全文获取类型
收费全文 | 59篇 |
免费 | 4篇 |
国内免费 | 11篇 |
专业分类
化学 | 38篇 |
力学 | 9篇 |
数学 | 4篇 |
物理学 | 23篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2020年 | 7篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2014年 | 2篇 |
2013年 | 4篇 |
2012年 | 7篇 |
2011年 | 7篇 |
2010年 | 4篇 |
2009年 | 4篇 |
2008年 | 5篇 |
2007年 | 4篇 |
2006年 | 1篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有74条查询结果,搜索用时 15 毫秒
1.
Acoustic vector sensor signal processing 总被引:2,自引:0,他引:2
SUN Guiqing LI Qihu ZHANG Bin 《声学学报:英文版》2006,25(1):1-15
Acoustic vector sensor simultaneously, colocately and directly measures orthogonal components of particle velocity as well as pressure at single point in acoustic field so that is possible to improve performance of traditional underwater acoustic measurement devices or detection systems and extends new ideas for solving practical underwater acoustic engineering problems. Although acoustic vector sensor history of appearing in underwater acoustic area is no long, but with huge and potential military demands, acoustic vector sensor has strong development trend in last decade, it is evolving into a one of important underwater acoustic technology. Under this background, we try to review recent progress in study on acoustic vector sensor signal processing, such as signal detection, DOA estimation, beamforming, and so on. 相似文献
2.
Zhang Guiqing 《中国科学A辑(英文版)》2002,45(1):74-79
The electron pulsation event is defined in the paper. Firstly, a slow Halo CME on March 16, 2001 that led to low-energetic solar proton event, electron pulsation event and major geomagnetic storm was analyzed. And then, dozens of events are collected. The interrelations among the solar flare, CME, solar proton event, electron pulsation event and geomagnetic storm are studied. The results show that: (i) Solar proton events can be regarded as the indication that CMEs get to the earth and the electron pulsation events can be regarded as the indication of solar proton flux. (ii) Not only can fast CMEs strongly influence the earth, but also slow CMEs can influence the earth, and its influences are more frequent and cannot be neglected. (iii) Most of high-energetic solar proton events withE≥10 MeV can lead to geomagnetic storms, but most of the medium and weak geomagnetic storms result from low-energetic solar proton events that are caused by CMEs. (iv) Both the electron pulsation events and geomagnetic storms are the link effects of high- and low-energetic solar proton events, but the occurrence of electron pulsation event are generally prior to the geomagnetic storm. So in the circumstance where the near real-time observing data of the low-energetic solar proton event cannot be obtained, we can regard electron pulsation event as the indication of the low-energetic solar proton flux reaching the earth, which can be used as one of the important references of short-term prediction and alert of the geomagnetic storm. 相似文献
3.
Wenxia Feng Shouxin Cui Haiquan Hu Guiqing Zhang Zengtao Lv 《Journal of Physics and Chemistry of Solids》2011,72(6):740-743
We theoretically studied the phase transformation, electronic and elastic properties of Ti3SiC2 ceramic by using the pseudopotential plane-wave method within the density functional theory. Our results demonstrate that there exists a structural phase transition from α‐Ti3SiC2 to β‐Ti3SiC2 under pressure up to 384 GPa, and α‐Ti3SiC2 is the most stable phase at zero pressure. The calculated electronic band structure and density of states reveal the metallic behavior for the polymorphs of Ti3SiC2. The mechanical stability of α‐Ti3SiC2 at zero pressure is confirmed by the elastic constants, and is analyzed in terms of electronic level. By analyzing the ratio between bulk and shear moduli, we conclude that α‐Ti3SiC2 is brittle in nature. 相似文献
4.
5.
The phase transition of ScSb and YSb from the NaCl-type (B1) structure to the CsCl-type (B2) structure is investigated by the ab initio plane-wave pseudopotential density functional theory method. It is found that the pressures for transition from the B1 structure to the B2 structure obtained from the equal enthalpies are 38.3 and 32.1 GPa for ScSb and YSb, respectively. From the variations of elastic constants with pressure, we find that the B1 phase of ScSb and YSb compounds are unstable when applied pressures are larger than 46.3 and 64.2 GPa, respectively. Moreover, the detailed volume changes during phase transition are analyzed. 相似文献
6.
Rufan Chen Ji‐Long Shi Yuan Ma Guiqing Lin Xianjun Lang Cheng Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(19):6496-6500
The construction of stable covalent organic frameworks (COFs) for various applications is highly desirable. Herein, we report the synthesis of a novel two‐dimensional (2D) porphyrin‐based sp2 carbon‐conjugated COF (Por‐sp2c‐COF), which adopts an eclipsed AA stacking structure with a Brunauer—Emmett—Teller surface area of 689 m2 g?1. Owing to the C=C linkages, Por‐sp2c‐COF shows a high chemical stability under various conditions, even under harsh conditions such as 9 m HCl and 9 m NaOH solutions. Interestingly, Por‐sp2c‐COF can be used as a metal‐free heterogeneous photocatalyst for the visible‐light‐induced aerobic oxidation of amines to imines. More importantly, in comparison to imine‐linked Por‐COF, the inherent structure of Por‐sp2c‐COF equips it with several advantages as a photocatalyst, including reusability and high photocatalytic performance. This clearly demonstrates that sp2 carbon‐linked 2D COFs can provide an interesting platform for heterogeneous photocatalysis. 相似文献
7.
8.
Dongmei He Li Zeng Guiqing Zhang Qinggang Li Wenjuan Guan Zuoying Cao Shengxi Wu 《应用有机金属化学》2019,33(9)
A new compound, α‐aminophosphonate derivative containing pyridine ring (PPDE), was designed and synthesized as an extractant for the separation of nickel from metal impurities. Over 94.5% of Ni (II) extraction from sulfuric acid solution was achieved by using PPDE with an equilibrium pH of 4.02. Meanwhile, high separation coefficients of 23.8 for Ni to Co, 84.9 for Ni to Mn, 254.1 for Ni to Ca and 696.7 for Ni to Mg, respectively, were obtained. It was noted that PPDE exhibited an excellent regenerability, and the extraction of Ni with the recycled organic phase ranged from 92.5% to 93.9% during six circulations. The extracted nickel complex was determined as [Ni (PPDE)2(DNNSA?)2(H2O)4], which was supported by the data obtained from Fourier transform‐infrared, UV–Vis and electrospray ionization‐mass spectrometry spectra. 相似文献
9.
研究了Fe3+-金橙G(OG)体系的共振光散射光谱,发现Fe3+对OG的共振光散射有增强效应。进一步研究发现,其增强值(△I)与加入Fe3+的质量浓度呈线性关系,对条件进行了优化,并建立了一种测定Fe3+的新方法,方法的线性范围为0.028~1.00μg/mL,检出限为0.009μg/mL,用于水样中痕量Fe3+的测定,结果满意。 相似文献
10.