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101.
102.
A simplified technique for synthesizing LiMn2O4 directly from lithium acetate and manganese acetate is introduced. The reaction mechanism is investigated by IR spectroscopy. Lithium-doped spinel materials show stronger Mn–O bonds and more stable structure than pure spinel by the IR spectroscopy investigations. The resultant materials show well-crystallized and small particles with a narrow size distribution and have a high initial reversible capacity of 127.6 mA h/g for x = 0.06 and can retain a capacity of 107 mA h/g after 100 cycles. 相似文献
103.
本文用变分方法考虑方程-Δpu=g(x,u)+f(x,u)无穷多解的存在性.这里Ω Rn是一个具有光滑边界 Ω的有界域,g∈C(Ω×R),g(x,t)关于t是奇的. 相似文献
104.
Guang‐Zhen Liu Hong‐Xia Zhang Zhi‐En Lin Shou‐Tian Zheng Jie Zhang Prof. Dr. Jing‐Tai Zhao Prof. Dr. Guo‐Ming Wang Dr. Guo‐Yu Yang Prof. Dr. 《化学:亚洲杂志》2007,2(10):1230-1239
The self‐assembly of Ge–O polyhedra by metal‐complex templates leads to initial examples of open germanate structures under mild solvothermal conditions. These materials are constructed from Ge–O cluster building bocks (Ge7X19 (X=O, OH, or F) or Ni@Ge14O24(OH)3) and span the full range of dimensionalities from 1D chains of Ge7O13(OH)2F3?Cl?2[Ni(dien)2] (FJ‐ 6 ) to 2D layers of Ge7O14F3?0.5[In(dien)2]?0.5H3dien? 2H2O ( 1 ) and 3D frameworks of Ni@ Ge14O24(OH)3?2[Ni(L)3] (FJ‐ 1 a /FJ‐ 1 b ) (dien=diethylenetriamine, L=ethylenediamine (en) or 1,2‐diaminopropane (enMe)). The Ge7X19 cluster in FJ‐ 6 and 1 is formed by condensation of four GeX4 tetrahedra, two GeX5 trigonal bipyramids, and one GeX6 octahedron with a μ3‐O atom at the center of the cluster, whereas the Ni@ Ge14O24(OH)3 cluster in FJ‐ 1 a /FJ‐ 1 b is formed by condensation of nine peripheral GeO4 tetrahedra and five interior GeO3Ni units with one μ5‐Ni atom at the center of the cluster. FJ‐ 6 is characterized by a pair of racemic Ge7O14(OH)2F3 cluster chains and represents only one example of 1D germanates; 1 exhibits unique germanate layers with uniform 10‐membered‐ring apertures encapsulating an unknown indium complex, and the framework structure of FJ‐ 1 a /FJ‐ 1 b with large 24‐membered‐ring channels is the first example of porous materials that contain metal–metal bonds (Ge2+? Ni+). These initial examples of germanates from metal‐complex templates provide a useful model system for understanding the mechanisms of host–guest interactions, which may further facilitate the design and development of new porous materials “on demand”. It is shown that the symmetry and configuration of the guest metal complex can be imprinted onto the host inorganic framework through hydrogen bonding between host and guest. 相似文献
105.
Two new organically templated borates, [H2DAB][B7O9(OH)5]·2H2O ( 1 ) and [H2DAB][B7O10(OH)3] ( 2 ), have been synthesized under mild conditions in the presence of DAB acting as structure‐directing agent (DAB = 1,4‐diaminobutane). The structures were determined by single crystal X‐ray diffraction and further characterized by FTIR, elemental analysis, and thermogravimetric analysis. Both 1 and 2 crystallize in the same triclinic system, space group (No. 2); 1: a = 8.238(4) Å, b = 8.348 (5) Å, c = 14.574(8) Å, a = 101.050(3)°, β = 92.313(7)°, γ = 112.694(5)°, V = 900.3(8) Å3, Z = 2; 2: a = 8.8769(3) Å, b = 9.3204(2) Å, c = 10.2204(5) Å, α = 74.474(2)°, β = 85.292(5)°, γ = 72.730(2)°, V = 778.01(5) Å3, Z = 2. The structure of 1 consists of [B7O9(OH)5]2? groups, which represents the first example of organically templated heptaborate. The structure exhibits interesting hydrogen‐bonded network formed by borate polyanion [B14O20(OH)6]4?, which can be regarded as being constructed from the dehydration of the FBBs in 1 . The diprotonated organic amines are filled in the free space of the hydrogen‐bonded network and interact with the inorganic framework by extensive hydrogen bonds. 相似文献
106.
利用溶液法合成了配合物[Ni(Hlact)2(phen)]·2H2O(1),并对该配合物进行了元素分析、红外光谱和X-射线单晶衍射表征。通过荧光光谱法研究了不同温度下配合物1与牛血清白蛋白相互作用时的荧光强度的变化,计算了在不同温度下,配合物1与牛血清白蛋白(BSA)的结合常数、结合位点数以及热力学函数,并进一步讨论了配合物1与BSA相互作用时的作用力类型和两者之间的距离。结果表明,配合物1对牛血清白蛋白的荧光猝灭为静态猝灭过程,它与牛血清白蛋白的相互作用有一个位点,结合常数的平均值5.06×105L·mol-1,作用距离为2.35 nm,相互作用力表现为氢键和范德华力。 相似文献
107.
Four amino acid derivatives and two binaphthyl compounds were enantioseparated successfully by HPLC with a chiral stationary phase commercially named Kromasil CHI-DMB, which contains an immobilized network polymer derived from L-tartaric acid. Chromatographic experiments were performed under normal phase conditions. n-Hexane/2-propanol was used as mobile phase. The effects of the content of 2-propanol and the column temperature on the retention and enantioseparation were studied systematically. Associated apparent thermodynamic parameters were calculated from the van’t Hoff plots. It was found that the enantioseparations of these amino acid derivatives were typical enthalpy driven, but for binaphthyl compounds the entropy term was also favorable to enantioselectivity in most cases. From the changes of the thermodynamic parameters and the isoenantioselective temperatures with the variety of mobile phase polarity, it was deduced that the CSP underwent remarkable conformational change when the content of 2-propanol was below 3%. 相似文献
108.
109.
Denote by
n
the set of the hexagonal chains with n hexagons. For any B
n
n
, let m
k
(B
n
) and i
k
(B
n
) be the numbers of k-matchings and k-independent sets of B
n
, respectively. In the paper, we show that for any hexagonal chain B
n
n
and for any k0, m
k
(L
n
)m
k
(B
n
)m
k
(Z
n
) and i
k
(L
n
)i
k
(B
n
)i
k
(Z
n
), with left equalities holding for all k only if B
n
=L
n
, and the right equalities holding for all k only if B
n
=Z
n
, where L
n
and Z
n
are the linear chain and the zig-zag chain, respectively. These generalize some related results known before. 相似文献
110.