全文获取类型
收费全文 | 183篇 |
免费 | 12篇 |
专业分类
林业 | 9篇 |
农学 | 12篇 |
52篇 | |
综合类 | 7篇 |
农作物 | 6篇 |
水产渔业 | 11篇 |
畜牧兽医 | 75篇 |
园艺 | 8篇 |
植物保护 | 15篇 |
出版年
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 6篇 |
2019年 | 4篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 7篇 |
2012年 | 13篇 |
2011年 | 17篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 9篇 |
2007年 | 13篇 |
2006年 | 8篇 |
2005年 | 10篇 |
2004年 | 11篇 |
2003年 | 9篇 |
2002年 | 9篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1977年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有195条查询结果,搜索用时 15 毫秒
1.
Gina M Davis-Wurzler 《Veterinary Clinics of North America: Small Animal Practice》2006,36(3):607-40, vii
Motivation in writing this article stems from many things: a lack of time spent in the veterinary curriculum discussing vaccines, a growing concern(by the general public and the veterinary community) regarding adverse reactions associated with vaccines, and a desire to prevent a recurrence of preventable infectious diseases resulting from a fear-driven cessation of vaccine administration. The objectives of this article are to present a basic review of immunology as related to vaccines, to discuss general guidelines for pediatric vaccines in canine and feline patients,and to offer suggestions as to how we can most positively influence our patients' health from the first visit. 相似文献
2.
3.
Comparison of the results of abdominal ultrasonography and exploratory laparotomy in the dog and cat
Pastore GE Lamb CR Lipscomb V 《Journal of the American Animal Hospital Association》2007,43(5):264-269
Results of preoperative ultrasonography and exploratory laparotomy were reviewed retrospectively in a series of 100 small animals to assess the agreement between ultrasonographic and surgical findings and to identify abdominal lesions likely to be missed by ultrasonography. Good agreement occurred between ultrasound reports and surgical reports in 64% of the animals, which supported the use of ultrasonography in potential surgical candidates. A major discrepancy was observed between the ultrasound report and surgical findings in 25% of the animals. Of the various types of pathology encountered in the study, gastrointestinal ulceration or perforation was the most likely lesion to be missed by ultrasonography. 相似文献
4.
Cruciferous oilseeds are important sources of oil, proteins, and glucosinolates (GLs), potentially available when biorefinery processes are used. The proposed extraction technology is based on the use of reverse micelles (RMs) made with cetyltrimethylammonium bromide (CTAB) dispersed in organic solvent. The physicochemical properties of this extraction system and the good water solubility of many high value compounds, such as GLs and some proteins, permit the simultaneous extraction of oil, and these products from cruciferous oilseed meals. This procedure is based on three main steps: (i) seed conditioning; (ii) solid-liquid extraction by RM solution; and (iii) back-transfer of the RM solution for recovery of the extracted compounds. The method makes it possible to simultaneously extract almost the same amount of oil as with pure organic solvents used in the current extraction plants and more than 90% of soluble proteins and GLs. It is a promising biorefinery technology alternative to traditional oil extraction processes. 相似文献
5.
Iglesias MT De Lorenzo C Del Carmen Polo M Martín-Alvarez PJ Pueyo E 《Journal of agricultural and food chemistry》2004,52(1):84-89
With the aim of finding methods that could constitute a solid alternative to melissopalynological and physicochemical analyses to determine the botanical origin (floral or honeydew) of honeys, the free amino acid content of 46 honey samples has been determined. The honeys were collected in a small geographic area of approximately 2000 km(2) in central Spain. Twenty-seven honey samples were classified as floral and 19 as honeydew according to their palynological and physicochemical analyses. The resulting data have been subjected to different multivariant analysis techniques. One hundred percent of honey samples have been correctly classified into either the floral or the honeydew groups, according to their content in glutamic acid and tryptophan. It is concluded that free amino acids are good indicators of the botanical origin of honeys, saving time compared with more tedious analyses. 相似文献
6.
Michels GM Knapp DW DeNicola DB Glickman N Bonney P 《Journal of the American Animal Hospital Association》2002,38(5):458-466
The purpose of this study was to determine if the presence of histopathologically tumor-free versus nontumor-free margins was prognostic for relapse or tumor-related death in dogs following surgical excision of single or multiple cutaneous mast cell tumors confined to the skin without evidence of metastasis to lymph nodes or other noncutaneous sites. Differences in tumor-related death or frequency of relapse between the two groups were not significant. Failure to achieve histopathological tumor-free margins frequently did not lead to local relapse. All tumor-related deaths occurred following local relapse. The lack of statistical support for an association between prognosis and histopathological tumor-free versus nontumor-free margins may be a result of small sample size. 相似文献
7.
