全文获取类型
收费全文 | 1192篇 |
免费 | 31篇 |
国内免费 | 57篇 |
专业分类
林业 | 57篇 |
农学 | 159篇 |
基础科学 | 29篇 |
46篇 | |
综合类 | 494篇 |
农作物 | 127篇 |
水产渔业 | 20篇 |
畜牧兽医 | 78篇 |
园艺 | 264篇 |
植物保护 | 6篇 |
出版年
2024年 | 1篇 |
2023年 | 11篇 |
2022年 | 17篇 |
2021年 | 16篇 |
2020年 | 22篇 |
2019年 | 11篇 |
2018年 | 8篇 |
2017年 | 24篇 |
2016年 | 35篇 |
2015年 | 23篇 |
2014年 | 65篇 |
2013年 | 56篇 |
2012年 | 55篇 |
2011年 | 74篇 |
2010年 | 71篇 |
2009年 | 112篇 |
2008年 | 93篇 |
2007年 | 89篇 |
2006年 | 69篇 |
2005年 | 80篇 |
2004年 | 46篇 |
2003年 | 43篇 |
2002年 | 23篇 |
2001年 | 26篇 |
2000年 | 32篇 |
1999年 | 25篇 |
1998年 | 19篇 |
1997年 | 21篇 |
1996年 | 18篇 |
1995年 | 19篇 |
1994年 | 19篇 |
1993年 | 16篇 |
1992年 | 9篇 |
1991年 | 4篇 |
1990年 | 10篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 1篇 |
排序方式: 共有1280条查询结果,搜索用时 15 毫秒
1.
《中国油料作物学报(英文)》2021,6(3):137-144
Microwave, as a new heat treatment technology, has the characteristics of uniform and fast heating speed. It is an energy-saving technology known for improving oilseed product quality. Its efficiency mainly depends on the roasting power and time. However, the production of high-quality peanut butter using short-time roasting conditions are limited. Herein, we determined an appropriate microwave roasting power and time for peanuts and evaluated its impacts on the quality of peanut butter. Different roasting powers (400 W, 800 W and 1200 W) and times (4, 4.5, 5, and 5.5 min) were preliminarily tested. Among them, 800 W at 5 min was the most suitable. The roasting efficiency was further evaluated using color, sensory, bioactive compounds, storage stability, and safety risk factors of peanut butter produced from four peanut cultivars (Silihong, Baisha-1016, Yuanza-9102, and Yuhua-9414). The pre-treated butter obtained from three cultivars (Silihong, Yuanza-9102, and Yuhua-9414) with moisture content between 5% and 7.2% had a similar sensory score (6–7) as the commercial on a 9-point hedonic scale compare to the other. The color of the pre-treated peanut butter varies statistically with the commercial but remained in the recommended range of Hunter L1 values of 51–52, respectively, for high initial moisture peanut cultivars. The total polyphenol (35.20-31.59 ± 0.59 μmol GAE/g) and tocopherol (19.05 ± 0.35 mg/100 g) content in the butter obtained from three cultivars (Yuahua-9102, Yuhua, and Baisha-1016) and Silihong respectively, were significantly (P < 0.05) higher than those in the commercial butter. The induction times of all pre-treated butter (19.80 ± 0.99–7.84 ± 0.07 h) were significantly (P < 0.05) longer during storage at accelerated temperature than commercial samples. In addition, no benzo[a]pyrene was found in the pre-treated samples. Collectively, the microwave pretreated peanut butter was superior to the commercial one. These findings provided data support and a reference basis to promote microwave use for peanut butter production. 相似文献
2.
种子的安全贮藏是玉米获得高产的前提。阐述玉米种子的贮藏特性和贮藏过程中保持种子活力的主要措施,同时简单介绍了几种种子活力鉴定的方法,供相关工作者参考。 相似文献
3.
种子在自然贮藏过程中常常伴随着内部生理机能的恶化,线粒体作为种子内活性氧(reactive oxide species,ROS)产生的主要位点是最先遭到破坏的细胞器。为探讨不同贮藏年限对老芒麦种胚线粒体抗氧化功能的影响,本试验以室温贮藏0~4年的老芒麦种子为材料,分析比较其老化规律及种胚线粒体抗氧化特性的变化规律。结果表明:随着贮藏年限的延长,老芒麦种子发芽势、发芽率和种苗鲜重逐渐下降,死种子逐渐增多,种胚线粒体苹果酸脱氢酶(mitochondria malate dehydrogenase,MDH)、谷胱甘肽还原酶(glutathione reductase,GR)、单脱氢抗坏血酸还原酶(monodehydroascorbate reductase,MDHAR)活性逐渐下降,但在死种子中超氧化物歧化酶(superoxide dismutase,SOD)活性显著升高。此外,在贮藏过程中老芒麦种胚线粒体O2·-产生速率不断上升,而H2O2含量则呈现逐渐降低的趋势,表明线粒体中O2·-的积累与细胞氧化损伤密切相关。 相似文献
4.
