全文获取类型
收费全文 | 179篇 |
免费 | 6篇 |
国内免费 | 14篇 |
专业分类
林业 | 3篇 |
农学 | 9篇 |
基础科学 | 2篇 |
12篇 | |
综合类 | 68篇 |
农作物 | 12篇 |
水产渔业 | 4篇 |
畜牧兽医 | 58篇 |
园艺 | 24篇 |
植物保护 | 7篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 10篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 2篇 |
2017年 | 8篇 |
2016年 | 13篇 |
2015年 | 6篇 |
2014年 | 11篇 |
2013年 | 17篇 |
2012年 | 12篇 |
2011年 | 9篇 |
2010年 | 12篇 |
2009年 | 11篇 |
2008年 | 9篇 |
2007年 | 14篇 |
2006年 | 5篇 |
2005年 | 7篇 |
2004年 | 7篇 |
2003年 | 4篇 |
2002年 | 7篇 |
2001年 | 5篇 |
2000年 | 7篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
排序方式: 共有199条查询结果,搜索用时 31 毫秒
121.
水稻新品种"吉农大27"选育报告 总被引:1,自引:1,他引:0
"吉农大27"水稻新品种是以"吉86-11"为母本、"吉农大3"为父本进行有性杂交后经系谱法选育而成.2年区域试验和1年生产试验平均产量分别为8 497.5 kg/hm2和8 764.5 kg/hm2,分别比对照品种"吉玉粳"增产4.7%和9.0%.该品种干2008年1月通过吉林省农作物品种审定委员会审定,其主要特点是高产、抗病、优质,适宜吉林省中熟、中早熟稻作区种植,尤其适宜吉林、通化、白城地区种植. 相似文献
122.
123.
针对2012年陕北省佳县"7·27"特大暴雨侵蚀灾害,以暴雨中心区(王家砭镇)受灾最严重的行政村为对象,调查了"7·27"特大暴雨中道路、河岸、河道、房屋建筑、坡耕地、退耕林地、退耕草地等的侵蚀灾害情况。选取不同恢复措施的典型坡面,量测了地表植被、地形、土壤结皮等状况和"7·27"暴雨侵蚀产生的土壤侵蚀量。重点调查了不同生态恢复措施与恢复效果在该次暴雨中的抗侵蚀作用。对"7·27"特大暴雨侵蚀灾害的原因进行了初步分析。结果表明,植被盖度、植被物种多样性、坡度以及土壤生物结皮对于暴雨侵蚀的防御具有重要影响。 相似文献
124.
以巴西橡胶树花芽为材料,利用RT-PCR技术从总RNA中扩增获得1个MADS基因。cDNA长度1 063 bp,开放阅读框717 bp,编码239个氨基酸,命名为HbMADS-27。在HbMADS-27氨基酸序列中具有1个较强的跨膜区,二级结构分析结果表明其属于混合型蛋白。HbMADS-27在N端前34~50氨基酸区域内为较强的疏水区,但整条多肽链表现为亲水性。对20个MADS蛋白进行系统进化分析,结果发现,巴西橡胶树的HbMADS-27基因与蓖麻的MADS-27基因亲缘关系最近,而与拟南芥MADS-27基因亲缘关系相对较远。 相似文献
125.
ZHAO Yan-jiao YAN Yuan-yuan LI Dan LUO Xue-lan YANG Peng ZHOU Fu-long YANG Rui-xia TANG Shuang-yi OU He-sheng 《园艺学报》2000,36(10):1745-1753
AIM To investigate the effect of 27nt-miRNA (27nt-miR) on apoptosis of human umbilical vein endothelial cells (HUVECs) induced by oxidized low-density lipoprotein (Ox-LDL) and its underlying mechanism. METHODS HUVECs were cultured in vitro and grouped as below: normal control group, Ox-LDL group, 27nt-miR+Ox-LDL group, anti-27nt-miR+Ox-LDL group and negative control+Ox-LDL group. The cells in Ox-LDL group were treated with Ox-LDL at 40 mg/L for 48 h, while those in normal control group were untreated but cultured normally. The cells in 27nt-miR+Ox-LDL group, anti-27nt-miR+Ox-LDL group and negative control+Ox-LDL group were transfected with their corresponding lentiviral vectors under the same procedure, followed by treatment with Ox-LDL at 40 mg/L for 48 h to induce apoptosis. The cell viability was measured by CCK-8 assay. The migration capacity was detected by scratch assay. The caspase-3 activity was measured by caspase-3 activity assay kit. The apoptotic rate was analyzed by Hoechst 33258 and flow cytometry. The mRNA and protein expression levels of Bcl-2, Bax and caspase-3 were determined by RT-qPCR and Western blot. RESUITS: Compared with negative control+Ox-LDL group, the cell viability and migration ability were significantly decreased by over-expression of 27nt-miR in the HUVECs (P <0.05), while the activity of caspase-3 and apoptosis induced by Ox-LDL were significantly increased (P <0.05). Furthermore, the mRNA and protein expression levels of Bax and caspase-3 were significantly up-regulated (P <0.05), and the mRNA and protein expression level of Bcl-2 was down-regulated in 27nt-miR+Ox-LDL group (P <0.05). Meanwhile, all the above indexes showed an opposite tendency in anti-27nt-miR+Ox-LDL group. CONCLUSION 27nt-miR promotes Ox-LDL-induced apoptosis and inhibits the viability and migration of HUVECs in vitro , possibly through regulating the expression of apoptotic/anti-apoptotic proteins such as Bax,caspase-3 and Bcl-2. 相似文献
126.