Photosynthetic light acclimation in red pine (Pinus resinosa Ait.) seedlings was examined in a greenhouse study to better understand the physiological response of this species to increased light intensity following release from competition. Seedlings grown in a high (HL), medium (ML) or low (LL) light environment for 12 weeks were transferred to high light. Gas exchange and chlorophyll fluorescence of ML and LL seedlings were measured prior to and following transfer and compared with the HL control treatment. Photosynthetic characteristics were related to initial light treatment and time after transfer. Acclimation of gas exchange features to high light in shade formed ML and LL foliage was relatively rapid, with similar values among light treatments within 57 days of transfer. Acclimation of net photosynthetic rate was similar in ML and LL seedlings, and was associated primarily with increased mesophyll conductance to CO2. The ratio of variable to maximal chlorophyll fluorescence (Fv/Fm) decreased initially after transfer, especially in LL seedlings, but recovered to normal values after 57 days. Red pine seedlings appear to be well adapted for photosynthetic acclimation to high light intensity, consistent with that reported for other early successional tree species. 相似文献
8.
Plaza C Senesi N García-Gil JC Brunetti G D'Orazio V Polo A 《Journal of agricultural and food chemistry》2002,50(17):4867-4874
The effect of three annually consecutive additions of pig slurry at two rates (90 and 150 m3 x ha(-1) x year(-1) on soils and soil humic acids (HAs) was investigated in a field experiment under semiarid conditions. Soils and pig slurries were analyzed by standard methods. The HAs were isolated from soils and pig slurry by a conventional procedure based on alkaline extraction, acidic precipitation to pH 1, purification by repeated alkaline dissolutions and acidic precipitations, water washing, dialysis, and final freeze-drying. The HAs obtained were analyzed for elemental (C, H, N, S, and O) and acidic functional group (carboxylic and phenolic) composition, and by UV-vis, FT-IR, fluorescence, and ESR spectroscopies. With respect to the control soil, the pig slurry amended soils had greater pH and electrical conductivity, slightly larger total N content, and smaller values of C/N ratio. A decrease of total organic C was observed only in soils amended for 2 and 3 years at the higher slurry rate. With respect to control soil HA, pig slurry HA was characterized by larger contents of S- and N-containing groups, smaller acidic functional group and organic free radical contents, a prevalent aliphatic character, extended molecular heterogeneity, and smaller aromatic polycondensation and humification degrees. Amendment with pig slurry HA determines a number of modifications in soil HAs, including increase of C, S, and COOH contents, C/N ratios, and aliphaticity and decrease of extraction yields and N, O, phenolic OH, and organic free radical contents. These effects are generally more evident after the first year of slurry application and tend to disappear with increasing number of treatments. Most probably, over the years the slightly humified slurry HA is mineralized through extended microbial oxidation, whereas only the most recalcitrant components, such as S-containing, phenolic, and aliphatic structures, are partially accumulated by incorporation into soil HA. 相似文献
9.
Tissue culture micropropagation of Douglas-fir 总被引:1,自引:0,他引:1
A procedure was developed for plantlet production from embryos of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco]. The Medium for Conifer Morphogenesis, used at full strength, and supplemented with 10 M benzyladenine for 17 days produced an average of 6.8 shoots on more than 90% of the embryos. The percentage of shoot-forming embryos as well as the average number of shoots per embryo varied significantly among eight seedlots. For secondary multiplication, 89% of the adventitious shoots produced axillary buds on MCM with 5 M benzyladenine. However, 0.5 M BA was more suitable for the elongation of axillaries. Rooting ranged from 0–87% depending upon the treatment. The highest percentage was obtained with a 7-week incubation in peat:perlite containing 1/5-strength medium, 1% sucrose and 2.7 M naphthaleneacetic acid, followed by 5 weeks on peat:perlite with 1/5-strength major and minor salts, full iron and organics, 1% sucrose and 0.1% charcoal. 相似文献
10.
Simon R. M. Jones Benjamin Goh Gina Prosperi-Porta 《Aquaculture (Amsterdam, Netherlands)》2003,220(1-4):157-164
The effect of fixative and duration of fixation on the sensitivity of a non-radioactive in situ hybridisation (ISH) protocol to detect Kudoa thyrsites small subunit ribosomal deoxyribonucleic acid (DNA) was investigated. Strong ISH reactions were detected in 5-μm sections of paraffin-embedded Atlantic salmon muscle after fixation for 1 day in Davidson's solution (DS). Reactions were weak following 3 or 5 days fixation and absent after 17 or 28 days fixation. Strong ISH reactions were observed after 1, 3 or 5 days fixation in neutral buffered formalin (NBF). The reactions were weak after 17 days and weak to nonexistent after 28 days of fixation. Reactions were consistently strong after fixation in 95% ethanol for up to 28 days. Some mature spores reacted weakly or not at all by ISH. Parasite DNA was weakly amplified by polymerase chain reaction (PCR) from paraffin-embedded muscle after 1 day of fixation in DS but not after fixation for 3, 5, 17 or 28 days. Amplified DNA was detected after fixation in NBF for 1, 3 and 5 days, but not after 17 or 28 days. In contrast, PCR consistently amplified DNA from paraffin-embedded, ethanol-fixed muscle. Caution should be used in the choice of fixative and duration of fixation when preserving Atlantic salmon tissues for molecular diagnosis of K. thyrsites. 相似文献