为解决草莓采后果实腐烂变质问题,将草莓置于甘草提取液、乳酸钙溶液、蒸馏水中浸泡1 min,取出晾干后常温贮藏,比较3组草莓失重率、腐烂率、可溶性糖、维生素C含量、超氧化物歧化酶SOD活性的变化。与对照组相比,贮藏7天后,甘草提取液组草莓失重率降低34.72%、腐烂率降低31.56%、可溶性糖含量提高99.10%、维生素C含量提高154.55%、超氧化物歧化酶SOD活性提高206.24%,乳酸钙处理和甘草提取液保鲜效果没有显著差异(P>0.05)。实验期内,2种处理方法均可提高草莓保鲜效果。 相似文献
5.
鹅掌楸花粉保存条件的比较研究 总被引:19,自引:0,他引:19
研究比较了鹅掌楸花粉的几种保存条件。结果表明:(1)新鲜花粉在超低温(-196℃,LN2)条件下可保持5d。花粉存活率(76.51%)与对照(新鲜花粉)几乎相同(75.55%)。在电镜下观察其超微结构无异常变化。而保存15d的花粉细胞超向结构发生严重损伤,内膜系统及细胞器降解。25d后几乎观察不到存活的花粉。(20在-25℃保存条件下,以二甲基亚砜为保护剂,添加蔗糖作为辅佐剂保存效果较好。(3)4 相似文献
6.
7.
阔叶红松林倒木贮量动态研究 总被引:4,自引:2,他引:4
本文研究了中国吉林省长白山区阔叶红松林倒木贮量的动态变化规律。阔叶红松林倒木贮量包括其现有倒木及其年输入量等贮量的变化规律。阔叶红松林现有倒木贮量开始为16.25 t·hm-2,以后随时间减少,到100年分解掉其干重的85%左右,300年后所剩无几。倒木年输入量平均约为0.6 t·hm-2,其贮量是随时间而增加,200年后稳定在31 t·hm-2,可保持到该群落的顶级时期。倒木总贮量的变化在初期呈增加趋势,而后随着现有倒木的完全分解,倒木贮量就与其倒木的年输入趋于一致,最后稳定在上述水平上。图4表2参9。 相似文献
8.
In this study, the changes in vitamin C, l-ascorbic acid (AA) and l-dehydroascorbic acid (DHA) levels in broccoli flower buds were examined during pre-storage and storage periods, simulating refrigerated transport with wholesale distribution and retail, respectively. Broccoli heads were pre-stored for 4 or 7 days at 0 °C or 4 °C in the dark and then stored for 3 days at 10 °C or 18 °C. During storage the broccoli heads were exposed for 12 h per day to three different levels of visible light (13, 19 or 25 μmol m−2 s−1) or a combination of visible light (19 μmol m−2 s−1) and UV-B irradiation (20 kJ m−2 d−1), or they were stored in the dark. The vitamin C content in broccoli flower buds during storage was significantly affected by pre-storage period and temperature. Higher vitamin C levels in flower buds after storage were observed for broccoli heads pre-stored for 4 days or at 0 °C as compared to those pre-stored for 7 days or at 4 °C. Storage temperature also affected vitamin C in broccoli flower buds, with higher levels observed for broccoli stored at 10 °C than at 18 °C. Hence, vitamin C in broccoli flower buds was demonstrated to decrease together with increasing pre-storage period, pre-storage temperature and storage temperature. AA in broccoli flower buds was influenced mainly by storage temperature and to a minor extent by pre-storage temperature. The DHA level and DHA/AA ratio were stable in flower buds of broccoli pre-stored for 7 days, whereas increasing tendencies for both DHA level and ratio were observed after pre-storage for 4 days. These results indicate a shift in the ascorbate metabolism in broccoli flower buds during storage at low temperatures, with its higher rate observed for broccoli pre-stored for shorter time. There were no effects of the light and UV-B irradiation treatments on vitamin C, AA and DHA levels in broccoli flower buds. 相似文献
9.
10.