全文获取类型
收费全文 | 120篇 |
免费 | 0篇 |
专业分类
化学 | 73篇 |
力学 | 9篇 |
数学 | 11篇 |
物理学 | 27篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2014年 | 3篇 |
2013年 | 8篇 |
2012年 | 16篇 |
2011年 | 11篇 |
2010年 | 7篇 |
2009年 | 3篇 |
2008年 | 5篇 |
2007年 | 3篇 |
2006年 | 8篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有120条查询结果,搜索用时 0 毫秒
101.
Su-Dong Cho Deok-Heon Kweon Young-Jin Kang Sang-Gyeong Lee Woo Song Lee Yong-Jin Yoon 《Journal of heterocyclic chemistry》1999,36(5):1151-1156
Some 6,7-dimethoxy-1-halobenzyl-1,2,3,4-tetrahydroisoquinolines were synthesized from 2-(3,4-dimethoxyphenyl)ethylamine and halophenylacetic acids in three steps in good yield. 相似文献
102.
Deok-Heon Kweon Young-Jin Kang Hyun-A Chung Jung-Won Park Woo Song Lee Yong-Jin Yoon Sung-Kyu Kim Motoo Shiro 《Journal of heterocyclic chemistry》1999,36(5):1301-1306
This paper presents the synthesis of 4,5-dichloro-1-(4,5-dichloropyridazin-3-yl)pyridazin-6-one from 4,5-dichloropyridazin-6-one. 相似文献
103.
Na Young Kwon Geun Seok Jang Ji Hye Son Minjung Lee Hye‐Jin Cho Hee‐Seok Kweon Taek Seung Lee 《Journal of polymer science. Part A, Polymer chemistry》2011,49(1):138-146
Anionically charged fluorescent conjugated polyelectrolytes of poly{[4,7‐(2,1,3‐benzothiadiazole)‐alt‐1,4‐phenylene]‐co‐[2,5‐bis(4‐sulfonatobutoxy)‐alt‐1,4‐phenylene]} ( P1 ) and poly{[4,7‐(bis(thiophen‐2‐yl)benzo‐2,1,3‐thiadiazole)‐alt‐1,4‐phenylene]‐co‐[2,5‐bis(4‐sulfonatobutoxy)‐alt‐1,4‐phenylene]} ( P2 ) were synthesized by Suzuki crosscoupling polymerization in the presence of a palladium catalyst. The conjugated polyelectrolytes with sulfonate groups, as efficient signal amplifying reporters, were carefully designed to be soluble in water over the entire pH range examined and interact with proteins through intermolecular forces. The polymers exhibited blue emission in aqueous solutions but green or red emission in solid form depending on the conjugation length due to intermolecular exciton migration. The anionic conjugated polymers exhibited blue‐to‐green or blue‐to‐red changes in fluorescence upon exposure to charged proteins, indicating that the polymers have potential applications in fluorescent array systems for protein. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
104.
105.
Yongkyoung Kweon Ji-Yong Park Young-Joo Kim Yun-Sang Lee Jae-Min Jeong 《Molecules (Basel, Switzerland)》2021,26(1)
Hydrogen sulfide (H2S) is the third gasotransmitter and is generated endogenously in hypoxic or inflammatory tissues and various cancers. We have recently demonstrated that endogenous H2S can be imaged with [99mTc]Tc-gluconate. In the present study, we detected H2S generated in hypoxic tissue, both in vitro and in vivo, using [99mTc]Tc-gluconate. In vitro uptake of [99mTc]Tc-gluconate was measured under hypoxic and normoxic conditions, using the colon carcinoma cell line CT26, and was higher in hypoxic cells than that in normoxic cells. An acute hindlimb ischemia-reperfusion model was established in BALB/c mice by exposing the animals to 3 h of ischemia and 3 h of reperfusion prior to in vivo imaging. [99mTc]Tc-gluconate (12.5 MBq) was intravenously injected through the tail vein, and uptake in the lower limb was analyzed by single-photon emission computed tomography/computed tomography (SPECT/CT). SPECT/CT images showed five times higher uptake in the ischemic limb than that in the normal limb. The standard uptake value (SUVmean) of the ischemic limb was 0.39 ± 0.03, while that of the normal limb was 0.07 ± 0.01. [99mTc]Tc-gluconate is a novel imaging agent that can be used both in vitro and in vivo for the detection of endogenous H2S generated in hypoxic tissue. 相似文献
106.
