首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   51篇
  免费   6篇
林业   4篇
基础科学   1篇
  9篇
综合类   1篇
农作物   1篇
水产渔业   2篇
畜牧兽医   32篇
园艺   2篇
植物保护   5篇
  2022年   1篇
  2019年   2篇
  2018年   4篇
  2017年   2篇
  2016年   2篇
  2015年   2篇
  2013年   7篇
  2012年   9篇
  2011年   3篇
  2010年   2篇
  2009年   3篇
  2008年   3篇
  2007年   3篇
  2006年   4篇
  2004年   2篇
  2003年   2篇
  2002年   1篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1940年   1篇
排序方式: 共有57条查询结果,搜索用时 15 毫秒
21.
A chemical method for the efficient destruction of 2,4,6-trichloroanisole (TCA) and pentachloroanisole (PCA) in aqueous solutions by using hydrogen peroxide as an oxidant catalyzed by molybdate ions in alkaline conditions was developed. Under optimal conditions, more than 80.0% TCA and 75.8% PCA were degraded within the first 60 min of reaction. Chloroanisoles destruction was followed by a concomitant release of up to 2.9 chloride ions per TCA molecule and 4.6 chloride ions per PCA molecule, indicating an almost complete dehalogenation of chloroanisoles. This method was modified to be adapted to chloroanisoles removal from the surface of cork materials including natural cork stoppers (86.0% decrease in releasable TCA content), agglomerated corks (78.2%), and granulated cork (51.3%). This method has proved to be efficient and inexpensive with practical application in the cork industry to lower TCA levels in cork materials.  相似文献   
22.
A series of 1-(3-pyridyl)-1-substituted-but-3-yn-1-ols and some related compounds were synthesised and tested for antifungal activity against eight phytopathogenic fungi of different taxonomic classes. High activity was shown in particular against Sphaerotheca fuliginea on Cucumis sativus. The compounds containing aromatic substituents gave the best results, not only in protectant but also in systemic and eradicant tests. The quantitative structure-activity relationship suggests that steric effects play an important role in determining fungicidal activity.  相似文献   
23.
A 12‐year‐old, male, fox terrier dog presented with an abnormal gait of the left pelvic limb. Computed tomography revealed a large, homogeneous, hypoattenuating, noncontrast enhancing mass within the left epaxial muscles that invaded the L5–6 vertebral canal and caused spinal cord compression. Imaging findings were consistent with an infiltrative lipoma. The mass was removed and a left hemilaminectomy was performed in the affected area. Histopathology confirmed the mass to be an infiltrative lipoma. The dog recovered and regained neurologic function within 2 weeks. Computed tomography assisted preoperative planning by characterizing the shape, size, and location of the mass.  相似文献   
24.
Brachial plexus avulsions commonly occur in cats due to traumatic injuries involving the shoulder. Ultrasound may be an effective method for detecting injured nerves. Additional applications may include characterization of brachial plexus neoplasms and guidance of anesthetic nerve blocks. Aims of this study were to describe ultrasonographic approaches and the normal appearance of this plexus and other major nerves of the thoracic limb in cats. Eight feline cadavers were used to determine anatomic landmarks, obtain cross‐sectional anatomic images of the target nerves, and compare these with ultrasound images. An ultrasonographic study was performed in five fresh feline cadavers to assess the brachial plexus and its major components at the levels of the axilla and proximal, middle and distal (lateral and medial approaches) humeral regions. Five healthy adult cats were recruited for an in vivo ultrasonographic study using the same protocol described for the cadaver ultrasonographic study. The roots of the brachial plexus appeared as a cluster of small, round hypoechoic structures surrounded by a hyperechoic rim in the axillary approach. The radialis, medianus, and ulnaris nerves were individually visualized on proximal and middle humeral approaches. The medianus and ulnaris nerves were easily identified on the medial aspect of the humerus in the distal approach. The superficial branch of radialis nerve was seen on the lateral aspect of the distal humerus approach. The nerves appeared as oval‐to‐round hypoechogenic structures with a hyperechogenic rim. Future studies are needed to compare findings from this study with those in cats with confirmed brachial plexus injuries or other lesions.  相似文献   
25.
The herbicide terbuthylazine is widely used within the EU; however, its frequent detection in surface and groundwater, together with its intrinsic toxicological properties, may pose a risk both for human and environmental health. Organic amendments have recently been proposed as a possible herbicide sorbent in soil, in order to limit herbicide movement from soil to water. The environmental fate of terbuthylazine depends not only in its mobility but also in its persistence. The latter is directly dependent on microbial degradation. For this reason, the effects of pine and oak residues on terbuthylazine soil microbial community functioning and on the potential of this community for terbuthylazine degradation were studied. For this purpose, degradation kinetics, soil dehydrogenase activity and the number of live bacteria were assessed in a clay loam soil treated with terbuthylazine and either amended with pine or oak wood or unamended (sterilised and non-sterilised). At day 65, 85?% of the herbicide applied still persisted in the sterile soil, 73?% in the pine-amended one and 63?% in the oak-amended and unamended ones. Pine residues increased the sorption of terbuthylazine to soil and hampered microbial degradation owing to its high terbuthylazine sorption capacity and a decrease in the bioavailability of the herbicide. On the contrary, in the presence of oak residues, the herbicide sorption did not increase significantly. The overall results confirm the active role of the soil microbial community in terbuthylazine degradation in amended and unamended soils and in a liquid enrichment culture performed using an aliquot of the same soil as the inoculum. In this clay loam soil, in the absence of amendments, the herbicide was found to be quite persistent (t 1/2?>?95?days), while in the enrichment culture, the same natural soil bacterial community was able to halve terbuthylazine in 24?days. The high terbuthylazine persistence in this soil was presumably ascribable to its texture and in particular to the mineralogy of the clay fraction.  相似文献   
26.
Twenty-three acetylenic or halovinyl carbonyl compounds with heterocyclic substituents were synthesised and tested in vivo against eight phytopathogenic fungi of different taxonomic classes. Some of them were fungicidal against Uromyces appendiculatus on Phaseolus vulgaris, though none showed a wide spectrum of activity.  相似文献   
27.
28.
29.

