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91.
Yoji Miyajima Shin-ya Komatsu Masatoshi Mitsuhara Satoshi Hata Hideharu Nakashima Nobuhiro Tsuji 《哲学杂志》2015,95(11):1139-1149
Microstructural changes, such as the density of grain boundary (GB) and dislocation density, due to isochronal annealing in severely plastic-deformed commercial purity aluminium up to 523 K was evaluated using electrical resistivity measurements and scanning transmission electron microscopy. Eventually, the GB density decreases from about 7.2 × 106 to about 2 × 106 m?1, whilst the dislocation density decreases from an initial value of around 1.3 × 1014 m?2 down to around 4 × 1013 m?2. 相似文献
92.
本文研究了在非均匀磁场尘埃等离子体中不规则尘埃颗粒的复杂运动, 包括圆滚运动、尖头圆滚运动、圆周运动以及波浪运动等. 放置在电极上的圆柱形磁铁的主要作用是改变鞘层的径向分布, 进而对颗粒产生径向约束, 使尘埃颗粒悬浮于圆柱形磁铁周围, 其磁场并不足以磁化颗粒使其做圆滚运动. 通过与球形尘埃颗粒的对比实验发现, 圆滚运动是不规则尘埃颗粒在等离子体中特有的一种运动. 我们提出了一种新的机理: 由于不规则颗粒的自旋而引起的横向反Magnus力对颗粒的圆滚运动起了重要的作用. 文中通过受力分析定性地对实验中观察到的非球形颗粒的各种运动给出了合理的解释. 相似文献
93.
近红外反射光谱快速测定玉米DDGS营养成分的研究 总被引:4,自引:0,他引:4
试验探讨了近红外反射光谱测定玉米DDGS的8项重要营养成分,包括水分、蛋白、粗脂肪、粗灰分、总磷、中性洗涤纤维、酸性洗涤纤维、粗纤维的可行性.从国内18个工厂采集93个玉米DDGS样品,使用偏最小二乘法,采取15种不同的导数和去散射光谱预处理方法建立近红外模型.在光谱预处理中,二阶导数产生了较好的预测效果.使用70个与... 相似文献
94.
In this paper, we try to study the effect of two different ionic and nonionic amines dodecylamine (DDA) and hexadecyldimethylamine (DMHA) considered as weak bases and surfactant on the growth of ZnO nanorods using hydrothermal synthesis technique. The self-assembly of oriented attachment (OA) of ZnO nano- and microrods has been successfully obtained by this technique at temperatures greater than 150?°C. The ZnO nano/microrods were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Raman scattering spectroscopy, Fourier transform infrared (FTIR) and photoluminescence. The XRD measurements show that ZnO prepared by DDA amine presents small grain size in comparison to ZnO obtained from DMHA amine. From SEM characterization, we show that DDA amine has a great effect on the OA of several homogenous ZnO microrods building blocks. The growth process is explained by the formation of ZnO OA in microstructures scale which is depending on ionic character of amines. Optic measurements (Raman, FTIR and photoluminescence) are presented and commented. 相似文献
95.
ZHENG Renrong CHEN Zhiqian & ZHU Shunquan . Department of Physics Shanghai Normal University Shanghai China . Department of Physics Southwest Normal University Chongqing China . Department of Computer Electric Technology Shanghai Business School Shanghai China 《中国科学G辑(英文版)》2005,48(4):431-441
1 IntroductionThe superconductivity of small metallic grains has been attracting a lot of attentions. On one hand, Anderson[1] predicted that the superconductivity would disappear if a me- tallic grain was so small that the spaces between the nearest neighbor energy levels in the system became larger than the energy gap of the bulk metallic superconductor; On the other hand, it was found in experiments made in the 1960s[2] that the critical tem- perature of superconductivity of small metallic … 相似文献
96.
97.
Tomás?Pérez-RuizEmail author Carmen?Martínez-Lozano Virginia?Tomás Antonio?Sanz Raquel?Garre 《Mikrochimica acta》2003,142(4):231-235
A flow-injection configuration for the spectrophotometric determination of ferbam is proposed. The procedure is based on the online decomposition of ferbam and complexation of the released Fe3+ with oxalate. The ferrioxalate formed is decomposed upon irradiation with visible light. The Fe2+ produced in the photochemical reaction was monitored by measuring the absorbance after complexation with ferrozine (max=562nm). The method shows a linear range between 1.0 and 30µgmL–1 (2.5×10–6–7.2×10–5molL–1) with a limit of detection of 0.2µgmL–1. Repeatibility was 0.53% expressed as relative standard deviation (n=10), and reproducibility, studied on five different days, was ±1.23%. The sampling frequency was about 45samplesh–1. The applicability of the method was tested in the determination of ferbam in waters and grains.Received December 2, 2002; accepted April 13, 2003
Published online July 16, 2003 相似文献
98.
99.
针对矿场调剖实际需求,利用仪器检测和物理模拟方法,开展了体膨颗粒吸水率与溶胀率、抗剪切性、渗流特性、传输运移能力、粒径与油藏孔隙匹配关系和驱油效果实验研究.结果表明:随时间延长,体膨颗粒吸水率和溶胀率增大,并且初期增幅较大,24小时后增幅减缓.体膨颗粒抗剪切性能较好,经地层剪切后83%以上仍为大颗粒.体膨颗粒粒径愈小,溶剂水矿化度愈低,吸水率和溶胀率愈大,抗剪切能力愈差;与污水相比较,污水配置聚合物溶液中体膨颗粒吸水率和溶胀率较小,抗剪切性较好,当体膨颗粒浓度为6000mg/L时,"体膨颗粒粒径/平均喉道直径"范围在4.18~5.40之间可适用于油藏.推荐体膨颗粒浓度6000mg/L,注入量0.38PV,调剖半径51.3m,为避免封堵近井地带,可先选择小粒径颗粒注入,并逐渐增大粒径. 相似文献
100.
In this study, dried distillers grains (DDG) was liquefied in acidic conditions at atmospheric pressure, and polyurethane
foams were subsequently prepared from the liquefied DDG. Liquefaction was examined over a range of conditions including liquefaction
time of 1–3 h, temperature of 150–170 °C, sulfuric acid (as catalyst) concentration of 1.0–3.0 wt%, and liquefaction solvent
(ethylene carbonate) to DDG ratio of 3:1–5:1. The bio-polyols in the liquefied DDG were rich in hydroxyl groups, which can
react with methylene diphenyl diisocyanate (MDI) to form cross-linked polyurethane networks. The biodegradability of the prepared
polyurethane foams was also evaluated. This study strives to broaden the application of DDG as a feedstock for bio-polyurethane
preparation. 相似文献