全文获取类型
收费全文 | 1851篇 |
免费 | 113篇 |
国内免费 | 10篇 |
专业分类
林业 | 139篇 |
农学 | 72篇 |
基础科学 | 5篇 |
424篇 | |
综合类 | 149篇 |
农作物 | 118篇 |
水产渔业 | 151篇 |
畜牧兽医 | 711篇 |
园艺 | 42篇 |
植物保护 | 163篇 |
出版年
2024年 | 4篇 |
2023年 | 25篇 |
2022年 | 39篇 |
2021年 | 74篇 |
2020年 | 69篇 |
2019年 | 54篇 |
2018年 | 81篇 |
2017年 | 62篇 |
2016年 | 73篇 |
2015年 | 39篇 |
2014年 | 71篇 |
2013年 | 111篇 |
2012年 | 106篇 |
2011年 | 171篇 |
2010年 | 111篇 |
2009年 | 75篇 |
2008年 | 107篇 |
2007年 | 105篇 |
2006年 | 94篇 |
2005年 | 85篇 |
2004年 | 84篇 |
2003年 | 71篇 |
2002年 | 73篇 |
2001年 | 38篇 |
2000年 | 24篇 |
1999年 | 12篇 |
1998年 | 6篇 |
1997年 | 11篇 |
1996年 | 10篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 10篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1982年 | 2篇 |
1981年 | 6篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1976年 | 2篇 |
1973年 | 3篇 |
1968年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有1974条查询结果,搜索用时 31 毫秒
1.
2.
通过对稳定剂的稳定效果、糖酸比例、工艺条件等几个方面的研究,表明乳清清凉饮料的最佳条件:稳定剂含量为0.25%,白砂糖10.0%,采用90-95℃,5min杀菌,发酵温度为42±0.5℃,时间5.5h。 相似文献
3.
4.
Paolo Zucca Giovanni Di Guardo Roberto Pozzi-Mucelli Dino Scaravelli Marco Francese 《Journal of zoo and wildlife medicine》2004,35(3):391-394
A mature male Risso's dolphin (Grampus griseus) stranded along the coasts of Friuli Venezia Giulia, northeast Italy, in May 2001. Parasitic infection with Crassicauda grampicola is often found in the tympanic bullae and pterygoid sinuses in many of the Risso's dolphins examined from the same area. For this reason, it was decided to perform computed tomography of the head to assess this imaging technique for the diagnosis of crassicaudosis in dolphins. A full postmortem examination confirmed the pathologic findings of the computed tomography scan. This technique can be considered a useful adjunct in the diagnosis of cranial crassicaudosis in live dolphins. 相似文献
5.
Rosario Preziosi Maria Morini Giuseppe Sarli 《Journal of veterinary diagnostic investigation》2004,16(6):554-561
Thirty-one canine cutaneous masses, diagnosed as mast cell tumors (MCT) by histopathologic analysis, were used to evaluate the immunohistochemical pattern of expression of KIT protein (CD117), a type III tyrosine kinase protein involved in mast cell growth and differentiation. Lesions were graded as I (well differentiated), II (intermediate differentiation), or III (poorly differentiated) according to the following morphologic features: invasiveness, cellularity and cellular morphology, mitotic index, and stromal reaction. Immunohistochemical KIT expression was compared with histologic grade and some histomorphologic features (cell differentiation and nuclear grade) evaluated separately. A possible predictive role of biologic behavior in MCTs for KIT expression was also investigated. Immunohistochemical analysis revealed three different patterns of KIT expression: a cytoplasmic diffuse pattern, a membranous pattern with immunostaining located on the cell surface, and a cytoplasmic perinuclear pattern, where KIT expression was detected in the cytoplasm of the neoplastic mast cells, close to the nucleus. Statistical analysis showed a close relationship between different KIT immunohistochemical patterns and histologic grade (P < 0.00000), cell differentiation (P < 0.00000), and nuclear grade (P < 0.0024). According to Kaplan-Meier-estimated survival curves compared by survival analysis, KIT expression was significantly associated with survival time (P = 0.037) but not cancer-free interval (P = 0.50). Similar to other well-known histomorphological features, KIT expression is a useful parameter of malignancy in cutaneous MCTs. KIT expression also predicted the biological behavior of the tumors in this study. 相似文献
6.
Prognostic value of echocardiographic indices of left atrial morphology and function in dogs with myxomatous mitral valve disease 下载免费PDF全文
7.
8.
9.
Effect of resistant starch on the intestinal health of old dogs: fermentation products and histological features of the intestinal mucosa 下载免费PDF全文
M. C. Peixoto É. M. Ribeiro A. P. J. Maria B. A. Loureiro L. G. di Santo T. C. Putarov F. N. Yoshitoshi G. T. Pereira L. R. M. Sá A. C. Carciofi 《Journal of animal physiology and animal nutrition》2018,102(1):e111-e121
The effects of resistant starch (RS) intake on nutrient digestibility, microbial fermentation products, faecal IgA, faecal pH, and histological features of the intestinal mucosa of old dogs were evaluated. The same formulation was extruded in two different conditions: one to obtain elevated starch cooking degree with low RS content (0.21%) and the other lower starch cooking with high RS content (1.46%). Eight geriatric Beagles (11.5 ± 0.38 years old) were fed each diet for 61 days in a crossover design. Food intake, nutrient digestibility, fermentation products, faecal pH, and faecal IgA were examined via variance analysis. Histological results of intestinal biopsies were assessed via Wilcoxon test for paired data. The morphometric characteristics of large intestine crypts were evaluated via paired t tests (p < .05). Protein, fat, and energy digestibilities were higher for the low‐RS diet (p < .05). Dogs receiving the high‐RS diet had lower faecal pH and higher values for propionate, butyrate, total volatile fatty acids, and lactate (p < .05). No differences between diets were found in the histological parameters of the gut mucosa, and only a tendency for deeper crypts in the descending colon was observed for dogs fed the high‐RS diet (p = .083). The intake of a corn‐based kibble diet manufactured with coarse ground raw material and low starch gelatinization to obtain 1.4% of RS affected microbial fermentation products and faecal pH and tended to increase crypt depth in the descending colon of old dogs. 相似文献
10.