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61.
Yujing Zuo Zhiming Gou Jie Zhang Shengyu Feng 《Macromolecular rapid communications》2016,37(7):597-604
A series of high‐efficiency, full‐color fluorescent elastomers based on polysiloxane matrix prepared by an easy thiol‐ene “click” reaction is reported here. It is found for the first time that the same elastomer can emit transformable colors by conveniently altering the excitation wavelength because of the effect of energy transfer and the “fluorescence switch” of lanthanide ions. A fluent change in emission colors can also be feasible and conveniently reproducible by varying the stoichiometric ratio of lanthanide ions and rhodamine‐B in solution and in polymer elastomers. The obtained elastomers are further coated onto commercially available UV‐LED cells from the solution medium followed by an in situ cross‐linking step.
62.
Jianhua Cao Yajing Liu Lifang Zhang Fenghua Du Yingqian Ci Yan Zhang Hao Xiao Xinyue Yao Shengyu Shi Lin Zhu Hank F. Kung Jinping Qiao 《Journal of Radioanalytical and Nuclear Chemistry》2017,312(2):263-276
Ten novel PEG-modified nitroimidazole derivatives labeled with 18F were synthesized via “hot-click” reaction and evaluated as PET tumor tracers. The radiolabeling method was convenient and efficient, all compounds displayed high radiochemical purity (>95%), high yield (30–50%) and good stability in saline and human serum. The biodistribution studies in EMT-6 tumor-bearing mice demonstrated their tumor uptake values at 60 min postinjection were 1.46–2.99%ID/g, which were lower than [18F]FMISO (5.43%ID/g), their tumor-to-liver ratios were 0.73–1.07, higher than [18F]FMISO (0.69). In vitro MCF-7 cell uptake studies showed their uptake values have no significant difference between hypoxic and aerobic cells. 相似文献
63.
Yanfei Wang Zhihua Sun Hailong Hu Shengyu Jing Bing Zhao Weiqing Xu Chun Zhao John R. Lombardi 《Journal of Raman spectroscopy : JRS》2007,38(1):34-38
The adsorption of 4‐mercaptopyridine (4‐Mpy) molecules on ZnS nanocrystals was investigated by means of Raman spectroscopy. We compared the Raman signals of 4‐Mpy molecules adsorbed on ZnS nanocrystals and Ag substrate. The differences in the adsorption of 4‐Mpy molecules on the semiconductor and the metal substrate were noted. The results demonstrated that adsorbed species on the semiconductor ZnS nanocrystals can be detected by Raman spectroscopy. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
64.
超高效液相色谱-电喷雾电离串联质谱联用法检测茶叶中阿维菌素类药物残留 总被引:10,自引:0,他引:10
建立了采用超高效液相色谱-电喷雾电离串联质谱同时检测茶叶中爱比菌素、甲胺基阿维菌素、乙酰胺基阿维菌素、伊维菌素、多拉菌素、莫西丁克残留的方法。试样经饱和氯化钠溶液浸润后,用乙腈提取,C18固相萃取小柱净化,超高效液相色谱-电喷雾串联质谱法(UPLC/ESI-MS/MS)测定。对流动相、监测离子、校正曲线等进行了优化和探讨。6种分析物在2.0~50 μg/L范围内线性关系良好,相关系数均大于0.9920。莫西丁克在5,10,20 μg/kg,其余分析物在2,5,10 μg/kg加标水平的平均回收率为61.7%~85.4%,相对标准偏差为9.37%~17.19%。该方法可靠、稳定,可满足茶叶中阿维菌素类药物残留检测与确证的需要。 相似文献
65.
有机硅材料具有优异的热稳定性、生物相容性、电绝缘性能和透气性等,在国民经济各个领域已得到广泛应用.近年来,具有自修复和可塑性的有机硅超分子材料引起了人们的广泛关注,各种各样的功能材料不断被开发出来.本文综合评述了有机硅超分子材料的合成、性能和应用等方面的近期研究进展,重点阐述了氢键型、金属配位键型、Lewis酸碱对型、离子键型及π-π堆积型有机硅超分子材料,并对其发展前景进行了展望. 相似文献
66.
含N、S官能基聚硅烷* 总被引:1,自引:0,他引:1
综述了近年来含N、S官能基聚硅烷的研究进展。介绍了吡啶、联吡啶、吡咯等含N官能基与噻吩、硫代官能团等含S官能基取代聚硅烷的制备和光电性能表征,概括了含N,S官能团聚硅烷的分子设计、物理性能与应用领域。最后展望了含N、S官能团聚硅烷研究的发展方向与应用前景。 相似文献
67.
