全文获取类型
收费全文 | 127篇 |
免费 | 4篇 |
国内免费 | 26篇 |
专业分类
化学 | 150篇 |
晶体学 | 2篇 |
综合类 | 1篇 |
物理学 | 4篇 |
出版年
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 6篇 |
2014年 | 7篇 |
2013年 | 11篇 |
2012年 | 16篇 |
2011年 | 10篇 |
2010年 | 4篇 |
2009年 | 4篇 |
2008年 | 3篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 5篇 |
2003年 | 7篇 |
2002年 | 1篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 12篇 |
1998年 | 1篇 |
1997年 | 7篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有157条查询结果,搜索用时 15 毫秒
51.
52.
现场红外光谱电化学;亚铁氰化钾;对苯二酚;双光窗夹套式红外反射薄层电化学池的制作与表征 相似文献
53.
Xian Yang Sergio Navarro Garcia Tobias Janoschka Dnes Knya Martin D. Hager Ulrich S. Schubert 《Molecules (Basel, Switzerland)》2021,26(13)
Owing to their broad range of redox potential, quinones/hydroquinones can be utilized for energy storage in redox flow batteries. In terms of stability, organic catholytes are more challenging than anolytes. The two-electron transfer feature adds value when building all-quinone flow battery systems. However, the dimerization of quinones/hydroquinones usually makes it difficult to achieve a full two-electron transfer in practical redox flow battery applications. In this work, we designed and synthesized four new hydroquinone derivatives bearing morpholinomethylene and/or methyl groups in different positions on the benzene ring to probe molecular stability upon battery cycling. The redox potential of the four molecules were investigated, followed by long-term stability tests using different supporting electrolytes and cell cycling methods in a symmetric flow cell. The derivative with two unoccupied ortho positions was found highly unstable, the cell of which exhibited a capacity decay rate of ~50% per day. Fully substituted hydroquinones turned out to be more stable. In particular, 2,6-dimethyl-3,5-bis(morpholinomethylene)benzene-1,4-diol (asym-O-5) displayed a capacity decay of only 0.45%/day with four-week potentiostatic cycling at 0.1 M in 1 M H3PO4. In addition, the three fully substituted hydroquinones displayed good accessible capacity of over 82%, much higher than those of conventional quinone derivatives. 相似文献
54.
Here, Pd nanoparticles and poly(taurine) film was prepared on the glassy carbon electrode surface (Pd/Poly(TAU)/GCE) by the rapid electrochemical technique. The proposed composite surface was characterized by scanning electron microscopy(SEM), X‐ray photoelectron spectroscopy(XPS) and electrochemical impedance spectroscopy(EIS). Enhanced electron transfer ability and higher electroactive surface area were achieved at Pd/Poly(TAU)/GCE as compared to the bare GCE and polymer film electrode. The new and highly stable Pd/Poly(TAU)/GCE was employed for the individual and simultaneous determination of hydroquinone and catechol which were environmentally toxic. Under the optimized conditions, HQ and CC were individually determined by using the differantial pulse voltammetry in the linear ranges of 0.008–100 μM and 0.001–100 μM with the detection limits of (LOD) 2.1 nM and 0.68 nM, respectively. In case of simultaneous determination, LODs were found as 10 nM and 0.88 nM for HQ and CC, respectively. The content of both analytes in the real sample analysis was evaluated in the river water and tap water successfully. 相似文献
55.
用Nafion将单壁碳纳米管(SWCNT)固定到玻碳电极(GCE)上,再利用电化学聚合方法将L-白氨酸(L-LEU)聚合到SWCNT/GCE上,制备得到poly L-LEU/SWCNT/GCE修饰电极。采用循环伏安法(CV)、差分脉冲伏安法(DPV)和电化学交流阻抗法(EIS)研究了对苯二酚(HQ)、邻苯二酚(CC)共存时,二者在修饰电极上的电化学行为。结果表明:此修饰电极对HQ和CC有很好的电催化和分离作用。二者在修饰电极上的氧化还原峰电流与GCE相比显著增强,HQ和CC的氧化峰电位差和还原峰电位差分别为124 mV和131 mV。HQ和CC的检测线性范围分别为2.0×10-7~1.0×10-4、5.0×10-7~1.0×10-4mol/L。检出限分别为8.0×10-8、1.0×10-7mol/L。制备的修饰电极重现性、稳定性良好。在模拟废水中采用该修饰电极对HQ和CC进行检测,结果满意。 相似文献
56.
