全文获取类型
收费全文 | 913篇 |
免费 | 46篇 |
国内免费 | 3篇 |
专业分类
林业 | 49篇 |
农学 | 27篇 |
基础科学 | 4篇 |
177篇 | |
综合类 | 67篇 |
农作物 | 44篇 |
水产渔业 | 58篇 |
畜牧兽医 | 470篇 |
园艺 | 25篇 |
植物保护 | 41篇 |
出版年
2023年 | 14篇 |
2022年 | 16篇 |
2021年 | 40篇 |
2020年 | 38篇 |
2019年 | 34篇 |
2018年 | 40篇 |
2017年 | 31篇 |
2016年 | 16篇 |
2015年 | 29篇 |
2014年 | 39篇 |
2013年 | 59篇 |
2012年 | 63篇 |
2011年 | 76篇 |
2010年 | 42篇 |
2009年 | 51篇 |
2008年 | 51篇 |
2007年 | 64篇 |
2006年 | 55篇 |
2005年 | 35篇 |
2004年 | 34篇 |
2003年 | 25篇 |
2002年 | 29篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 13篇 |
1998年 | 2篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1955年 | 2篇 |
1954年 | 1篇 |
排序方式: 共有962条查询结果,搜索用时 15 毫秒
41.
Intracavitary Cisplatin Chemotherapy Experience with Six Dogs 总被引:1,自引:0,他引:1
Antony S. Moore MVSc Claudia Kirk DVM Aglaia Cardona DVM 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1991,5(4):227-231
Six dogs with a median age of 7 years (range = 5-14 years) were presented for signs referable to thoracic or abdominal effusion associated with neoplasia of the body cavities. Intracavitary cisplatin was administered at 50 mg/m2 every 4 weeks for a median of 2.5 treatments (mean = 3, range = 1-6). Three dogs with pleural mesothelioma had complete resolution of effusion for 289, 129, and greater than 306 days without evidence of tumor growth. Resolution of effusion occurred after one treatment in two dogs and after two treatments in one dog. In three dogs with carcinomatosis of unknown origin, complete responses was seen in two dogs after one treatment for 255 and greater than 807 days, respectively. Intracavitary chemotherapy with cisplatin was associated with palliation and control of malignant pleural and/or abdominal effusion in five of six dogs. Toxicity was minimal, and this method of therapy should be further explored in dogs with similar malignancies. 相似文献
42.
Three-day-old specific pathogen-free chickens (n = 24) located in isolators were inoculated orally with Helicobacter pullorum. One group (n = 12) was infected with a H. pullorum field isolate from human origin, another one (n = 12) with the American Type Culture Collection H. pullorum reference isolate 51801 originating from chickens. Both isolates were positive for cytolethal distending toxin, investigated using a polymerase chain reaction (PCR). A third group (n = 4) was kept as a negative control. Starting on day 7 of life, birds from each group were euthanatized at different time points up to 35 days. Various organ samples were taken aseptically and processed by culture and a H. pullorum-specific PCR. In the group infected with the human isolate the nucleic acid of H. pullorum was detected in the caecal tonsils and caeca of 12 and 11 birds, respectively. Live bacteria were cultivated from the caecal tonsils and caeca of five birds 24 and 31 days postinfection. Live bacteria were also isolated from the heart of one bird, whereas PCR had to be used to detect the nucleic acid of H. pullorum in the gallbladder of four birds. No live bacteria were reisolated at any time from birds infected with the avian isolate, but bacterial nucleic acid was detected in the caeca of five birds and in the gallbladder of one. In both groups neither live H. pullorum nor its nucleic acid were detected in the liver, spleen, and duodenum. Compared to the avian H. pullorum isolate the human isolate proved to be more invasive. No obvious clinical symptoms or disease was seen in the chickens during the entire experiment. The reisolation of live bacteria at the end of the experiments indicates that H. pullorum could enter the food chain even after early infection in birds. Furthermore, PCR was demonstrated to be helpful in tracing these fastidious bacteria. 相似文献
43.
New Forests - Pinus pinea is an interesting species for its valued pine nuts. Despite the high demand for this nut, the species is mostly harvested from natural forests, because the time elapsed... 相似文献
44.
Daniela Alberghina Stefania Casella Claudia Giannetto Simona Marafioti Giuseppe Piccione 《Canadian journal of veterinary research》2013,77(4):293-296
Serum protein electrophoresis (SPE) is a technique that could be considered one of the most useful diagnostic aids available to the clinician. The effect of storage time and temperature on the total proteins and electrophoretic fractions (albumin, α1-, α2-, β1-, β2-, and γ-globulins) was assessed in 24 healthy horses. All samples, collected by jugular vein puncture, were centrifuged and divided into 4 aliquots. The 1st aliquot was analyzed within 3 h from collection (time 0), the 2nd was refrigerated at +4°C for 24 h, the 3rd was refrigerated at +4°C for 48 h, and the last was frozen at −20°C for 48 h. One-way repeated-measures analysis of variance (ANOVA) showed a significant effect (P < 0.05) of the different storage conditions on the concentrations of all the parameters studied and significant variations in the percentages of albumin, α1-globulins, α2-globulins, and γ-globulins. Compared with time 0 the total protein concentration increased significantly after 48 h at −20°C, the albumin percentage decreased after 48 h at −20°C, the α1-globulin percentage increased after 24 h at +4°C, the α2-globulin percentage increased after 48 h at +4°C and at −20°C, and the γ-globulin percentage increased after 48 h at −20°C. The results should help veterinary practitioners handle and store equine serum samples appropriately. Further investigations at different storage times and temperatures could be useful. 相似文献
45.