Dengxu Wang Lei Xue Liguo Li Bei Deng Shengyu Feng Hongzhi Liu Xian Zhao 《Macromolecular rapid communications》2013,34(10):861-866
Heck coupling reactions are introduced as an efficient method to prepare porous polymers. Novel inorganic‐organic hybrid porous polymers (HPPs) were constructed via Heck coupling reactions from cubic functional polyhedral oligomeric silsesquioxanes (POSS), iodinated octaphenylsilsesquioxanes (OPS) and octavinylsilsesquioxanes (OVS) using Pd(OAc)2/PPh3 as the catalyst. Here, two iodinated OPS were used, IOPS and p‐I8OPS. IOPS was a mixture with 90% octasubstituted OPS (I8) and some nonasubstituted OPS (I9), while p‐I8OPS was a nearly pure compound with ≥99% I8 and ≥93% para‐substitution. IOPS and p‐I8OPS reacted with OVS to produce the porous materials HPP‐1 and HPP‐2, which exhibited comparable specific surface areas with SBET of 418 ± 20 m2 g−1 and 382 ± 20 m2 g−1, respectively, with total pore volumes of 0.28 ± 0.01 cm3 g−1 and 0.23 ± 0.01 cm3 g−1, respectively. HPP‐1 showed a broader pore size distribution and possessed a more significant contribution from the mesopores, when compared with HPP‐2, thereby indicating that IOPS may induce more disorder because of the geometrical asymmetry. HPP‐1 and HPP‐2 possessed moderate carbon dioxide uptakes of 134 and 124 cm3 g−1 at 1 bar at 195 K, making them promising candidates for CO2 capture and storage. The synthesized porous polymers may be easily post‐functionalized using the retained ethenylene groups.
68.
Prof. Shengyu Dai Prof. Changle Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(35):14994-15000
The polyolefin industry is dominated by gas-phase and slurry-phase polymerization using heterogeneous catalysts. In contrast, academic research is focused on homogeneous systems, especially for late-transition-metal catalysts. The heterogenization of homogeneous catalysts is a general strategy to provide catalyst solutions for existing industrial polyolefin synthesis. Herein, we report an alternative, potentially general strategy for using homogeneous late-transition-metal catalysts in gas-phase and slurry-phase polymerization. In this self-supporting strategy, catalysts with moderate chain-walking capabilities produced porous polymer supports during gas-phase ethylene polymerization. Chain walking, in which the metal center can move up and down the polymer chain during polymerization, ensures that the metal center can travel along the polymer chain to find suitable sites for ethylene enchainment. This strategy enables simple heterogenization of catalysts on solid supports for slurry-phase polymerization. Most importantly, various branched ultra-high-molecular-weight polyethylenes can be prepared under various polymerization conditions with proper catalyst selection. 相似文献
69.
溶剂转移-气相色谱-质谱法和选择洗脱-气相色谱法测定大蒜中289种农药多残留 总被引:4,自引:0,他引:4
以溶剂转移净化为核心步骤,建立了一种适用于大蒜样品中农药多残留分析的前处理方法(方法I),配以一个辅助方法(方法II),构成大蒜中常见289种农药多残留的分析体系(方法I283种,方法II6种)。方法I中,样品用乙腈-水溶液提取,盐析分配,溶剂转移和固相萃取(SPE)净化后进行气相色谱-质谱(GC-MS)分析;方法II中,样品用无水Na2SO4配合乙酸乙酯均质研磨,超声波辅助提取,提取液经Primary Secondary Amine (PSA)粉末分散固相萃取和LC-Si柱选择洗脱净化后进行GC分析。GC-MS采用选择离子监测(SIM)方式,GC采用火焰光度检测器(FPD)检测,外标法定量。方法简便、快速,通过优化前处理和上机条件,在最优条件下进行测试,方法的定量限(S/N≥10)为0.01~0.05 mg/kg。方法I中,在加标水平为0.02、0.20 mg/kg时,回收率为52%~163%,其中回收率在70%~120%之间的占88%,相对标准偏差为2.4%~18%;方法II中,在加标水平为0.01、0.02、0.10、0.20 mg/kg时,回收率为70%~111%,相对标准偏差为3.2%~9.3%。详细描述了实验模型的构建,并对GC-MS灵敏度的提高提出了新的见解。该方法准确、灵敏、快速,可满足大蒜中多种农药残留的检测要求。 相似文献
70.