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991.
A chloromethylated styrene-divinylbenzene copolymer support system functionalized with 4-benzaldehyde and 2-benzaldehyde was prepared.The degree of functionalization with aldehyde groups is well suited for the subsequent use of the products as Wittig reagents.The polymer bound aldehyde was reacted with Wittig reagents to give olefin groups grafted on styrene-divinylbenzene copolymers.The reactions were carried out in phase transfer catalysis conditions.A simple procedure for the calculation of the degree of functionalization and the statistical modeling of the structural repetitive unit of the copolymer are reported. 相似文献
992.
几种取代胡椒醛缩合不对称卟啉化合物的合成及结构表征 总被引:1,自引:0,他引:1
利用微波加热法, 以6-硝基胡椒醛、两种R取代苯甲醛(R=H, Cl)、吡咯为原料, 在丙酸中缩合, 合成了两种新的不对称卟啉化合物5-(2-硝基-4,5-亚甲二氧基)苯基-10,15,20-三苯基卟啉(2)和5-(2-硝基-4,5-亚甲二氧基)苯基-10,15, 20-三对氯苯基卟啉(3). 将2和3还原得到了化合物5-(2-氨基-4,5-亚甲二氧基)苯基-10,15,20-三苯基卟啉(4)和5-(2-氨
基-4,5-亚甲二氧基)苯基-10,15,20-三对氯苯基卟啉(5). 新化合物结构分别经UV-Vis, IR, 1H NMR及元素分析所证实. 荧光测试表明, 几个化合物都有比较好的荧光强度, 且氨基取代化合物的荧光强度比相应的硝基化合物的大. 相似文献
993.
叶绿素-a衍生物的化学反应和多取代卟吩(啉)合成的研究进展 总被引:13,自引:0,他引:13
天然产物叶绿素-a衍生物所具有的特殊理化性质以及连带多种活性取代基团的非对称性骨架结构, 决定其化学反应的活泼性和实际应用的广泛性. 基于以叶绿素-a及其衍生物为研究对象的化学反应和结构修饰, 综述了近期多取代卟吩(啉)合成的研究进展. 相似文献
994.
R. Sridarane G. Raje D. Shanmukaraj B. J. Kalaiselvi M. Santhi S. Subramanian S. Mohan B. Palanivel R. Murugan 《Journal of Thermal Analysis and Calorimetry》2004,75(1):169-178
The understanding of molecular level structural information of phosphate glasses is very much essential. The unique microwave-absorbing ability of NaH2PO4·2H2O was found to be very useful for preparing crystal and glassy sodium super ionic conductors (Nasicon's) as a component of batch mixtures. In this work NaPO3 glass was prepared by both conventional melt quench and microwave heating from NaH2PO4·2H2O as a starting material. The structure of NaPO3 glass and their structural evolution upon heating through glass transition were probed by combination of complementary techniques like differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) and thermo-Raman spectroscopy.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
995.
介绍一个有机化学综合实验,实验以N-苄基马来酰亚胺为反应物,在三丁基膦催化下发生自身三分子串联环化反应生成N-苄基马来酰亚胺三聚体,并利用核磁共振氢谱(1H NMR)、碳谱(13C NMR)和X射线单晶衍射对产物结构进行表征。有机化学综合实验不仅可以有效提升学生的基本实验操作能力,巩固对专业知识的理解,而且有利于培养学生严谨的科学态度和科研兴趣,为后续的学习和深造打下坚实基础。 相似文献
996.
水系钠离子电池具有钠资源丰富、成本低廉、安全可靠、维护简单等特点,在可再生能源规模储存领域具有重要应用前景。NASICON型NaTi2(PO4)3具有可逆容量高、工作电位低、离子传输快等优点,是目前最受关注的水系钠离子电池负极材料。但是,该材料在传统的水系电解液中结构不稳定,循环性能不足。本论文通过调控Na2SO4浓度和引入MgSO4添加剂,构建了一种新型硫酸盐功能电解液(2 mol·L-1 Na2SO4 + 0.3 mol·L-1 MgSO4)。该电解液能够显著增强NaTi2(PO4)3/C材料在充放电循环过程中的结构稳定性,从而提高其电化学可逆性和稳定性。电化学测试表明,NaTi2(PO4)3/C基于该电解液在100 mA·g-1条件下的可逆容量为93.4 mAh·g-1,循环100次后容量保持率高达96.5%;基于该电解液构建的Na2Ni[Fe(CN)6]|NaTi2(PO4)3/C电池可以稳定循环500次以上。本论文结合XRD、XPS等技术讨论分析了该电解液的功能作用机制,其研究结果为设计低成本高性能水系钠离子电池提供了新思路和实验基础。 相似文献
997.