酪氨酸酶通过乙二胺作为悬臂分子稳定地固定到功能化氧化石墨烯上,再将该杂化材料修饰玻碳电极表面制成新型生物传感器。酪氨酸酶固定在氧化石墨烯上的物理化学行为通过X射线光电子光谱和电化学阻抗进行表征,显示功能化氧化石墨烯可以促进固定酶的活性位点与修饰电极之间的电子传递。通过循环伏安法研究该电极的直接电化学和电催化行为,表明其电化学行为是一个直接的吸附控制氧化还原反应。在优化实验条件下,对苯二酚在3.0~200.0μmol/L浓度范围内与其氧化峰电流呈良好的线性关系,检出限(S/N=3)达1.0μmol/L。该生物传感器显示了较好的重现性、稳定性及选择性,在实际水样检测中得到良好应用。 相似文献
57.
William L. Harrison Feng Wang Jeffery B. Mecham Vinayak A. Bhanu Melinda Hill Yu Seung Kim James E. McGrath 《Journal of polymer science. Part A, Polymer chemistry》2003,41(14):2264-2276
New sulfonated poly(arylene ether sulfone) copolymers with high molecular weights were successfully synthesized with controlled degrees of disulfonation of up to 70 mol % via the direct copolymerization of sulfonated aromatic dihalides, aromatic dihalides, and one of four structurally distinct bisphenols. The disodium salts of the 3,3′‐disulfonated‐4,4′‐dichlorodiphenyl sulfone and 3,3′‐disulfonated‐4,4′‐difluorodiphenyl sulfone comonomers were synthesized via the sulfonation of 4,4′‐dichlorodiphenyl sulfone or 4,4′‐difluorodiphenyl sulfone with 30% fuming sulfuric acid at 110 °C. Four bisphenols (4,4′‐bisphenol A, 4,4′‐bisphenol AF, 4,4′‐biphenol, and hydroquinone) were investigated for the syntheses of novel copolymers with controlled degrees of sulfonation. The composition and incorporation of the sulfonated repeat unit into the copolymers were confirmed by 1H NMR and Fourier transform infrared spectroscopy. Solubility tests on the sulfonated copolymers confirmed that no crosslinking and probably no branching occurred during the copolymerizations. Tough, ductile films were solvent‐cast that exhibited increased water absorption with increasing degrees of sulfonation. These copolymers are promising candidates for high temperature proton‐exchange membranes in fuel cells, which will be reported separately in part II of this series. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2264–2276, 2003 相似文献
58.
Hydroquinone can be complexed on MoO3 surfaces and is converted top-benzoquinone in a mild solid phase redox reaction while MoO3 is reduced to Mo(V) and Mo(III) species. 相似文献
59.
采用循环伏安法(CV)制备了曙红修饰玻碳电极(eosin Y/GCE),电化学交流阻抗法对修饰电极表面进行了表征,研究了特丁基对苯二酚(TBHQ)在该修饰电极上的电化学行为,建立了循环伏安法和差分脉冲伏安法(DPV)测定TBHQ的新方法。研究表明,修饰电极对TBHQ的氧化还原具有较好的电催化活性,在eosin Y/GCE上的氧化还原峰电位差从297 m V降至85 m V。在20~400 m V·s-1范围内,其氧化还原峰电流与扫速的平方根呈良好的线性关系,表明TBHQ在eosin Y/GCE上的电极反应受扩散控制。在0.10 mol·L-1磷酸盐缓冲溶液(p H 6.5)中,扫速为100 m V·s-1时,此修饰电极的DPV响应与TBHQ浓度在1~200μmol·L-1范围内呈线性关系,检出限(S/N=3)为0.1μmol·L-1。此修饰电极具有良好的选择性、重现性和稳定性,应用于油品中TBHQ的测定,回收率达95.0%~102.5%。该电极有望应用于多种食品中抗氧化剂的检测。 相似文献
60.
采用涂覆法制备了CoAl_2O_4/蜂窝陶瓷催化剂。利用X射线衍射、N_2吸附-脱附和透射电镜等方法对所制备的催化剂进行了表征,并分析了其催化臭氧化降解对苯二酚的效能。结果表明,CoAl_2O_4/蜂窝陶瓷的晶相属于典型的尖晶石结构,具有较大的比表面积、孔容和孔径,分别达到77 m~2·g~(-1)、0.001 7 cm~3·g~(-1)和3.9 nm。CoAl_2O_4/蜂窝陶瓷催化臭氧化对苯二酚的去除率高达81.2%,COD去除率可达47.7%。在叔丁醇存在的条件下,对苯二酚的去除率显著下降,说明CoAl_2O_4/蜂窝陶瓷催化臭氧化遵循羟基自由基机理。 相似文献