全文获取类型
收费全文 | 150篇 |
免费 | 0篇 |
专业分类
林业 | 12篇 |
农学 | 1篇 |
24篇 | |
综合类 | 19篇 |
农作物 | 2篇 |
水产渔业 | 3篇 |
畜牧兽医 | 84篇 |
植物保护 | 5篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2014年 | 1篇 |
2013年 | 5篇 |
2012年 | 3篇 |
2011年 | 4篇 |
2010年 | 3篇 |
2009年 | 1篇 |
2008年 | 4篇 |
2007年 | 11篇 |
2006年 | 5篇 |
2005年 | 7篇 |
2004年 | 9篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1965年 | 1篇 |
1937年 | 1篇 |
排序方式: 共有150条查询结果,搜索用时 46 毫秒
21.
22.
23.
24.
25.
Aharonian F Akhperjanian AG Bazer-Bachi AR Beilicke M Benbow W Berge D Bernlöhr K Boisson C Bolz O Borrel V Braun I Brown AM Bühler R Büsching I Carrigan S Chadwick PM Chounet LM Coignet G Cornils R Costamante L Degrange B Dickinson HJ Djannati-Ataï A Drury LO Dubus G Egberts K Emmanoulopoulos D Espigat P Feinstein F Ferrero E Fiasson A Fontaine G Funk S Funk S Füssling M Gallant YA Giebels B Glicenstein JF Goret P Hadjichristidis C Hauser D Hauser M Heinzelmann G Henri G Hermann G Hinton JA 《Science (New York, N.Y.)》2006,314(5804):1424-1427
The detection of fast variations of the tera-electron volt (TeV) (10(12) eV) gamma-ray flux, on time scales of days, from the nearby radio galaxy M87 is reported. These variations are about 10 times as fast as those observed in any other wave band and imply a very compact emission region with a dimension similar to the Schwarzschild radius of the central black hole. We thus can exclude several other sites and processes of the gamma-ray production. The observations confirm that TeV gamma rays are emitted by extragalactic sources other than blazars, where jets are not relativistically beamed toward the observer. 相似文献
26.
Ohlerth S Dennler M Rüefli E Hauser B Poirier V Siebeck N Roos M Kaser-Hotz B 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2008,22(5):1095-1102
Background: Although B-mode ultrasound is very sensitive for the detection of splenic lesions, its specificity is low. Contrast harmonic imaging is used successfully to differentiate benign from malignant liver lesions in humans and dogs.
Hypothesis: Contrast harmonic imaging could be useful to differentiate benign and malignant splenic lesions in dogs.
Animals: Sixty dogs (clinical patients) with splenic abnormalities detected during abdominal ultrasonography.
Methods: A prospective study was performed with a Philips ATL 5000 unit for contrast pulse inversion harmonic imaging (mechanical index: 0.08, contrast medium: SonoVue). Perfusion was assessed subjectively and quantitatively.
Results: Cytology or histology identified 27 benign (hyperplasia, extramedullary hematopoiesis, hematoma) and 29 malignant (hemangiosarcoma, malignant lymphoma, malignant histiocytosis, mesenchymal tumors without classification, mast cell tumors, and others) lesions and 4 normal spleens. Except for 1 benign nodule, extensive to moderate hypoechogenicity was only seen in malignant lesions during wash-in, at peak enhancement, and during wash-out ( P = .0001, odds ratios: 37.9 [95% CI 4.5–316.5], 66.4 [95% CI 8.0–551.1], and 36.9 [95% CI 4.4–308.4]). Although all but 1 benign lesion enhanced well and were mildly hypo-, iso-, or hyperechoic in comparison with the normal spleen during all blood pool phases, marked enhancement occurred both in benign as well as in malignant splenic lesions. Quantitative perfusion values did not differ significantly between benign and malignant lesions.
Conclusions and Clinical Importance: Moderate to extensive hypoechogenicity clearly identifies canine splenic malignant lesions. In nodules with marked enhancement, contrast harmonic ultrasound is of limited value and histology is needed. 相似文献
Hypothesis: Contrast harmonic imaging could be useful to differentiate benign and malignant splenic lesions in dogs.
Animals: Sixty dogs (clinical patients) with splenic abnormalities detected during abdominal ultrasonography.
Methods: A prospective study was performed with a Philips ATL 5000 unit for contrast pulse inversion harmonic imaging (mechanical index: 0.08, contrast medium: SonoVue). Perfusion was assessed subjectively and quantitatively.
Results: Cytology or histology identified 27 benign (hyperplasia, extramedullary hematopoiesis, hematoma) and 29 malignant (hemangiosarcoma, malignant lymphoma, malignant histiocytosis, mesenchymal tumors without classification, mast cell tumors, and others) lesions and 4 normal spleens. Except for 1 benign nodule, extensive to moderate hypoechogenicity was only seen in malignant lesions during wash-in, at peak enhancement, and during wash-out ( P = .0001, odds ratios: 37.9 [95% CI 4.5–316.5], 66.4 [95% CI 8.0–551.1], and 36.9 [95% CI 4.4–308.4]). Although all but 1 benign lesion enhanced well and were mildly hypo-, iso-, or hyperechoic in comparison with the normal spleen during all blood pool phases, marked enhancement occurred both in benign as well as in malignant splenic lesions. Quantitative perfusion values did not differ significantly between benign and malignant lesions.
Conclusions and Clinical Importance: Moderate to extensive hypoechogenicity clearly identifies canine splenic malignant lesions. In nodules with marked enhancement, contrast harmonic ultrasound is of limited value and histology is needed. 相似文献
27.
28.
Marília Hauser Carolina R.C. Doria Roberto V. Santos Aurea García‐Vasquez Marc Pouilly Christophe Pcheyran Emmanuel Ponzevera Gislene Torrente‐Vilara Sylvain Brail Jacques Panfili Audrey Darnaude Jean‐Franois Renno Carmen García‐Dvila Jesus Nuez Franck Ferraton Gladys Vargas Fabrice Duponchelle 《水产资源保护:海洋与淡水生态系统》2019,29(3):397-408
29.
B. D. Jensen M. R. Finckh L. Munk T. P. Hauser 《European journal of plant pathology / European Foundation for Plant Pathology》2008,122(3):359-367
Sclerotinia soft rot, caused by Sclerotinia sclerotiorum, is a severe disease of cultivated carrots (Daucus carota ssp. sativus) in storage. It is not known whether Sclerotinia soft rot also affects wild carrots (D. carota ssp. carota), which hybridise and exchange genes, among them resistance genes, with the cultivated carrot. We investigated the susceptibility
of wild carrots to S. sclerotiorum isolates from cultivated carrot under controlled and outdoor conditions. Inoculated roots from both wild and cultivated plants
produced sclerotia and soft rot in a growth chamber test. Two isolates differed significantly in the ability to produce lesions
and sclerotia on roots of both wild carrots and cv. Bolero. Flowering stems of wild carrots produced dry, pale lesions after
inoculation with the pathogen, and above-ground plant weight was significantly reduced 4 weeks after inoculation in a greenhouse
test. Wild and cultivar rosette plants died earlier and fewer plants survived when inoculated with the pathogen under outdoor
test conditions. Cultivar plants died earlier than wild plants, but survived as frequently. Plants inoculated in the crown
died earlier and at a lower frequency than plants inoculated on leaves. Wild carrots may thus serve as a host of S. sclerotiorum and thus eventually benefit from any uptake of resistance genes, among them transgenes, via introgression from cultivated
carrots. 相似文献
30.