《Journal of separation science》2018,41(4):847-855
A liquid chromatography with tandem mass spectrometry method was developed for the determination of 27 glutamyl di‐ and tripeptides in food ingredients. Such compounds are of importance for the food industry, as they can modulate the perception of basic tastes (sweet, salty, and umami). Due to their high polarity, the hydrophilic interaction chromatography mode was selected to have sufficient retention on the column and the best separation was obtained on an amide hybrid silica stationary phase packed with 1.7 μm particles. Thorough optimization of the mobile phase was performed as the start‐composition had to be free of ammonium to avoid on‐column cis–trans isomerization of the first eluting proline dipeptide. A baseline separation was achieved for all α and γ isomers whereas only a partial resolution was obtained for γ‐Glu‐Leu and γ‐Glu‐Ile, for which only the position of a methyl group differs. A fast sample preparation, based on successive dilutions, was performed before injection into the liquid chromatography with tandem mass spectrometry system. The developed method was then applied for the semi‐quantification of glutamyl di‐ and tri‐peptides in four different food ingredients. The methodology will further support the optimization of production processes to select the conditions for which the peptide concentrations would be the highest. 相似文献
998.
E. I. Matrosov Z. A. Starikova A. I. Yanovsky D. I. Lobanoy I. M. Aladzheva O. V. Bykhovskaya T. A. Mastryukova M. I. Kabachnik 《Russian Chemical Bulletin》1998,47(9):1702-1709
The behavior of the phosphine-phosphine sulfide complexes of silver, [Ph2P(S)(CH2)
n
PPh2]
m
·AgNO3 (n=2 or 4;m=1 or 2), in pyridine was studied. Dissolution of the 1:1 complexes in pyridine leads to destruction of their dimeric structures
Ag2[Ph2P(S)(CH2)
n
PPh2]2(NO3)2 (A) to form the complexes Agpy
+−P(Ph2)(CH2)
n
Ph2P=S and Agpy
+−S=PPh2(CH2)
n
PPh2. The solid complexes isolated from pyridine restore dimeric structure A. According to the data of X-ray diffraction analysis,
the 1:2 complex isolated from pyridine has the structure [S=P(Ph2)(CH2)2(Ph2)P−(NO3)Ag(Py)−P(Ph2) (CH2)2(Ph2)P=S]Py. According to the data of IR spectroscopy, dissolution of this complex in chloroform leads to the formation of the
dimeric structure Ag2Ph2P(S)(CH2)2PPh2]4(NO3)2.
Deceased.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1751–1758, September, 1998. 相似文献
999.
Steven P. Nolan Kenneth L. Martin Dan Buzatu Mark L. Trudell Edwin D. Stevens Paul J. Fagan 《Structural chemistry》1993,4(6):367-375
The synthetic, thermodynamic and structural investigations of organoruthenium complexes of the form Cp*Ru(triene)OTf (Cp*=n5-(CH3)5C5; triene=anisole 1, indole 2, cycloheptatriene 3, OTf=OSO2CF3) are presented in this contribution. A direct entryway into the thermochemistry of these complexes is made possible by the rapid and quantitative arene/triene substitution for the three acetonitrile ligands in Cp*Ru(CH3CN)3OTf. The solution calorimetric study establishes the following order of stability: cycloheptatriene < anisole < indole. This study helps clarify the enthalpic and entropic components to the thermodynamic driving forces behind the formation of ruthenium arene/triene complexes. The solid-state structures of these three complexes(1–3) were determined by X-ray single-crystal studies. Thermodynamic factors affecting the Ru-triene bond energy are compared with structural results for these three ruthenium complexes. 相似文献
1000.
[Mn(ATO)~2(H~2O)~4](PA)~2的制备、结构表征和热分 解机理研究 总被引:5,自引:0,他引:5
对新型配合物------苦味酸二(4-氨基-1,2,4-三唑-5-酮)四水合锰采用元素分析、FT-IR分析、粉末X射线衍射分析和单晶结构分析基础上,在线性升温条件下,用DSC,TG-DTG技术对该化合物的热分解过程进行了研究,得出了其热分解机理。 相似文献