全文获取类型
收费全文 | 2517篇 |
免费 | 63篇 |
国内免费 | 4篇 |
专业分类
林业 | 71篇 |
农学 | 26篇 |
基础科学 | 18篇 |
255篇 | |
综合类 | 1219篇 |
农作物 | 76篇 |
水产渔业 | 100篇 |
畜牧兽医 | 677篇 |
园艺 | 38篇 |
植物保护 | 104篇 |
出版年
2023年 | 6篇 |
2022年 | 12篇 |
2021年 | 20篇 |
2020年 | 24篇 |
2019年 | 26篇 |
2018年 | 25篇 |
2017年 | 18篇 |
2016年 | 17篇 |
2015年 | 23篇 |
2014年 | 23篇 |
2013年 | 70篇 |
2012年 | 102篇 |
2011年 | 132篇 |
2010年 | 73篇 |
2009年 | 62篇 |
2008年 | 137篇 |
2007年 | 129篇 |
2006年 | 143篇 |
2005年 | 149篇 |
2004年 | 140篇 |
2003年 | 132篇 |
2002年 | 128篇 |
2001年 | 53篇 |
2000年 | 52篇 |
1999年 | 18篇 |
1998年 | 16篇 |
1997年 | 11篇 |
1996年 | 16篇 |
1995年 | 41篇 |
1994年 | 47篇 |
1993年 | 46篇 |
1992年 | 41篇 |
1991年 | 54篇 |
1990年 | 44篇 |
1989年 | 55篇 |
1988年 | 56篇 |
1987年 | 50篇 |
1986年 | 54篇 |
1985年 | 54篇 |
1984年 | 46篇 |
1983年 | 40篇 |
1982年 | 46篇 |
1981年 | 31篇 |
1980年 | 25篇 |
1979年 | 19篇 |
1978年 | 21篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1967年 | 7篇 |
1963年 | 4篇 |
排序方式: 共有2584条查询结果,搜索用时 15 毫秒
1.
Hematology and serum biochemistry values are reported for 33 Attwater's prairie chickens (Tympanuchus cupido attwateri) that were captive-reared at the San Antonio Zoo as part of a federal reintroduction program in Texas. Hematologic values include packed cell volume, and total and differential white blood cell counts. The biochemical values include concentrations of serum calcium, total protein, albumin, phosphorus, glucose, uric acid, and cholesterol. Mathematic computation of globulin concentration and albumin: globulin ratios were conducted. Also, determination of the serum activities of creatine kinase and aspartate aminotransferase was done. 相似文献
2.
3.
Decapsulation of Artemia spp. cysts in strong hypochlorite solutions reportedly increases the number of nauplii that hatch. Commercial cysts of Artemia franciscano were subjected to four decapsulation methods prior to hatching them in aerated seawater. Samples were removed from the hatch vessels every 5 h from 15 through 45 h, and fully hatched nauplii were counted. The experiment was performed three times. No significant difference was seen between mean numbers of control nauplii and nauplii obtained using the decapsulation method that yielded the best hatch: oxidation for 15 min in equal parts Clorox® and seawater plus 6 mL of a 40% NaOH solution, followed by reduction with 100 mL of 0.7 M sodium thiosulfate. A third treatment was inferior to either of these, and two others produced very low yields. It was concluded that of the methods evaluated, none is superior to no treatment at all, and some are clearly detrimental to developing Artemia embryos. 相似文献
4.
5.
6.
Kerr RA 《Science (New York, N.Y.)》1991,251(4995):746-747
7.
8.
Jain NC Blue JT Grindem CB Harvey JW Kociba GJ Krehbiel JD Latimer KS Raskin RE Thrall MA Zinkl JG 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1991,20(3):63-82
Blood and bone marrow smears from 49 dogs and cats, believed to have myeloproliferative disorders (MPD), were examined by a panel of 10 clinical pathologists to develop proposals for classification of acute myeloid leukemia (AML) in these species. French-American-British (FAB) group and National Cancer Institute (NCI) workshop definitions and criteria developed for classification of AML in humans were adapted. Major modifications entailed revision of definitions of blast cells as applied to the dog and cat, broadening the scope of leukemia classification, and making provisions for differentiating erythremic myelosis and undifferentiated MPD. A consensus cytomorphologic diagnosis was reached in 39 (79.6%) cases comprising 26 of AML, 10 of myelodysplastic syndrome (MDS), and 3 of acute lymphoblastic leukemia (ALL). Diagnostic concordance for these diseases varied from 60 to 81% (mean 73.3 +/- 7.1%) and interobserver agreement ranged from 51.3 to 84.6% (mean 73.1 +/- 9.3%). Various subtypes of AML identified included Ml, M2, M4, M5a, M5b, and M6. Acute undifferentiated leukemia (AUL) was recognized as a specific entity. M3 was not encountered, but this subclass was retained as a diagnostic possibility. The designations M6Er and MDS-Er were introduced where the suffix "Er" indicated preponderance of erythroid component. Chief hematologic abnormalities included circulating blast cells in 98% of the cases, with 36.7% cases having >30% blast cells, and thrombocytopenia and anemia in approximately 86 to 88% of the cases. Bone marrow examination revealed panmyeloid dysplastic changes, particularly variable numbers of megaloblastoid rubriblasts and rubricytes in all AML subtypes and increased numbers of eosinophils in MDS. Cytochemical patterns of neutrophilic markers were evident in most cases of Ml and M2, while monocytic markers were primarily seen in M5a and M5b cases. It is proposed that well-prepared, Romanowsky-stained blood and bone marrow smears should be examined to determine blast cell types and percentages for cytomorphologic diagnosis of AML. Carefully selected areas of stained films presenting adequate cellular details should be used to count a minimum of 200 cells. In cases with borderline diagnosis, at least 500 cells should be counted. The identity of blast cells should be ascertained using appropriate cytochemical markers of neutrophilic, monocytic, and megakaryocytic differentiation. A blast cell count of > 30% in blood and/or bone marrow indicates AML or AUL, while a count of < 30% blasts in bone marrow suggests MDS, chronic myeloid leukemias, or even a leukemoid reaction. Myeloblasts, monoblasts, and megakaryoblasts comprise the blast cell count. The FAB approach with additional criteria should be used to distinguish AUL and various subtypes of AML (Ml to M7 and M6Er) and to differentiate MDS, MDS-ER, chronic myeloid leukemias, and leukemoid reaction. Bone marrow core biopsy and electron microscopy may be required to confirm the specific diagnosis. Immunophenotyping with lineage specific antibodies is in its infancy in veterinary medicine. Development of this technique is encouraged to establish an undisputed identity of blast cells. Validity of the proposed criteria needs to be substantiated in large prospective and retrospective studies. Similarly, clinical relevance of cytomorphologic, cytochemical, and immunophenotypic characterizations of AML in dogs and cats remains to be determined. 相似文献
9.
Kerr RA 《Science (New York, N.Y.)》1988,239(4841):729-730
10.