全文获取类型
收费全文 | 1380篇 |
免费 | 143篇 |
国内免费 | 104篇 |
专业分类
化学 | 1031篇 |
晶体学 | 15篇 |
力学 | 48篇 |
综合类 | 3篇 |
数学 | 217篇 |
物理学 | 313篇 |
出版年
2023年 | 27篇 |
2022年 | 20篇 |
2021年 | 34篇 |
2020年 | 43篇 |
2019年 | 52篇 |
2018年 | 42篇 |
2017年 | 36篇 |
2016年 | 52篇 |
2015年 | 58篇 |
2014年 | 55篇 |
2013年 | 77篇 |
2012年 | 116篇 |
2011年 | 95篇 |
2010年 | 81篇 |
2009年 | 70篇 |
2008年 | 80篇 |
2007年 | 73篇 |
2006年 | 70篇 |
2005年 | 72篇 |
2004年 | 55篇 |
2003年 | 45篇 |
2002年 | 57篇 |
2001年 | 56篇 |
2000年 | 38篇 |
1999年 | 31篇 |
1998年 | 13篇 |
1997年 | 18篇 |
1996年 | 27篇 |
1995年 | 18篇 |
1994年 | 15篇 |
1993年 | 9篇 |
1992年 | 18篇 |
1991年 | 13篇 |
1990年 | 10篇 |
1989年 | 9篇 |
1988年 | 11篇 |
1987年 | 4篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 5篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有1627条查询结果,搜索用时 15 毫秒
1.
Rui Feng Zi-Ying Li Zhao-Quan Yao Zi-Ang Guo Yi-Nan Zhang Hao-Xiang Sun Wei Li Xian-He Bu 《中国科学:化学(英文版)》2022,65(1):128-134
The rational designability and chemical tunability of metal-organic frameworks(MOFs)are enabling tributes to efficaciously enhance their room temperature phosphorescence(RTP)performance.A family of stable anionic MOFs,[Zn2(4,5-ImDC)2]M2(NKU-132,M=(CH3)2NH2or(CH2CH3)2NH2),featuring significant RTP have been synthesized.By rational cation selection and in-situ replacement from dimethylammonium to diethylammonium,the phosphorescence lifetime is increased from 30.88 to126.3 ms,along with less sensitivity to air.This work provides an anti-quenching and lifetime tuning example for RTP-MOFmaterials via facile host-guest chemistry. 相似文献
2.
3.
4.
Anh N. Hong Diana Luong Mohammed Alghamdi Wei-Cheng Liao Weiyi Zhang Emily Kusumoputro Yichong Chen Prof. P. Alex Greaney Prof. Yongtao Cui Prof. Jing Shi Prof. Xianhui Bu Prof. Boniface P. T. Fokwa Prof. Pingyun Feng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(52):e202201576
Two new rod-packing metal–organic frameworks (RPMOF) are constructed by regulating the in situ formation of the capping agent. In CPM-s7, carboxylate linkers extend 1D manganese-oxide chains in four additional directions, forming 3D RPMOF. The substitution of Mn2+ with a stronger Lewis acidic Co2+, leads to an acceleration of the hydrolysis-prone sulfonate linker, resulting in presence of sulfate ions to reduce two out of the four carboxylate-extending directions, and thus forming a new 2D rod-packing CPM-s8. Density functional theory calculations and magnetization measurements reveal ferrimagnetic ordering of CPM-s8, signifying the potential of exploring 2D RPMOF for effective low-dimensional magnetic materials. 相似文献
5.
Guangrui Chen Yuxing Yan Dr. Jie Wang Prof. Yong Sik Ok Guiyuan Zhong Prof. Bu Yuan Guan Prof. Yusuke Yamauchi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(44):19831-19836
Mesoporous core–shell nanostructures with controllable ultra-large open channels in their nanoshells are of great interest. However, soft template-directed cooperative assembly to mesoporous nanoshells with highly accessible pores larger than 30 nm, or even above 50 nm into macroporous range, remains a significant challenge. Herein we report a general approach for precisely tailored coating of hierarchically macro-/mesoporous polymer and carbon shells, possessing highly accessible radial channels with extremely wide pore size distribution from ca. 10 nm to ca. 200 nm, on diverse functional materials. This strategy creates opportunities to tailor the interfacial assembly of irregular mesostructured nanounits on core materials and generate various core–shell nanomaterials with controllable pore architectures. The obtained Fe,N-doped macro-/mesoporous carbon nanoshells show enhanced electrochemical performance for the oxygen reduction reaction in alkaline condition. 相似文献
6.
Dr. Qiao Chen Xin Yi Meirong Huang Wenjia Wu Qiyang Song Changjiang Nie Prof. Shun Wang Prof. Hongwei Zhu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(33):7463-7469
Precursors and catalysts play vital roles in chemical reactions. Considerable efforts have been devoted to the investigation of catalysts for graphene growth by chemical vapor deposition in recent years. However, there has been little research on precursors because of a lack of innovation in term of creating a controllable feeding method. Herein, we present a novel sustained and controlled release approach, and develop a convenient, safe, and potentially scalable feeding system with the assistance of matrix materials and a simple portable feeder. As a result, a highly volatile liquid precursor can be fed accurately to grow large-area, uniform graphene films with optimal properties. This feeding approach will further benefit the synthesis of other two-dimensional materials from various precursors. 相似文献
7.
