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241.
242.
无载频脉冲探地雷达性能分析及其FD—TD法数值模拟计算 总被引:1,自引:0,他引:1
探测深度和分辩率是探地雷达的两项重要指标。本文分别对无载频脉冲探地雷达的探测深度和分辩率进行了分析,指出了影响雷达探测深度和分辩率的因素,并利用2。5维时时有限差分方法对雷达的探测性能进行了数值模拟计算,给出了地下单体目标和多体目标的回波信号电平图,并将部分计算结果与实验测试结果进行了对比,二者具有好的一致性。 相似文献
243.
SHI Wei LIU Hai-yan REN Dong-mei MA Zhuo SUN Wen-dong 《高等学校化学研究》2006,22(3):364-367
Introduction Theisobutane/butenealkylationintherefiningin dustryforobtainingacleangasolinewithahigh octane valueisveryimportant[1,2].Sulfuricandhydrofluoric acidsareusedascatalystsinthecurrentindustrial processesfortheisobutane/butenealkylation,inwhich ca… 相似文献
244.
急倾斜煤层地下气化数学模型的研究 总被引:5,自引:1,他引:5
煤炭地下气化产气过程与气化炉体的温度分布和渗流条件密切相关。根据急倾斜煤层赋存条件和气化过程的特点,建立了急倾斜煤层地下气化数学模型。介绍了模型参数的确定方法,采用控制容积方法对模型进行了求解,并在模型实验的基础上,对计算结果进行了分析。从温度场分布来看,计算值略高于实测值,各测点相对误差基本均在10%以内。根据模拟计算结果,随着气化通道长度增加,煤气热值提高,但在还原区以后,提高的幅度减小,温度场对煤气热值产生显著影响。由于受温度的影响,在高温区,煤气组分浓度场实测值的变化梯度大于计算值。结果表明,模拟值与实验值能够较好地相吻合,说明对急倾斜煤层地下气化温度场和浓度场的数值模拟是合理的。 相似文献
245.
ZHANG Ting-Ting JU Yan-Ling WANG Chun-Yan LI Yan-Qiu LI Xia 《结构化学》2007,26(7):838-842
The complex [Eu(3-IBA)3·2,2'-bipy]2 was synthesized from 3-iodobenzoic acid (3-HIBA), 2,2'-bipyridine (2,2‘-bipy) and EuCl3·6H2O by hydrothermal synthesis, and its crystal structure was determined by X-ray single-crystal diffraction. It is of triclinic, space group Pi, with a = 10.958(2), b = 12.311(3), c = 12.556(3) A, α = 81.549(3), β = 82.404(4), γ = 78.348(3)°, Mr = 1049.15, V= 1631.7(6) A3, Z = 1, Dc = 2.135 g/cm^3, F(000) = 980, 2(MoKa) = 0.71073 A,μ(MoKa) = 4.804 mm^-1, the final R = 0.0329 and wR = 0.0723 for 4640 observed reflections with I 〉 2σ(I). The Eu(Ⅲ) ion is eight-coordinated and two Eu(Ⅲ) ions are held together by four 3-iodobenzoate groups in the bidentate bridging mode. The complex was characterized by DTA-TG, IR, UV and fluorescence spectra. 相似文献
246.
New hydrated potassium hexaborate K2[B6O9(OH)2] has been synthesized under mild solvothermal conditions. The structure was determined by single-crystal X-ray diffraction and further characterized by FT-IR, Rarnan spectra and DTA-TG. It crystallizes in the monoclinic system with space group P21/n, a=0.9036(2) nm, b=0.66052(18) nm, c=1.5997(4) nm, β=91.862(4)°, V=0.9543(4) nm^3 and Z=4. Its crystal structure consists of K-O polyhedra and 1-D stepped polyborate chains constructed by new [B6O9(OH)2]2- fundamental building blocks. 1-D polyborate chains contain 3,8-membered boron rings. Adjacent chains are further linked via H-bonding interactions into 2-D layers. The K^+ cations reside not only between the layers but also in the 8-membered boron rings of the chains, compensating the negative charges of the borate chains and holding the layers together into the 3-D structure through bonding with oxygen atoms of the chains. 相似文献
247.
A new metal-organic coordination polymer [Cd(5-hip)(phen)]n·nH2O 1 has been hydro- ermally synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. The crystal of the complex crystallizes in monoclinic, space group P2/n with a = 8.8071(17), b =12.386(2), c = 16.981(3) A, β = 100.182(2)°, V = 1823.2(6) A^3, Mr=. 490.73, Dc =1.788 g/cm^3,μ(MoKa) = 1.240 mm^-1, F(000) = 976, Z= 4, the final R = 0.0458 and wR = 0.1373 for 2864 observed reflections (I 〉 2σ(I)). The Cd atoms are coordinated by two N atoms from the phen ligands and four O atoms from 5-hydroxyisophthalate ligands in a highly distorted octahedral geometry. 相似文献
248.
One novel complex [Ni(phen)3],(C8H12O4)·(H2O)14 with hexane dicarboxylic acid and 1,10-phenanthroline has been hydrothermally synthesized and characterized. Crystal data: monoclinic, space group C2/c, a = 2.3475(5), b = 1.2208(2), c = 1.9499(4) nm, β= 114.682(3)°, V = 5.0778(16) nm^3, Dc = 1.339 g/cm^3, Z = 4,μ(MoKa) = 0.458 mm^-1, F(000) = 2168, GOOF = 1.014, R = 0.0401 and wR = 0.0961. The nickel(H) center in the title complex is coordinated with six nitrogen atoms of three 1,10-phenanthroline molecules, giving a distorted octahedral coordination geometry. However, the nickel(Ⅱ) ion does not coordinate to the hexane dicarboxylic acid. The complex molecules form a 3D structure through hydrogen bonds. TG analysis shows that the title complex is stable below 240.0 ℃. 相似文献
249.