全文获取类型
收费全文 | 288篇 |
免费 | 21篇 |
国内免费 | 1篇 |
专业分类
林业 | 29篇 |
农学 | 11篇 |
58篇 | |
综合类 | 30篇 |
农作物 | 30篇 |
水产渔业 | 20篇 |
畜牧兽医 | 106篇 |
园艺 | 9篇 |
植物保护 | 17篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 9篇 |
2019年 | 11篇 |
2018年 | 7篇 |
2017年 | 5篇 |
2016年 | 5篇 |
2015年 | 8篇 |
2014年 | 14篇 |
2013年 | 14篇 |
2012年 | 25篇 |
2011年 | 16篇 |
2010年 | 19篇 |
2009年 | 9篇 |
2008年 | 20篇 |
2007年 | 24篇 |
2006年 | 13篇 |
2005年 | 12篇 |
2004年 | 20篇 |
2003年 | 13篇 |
2002年 | 12篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1978年 | 2篇 |
1961年 | 1篇 |
排序方式: 共有310条查询结果,搜索用时 31 毫秒
121.
122.
Pablo Gonzalez-de-Santos Angela Ribeiro Cesar Fernandez-Quintanilla Francisca Lopez-Granados Michael Brandstoetter Slobodanka Tomic Stefania Pedrazzi Andrea Peruzzi Gonzalo Pajares George Kaplanis Manuel Perez-Ruiz Constantino Valero Jaime del Cerro Marco Vieri Gilles Rabatel Benoit Debilde 《Precision Agriculture》2017,18(4):574-614
Feeding the growing global population requires an annual increase in food production. This requirement suggests an increase in the use of pesticides, which represents an unsustainable chemical load for the environment. To reduce pesticide input and preserve the environment while maintaining the necessary level of food production, the efficiency of relevant processes must be drastically improved. Within this context, this research strived to design, develop, test and assess a new generation of automatic and robotic systems for effective weed and pest control aimed at diminishing the use of agricultural chemical inputs, increasing crop quality and improving the health and safety of production operators. To achieve this overall objective, a fleet of heterogeneous ground and aerial robots was developed and equipped with innovative sensors, enhanced end-effectors and improved decision control algorithms to cover a large variety of agricultural situations. This article describes the scientific and technical objectives, challenges and outcomes achieved in three common crops. 相似文献
123.
Bellavance A Bonneville-Hébert A Desrochers A Fecteau G 《The Canadian veterinary journal. La revue veterinaire canadienne》2010,51(7):767-769
A 2-day-old Holstein calf was admitted to the Veterinary Teaching Hospital (VTH) in St-Hyacinthe for respiratory distress. Thoracic auscultations revealed asymmetric lung sounds. A diaphragmatic hernia was diagnosed on thoracic radiographs. Herniorrhaphy was performed; postoperative recovery was uneventful. This case indicates that diaphragmatic hernia in calves can be surgically treated successfully. 相似文献
124.
Buczinski S Francoz D Fecteau G DiFruscia R 《The Canadian veterinary journal. La revue veterinaire canadienne》2010,51(10):1123-1129
This retrospective study identified clinical signs, underlying cardiac conditions, blood findings, echocardiographic findings, and prognosis for 59 cattle with clinical signs of congestive heart failure. Signalment; history; clinical signs; clinicopathologic, echocardiographic, and radiographic findings; and treatment were determined by reviewing medical records. Follow-up information was obtained by telephone conversation with owners. Most patients were tachycardic (n = 50), and tachypneic (n = 55). Pericarditis of traumatic origin (n = 21), by extension from pleuritis (n = 3), or of idiopathic origin (n = 1) was diagnosed in 25 cases. Other diagnoses were congenital heart defect (n = 13), cardiomyopathy (n = 9), bacterial endocarditis (n = 7), and neoplasm (n = 5). Twelve cases (20%) were discharged. Long-term survival was good in 2 out of 3 cases treated by pericardiostomy. The prognosis is poor in cases of heart failure in cattle and deaths within 1 mo (n = 3) or between 1 to 3 mo after discharge (n = 3) were common in cases for which follow-up was available (n = 8). 相似文献
125.
