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131.
结合LG型冻干试验机的工作原理及结构特点,优化设计出双联式真空冷冻干燥设备。采用一台电机带动,两个捕集器内置的干燥仓体结构,可交替使用进行对照试验,避免了等待融冰的时间。采用3因素2水平L_8(27)正交试验得出草莓解析的优化参数:质量为3 250 g,真空度为84 Pa,搁板温度为75℃。并分析了不同干燥温度对冻干草莓含水率的影响。 相似文献
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胡萝卜真空渗透脱水工艺试验 总被引:3,自引:1,他引:2
为获得真空条件下胡萝卜渗透脱水的最佳工艺条件,通过试验探讨了切片厚度、真空度、渗透液浓度、温度等因素对胡萝卜真空渗透脱水特性的影响。结果表明:真空条件能有效提高果蔬渗透脱水效率;失水率、固形物增加率均随着切片厚度的减小,真空度的提高,渗透液浓度、温度的增大而增大;当真空度达到10 kPa(绝对压力)附近时,固形物增加率增幅明显快于失水率。胡萝卜脉冲真空渗透脱水较优的工艺参数为:切片厚度4 mm、真空度30 kPa、渗透液浓度60%、温度40℃,采用该组参数渗透脱水240 min质量损失率可达40.1%。研究结果可为胡萝卜等蔬菜的干制加工预处理提供技术依据。 相似文献
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Xanthomonas axonopodis pv. phaseoli (Xap) is an important seedborne pathogen of Phaseolus vulgaris. Accurate seed health testing methods are critical to protect seed quality and meet phytosanitary requirements. Currently employed selective media‐based methods include several variations in extraction procedures. In order to optimize pathogen extraction from seeds, the influence of different extraction steps on the sensitivity of Xap detection was assessed. Seeds were inoculated by vacuum infiltration with Xap to achieve inoculum levels from 101 to 105 CFU per seed; one contaminated seed was mixed into 1000‐seed subsamples of uncontaminated P. vulgaris seeds. Thirty subsamples of 1000 seeds were tested using each different extraction procedure. These included soaking whole seeds in sterilized saline phosphate buffer, either overnight at 4°C or for 3 h at room temperature, with or without vacuum extraction, and either with or without concentrating the seed extract by centrifuging. Seed extract dilutions were cultured on semiselective agar media MT and XCP1. The percentages of positive subsamples were compared to measure the effects of each extraction step on detection sensitivity. Vacuum extraction and centrifugation of seed extracts increased sensitivity; the highest sensitivity was obtained with the 3 h vacuum extraction followed by centrifugation. These results were confirmed with naturally infested seeds; Xap was detected in 48 of 70 samples using the 3 h vacuum extraction with centrifugation, whereas only 35 of 70 field samples tested positive using overnight soaking, a significant difference. The results suggest that these steps would be valuable modifications to the current method approved by the International Seed Testing Association (ISTA). 相似文献
136.
结合工程实际情况,通过在施工过程中的施工工艺、实测效果及各监测项目变化规律、加固效果的分析等方面的研究,得出结论:真空预压排水固结法在处理软基加固方面是行之有效的处理方法。 相似文献
137.
YI Songlin ZHANG Biguang LIU Yurong WANG Shu College of Materials Science Technology Beijing Forestry University Beijng P.R.China 《中国林业科技(英文版)》2007,6(3):51-54
The objective of this experiment is to explore how the thickness and the length of the specimen affect the vacuum drying rate, andto explore whether the different lengths of specimens have different vacuum drying rates. The results are as follows: in a Certain range of dimension and pressure, the length of specimens has more effect on the vacuum drying rate than the thickness. When the ratio of end area to volume is less than 0. 10 cm^-1, the drying rate decreases exponentially with the increasing of the length. 相似文献
138.
介绍了LXA双锥真空回转干燥器的结构和工作原理,指出了该设备在实际使用过程中存在物料中落入异物的问题;详细分析了物料中落入异物问题产生的原因所在。同时,详细阐述了解决存在问题时所进行的结构改进设计过程以及改进后所达到的良好效果。 相似文献
139.
Chunbao LI Juqing WU Nan ZHANG Song ZHANG Juan LIU Jinping LI Hongmin LI Xianchao FENG Yanqing HAN Zhiyuan ZHU Xinglian XU Guanghong ZHOU 《Animal Science Journal》2009,80(5):591-596
This work investigated the effects of boning method and postmortem aging on pork loin color, shearing value and sensory attributes. Two experiments were assigned. In Experiment I, 30 Chinese native black pigs were slaughtered and their carcasses were divided into three groups: (i) hot-boning: carcasses were fabricated within 45 min postmortem just after dressing; (ii) cold boning at 24 h: carcasses were fabricated after chilling at 0°C for 24 h; (iii) cold boning at 36 h: carcasses were fabricated after chilling at 0°C for 36 h. In Experiment II, right sides of the second group in Experiment I were used and primal cuts were vacuum packed and aged for 1 day, 8 days and 16 days. Pork loins ( Longissimus lumborum ) were used for color measurement, shearing test, and sensory evaluation. Among three boning methods, cold-boning at 36 h postmortem had the advantages of giving muscles a better color, the lowest cooking loss and cooked shearing value, and the highest sensory tenderness, juiciness, flavor and overall liking. Postmortem aging could improve pork quality characteristics, but it is not the fact that the longer aging time is, the better pork quality would be. Eight days may be enough to obtain an acceptable sensory attribute. These results are meaningful for pork processing and pork consumption. 相似文献
140.