[目的]研究不同氮肥运筹对钵苗机插水稻性状及产量的影响。[方法]以杂交籼稻Ⅱ优118和常规粳稻武运粳27为材料,研究不同基蘖肥和穗肥比例对水稻茎蘖动态、成穗率、产量及其构成因素的影响。[结果]基蘖肥:穗肥为7∶3的氮肥运筹方式有利于提高穗数,增加产量;Ⅱ优118以基蘖肥178.5 kg/hm~2、总用氮量255 kg/hm~2的处理的产量最高;武运粳27以基蘖肥252.0 kg/hm~2、总用氮量360 kg/hm~2的处理的群体产量最高。[结论]该研究为钵苗机插水稻的最佳氮肥运筹方式的推广提供理论基础。 相似文献
127.
Liu LI Meng-meng ZHENG Xiao-fang MA Yuan-jun LI Qing-yu LI Guo-ping WANG Ni HONG 《农业科学学报》2019,18(11):2549-2560
Apple stem pitting virus (ASPV) is an important causal agent of pear diseases. Nowadays, the infection status and molecular characteristics of the virus in old pear trees have never been investigated. In this study, we provide the first complete genome sequence of an ASPV isolate LYC from an over 300-year-old tree of a local Pyrus bretschneideri cultivar ‘Chili’ specifically grown at Laiyang area in China. ASPV-LYC possesses a chimeric genome consisting of 9 273 nucleotides excluding a poly(A) tail at its 3’ end and harboring a recombination region in its open reading frame (ORF1) with Aurora-1 and KL9 identified as the major and minor parents. Western blot analysis with antisera against recombinant coat proteins (CPs) of three ASPV isolates from pear indicates that ASPV-LYC is serologically related to these ASPV isolates, but with differential activities. Further biological tests on indicator plants of Pyronia veitchii show that ASPV-LYC can induce serious leaf and stem symptoms as other ASPV isolates. The results provide an important information for understanding molecular evolution of ASPV and suggest a need to prevent dissemination of the isolate among pear trees. 相似文献
128.
129.
130.
为了解浙江地区地方品种鸡中J亚群禽白血病病毒(subgroup J avian leukosis vrius,ALV-J)的感染情况与流行毒株的分子特征,对浙江省部分地方品种鸡体内ALV的p27抗原进行了检测,从疑似感染鸡群中检测分离到5株ALV-J,并对其GP85基因进行PCR分子克隆和序列分析。研究结果显示:在检测的19个地方鸡品系中,所有品系的鸡样本都呈现抗原阳性,其中101系的抗体阳性率最高,母鸡阳性率为40.48%,公鸡阳性率为16.54%;126系次之,母鸡阳性率为28.87%,公鸡阳性率为3.30%;171系抗体阳性率最低,其母鸡阳性率仅为4.08%,公鸡的感染率为0。为了解地方鸡群中ALV-J的遗传变异,对分离到的5株ALV-J的GP85基因进行了分子克隆和序列分析。结果表明,5个分离毒株的GP85基因大小均为924 bp,与预期一致;本研究样品序列之间的核苷酸同源性为90.8%~98.5%,与原型毒株HPRS103核苷酸相似性为90.3%~97.0%,与国内其他分离株的同源性为86.5%~99.0%。分离株与福建(FJ201308株)和广东(WF13株)分离株的同源性... 相似文献