全文获取类型
收费全文 | 412篇 |
免费 | 8篇 |
国内免费 | 2篇 |
专业分类
化学 | 318篇 |
晶体学 | 7篇 |
力学 | 2篇 |
数学 | 12篇 |
物理学 | 83篇 |
出版年
2022年 | 5篇 |
2021年 | 4篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 6篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 16篇 |
2012年 | 11篇 |
2011年 | 16篇 |
2010年 | 8篇 |
2009年 | 14篇 |
2008年 | 15篇 |
2007年 | 20篇 |
2006年 | 17篇 |
2005年 | 20篇 |
2004年 | 18篇 |
2003年 | 14篇 |
2002年 | 14篇 |
2001年 | 20篇 |
2000年 | 9篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1981年 | 11篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 14篇 |
1977年 | 10篇 |
1976年 | 7篇 |
1975年 | 9篇 |
1974年 | 6篇 |
1973年 | 3篇 |
排序方式: 共有422条查询结果,搜索用时 15 毫秒
81.
82.
M. Sakata und M. Doi 《Colloid and polymer science》1978,256(4):395
Ohne Zusammenfassung 相似文献
83.
H. Sakata K. Yamashita H. Takeuchi M. Tomiki 《Applied physics. B, Lasers and optics》2008,92(2):243-246
We present a diode-pumped microcavity dye laser composed of a top organic reflector and a bottom inorganic reflector. The
top organic reflector consists of alternate thin films of cellulose acetate and poly(N-vinylcarbazole) doped with coumarin
540A to construct a distributed-feedback (DFB) resonator. Pumped directly by an InGaN-based blue laser diode (LD) with a pulse
duration of 4 ns, the microcavity dye laser exhibited a single-mode oscillation at 563 nm with a threshold pump LD power of
290 mW/pulse. The emission of the microcavity dye laser was measured through an optical fiber, resulting in a peak power of
2.5 mW for a pump LD power of 320 mW.
PACS 42.55.Mv; 42.55.Sa; 42.55.Xi 相似文献
84.
Synthesis and structures of the title compounds 2a–d are described. In spite of non-parallel orientation of the two base rings, fairly large hypochromism was observed for 2a–d. 相似文献
85.
A time-resolved transient photocurrent in the nanosecond region when illuminating the MoSe2 — I? semiconductorliquid junction with a pulsed laser, consists of a rapid one which immediately follows the incident light pulse and of another one with a slower decay. From the dependence of the photocurrent on light intensity, bias voltage and the effective concentration of the electrolyte, the two observed components in the spectrum were explained to originate from charge-carrier generation in the solid and electron transfer across the electrode interface, respectively. 相似文献
86.
Strained InGaAsP multi-quantum well (MQW) buried hetero- (BH) laser diodes (LDs) on a p-InP substrate were fabricated by selective metalorganic vapor phase epitaxy (MOVPE). In the laser fabrication process, both the strained MQW active layer and current blocking structure were directly formed by selective MOVPE without a semiconductor etching process. This novel laser fabrication process produces extremely uniform device characteristics that are essential to the deployment of optical subscriber systems. Furthermore, important device design parameters (e.g. the active stripe shape or the leakage current path configuration) are precisely controlled by only the epitaxial growth steps. This highly controllable laser fabrication method results in a very low-threshold current with excellent uniformity (Ith = 1.78 ± 0.19 mA) for 20 consecutive LDs (L = 200 μm with 70%–90% coatings). 相似文献
87.
Yasuhiro Tanoue Akari Hara Norihisa Kai Kazunori Sakata Mamoru Hashimoto Takeshi Nagai 《Journal of heterocyclic chemistry》2007,44(5):1135-1137
The synthetic scheme of 6,6′‐dibromoindirubin ( 2 ) was investigated in detail. The reaction of 6‐fluoro‐3‐acetoxyindole ( 7 ) with isatin ( 8 ) in methanol with Na2CO3 produced 6′‐fluoroindirubin in moderate yields. Its structure determination was mainly undertaken using 1H NMR spectroscopy. On the basis of this result, the synthetic scheme of 2 reported by Cooksey was revised. 相似文献
88.
Sato K Sawaguchi T Sakata M Itaya K 《Langmuir : the ACS journal of surfaces and colloids》2007,23(26):12788-12790
Nearly perfect single crystals of pentacene were grown from trichlorobenzene solution. The surface structure of pentacene single crystals has been investigated by frequency modulation atomic force microscopy. Molecularly flat and extraordinarily wide terraces, extended over the width of more than a few micrometers with monomolecular steps, were consistently observed, suggesting that those pentacene crystals were nearly perfect single crystals. Molecular packing arrangements were revealed by FM-AFM for the first time. 相似文献
89.
90.