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991.
Preparation of Stereoregular Isotactic Poly(mandelic acid) through Organocatalytic Ring‐Opening Polymerization of a Cyclic O‐Carboxyanhydride 下载免费PDF全文
Dr. Antoine Buchard Dr. David R. Carbery Prof. Matthew G. Davidson Dr. Petya K. Ivanova Dr. Ben J. Jeffery Dr. Gabriele I. Kociok‐Köhn Dr. John P. Lowe 《Angewandte Chemie (International ed. in English)》2014,53(50):13858-13861
Poly(mandelic acid) (PMA) is an aryl analogue of poly(lactic acid) (PLA) and a biodegradable analogue of polystyrene. The preparation of stereoregular PMA was realized using a pyridine/mandelic acid adduct (Py?MA) as an organocatalyst for the ring‐opening polymerization (ROP) of the cyclic O‐carboxyanhydride (manOCA). Polymers with a narrow polydispersity index and excellent molecular‐weight control were prepared at ambient temperature. These highly isotactic chiral polymers exhibit an enhancement of the glass‐transition temperature (Tg) of 15 °C compared to the racemic polymer, suggesting potential future application as high‐performance commodity and biomedical materials. 相似文献
992.
Chiral Palladacycle Catalysts Generated on a Single‐Handed Helical Polymer Skeleton for Asymmetric Arylative Ring Opening of 1,4‐Epoxy‐1,4‐dihydronaphthalene 下载免费PDF全文
Dr. Takeshi Yamamoto Yuto Akai Prof. Dr. Michinori Suginome 《Angewandte Chemie (International ed. in English)》2014,53(47):12785-12788
Post‐polymerization C? H activation of poly(quinoxaline‐2,3‐diyl)‐based helically chiral phosphine ligands (PQXphos) with palladium(II) acetate afforded chiral phosphapalladacycles quantitatively. In situ generated palladacycles exhibited enantioselectivities up to 94 % ee in the palladium‐catalyzed asymmetric ring‐opening arylation of 1,4‐epoxy‐1,4‐dihydronaphthalenes with arylboronic acids. 相似文献
993.
以4-(1H-1,2,4-三氮唑)苯甲酸为配体,采用水热法合成了2种稀土配位聚合物[Tb(tbc3)(H2O)3]n(1)和{[Nd(tbc3)(H2O)3]·H2O}n(2)(Htbc=4-(1H-1,2,4-三氮唑)苯甲酸)。运用X-射线单晶衍射法对该配位聚合物进行了结构测定,并对其进行了元素分析、红外光谱、TG及荧光光谱表征。单晶结构表明,配位聚合物1为三斜晶系,空间群P1,配位聚合物2属于单斜晶系,空间群为P21/c。配位聚合物1和2均为一维链结构,均通过非共价键作用形成三维超分子构造。 相似文献
994.
((?)‐Menthyl (S)‐6′‐acrylyl‐2′‐methyloxy‐1,1′‐binaphthalene‐2‐carboxylate ( 3 ) was synthesized and anionically polymerized using n‐BuLi as an initiator in toluene. The monomer 3 was levorotatory and had an [α]D25 value of ?72.4, but its corresponding polymer poly‐ 3 was dextrorotatory and showed an [α]D25 value of +162.0. Poly‐ 3 was confirmed to exist in the form of one‐handed helical structure in solution by means of comparing the specific optical rotation and the CD spectra with that of 3 and the model compounds such as (?)‐menthyl (S)‐6′‐propionyl‐2′‐methyloxy‐1,1′‐binaphthalene‐2‐carboxylate 2b and (?)‐menthyl (S)‐6′‐heptanoyl‐2′‐methyloxy‐1,1′‐binaphthalene‐2‐carboxylate 2c . This conclusion was also confirmed by the fact that the g‐value of poly‐ 3 is about 11 times of that of monomer 3 . 相似文献
995.
