the completion of the infusions but was not different (P > .05) thereafter. There were significant reductions (P < .01) in plasma-ionized calcium and potassium after infusion of both sodium bicarbonate and sodium acetate. This study found that significant metabolic alkalosis in horses and corresponding shifts in electrolyte concentrations can be induced by intravenous infusion of solutions of either sodium bicarbonate or sodium acetate, and they persist for at least 3 hours. These data show that the short-term elevation in pH and bicarbonate ion concentration is momentarily higher after infusion of sodium bicarbonate. This is likely due to the direct infusion of bicarbonate ions in the sodium bicarbonate treatment, such that further metabolism is not required to be effective. However, the longer-term alkalosis did not differ between isomolar solutions of sodium bicarbonate and sodium acetate. 相似文献
16.
17.
Brian Reavy Maria Sandgren Hugh Barker Pekka Heino Per Oxelfelt 《European journal of plant pathology / European Foundation for Plant Pathology》1997,103(9):829-834
Resistance tests were made on seedlings of transformed lines of Nicotiana benthamiana which contain a transgene encoding the coat protein (CP) gene of a Scottish isolate of potato mop-top virus (PMTV). This transgene has been reported to confer strong resistance to the PMTV isolate from which the transgene sequence was derived and also to a second Scottish isolate. Plants of lines of the transgenic N. benthamiana were as resistant to two Swedish and two Danish PMTV isolates as to a Scottish isolate, and of five lines tested, greater than 93.5% of transgenic plants were immune. The coat protein gene sequences of these four Scandinavian isolates were very similar to those of the two Scottish isolates. The greatest divergence between the isolates was three amino acid changes and there was less than 2% change in CP gene nucleotide sequence. It is concluded that the PMTV CP transgene used in these experiments could confer resistance against isolates from different geographical areas because it is becoming apparent that the CP genes of PMTV isolates are highly conserved. 相似文献
18.
S.G. Nykamp DVM P.V. Scrivani DVM A.P. Pease DVM MS 《Veterinary radiology & ultrasound》2004,45(1):23-28
Computed tomography-dacryocystography (CT-DCG) was used to evaluate the nasolacrimal system in four patients (three dogs and one horse) that were admitted for evaluation of chronic epiphora, facial swelling, or facial trauma. The four patients are reviewed and the technique for performing CT-DCG is described. Additionally, the indications for this procedure are discussed. CT-DCG is advantageous because cross-sectional imaging provides superior resolution of the nasolacrimal apparatus and the relatively long, small-diameter, bony nasolacrimal canal in most veterinary patients. 相似文献
19.
20.