Objective

To study the effect of alternating the order of midazolam and alfaxalone administration on the incidence of behavioural changes, alfaxalone induction dose and some cardiorespiratory variables in healthy dogs.

Study design

Prospective, randomized, controlled, clinical trial.

Animals

A total of 33 client-owned dogs undergoing elective procedures.

Methods

Following intramuscular acepromazine (0.02 mg kg?1) and morphine (0.4 mg kg?1) premedication, anaesthesia was induced intravenously (IV) with a co-induction of either midazolam (0.25 mg kg?1) prior to alfaxalone (0.5 mg kg?1; group MA), or alfaxalone followed by midazolam at identical doses (group AM). The control group (CA) was administered normal saline IV prior to alfaxalone administration. Additional alfaxalone (0.25 mg kg?1 increments) was administered as required in all groups until orotracheal intubation was possible. Changes in behaviour, quality of induction, ease of intubation and incidence of adverse events at induction were recorded. Heart rate (HR), respiratory rate (fR) and systolic arterial blood pressure (SAP) were measured before treatments (baseline values), 30 minutes after premedication and at 0, 2, 5 and 10 minutes postintubation.

Results

The incidence of excitement was higher in group MA compared with groups CA (p = 0.005) and AM (p = 0.013). The mean induction dose of alfaxalone was lower in group AM compared with group CA (p = 0.003). Quality of induction and ease of intubation were similar among groups. Mean HR values decreased after premedication and increased after alfaxalone administration in all groups. Mean SAP values were similar between groups. The number of animals that required manual ventilation was higher in the MA group.

Conclusions and clinical relevance

Despite a lower occurrence of adverse events at induction in group AM compared with group MA and a reduction of alfaxalone dose requirement in group AM compared with group CA, the use of an alfaxalone–midazolam co-induction does not seem to produce any cardiovascular or respiratory benefits in healthy dogs.  相似文献   
30.
Abstract

Winter wheat was grown at five different experimental sites using various nutrient combinations of two nitrogen (N) and three calcium (Ca) doses. The three youngest leaves, including the flag leaf were sampled at anthesis together with the flag leaf post‐anthesis and the grain at final harvest. The leaves were weighed and their mineral nutrient contents analyzed and the grain was also weighed. Of the nine equations that were fitted the potential (log y versus log x) most consistently had the best correlation and, thus, best represents the relationships between leaf dry weights, while the inverse in both variables was best for estimating grain weight from leaf weight. The nutrient content of the leaves was related to leaf dry weight according to the following sequence of maximum R: ? (R = 0.703), potassium (K) (R = 0.580), Ca (R = 0.444), phosphorus (P) (R = 0.359), iron (Fe) (R = 0.291), and magnesium (Mg) (R = 0.290). The square‐root and the quadratic equations best reflected the maximum and minimum values for ? and K, respectively. Highly significant relationships between Ca and Mg, and leaf dry weight were less frequent. The leaf nutrients correlated with grain weight in the following order: Mg (R max = 0.521), ? (0.455), Ca (0.434), Fe (0.348), ? (0.346), ?n (0.339, and ? (0.323). Of these nutrients, only Ca affected grain weight according to a parabolic equation (quadratic or square‐root) while the rest were best fitted by logarithmic functions, both on X and Y or one variable separately and by a straight‐line in one instance.

The square‐root and the quadratic permit the calculation of the optimum concentration of nutrients, and thus, leaf nutritional diagnosis. The flag leaf at anthesis gives the most opportunities for this.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号