Dr. Nahyun Kwon Gabriel O. Jasinevicius Dr. Giulia Kassab Lili Ding Jiachuan Bu Letícia P. Martinelli Dr. Vinicius G. Ferreira Alexander Dhaliwal Dr. Harley H. L. Chan Yulin Mo Dr. Vanderlei S. Bagnato Prof. Dr. Cristina Kurachi Dr. Juan Chen Prof. Dr. Gang Zheng Prof. Dr. Hilde H. Buzzá 《Angewandte Chemie (International ed. in English)》2023,62(28):e202305564
Indocyanine green (ICG) is the only near-infrared (NIR) dye approved for clinical use. Despite its versatility in photonic applications and potential for photothermal therapy, its photobleaching hinders its application. Here we discovered a nanostructure of dimeric ICG (Nano-dICG) generated by using ICG to stabilize nanoemulsions, after which ICG enabled complete dimerization on the nanoemulsion shell, followed by J-aggregation of ICG-dimer, resulting in a narrow, red-shifted (780 nm→894 nm) and intense (≈2-fold) absorbance. Compared to ICG, Nano-dICG demonstrated superior photothermal conversion (2-fold higher), significantly reduced photodegradation (−9.6 % vs. −46.3 %), and undiminished photothermal effect (7 vs. 2 cycles) under repeated irradiations, in addition to excellent colloidal and structural stabilities. Following intravenous injection, Nano-dICG enabled real-time tracking of its delivery to mouse tumors within 24 h by photoacoustic imaging at NIR wavelength (890 nm) distinct from the endogenous signal to guide effective photothermal therapy. The unprecedented finding of nanostructure-driven ICG dimerization leads to an ultra-stable phototheranostic platform. 相似文献
8.
Xin Feng Dr. Kejun Bu Teng Liu Songhao Guo Zongdong Sun Tonghuan Fu Yongshan Xu Dr. Kailang Liu Dr. Sijie Yang Dr. Yinghe Zhao Prof. Huiqiao Li Prof. Xujie Lü Prof. Tianyou Zhai 《Angewandte Chemie (International ed. in English)》2023,62(9):e202217238
The unique intermolecular van der Waals force in emerging two-dimensional inorganic molecular crystals (2DIMCs) endows them with highly tunable structures and properties upon applying external stimuli. Using high pressure to modulate the intermolecular bonding, here we reveal the highly tunable charge transport behavior in 2DIMCs for the first time, from an insulator to a semiconductor. As pressure increases, 2D α-Sb2O3 molecular crystal undergoes three isostructural transitions, and the intermolecular bonding enhances gradually, which results in a considerably decreased band gap by 25 % and a greatly enhanced charge transport. Impressively, the in situ resistivity measurement of the α-Sb2O3 flake shows a sharp drop by 5 orders of magnitude in 0–3.2 GPa. This work sheds new light on the manipulation of charge transport in 2DIMCs and is of great significance for promoting the fundamental understanding and potential applications of 2DIMCs in advanced modern technologies. 相似文献
9.
Hui Luo Dr. Kejun Bu Dr. Yanfeng Yin Dong Wang Cuimi Shi Songhao Guo Tonghuan Fu Jiayuan Liang Bingyan Liu Dr. Dongzhou Zhang Prof. Liang-Jin Xu Prof. Qingyang Hu Prof. Yang Ding Prof. Shengye Jin Prof. Wenge Yang Prof. Biwu Ma Prof. Xujie Lü 《Angewandte Chemie (International ed. in English)》2023,62(37):e202304494
Low-dimensional (low-D) organic metal halide hybrids (OMHHs) have emerged as fascinating candidates for optoelectronics due to their integrated properties from both organic and inorganic components. However, for most of low-D OMHHs, especially the zero-D (0D) compounds, the inferior electronic coupling between organic ligands and inorganic metal halides prevents efficient charge transfer at the hybrid interfaces and thus limits their further tunability of optical and electronic properties. Here, using pressure to regulate the interfacial interactions, efficient charge transfer from organic ligands to metal halides is achieved, which leads to a near-unity photoluminescence quantum yield (PLQY) at around 6.0 GPa in a 0D OMHH, [(C6H5)4P]2SbCl5. In situ experimental characterizations and theoretical simulations reveal that the pressure-induced electronic coupling between the lone-pair electrons of Sb3+ and the π electrons of benzene ring (lp-π interaction) serves as an unexpected “bridge” for the charge transfer. Our work opens a versatile strategy for the new materials design by manipulating the lp-π interactions in organic–inorganic hybrid systems. 相似文献
10.
Sustainable Synthesis of Chiral Tetrahydrofurans through the Selective Dehydration of Pentoses 下载免费PDF全文
Robert W. Foster Dr. Christopher J. Tame Dr. Dejan‐Krešimir Bučar Prof. Helen C. Hailes Dr. Tom D. Sheppard 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(45):15947-15950
L ‐Arabinose is an abundant resource available as a waste product of the sugar beet industry. Through use of a hydrazone‐based strategy, L ‐arabinose was selectively dehydrated to form a chiral tetrahydrofuran on a multi‐gram scale without the need for protecting groups. This approach was extended to other biomass‐derived reducing sugars and the mechanism of the key cyclization investigated. This methodology was applied to the synthesis of a range of functionalized chiral tetrahydrofurans, as well as a formal synthesis of 3R‐3‐hydroxymuscarine. 相似文献