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1.
Poly(aryl ether ketone) composite membrane as a high‐performance lithium‐ion batteries separator 下载免费PDF全文
Min Xie Mingying Yin Guangdi Nie Jun Wang Ce Wang Danming Chao Xincai Liu 《Journal of polymer science. Part A, Polymer chemistry》2016,54(17):2714-2721
We described the design and synthesis of a modified poly(aryl ether ketone) bearing phenolphthalein and allyl groups (P‐PAEK) via nucleophilic polycondensation. A new kind of composite separator, crosslinked P‐PAEK/polyvinylidene fluoride (c‐P‐PAEK/PVDF) membrane was successfully prepared using phase separation, phase inversion method, and UV crosslinking technique. As a separator of lithium‐ion battery, c‐P‐PAEK/PVDF membrane demonstrates high porosity and uniform distribution of pores with interconnected pathways. Low thermal shrinkage, distinct shut‐down effect, high liquid electrolyte uptake capacity, and exciting liquid electrolyte wettability of the prepared c‐P‐PAEK/PVDF membrane have been revealed through comprehensive study. Moreover, the c‐P‐PAEK/PVDF membrane was applied to assemble a conventional Li/LiFePO4 coin cell, which exhibited hopeful cell performance. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2714–2721 相似文献
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3.
Hu Jinbang Liu Wei Xia Liangjun Yu Guangdi Huang Hongbo Guo Heng Zhang Wen Wang Yunli Xu Weilin 《Cellulose (London, England)》2021,28(12):7909-7924
Cellulose - Cellulosic Juncus effusus fiber with porous structure, belonging to the carbohydrate polymers group, was chemically modified by a resin to form a cellulose-based adsorbent (FA–JE)... 相似文献
4.
Jiqing Xu Renzhang Wang Chunxiao Guo Guoyu Yang Qingxin Zeng Weiming Bu Ling Ye Yuguo Fan Guangdi Yang 《中国科学B辑(英文版)》2001,44(2):137-146
A nickel-1,10-phenanthroline complex supported on an octamolybdate, [(Ni(phen)2
2(ξ-Mo8O26)], has been hydrothermally synthesized with MoO3, H2MoO4, Ni(OAc)2 6H3O and 1,10-phenathroline (1,10-phen) as raw materials. The crystals of the compound belong to monoclinic P21/n space group,a = 1.2952(2),b = 1.6659(10),c = 1.3956(12) nm, β =106.273(8)°,V = 2.8906(5) nm3,Z = 2. 5604 observable reflections (I >2σ(I)) were used for structure resolution and refinements to converge to finalR
1 = 0.0414,wR
2 = 0.0815. The result of structure determination shows that the compound contains octamolybdate possessing a novel structure
type (named as ξ-isomer). The feature of ξ-[Mo8O26]4- is that it is composed of Mo6O6 ring and two MoO6 octahedral located at cap positions on opposite faces. The Mo6O6 ring contains two octahedral and four trigonal-bipyramidal MoVI atoms. Each ξ-[Mo8O26]4- unit is bonded with two [Ni(phen)2]2+ through terminal oxygen atoms of octahedral and neighbouring trigonal-bipyramidal Mo atom in the Mo6O6 ring. IR and UV-Vis spectra of the compound were measured and its electronic structure was studied by EHMO method. 相似文献
5.
Hill MP Carroll EC Vang MC Addington TA Toney MD Larsen DS 《Journal of the American Chemical Society》2010,132(47):16953-16961
The mechanisms of pyridoxal 5'-phosphate (PLP)-dependent enzymes require substrates to form covalent "external aldimine" intermediates, which absorb light strongly between 410 and 430 nm. Aspartate aminotransferase (AAT) is a prototypical PLP-dependent enzyme that catalyzes the reversible interconversion of aspartate and α-ketoglutarate with oxalacetate and glutamate. From kinetic isotope effects studies, it is known that deprotonation of the aspartate external aldimine C(α)-H bond to give a carbanionic quinonoid intermediate is partially rate limiting in the thermal AAT reaction. We show that excitation of the 430-nm external aldimine absorption band increases the steady-state catalytic activity of AAT, which is attributed to the photoenhancement of C(α)-H deprotonation on the basis of studies with Schiff bases in solution. Blue light (250 mW) illumination gives an observed 2.3-fold rate enhancement for WT AAT activity, a 530-fold enhancement for the inactive K258A mutant, and a 58600-fold enhancement for the PLP-Asp Schiff base in water. These different levels of enhancement correlate with the intrinsic reactivities of the C(α)-H bond in the different environments, with the less reactive Schiff bases exhibiting greater enhancement. Time-resolved spectroscopy, ranging from femtoseconds to minutes, was used to investigate the nature of the photoactivation of C(α)-H bond cleavage in PLP-amino acid Schiff bases both in water and bound to AAT. Unlike the thermal pathway, the photoactivation pathway involves a triplet state with a C(α)-H pK(a) that is estimated to be between 11 and 19 units lower than the ground state for the PLP-Val Schiff base in water. 相似文献
6.
