全文获取类型
收费全文 | 87篇 |
免费 | 8篇 |
专业分类
林业 | 8篇 |
农学 | 2篇 |
15篇 | |
综合类 | 13篇 |
农作物 | 3篇 |
水产渔业 | 5篇 |
畜牧兽医 | 35篇 |
园艺 | 8篇 |
植物保护 | 6篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2014年 | 1篇 |
2013年 | 6篇 |
2012年 | 6篇 |
2011年 | 11篇 |
2010年 | 5篇 |
2009年 | 2篇 |
2008年 | 5篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 1篇 |
1998年 | 1篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1988年 | 1篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有95条查询结果,搜索用时 218 毫秒
21.
COMPARISON OF THORACIC ULTRASONOGRAPHY AND RADIOGRAPHY FOR THE DETECTION OF INDUCED SMALL VOLUME PNEUMOTHORAX IN THE HORSE
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)
Jessica Partlow Florent David Luanne Michelle Hunt Fabien Relave Laurent Blond Manuel Pinilla Jean‐Pierre Lavoie 《Veterinary radiology & ultrasound》2017,58(3):354-360
Small volume pneumothorax can be challenging to diagnose in horses. The current standard method for diagnosis is standing thoracic radiography. We hypothesized that thoracic ultrasonography would be more sensitive. Objectives of this prospective, experimental study were to describe a thoracic ultrasound method for detection of small volume pneumothorax in horses and to compare results of radiography and ultrasound in a sample of horses with induced small volume pneumothorax. Six mature healthy horses were recruited for this study. For each horse, five 50 ml air boluses were sequentially introduced via a teat cannula into the pleural space. Lateral thoracic radiographs and standardized ultrasound (2D and M‐mode) examinations of both hemithoraces were performed following administration of each 50 ml air bolus. Radiographs and ultrasound images/videos were analyzed for detection of pneumothorax by four independent investigators who were unaware of treatment status. Sensitivity, specificity, positive predictive values, negative predictive values, and agreement among investigators (Kappa test, κ) were calculated for radiography, 2D and M‐mode ultrasound. Comparisons were made using a chi‐squared exact test with significance set at P < 0.05. Two‐dimensional (84%) and M‐mode (80%) ultrasound were more sensitive than radiography (48%) for pneumothorax detection (P = 0.02 and P = 0.04, respectively). Specificity and positive predictive values were similar for all three imaging modalities (P = 1). Agreement between investigators for pneumothorax detection was excellent for 2D ultrasound (κ = 1), very good for M‐mode ultrasound (κ = 0.87), and good for radiography (κ = 0.79). Findings from this experimental study supported the use of thoracic ultrasonography as a diagnostic method for detecting pneumothorax in horses. 相似文献
22.
Florent M. Kinkingninhoun-Mêdagbé Aliou Diagne Franklin Simtowe Afiavi R. Agboh-Noameshie Patrice Y. Adégbola 《Agriculture and Human Values》2010,27(1):57-69
This paper examines the occurrence and impact of gender discrimination in access to production resources on the income, productivity,
and technical efficiency of farmers. Through an empirical investigation of farmers from Koussin-Lélé, a semi-collective irrigated
rice scheme in central Benin, we find that female rice farmers are particularly discriminated against with regard to scheme
membership and access to land and equipment, resulting in significant negative impacts on their productivity and income. Although
women have lower productivity, they are as technically efficient as men. The findings suggest that there is considerable scope
for improving the productivity of women through increasing their access to production resources. 相似文献
23.