Austen H. Motily Je Ir Ryu Keunsoo Kim Kenneth Kim Chol-Bum M. Kweon Tonghun Lee 《Proceedings of the Combustion Institute》2021,38(4):5665-5672
Fuel-flexible aircraft propulsion systems using compression ignition engines will require novel strategies for reducing the ignition delay of low-reactivity fuels to feasible timescales. Hot surface ignition of fuel sprays has been implemented in some practical situations, but the complex nature of flame formation within the spray structure poses significant challenges. In order to design next-generation ignition devices, the capacity of hot surface heating elements to promote fuel spray ignition must be investigated. In this study, a rapid compression machine (RCM) was used to examine the ignition process of a single kerosene-based F-24 jet fuel spray with a cylindrical heating element inserted into the spray periphery. The experiments, performed with moderately high injection pressures of 40 MPa, have demonstrated two modes of ignition governed by surface temperature and insertion depth of the heating element. There exists an optimal position where the heating element tip is located in the fuel vapor cone around the liquid spray. For this configuration, a critical surface temperature was identified (~1250 K), above which short ignition delays associated with a “spray ignition” mode are consistently achieved. In this case, a local ignition flame kernel propagates downstream to the flame lift-off length before full ignition of the spray. In comparison, below the critical temperature a slower “volumetric” mode results. The extended ignition delays associated with this mode may be impractical for compression ignition engines operating at high speeds and increased altitude. 相似文献
107.
The aim of this study is to measure the dose area product (DAP) in digital radiography by using a DAP meter to determine the X-ray exposure. Pediatric X-ray examinations can be obtained for any radiographic examinations using the selected radiographic examination parameters (kVp and mAs), the DAP information recorded. The best peak signal-to-noise ratio (PSNR) at a fixed tube voltage of 70 kVp was obtained at tube currents of 20 and 32 mA, whereas the best PSNR at a fixed tube current of 25 mA was obtained at a tube voltage of 73 kVp. The fixed tube voltage of 70 kVp and the fixed tube current of 25 mA could help to obtain the best image quality and depict the spatial resolution of an anthropomorphic torso phantom radiographic examination. The normalized data over the DAP were provided to determine the patient dose from radiography. 相似文献
108.
Jae Hwan Yang Jin Myeong Shin Chang Hwa Lee Chul Min Heo Min Ku Jeon Kweon Ho Kang 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(1):211-219
The present study a promising method for stabilizing spent filters trapping cesium and technetium by using magnesium phosphate ceramics. Simulated spent filters were fabricated by vaporizing nonradioactive cesium and rhenium (a surrogate of Tc) through the voloxidizer. In order to reveal the characteristics of spent filters, phase structures and thermal stability were analyzed by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy, and thermogravimetric analysis techniques. Waste forms were fabricated by crushing spent filters and mixing them with magnesium oxide and potassium phosphate. Characterizations of the waste forms were performed by the analyses of compressive strength, apparent porosity, XRD, and scanning electron microscopy. The waste forms showed the excellent mechanical property compared with that of ordinary Portland cement, with the highest compressive strength of 38.1 MPa in the sample with 30 wt% of Cs-filter. Microstructural analysis suggests that waste materials are encapsulated by the binding matrix composed of magnesium potassium phosphate. The results of characterization suggest that fabricating a sound and durable waste form is possible with magnesium phosphate ceramics. 相似文献
109.
Kang G Son H Lim JM Kweon HS Lee IS Kang D Jung JH 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(19):5843-5847
The zinc tank: A new fluoro-chromogenic chemosensor based on BODIPY-functionalized Fe(3)O(4) nanoparticles (1) has been prepared. Chemoprobe 1 exhibits high selectivity for Zn(2+) over other competing metal ions tested. Moreover, confocal microscopy experiments established that 1 can be used for detecting Zn(2+) levels in living cells (see figure). 相似文献
110.
Oh Sung Kwon Jae Ryong Kweon 《Nonlinear Analysis: Theory, Methods & Applications》2012,75(5):2936-2956
We show existence and regularity for the boundary value problems of the Navier–Stokes equations with non-standard BCs on a bounded plane domain with non-convex corners. We assign the vorticity value and the velocity normal component over the non-convex corner, the dynamic pressure value over inflow and outflow boundaries, and so on. We construct the corner singularity functions for the Stokes operator with zero vorticity and velocity normal component BCs, subtract its leading singularity from the solution by defining the coefficient of the singularity and show increased regularity for the remainder. The solution is determined by the smoother part and the coefficients of the singularities. It is seen from the singularity that the dynamic pressure has a transition layer that changes the sign (at in the domain). The obtained results can be applied to general polygonal domains and the cavity flows. 相似文献