在改进的条件下,二苯并-18-冠-6硝化反应的产率达90%以上。提出一种分离二硝基二苯并-18-冠-6的顺、反异构体的方法。反应产物经元素分析和红外光谱鉴定,异角X射线衍射法测定了顺式二硝基二苯并-18-冠-6的晶体结构。晶体空间群为P2_1/n,α=15.95i(7),b=20.411(9),c=8.173(4),β=101.09(4)°,Z=4。结构用直接法解出,R=0.067。 相似文献
7.
Hengbin Zhang Shuyun Niu Guangdi Yang Fu Nie Shujia Li 《Transition Metal Chemistry》1994,19(5):498-502
Summary [Et2N] [Co(NH2CSNHNH2)3] [Mo8O26] ·4Me2NCHO, obtained by reacting MoCl5, CoCl2, thiosemicarbazide and DMF in nonaqueous solvents under i.r. radiation, was characterized by spectroscopy and X-ray crystallography. It contains an octanuclear molydenum anion with two pentabridging oxygen atoms and a cobalt-centred cation bonded to nitrogen and sulphur ligands. 相似文献
8.
本文报导了X射线衍射法确定的三氯化钕异丙醇络合物[NdCl3·(CH3CHOHCH3)3]2的晶体结构。在晶体中每二个钕离子通过二个氯离子形成的氯桥相联,组成一个双核稀土络合物分子。其中每个Nd离子是七配位的。 相似文献
9.
合成了分子式为[Ln~2(phen)~2L],phen=C~1~2H~8N~2[ALn=Nd,L=(CH~3COO)~4(ONO~2)~2,BLn=Sm,L=(C~6H~5COO)~6,CLn=Eu,L=(C~6H~5COO)~6]3种同双核配合物。用X射线四圆衍射仪测定了3种化合物的结构。在化合物A分子中,2个Nd(III)原子由4个CH~3COO^-基团桥联,以phen和ONO~2^-为端基,构成了一个具有C~2对称性的双核分子。配合物B和C具有完全相同的结构,它们是以4个苯甲酸根为桥,2个phen和2个C~6H~5COO^-为端基的中心对称双核分子,其中6个苯甲酸根的成键状态可分为3种状况。在3种化合物中,每个Ln均为9配位,呈不规则多面体。Ln-Ln距离,A为0.397nm,B和C均为0.405nm。测定了各配合物的变温磁化率,通过对磁性质研究,发现化合物A在低温下具有反铁磁物质行为,并由理论拟合,求得了磁参数g,J值。 相似文献
10.
Guangdi Wang Richard B. Colecor 《Journal of the American Society for Mass Spectrometry》1996,7(10):1050-1058
Two diquaternary ammonium chloride salts have been used to examine the roles of solvent and counterion in determination of the degree of ion pairing in solution and the resultant charge state distributions in electrospray ionization mass spectrometry (ESI-MS). Three series of solvents, that is, alcohol, polar aprotic, and chlorinated solvents, have been employed to test the influence of solvent polarity and other parameters on the desorption behavior of diquaternary ammonium ions observed in ESI-MS. Solvents of higher polarity were found to yield gas-phase ions of higher charge states, in accordance with their reduced tendency toward ion pairing in solution. Counterion effects were investigated via the following approaches: (1) increase the diquaternary ammonium salt concentration; (2) increase the concentration of an external electrolyte that contained the common counterion Cl?; (3) replace Cl? with trifluoroacetate (TFAc ?); (4) increase the concentration of an external electrolyte that contained TFAc?. These experiments indicate that variation of the specific counterion employed alters the degree of influence that the counterion exerts (via ion pairing) on electrospray ionization mass spectra. Increasing amounts of trifluoroacetate ions in a variety of solvent systems invariably led to a progressive shift of the observed ESI-MS charge states of diquaternary ammonium ions toward lower values. 相似文献