Ladislas Séverine El-Mufleh Amelène Gérente Claire Chazarenc Florent Andrès Yves Béchet Béatrice 《Water, air, and soil pollution》2012,223(2):877-888
The concentrations of heavy metals in water, sediments, soil, roots, and shoots of five aquatic macrophytes species (Oenanthe sp., Juncus sp., Typha sp., Callitriche sp.1, and Callitriche sp.2) collected from a detention pond receiving stormwater runoff coming from a highway were measured to ascertain whether
plants organs are characterized by differential accumulations and to evaluate the potential of the plant species as bioindicators
of heavy metal pollution in urban stormwater runoff. Heavy metals considered for water and sediment analysis were Cd, Cr,
Cu, Ni, Pb, Zn, and As. Heavy metals considered for plant and soil analysis were Cd, Ni, and Zn. The metal concentrations
in water, sediments, plants, and corresponding soil showed that the studied site is contaminated by heavy metals, probably
due to the road traffic. Results also showed that plant roots had higher metal content than aboveground tissues. The floating
plants displayed higher metal accumulation than the three other rooted plants. Heavy metal concentrations measured in the
organs of the rooted plants increased when metal concentrations measured in the soil increased. The highest metal bioconcentration
factors (BCF) were obtained for cadmium and nickel accumulation by Typha sp. (BCF = 1.3 and 0.8, respectively) and zinc accumulation by Juncus sp. (BCF = 4.8). Our results underline the potential use of such plant species for heavy metal biomonitoring in water, sediments,
and soil. 相似文献
24.
Ammonia in cigarette mainstream smoke was quantified by LC-MS/MS after derivatization. Two different reagents, fluorescamine and dansyl chloride, were investigated, but only the latter gave stable derivatives; therefore, it was considered the most appropriate choice. Smoke samples were collected on a Cambridge filter pad followed by an impinger containing a solution of hydrochloric acid. Ammonia was then derivatized with a 18.5 mM solution of dansyl chloride in acetonitrile at 70 °C for 30 min in a vial with the internal standard, (15)ND(4)Cl. The resulting derivative was analyzed by LC-MS/MS detection with an atmospheric pressure chemical ionization (APCI) interface in the positive ionization mode using multiple-reaction monitoring (MRM). Good linearity was obtained in the concentration range of 0.02-1.65 μg/mL (r(2) ≥ 0.999), and the limit of detection (LOD) was established at 0.006 μg/mL. This method has the advantage of being sensitive, efficient, and reliable and is not hindered by interferences from the sample matrix. It should thus be considered a reference method of choice for the determination of ammonia in smoke. 相似文献
25.
Araújo MM Marchioni E Bergaentzle M Zhao M Kuntz F Hahn E Villavicencio AL 《Journal of agricultural and food chemistry》2011,59(4):1244-1248
This study attempts to examine the folic acid stability after irradiation treatment, under different physical states, pH values, and atmosphere conditions. Aqueous folic acid samples, folic acid in powder, and wheat flour fortified with folic acid were irradiated by an electron beam (E-beam) between 0 (control) and 10.0 kGy. It was realized that the physical state of folic acid plays an important role on its stability toward E-beam processing, being largely unstable in solution, no matter the pH and atmosphere conditions assayed. Otherwise, folic acid in powder showed huge irradiation stability, even when mixed in a dry food matrix, such as fortified wheat flour samples. 相似文献
26.
27.
Kreysing M Pusch R Haverkate D Landsberger M Engelmann J Ruiter J Mora-Ferrer C Ulbricht E Grosche J Franze K Streif S Schumacher S Makarov F Kacza J Guck J Wolburg H Bowmaker JK von der Emde G Schuster S Wagner HJ Reichenbach A Francke M 《Science (New York, N.Y.)》2012,336(6089):1700-1703
Despite their diversity, vertebrate retinae are specialized to maximize either photon catch or visual acuity. Here, we describe a functional type that is optimized for neither purpose. In the retina of the elephantnose fish (Gnathonemus petersii), cone photoreceptors are grouped together within reflecting, photonic crystal-lined cups acting as macroreceptors, but rod photoreceptors are positioned behind these reflectors. This unusual arrangement matches rod and cone sensitivity for detecting color-mixed stimuli, whereas the photoreceptor grouping renders the fish insensitive to spatial noise; together, this enables more reliable flight reactions in the fish's dim and turbid habitat as compared with fish lacking this retinal specialization. 相似文献
28.
29.
30.
在中国,杭州,浙江大学华家池校区农场,对来自中国和西非贝宁不同生态型的70份芝麻核心样品的22个形态学性状进行评价.应用多元和主成分分析揭示其遗传多样性并将其分为8个聚类组.结果表明,主成分可解释45.2%的变异.尽管地理起源与遗传多样性没有密切相关,但利用形态标记进行聚类分析,可将非洲贝宁2个品种分为聚类Ⅲ,杭州6个品种分为聚类Ⅷ,中国东北和西北品种分为聚类Ⅴ. 相似文献