Buczinski S Francoz D Fecteau G Difruscia R 《The Canadian veterinary journal. La revue veterinaire canadienne》2010,51(11):1239-1246
In this retrospective study, features of 47 cattle suffering from heart disease (HD) without clinical signs of heart failure (HF) were reviewed. The most common reasons for referral were respiratory problems (n =14), anorexia (n = 13), fever (n = 10), and lameness (n = 9). Thirty-nine animals were tachypneic. In 31 cases, cardiac auscultation revealed abnormalities. The final diagnoses were bacterial endocarditis (BE; n = 19), congenital heart disease (CHD; n = 18), pericarditis (n = 8), cardiomyopathy (n = 1), and lymphoma (n = 1). Echocardiography was performed in 39 cases. Gross pathology examination confirmed the echocardiographic diagnosis in 4 of 5 cases of pericarditis, 6 of 6 cases of BE, and 4 of 6 cases of CHD. Short-term prognosis was guarded with 19 cases (40.4%) being discharged. Premature death within 2 mo after discharge (n = 5), early culling because of poor breeding performance (n = 5), and normal productive life in the herd (n = 5) were observed in the cases that were followed. Echocardiography may be the most sensitive tool for the antemortem diagnosis of heart disease in cattle. 相似文献
126.
127.
Discrimination of corn,grasses and dicot weeds by their UV-induced fluorescence spectral signature 总被引:1,自引:0,他引:1
Louis Longchamps Bernard Panneton Guy Samson Gilles D. Leroux Roger Thériault 《Precision Agriculture》2010,11(2):181-197
Real-time spot spraying of weed patches requires the development of sensors for the automatic detection of weeds within a
crop. In this context, the potential of UV-induced fluorescence of green plants for corn-weed discrimination was evaluated.
A total of 1 440 spectral signatures of fluorescence were recorded in a greenhouse from three plant groups (four corn hybrids,
four dicotyledonous weed species and four monocotyledonous weed species) grown in a growth chamber. With multi-variate analysis,
the full information contained in each spectrum was first reduced to the scores calculated from five principal components.
Then, a linear discriminant analysis was applied on these scores to classify spectra on a species/hybrids basis and, subsequently,
the resulting classes were aggregated according to the three plant groups. This two-step process minimized the error generated
by heterogeneous groups such as dicotyledonous weeds. The output of this classification shows the significant potential of
UV-induced fluorescence for plant group discrimination as the success rate reached 91.8%. No error was observed between corn
and dicot weeds and most of the errors between corn and grasses came from confusion between the hybrid Pioneer 39Y85 and Setaria glauca L. (Beauv.). Analysis also determined that the position of the fluorescence sensor on the leaf and the plant age had negligible
effects on the efficiency of fluorescence to discriminate plant groups. The factors to consider for transferring the results
about UV-induced fluoro-sensing from laboratory to the field are discussed. 相似文献
128.
Philippe Denerolle Gilles Bourdoiseau 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1999,13(5):413-415
The aim of the present study was to evaluate the long-term clinical outcome for dogs with leishmaniasis that were treated with 3 different protocols: combined treatment with antimony and allopurinol, antimony alone, or allopurinol alone. Ninety-six dogs included in this study were determined to have leishmaniasis on the basis of (1) clinical features, (2) identification of the parasite in smears of lymph node, bone marrow aspirates, or skin biopsies, and (3) specific immunofluorescent assay. Three groups of dogs were defined: 45 dogs (group 1) were treated with antimony (100 mg/kg s.c. q24h) given concurrently for 1 month with allopurinol (15 mg/kg p.o. q12h), and then allopurinol alone for 8 months at the same dosage; 40 dogs (group 2) were treated with antimony alone according to the manufacturer's instructions (200 mg/kg s.c. q24h at 2-day intervals for 3-6 months); and 11 dogs (group 3) were treated with allopurinol alone (15 mg/kg p.o. q12h for 1-20 months). Information concerning signalment, history, physical examination findings, serologic testing and number of dogs becoming seronegative, outcome for each treated dog (clinical cure versus failure), and long-term survival were recorded. The numbers of the clinical cures versus failures were significantly different among the 3 groups (chi2 = 17.77, P < .001), between groups 1 and 2 (chi2 = 8.02, P < .01), between groups 2 and 3 (chi2 = 11.00, P < .01), and between groups 1 and 3 (chi2 = 16.52, P < .001). No significant difference between groups 1 and 2 was noted in the type of failure (relapse or death), serologic test results, and number of survival years (chi2 = 2.79, P > .05). The results of the present study indicate that antimony in combination with allopurinol produces better results than antimony alone or allopurinol alone for the treatment of the canine leishmaniasis. With combination treatment, duration of treatment with antimony is shorter and long-term administration of allopurinol is well tolerated. 相似文献
129.
