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871.
Hao Xu Jie Zhu Xiong Wang Chao Shen Shengshen Meng Kai Zheng Chao Lei Longfeng Zhu 《Molecules (Basel, Switzerland)》2021,26(5)
Developing sustainable routes for the synthesis of zeolites is still a vital and challenging task in zeolite scientific community. One of the typical examples is sustainable synthesis of aluminosilicate EU-1 zeolite, which is not very efficient and environmental-unfriendly under hydrothermal condition due to the use of a large amount of water as solvent. Herein, we report a sustainable synthesis route for aluminosilicate EU-1 zeolite without the use of solvent for the first time. The physicochemical properties of the obtained EU-1 zeolite are characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry-differential thermal analysis (TG-DTA), N2 sorption, inductively coupled plasma (ICP) analysis, and solid nuclear magnetic resonance (NMR), which show the product has high crystallinity, uniform morphology, large BET surface area, and four-coordinated aluminum species. Moreover, the impact of synthesis conditions is investigated in detail. The sustainable synthesis of aluminosilicate EU-1 zeolite under solvent-free 相似文献
872.
Yibo Zhang Prof. Yuying Zheng Prof. Hongbo Geng Dr. Yang Yang Dr. Minghui Ye Dr. Yufei Zhang Prof. Cheng Chao Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(35):9031-9037
Metal phosphates have been widely explored in lithium ion batteries and sodium ion batteries owing to high theoretical capacities, mild toxicity and low cost. However, their potassium ion battery applications are less reported due to the limited conductivity and the slow diffusion kinetics. Considering these drawbacks, novel structured M2P2O7/C (M=Fe, Co, Ni) nanoflake composites are prepared through an organic-phosphors precursor-assisted solvothermal method and a subsequent high temperature annealing process. The designed Co2P2O7/C composite exhibits the highest rate capacity with 502 mAh g−1 at 0.1 A g−1 and good cyclability for 900 cycles at 1 A g−1 and 2 A g−1 when compared with Ni and Fe based composites. The superior electrochemical performance can be attributed to their unique nanoparticle-assembled nanoflake structure, which can afford enough active sites for K+ intercalation. In addition, the robust pyrophosphate crystal structure and the in situ formed carbon composition also have positive effects on enhancing the long-term cycling performance and the electrode's conductivity. Finally, this organic-phosphors precursor induced simple approach can be applied for easy fabrication of other pyrophosphate/carbon hybrids as advanced electrodes. 相似文献
873.
Lei Sun Jiahui Geng Dr. Mengyou Gao Dr. Dehua Zheng Zhongxin Jing Qingyun Zhao Prof. Jianjian Lin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(42):10998-11004
Fe0.95S1.05 with high reactivity and stability was incorporated into WS2 nanosheets via a one-step solvothermal method for the first time. The resulted hybrid catalyst has much higher catalytic activity than WS2 and Fe0.95S1.05 alone, and the optimal WS2/Fe0.95S1.05 hybrid catalyst was found by adjusting the feed ratio. The addition of Fe0.95S1.05 was proven to be able to enhance the hydrogen evolution reaction (HER) activity of WS2, and vice versa. At the same time, it was found that the catalytic effect of the hybrid catalyst was the best when the feed ratio was W : Fe=2 : 1. In other words, we confirmed that there is a synergistic effect between W- and Fe-based sulfide hybrid catalysts, and validated that the reason for the improved HER performance is the strong interaction between the two in the middle sulfur. WS2/Fe0.95S1.05-2 hybrid catalyst leads to enhanced HER activity, which shows a low overpotential of ∼0.172 V at 10 mA cm−2, low Tafel slope of ∼53.47 mV/decade. This study supplies innovative synthesis of a highly active WS2/Fe0.95S1.05 hybrid catalyst for HER. 相似文献
874.
Li Zhu Kun Liu Shudong Zheng Dr. Xiacong Zhang Prof. Dr. Jiatao Yan Prof. Dr. Wen Li Prof. Dr. Afang Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(40):10470-10476
Water-soluble and thermoresponsive macrocycles with stable inclusion toward guests are highly valuable to construct stimuli-responsive supramolecular materials for versatile applications. Here, we develop such macrocycles – ureido-substituted cyclodextrins (CDs) which exhibit unprecedented upper critical solution temperature (UCST) behavior in aqueous media. These novel CD derivatives showed good solubility in water at elevated temperature, but collapsed from water to form large coacervates upon cooling to low temperature. Their cloud points are greatly dependent on concentration and can be mediated through oxidation and chelation with silver ions. Significantly, the amphiphilicity of these CD derivatives is supportive to host-guest binding, which affords them inclusion abilities to guest dyes. The inclusion complexation remained nearly intact during thermally induced phase transitions, which is in contrast to the switchable inclusion behavior of lower critical solution temperature (LCST)-type CDs. Moreover, ureido-substituted CDs were exploited to co-encapsulate a pair of guest dyes whose fluorescence resonance energy transfer process can be switched by the UCST phase transition. We therefore believe these novel thermoresponsive CDs may form a new strategy for developing smart macrocycles and allow for exploring smart supramolecular materials. 相似文献
875.
