全文获取类型
收费全文 | 103篇 |
免费 | 3篇 |
国内免费 | 8篇 |
专业分类
化学 | 82篇 |
晶体学 | 1篇 |
力学 | 1篇 |
物理学 | 30篇 |
出版年
2022年 | 1篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 4篇 |
2017年 | 7篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 7篇 |
2012年 | 3篇 |
2011年 | 4篇 |
2010年 | 3篇 |
2009年 | 1篇 |
2008年 | 9篇 |
2007年 | 6篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2004年 | 12篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有114条查询结果,搜索用时 15 毫秒
111.
P. Schobinger-Papamantellos K.H.J. BuschowJ. Rodríguez-Carvajal 《Journal of magnetism and magnetic materials》2011,323(21):2592-2607
The temperature magnetic phase diagrams of the dimorphic HoSi compound were studied by neutron diffraction. The sample comprises 35.5% CrB- (Cmcm) and 64.5% FeB-type (Pnma) of structure. Both phases order antiferromagnetically below TN=25 K and undergo first-order magnetic transitions at Tic=16.5 K. Their T-phase diagrams comprise a low temperature (LT) 2.7 K−Tic and a high temperature (HT) range Tic−TN with distinct wave vectors.The LT magnetic ordering of the CrB-type HoSi with the wave vector q1=(1/2, 0, 1/2) corresponds to a uniaxial magnetic structure, with the Ho moments along the shortest axis c. At 2.7 K the ordered moment value is 8.6(2) μB/Ho atom. The HT ordering, described by the wave vector q2=(q2x, 0, q2z) with a T-variable length, corresponds to an amplitude modulated structure.The magnetic ordering of the FeB-type HoSi requires two symmetry independent vectors q3=(0, q3y, q3z) for the LT- and q4=(q4x, q4y, 0) for the HT range. Both vectors correspond to sine wave modulated structures with the Ho magnetic moments confined along the shortest axis b. The q3 vector has an almost invariable length vs. T close to ≈(0, 9/17, 1/11). At 2.7 K the amplitude of the wave is 10.9(1) μB/Ho atom. At Ticq3 jumps to the wave vector q4=(q4x, q4y, 0) with a T-variable length. At 17 K q4=(0.092(1), 0.538(3), 0). Around Tic there is a narrow coexistence range of the q3 and q4 competing phases. Various models are discussed and compared with the isomorphic RSi (R=rare earth) compounds counterparts of HoSi, a comparison that has led us to briefly review the magnetic structures available in the literature for this interesting class of compounds. 相似文献
112.
113.
Ho(Ⅲ)希夫碱大环配合物的合成、晶体结构及对DNA的切割活性 总被引:1,自引:0,他引:1
合成了一个新的希夫碱大环配体硝酸Ho(Ⅲ)配合物[Ho(H2L)(NO3)2](NO3)(H2L表示大环配体),并进行了系统的物理表征.晶体结构研究表明,配合物晶体结构属六方晶系,P3121空间群,晶胞参数a=1.47213(7)nm,c=2.8998(3)nm,α=90°,γ=120°,V=5.4424(7)nm3,Z=6,R=0.0331,wR=0.0928.中心离子Ho3+位于隔室大环配体的一侧,并与希夫碱大环上的2个酚基氧原子和3个氮原子配位,2个双齿配位硝酸根分别从希夫碱大环平面的两侧与中心离子配位,使中心离子形成扭曲的九配位三冠三棱柱构型.通过凝胶电泳实验初步研究了该配合物对pBR322质粒DNA的切割作用. 相似文献
114.
Florea Dumitrascu Ana-Maria Udrea Mino R. Caira Diana Camelia Nuta Carmen Limban Mariana Carmen Chifiriuc Marcela Popa Coralia Bleotu Anamaria Hanganu Denisa Dumitrescu Speranta Avram 《Molecules (Basel, Switzerland)》2022,27(9)
The efficient regioselective bromination and iodination of the nonsteroidal anti-inflammatory drug (NSAID) carprofen were achieved by using bromine and iodine monochloride in glacial acetic acid. The novel halogenated carprofen derivatives were functionalized at the carboxylic group by esterification. The regioselectivity of the halogenation reaction was evidenced by NMR spectroscopy and confirmed by X-ray analysis. The compounds were screened for their in vitro antibacterial activity against planktonic cells and also for their anti-biofilm effect, using Gram-positive bacteria (Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212) and Gram-negative bacteria (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853). The cytotoxic activity of the novel compounds was tested against HeLa cells. The pharmacokinetic and pharmacodynamic profiles of carprofen derivatives, as well as their toxicity, were established by in silico analyses. 相似文献