46.
Cold tolerance during juvenile development in sorghum: a comparative analysis by genomewide association and linkage mapping 下载免费PDF全文
Karin Fiedler Wubishet A. Bekele Claudia Matschegewski Rod Snowdon Silke Wieckhorst Arndt Zacharias Ralf Uptmoor 《Plant Breeding》2016,135(5):598-606
Improved cold tolerance during the juvenile phase is a major breeding goal to develop new sorghum cultivars suitable as an alternative energy crop in temperate regions. The objectives of this study were to identify marker‐trait associations for cold tolerance in a sorghum diversity panel fingerprinted with 2620 single nucleotide polymorphism (SNP) markers and to detect quantitative trait loci (QTL) in two F2:3 populations. Traits of interest were dry matter growth rate (DMGR), leaf appearance rate (LAR), chlorophyll content (SPAD) and chlorophyll fluorescence (Fv′/Fm′ and ФPSII) in relation to temperature. The association panel comprised 194 genotypes, while the F2:3 populations consisted of 80 and 92 genotypes. All populations were tested under controlled conditions in a minimum of four temperature regimes ranging from 9.4°C to 20.8°C. QTL were identified for means across environments and regression parameters describing temperature effects. Several marker‐trait associations for mean (m) DMGR, base temperature (Tb) of SPAD and ФPSII and temperature effect on LAR were validated by QTL detected in population 1 or 2. Promising QTL regions were found on chromosomes SBI‐01, SBI‐02, SBI‐03, SBI‐04, SBI‐06 and SBI‐09, among them genomic regions where candidate genes involved in the C‐repeat binding pathway or encoding cold‐shock proteins are located. 相似文献
47.
The effect of foliar application of cytokinin (benzyl-adenine, 150 mg L−1) and gibberellin (GA4 + GA7, 150 mg L−1) on growth and flower development of 5-year-old plants of two jojoba clones was studied. The plant growth regulators were applied on October 5, 1999 (spring) and the plants were evaluated 120, 240 and 360 days after application. Shoot length, total number of nodes and number of nodes with branching were statistically different between clones but not between the growth regulator treatments.The total number of flowers on both clones was significantly increased by treatment with benzyl-adenine (BA) and significantly reduced by treatment with gibberellin. The seed yields, evaluated 180 days after application, were not statistically different from the control due to an increase in flower abortion. One clone treated with gibberellin showed a significant decrease in number and weight of seeds, the other did not.Histology of axillary buds revealed that BA application on one clone (4.11.32) enlarged the flower meristem, differentiating multiple flower production. 相似文献
48.
Pinguinain is the name given to a proteolytic enzyme preparation obtained from Bromelia pinguin fruits that has been scarcely studied. The present paper deals on the reexamination of the proteases present in fruits of B. pinguin grown in Cienfuegos, Cuba. The preparation (partially purified pinguinain, PPP) showed the main characteristics of the cysteine proteases, i.e., optimum pH within alkaline range (pH 7.2-8.8), inhibition of proteolytic activity by thiol blocking reagents, which is usually reverted by addition of cysteine, a remarkable thermal stability and notable stability at high ionic strength values. Isoelectric focusing and zymogram of PPP revealed the presence of several proteolytic components between pI 4.6 and 8.1. Preliminary peptidase purification by cationic exchange chromatography showed the presence of two main proteolytic fractions with molecular masses of approximately 20.0 kDa, according to SDS-PAGE. 相似文献
49.
Dr. M. Ehlers 《Journal of pest science》1955,28(4):57-60
Zusammenfassung 1. In Versuchen, die im Jahre 1954 bei Berlin unter günstigen Befallsbedingungen durchgeführt wurden, zeigte ein zur Saatgutbekrustung mit 50 g je kg Samen angewendetes 90%iges Dieldrin-Präparat sichere und vorhaltende Wirkung gegen die Zwiebelfliege bei offensichtlich günstiger Nebenwirkung auf den Wuchs der Zwiebelpflanzen. Die Erträge an gesunden Zwiebelknollen lagen im Durchschnitt 7 mal höher als auf den unbehandelten Kontrollflächen. Keimschäden traten nicht ein und blieben auch bei Keimschäden traten nicht ein und blieben auch bei Keimversuchen mit länger gelagertem Saatgut relativ gering. Volumen und Drillfähigkeit des Saatgutes sowie die Qualität der geernteten Zwiebelknollen wurden nicht nachteilig verändert.2. DDT-Spritzpulver bestätigten ihre gute Wirkung bei Anwendung als Saatgutbekrustungsmittel (DDT 50 mit 400 g je kg, DDT 80 mit 200 g je kg), ohne jedoch die sichere und lang anhaltende Wirkung des Dieldrin-Präparates zu erreichen. Die Erträge lagen im Durchschnitt über 3 mal höher als bei unbehandelt. Mit DDT behandeltes Saatgut zeigt stärkere, mit der Dauer der Lagerung zunehmende Keimschädigung, so daß baldige Aussaat nach der Behandlung zu empfehlen ist.3. Es bestätigte sich, daß Lindan- und Lindan-DDT-Mittel zur Saatgutbehandlung wegen zu starker Keim-und Auflaufschäden ungeeignet sind. 相似文献
50.