Macro‐geographical differences influenced by family‐based expression on cultured pearl grade,shape and colour in the black‐lip ‘pearl oyster’ Pinctada margaritifera: a preliminary bi‐local case study in French Polynesia 下载免费PDF全文
Chin‐Long Ky Carole Blay Vaite Aiho Philippe Cabral Gilles Le Moullac Cédrik Lo 《Aquaculture Research》2017,48(1):270-282
In French Polynesia, the aquaculture of Pinctada margaritifera is carried out in numerous grow‐out sites, located over three archipelagos (Gambier, Society and Tuamotu). To evaluate the impact of macro‐geographical effects of these growing sites on pearl quality traits, five hatcheries produced families were used as homogeneous donor oysters in an experimental graft. The molluscs were then reared in two commercial locations: Tahaa Island (Society) and Rangiroa atoll (Tuamotu). At harvest, eight pearl quality traits were recorded and compared: surface defects, lustre, grade, circles, shape categories, darkness level, body and secondary colour and visual colour categories. Overall inter‐site comparison revealed that: (1) all traits were affected by grow‐out location except for lustre and round shape, and (2) a higher mean rate of valuable pearls was produced in Rangiroa. Indeed, for pearl grade, Rangiroa showed twice as many A‐B and less reject samples than Tahaa. This was related to the number of surface defects (grade component): in Rangiroa, twice as many pearls had no defects and less pearls had up to 10 defects. Concerning pearl shape, more circled and baroque pearls were found in Tahaa (+10%). For colour variation, 10% more pearls have an attractive green overtone in Rangiroa than in Tahaa, where more grey body colour were harvested. Lustre does not seem to be affected by these two culture site (except at a family scale). This is the first time P. margaritifera donor family have been shown to vary in the quality of pearls they produce depending on their grow‐out location. 相似文献
130.
Coho salmon yearlings, reared in France in a freshwater hatchery, were directly transferred to sea water at three different periods of the year: 14 January, 3 March and 14 April 1976. The last two experiments were realized at three different salinities: 25, 30 and 35‰.The results show important seasonal differences in the osmoregulatory responses. The direct transfer to 35‰ reveals some osmoregulatory problems which are not discernable at lower salinities. Yearlings transferred to a 35‰ sea water present a much higher and faster rise of plasma electrolytes and of branchial Na+K+ ATPase activity than fish transferred to a 25 or 30‰ sea water.It was found that a physiologically pre-adapted fish, characterized by a high level of branchial Na+K+ ATPase activity in fresh water (April) will present in sea water a slower and more regular increase in gill Na+K+ ATPase activity than fish with a low level of enzyme activity in fresh water (January–March). These smolts transferred to 25 and 30‰ sea water in April do not exhibit important variations, whereas a well-marked osmotic disequilibrium appears at 35‰. However, this osmotic stress is much more rapidly controlled than in the previous transfers.Our results suggest that the highest tolerance to sea water is reached only at time of smolting and that the time of transfer may have a direct influence on the intensity of the osmotic stress. These facts might be of considerable importance for the development of marine rearing of coho salmon in coastal areas where the salinities stay usually above 30‰ which constitutes an unusual environment for the species under consideration. 相似文献