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71.
Film forming kinetics and reaction mechanism of γ-glycidoxypropyltrimethoxysilane on low carbon steel surfaces 总被引:1,自引:0,他引:1
The film forming kinetics and reaction mechanism of γ-GPS on low carbon steel surfaces was investigated by FTIR-ATR, AFM, NSS and theoretical calculation method. The results from experimental section indicated that the reaction of γ-GPS on low carbon steel surfaces followed the conventional reaction mechanism, which can be described as reaction (I) (Me (Metal)-OH + HO-Si → Me-O-Si + H2O) and reaction (II) (Si-OH + Si-OH → Si-O-Si + H2O). During film forming process, the formation of Si-O-Fe bond (reaction (I)) exhibited oscillatory phenomenon, the condensation degree of silanol monomers (reaction (II)) increased continuously. The metal hydroxyl density had significant influence on the growth mechanisms and corrosion resisting property of γ-GPS films. The results from theoretical calculation section indicated that the patterns of reaction (I) and reaction (II) were similar, involving a nucleophilic attack on the silicon center. The formation of Si-O-Fe bond (reaction (I)) was kinetically and thermodynamically preferred, which had catalytic effect on its condensation with neighboring silanol monomers (reaction (II)). Our DFT calculations were good consistent with the experimental measurements. 相似文献
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Yu Xie Dan Liu Ming Gao Ru Tan Yan Wang Dongqi Yu 《Frontiers of Chemistry in China》2011,6(4):355-357
Well-aligned ZnO nanorod arrays were prepared on FTO substrate by hydrothermal method at low temperature for 5 h. The effect
of ammonia on the length of ZnO nanorod was studied in detail. The resulting materials were extensively characterized by scanning
electron microscopy (SEM), X-ray diffraction (XRD) and UV-visible absorption spectra (scatter mode). With the increase of
ammonia, the length of ZnO nanorod increases. 相似文献
74.
针对后疫情时代的教学需要和地方高校的信息化教学资源的不足,通过创建微信公众号和微信群,初步探索了微信融入无机化学实验教学的新模式。课前通过公众号的推文引导学生进行有目标的预习,养成自主学习和独立思考的习惯。课堂中,先通过微信群进行预习测试,并基于测试反馈调整需要重点讨论的实验要点,再通过微信群共享师生在实验过程中对实验操作、实验现象和实验结果拍摄的照片或视频,充分激发学生兴趣,提升学生的能力。课后结合拍摄的错误操作的照片撰写公众号推文,进行实验反馈,帮助学生形成反思的习惯。 相似文献
75.
《Journal of Saudi Chemical Society》2022,26(2):101421
N-methylation of amines and imines with formic acid as C1 source by easily prepared Pt NPs as heterogeneous catalyst is reported here. Primary, secondary amines and imines were successfully methylated in good to excellent yields under mild conditions. Both aromatic and aliphatic amines could be applied as substrates. Meanwhile, the heterogeneous Pt NPs were capable to be recylcled and reused for 7 times without significant decrease of reactivity. This protocol provided an indirect utilization pathway of CO2 by using formic acid as C1 source. 相似文献
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传统合成氨工艺存在能耗高、污染严重的问题. 因此, 高效、低能耗绿色合成氨工艺的开发迫在眉睫. 光电化学以H2O和N2为原料, 可以在太阳光驱动下, 在常温常压条件下实现氨的合成, 因而受到广泛重视. 但总的来说, 效率和产率都达不到实际要求. 新型高效催化剂及工艺的开发是提高合成氨产率及效率的关键. 非贵金属催化剂具备成本低、来源广泛、可操作性强的优势, 有利于光电化学合成氨的产业化. 本实验采用溶胶凝胶结合原位热裂解的方法制备了分散性好、结构均匀的BiOCl-Fe2O3@TiO2复合材料, 对其物相、微观结构、表面状态、光学性能、电学性能等方面进行了系统表征, 并探究了该材料在常温常压下光电化学合成氨的催化活性. 结果表明, 同纯介孔TiO2相比, BiOCl-Fe2O3@TiO2的吸收带隙变窄, 可见光吸收能力增强, 光生载流子的利用率增加, 光电合成氨的产率提升了7倍, 且BiOCl-Fe2O3@TiO2显示了优异的化学稳定性. 本研究工作为绿色合成氨催化材料及工艺设计提供了新思路. 相似文献
79.
A highly selective HBT-based “turn-on” fluorescent probe for hydrazine detection and its application
Zhen Chen Xinxin Zhong Wangbo Qu Ting Shi Heng Liu Hanping He Xiuhua Zhang Shengfu Wang 《Tetrahedron letters》2017,58(26):2596-2601
As one of the important industrial chemicals, hydrazine (N2H4) can be inhaled through the skin, leading to many serious health issues. In this paper, we constructed a novel turn-on fluorescent probe HBTM for N2H4 detection based on ESIPT and ICT mechanism by incorporating the methyl dicyanvinyl group to 2-(2′-hydroxylphenyl) benzothiazole (HBT) fluorophore. The probe showed the following advantages: high sensitivity with detection limit of 2.9 × 10?7 M, high selectivity over other related interfering species, wide linear range of 0–140 μM and pH value adaptation. Moreover, the probe could detect N2H4 on paper strips and image N2H4 in living cells. 相似文献
80.