Shilin Jiang Dr. Jianhui Lan Dr. Lin Wang Dr. Yalan Liu Yuke Zhong Yichuan Liu Dr. Liyong L.-Y. Yuan Dr. Lirong Zheng Prof. Zhifang Chai Prof. Weiqun Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(45):11721-11729
Molten salt electrolysis is a vital technique to produce high-purity lanthanide metals and alloys. However, the coordination environments of lanthanides in molten salts, which heavily affect the related redox potential and electrochemical properties, have not been well elucidated. Here, the competitive coordination of chloride and fluoride anions towards lanthanide cations (La3+ and Nd3+) is explored in molten LiCl-KCl-LiF-LnCl3 salts using electrochemical, spectroscopic, and computational approaches. Electrochemical analyses show that significant negative shifts in the reduction potential of Ln3+ occur when F− concentration increases, indicating that the F− anions interact with Ln3+ via substituting the coordinated Cl− anions, and confirm [LnClxFy]3−x−y (ymax=3) complexes are prevailing in molten salts. Spectroscopic and computational results on solution structures further reveal the competition between Cl− and F− anions, which leads to the formation of four distinct Ln(III) species: [LnCl6]3−, [LnCl5F]3−, [LnCl4F2]3− and [LnCl4F3]4−. Among them, the seven-coordinated [LnCl4F3]4− complex possesses a low-symmetry structure evidenced by the pattern change of Raman spectra. After comparing the polarizing power (Z/r) among different metal cations, it was concluded that Ln−F interaction is weaker than that between transition metal and F− ions. 相似文献
876.
Jian-Cai Huang Hui Xiao Dr. Zhixin Chen Dr. Wenxu Zheng Dr. Chang-Cang Huang Dr. Shu-Ting Wu Zenghong Xie Prof. Naifeng Zhuang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(56):14017-14024
Chiral compounds are known to be important not only because they are the fundamental components of living organisms, but also for their unique chiroptical properties. In recent years, scientists have fabricated several chiral organic supramolecular aggregates by using chiral physical fields, such as vortex flow. Herein, the relationship between dynamic chiroptical properties and rheological nature is discussed, suggesting the shear thinning properties of non-Newtonian fluids might help colloidal particles adopt a chiral arrangement in vortices. Furthermore, the storage modulus of colloids could be increased by adding a linking agent, which successfully kept the dynamic chiroptical properties in the static state. Moreover, the salt effect on the host–guest interaction involved in the colloids was studied, the results suggested a significant enhancement of the transferred dynamic circular dichroism for the achiral guest molecule. 相似文献
877.
878.
利用2,5-双(三氟甲基)对苯二甲酸(H2L)为主配体,氯化锌为金属盐,分别与辅助配体4,4''-联吡啶(4,4''-bipy)和2,2''-联吡啶(2,2''-bipy)通过溶剂热法反应合成了配合物[Zn(L)2(4,4''-bipy)(H2O)]n(1)和[Zn(L)(2,2''-bipy)]n(2)。通过X射线单晶衍射、红外光谱、元素分析、荧光光谱、热重分析等测试手段对其结构和性质进行了表征与研究。结果表明,配合物1是以Zn2+为金属节点,L2-和4,4''-bipy作为连接体相互连接,形成无限延伸的二维网状结构,层与层之间通过O5-H5B…O1氢键作用有序堆积形成三维结构。配合物2以Zn2+为金属节点,配体L2-上的每个羧基都通过双齿螯合的方式桥联锌离子并无限连接形成三维网状结构。 相似文献
879.
An important challenge facing K-ion batteries lies in exploring earth-abundant and safe cathode materials that can provide high capacity with high migration rate of K ions.Here,we propose a simple and efficient method for searching potential K cathode materials with first principles calculations.Our screening is based on combinations of weight capacity,K ion occupation ratio,volume change per K,and valence limit.With this screening method we predicted a series of potential K ions cathodes with favorable electrochemical performance,such as K2VPO4CO3-like structures with 1 D diffusion channels,3 D channel structures K2CoSiO4,layered materials KCoO2,KCrO2,KVF4 and K5V3F14,and others.These potential cathodes have small volume changes,suitable voltage,and high capacity,with small diffusion barriers.They may be useful in K-ion batteries with high energy density and rate performance. 相似文献
880.
Jian Ye Yipeng Zang Qingyu Wang Yida Zhang Da Sun Leijie Zhang Gongming Wang Xusheng Zheng Junfa Zhu 《Journal of Energy Chemistry》2021,(5):283-289
Performance breakthrough of electrocatalysts highly relies on the regulation of internal structures and electronic states.In present work,for the first time,we successfully synthesized nitrogen doped FeS2 nanoparticles(N-FeS2)as the electrocatalysts for hydrogen evolution reaction(HER).The band structure and electronic state of FeS2 are modulated by a nitrogen doping strategy,as confirmed by X-ray photoelectron spectroscopy(XPS),X-ray absorption spectroscopy(XAS)and density functional theory(DFT)calculations.Owing to the band structure and electronic state regulation as well as the weakening of H-S interaction,the designed N-FeS2 electrocatalyst exhibits superior catalytic performance with a low overpotential(~126 mV at 10 mA cm-2)and excellent activity stability under alkaline conditions,which is substantially improved as compared with that of the pure FeS2 counterpart.Our work demonstrates that the modulation of electron state and band structure of an electrocatalyst,which can provide a valuable guidance for designing excellent catalysts for hydrogen evolution reaction and beyond. 相似文献