Shun-Yang Yu Yan-Cang Li Tao Xiong Qun Yuan Yong-Ming Liu Zhong-Yi Yuan Yi Xiao 《中国化学快报》2014,25(2):364-366
In recent years, there has been a pronounced interest in solid-contact ion-selective electrodes (SC-ISEs), with emphasis on the use of conducting polymers as ion-to-electron transducer. In this work, a ladder conjugated polymer, thieno[3,2-b]thiophene (LCPT), was investigated in fabricating Cu2+-selective electrodes for the first time. The resulting electrodes were characterized by electrochemical impedance spectroscopy (EIS), chronopotentiometry, and the water layer test. Results proved that the active LCPT facilitates the ion-to-electron transduction, and avoids the detrimental aqueous layer formed at the interface of SC-ISEs. 相似文献
996.
A new Gd coordination polymer based on 2-(pyridin-4-yl)-I H-imidazole-4,5-dicarboxylate (H3PIDC) has been synthesized under hydrothermal conditions, formulated as {[Gd3(HPIDC)3(PIDC)(H2O)4].3H2O}n (1). The compound crystallizes in the monoclinic system, space group C2/c with a=20.951(7), b = 9.515(3), c = 27.483(10) A,β= 106.176(6)°, Z = 4, V= 5262(3) A3, C40 H45 Gd3 N12 O30, Dc = 2.071 g/cm3, Mr=1645.63, λ (MoKa)=0.71073A, μ=3.846mm-1, F(000)=3204, the final R=0.0390 and wR= 0.1332. Complex 1 is a two-dimensional MOF built up from T-shaped 3-connected HPIDC2 , PIDC3 and 4-connected metal nodes. Dielectric constant of complex 1 was measured at different frequencies with temperature variation. 相似文献
997.
998.
A new Cd(II) coordination polymer, namely, [Cd3(1,2,3-BTC)2(L)2]·2.25H2O (1, L = 2-(2-chloro-6-fluorophenyl)-1H-imidazo[4,5-A][1,10]phenanthroline and 1,2,3-BTC = 1,2,3-ben- zenetricarboxylate), has been synthesized under hydrothermal conditions. The compound was characterized by single-crystal X-ray diffraction. It crystallizes in triclinic, space group Pī with α = 11.650(2), b = 12.240(2), c = 19.760(4) A, α = 72.01(3), β = 77.11(3), γ = 83.48(3)°, V = 2609.4(9) A3, Z = 2, C56H31Cd3Cl2F2N8O14.25, Mr = 1489.99, Dc = 1.896 g/cm3, F(000) = 1466, μ(MoKa) = 1.401 mm^-1, R = 0.0401 and wR = 0.1104. Compound 1 shows a 1D chain structure, and the neigh- boring 1D chains of 1 are joined together by π···π interactions to result in a 2D supramolecular layer. In addition, the luminescent property of 1 has been studied in the solid state at room temperature. 相似文献
999.
With the improvement of high-tech and emergence of crossing and new fields,lanthanide-transition(Ln–M) heterometallic coordination polymers have attracted much attention of many researchers,which exhibit novel structures and unique properties with potential applications in the nonlinear optical materials,fluorescent materials,superconducting materials,magnetic materials,catalysis,bio-simulation,adsorption and separation,and so on.It is thus necessary to summarize Ln–M heterometallic coordination polymers.According to the transition metal ions,those coordination polymers are divided into six parts to explore the current applications and future developments. 相似文献
1000.
QV Jing-Yan MO Zong-Qiao SUN Ya-Qiu 《结构化学》2014,(7):990-994
A novel heterobimetaUic coordination polymer, {(NH4)2[Cd(H20)Fe(CN)6]}n 1, has been synthesized by using the slow diffusion method and structurally characterized by elemental analysis, 1R spectroscopy and single-crystal X-ray diffraction. The crystal crystallizes in the monoclinic system, space group P21/n, a = 7.4202(16), b = 14.939(3), c = 10.868(2) A and ,8 = 91.660(3)°. For 1, five CN groups of Fe(CN)6]4- are involved in bridging. The polymer displays a 3D open microporous framework with 5-connected uninodal (46.64) topology. 相似文献