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排序方式: 共有534条查询结果,搜索用时 109 毫秒
41.
42.
Yi ZHU Kumar Shyam Chenlu HU Zixuan CHEN Yapeng ZHANG Fengyi ZHAO Xianglun WEI Limin DUAN Nu XU Hao QIU 《原子核物理评论》2021,38(4):416-422
低温高密核物质测量谱仪(CEE)是研究高重子数密度区核物质性质的重离子碰撞实验谱仪。使用了先进的 SAMPA 电子学读出芯片的时间投影室(TPC)是 CEE 最核心的探测器。在集团重建的过程中,同一排读出板的信号被首先重建成 2 维集团,然后根据 2 维集团的 ADC 加权平均位置重建击中点。当信号 ADC 随漂移时间变化呈峰-谷-峰结构时,一个集团可能被重建成两个或更多击中点,从而提高双径迹分辨能力。使用模拟信号的测试显示,该重建算法在$x/ y$ 方向可以达到0.100/0.043 cm的位置分辨能力和1.1/2.8 cm的双径迹分辨能力。 相似文献
43.
Archana Vibhute Shyam Mokle Khushal Karamunge Vasant Gurav Yeshwant Vibhute 《中国化学快报》2010,21(8):914-918
<正>Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides several advantages such as environmentally friendly,short reaction times,high yields,non-hazardous and simple work-up procedure. 相似文献
44.
Carlos Rodríguez-Abreu Margarita Sanchez-Domínguez Bojan Šarac Marija Bešter Rogač Rekha Goswami Shrestha Lok Kumar Shrestha Dharmesh Varade Goutam Ghosh Vinod K. Aswal 《Colloid and polymer science》2010,288(8):923-935
Mixtures of a hydrophobic triblock copolymer (L121, PEO5PPO68PEO5) and a hydrophobic anionic surfactant (AOT, Sodium bis(2-ethylhexyl)sulfosuccinate), each alone forming turbid vesicular
solutions in water, aggregate to produce a thermodynamically stable, transparent and isotropic solution. Mixed AOT/L121 aggregates
could be confirmed by fluorescence, surface tension, differential scanning calorimetry (DSC) and isothermal titration calorimetry
(ITC). In an isotropic region, where mixed aggregates are formed, there is a synergistic interaction between monomers of AOT
and L121 in the mixture. In addition, Small Angle Neutron Scattering (SANS) experiments provided evidence that mixed aggregates
have the shape of either spheres (with a certain polydispersity) or very short ellipsoids (axial ratio below 2), confirming
a transition from giant multilamellar vesicles to small aggregates upon mixing the two hydrophobic amphiphiles. Upon dilution,
the morphology changes to disk-like. From an examination of the results of all the methods the peculiar behavior of the mixed
AOT/L121 system is explained. 相似文献
45.
Swades De Priyatosh Mandal Shyam S. Chakraborty 《Mathematical and Computer Modelling》2011,53(11-12):2093-2107
Standard analyses of wireless random access protocols that are available in the literature assume negligible propagation delay between any two nodes. This assumption holds good in reasonably short-range terrestrial RF (radio frequency) wireless networks. On the contrary, in wireless communications involving acoustic wave propagation, as in underwater wireless networks, even short distance propagation has appreciably large propagation delay. This observation has led to several recent simulation and experimental studies on underwater Aloha and slotted-Aloha (S-Aloha) protocols and also a few new proposals on random access protocols for underwater wireless ad hoc networks (UWN). To study the efficiency of more advanced multiaccess communication protocols for UWN, it is important to benchmark their performances with respect to the two basic random access protocols, Aloha and S-Aloha. This paper provides an analytic framework to capture the performance of Aloha and S-Aloha protocols in an underwater environment with high and random internodal signal propagation delay. The performance of underwater Aloha and S-Aloha are contrasted with those in short-range terrestrial RF wireless networks. The analysis shows that random internodal propagation delay has no effect on the underwater Aloha performance. It also sheds light on the throughput degradation of underwater S-Aloha with a slotting concept that achieves RF S-Aloha equivalent one-slot vulnerability. Additionally, a modified slotting concept is introduced where the slot size is judiciously reduced such that even by allowing some collisions the overall system throughput can be increased. Our calculations show that, with the modified slotting approach up to 17% throughput performance gain can be achieved over the naive (RF S-Aloha equivalent) slotting approach in UWN. Our analytic results are supported by discrete event simulations. 相似文献
46.
47.
Shyam Krishnan 《Tetrahedron letters》2007,48(43):7571-7573
A method for the synthesis of 3,3-disubstituted oxindole derivatives is described. This involves the base-mediated addition of malonate esters to 3-halo-3-alkyloxindoles. The addition is tolerant of a range of alkyl substituents at position 3 of the oxindole. Addition to an aryl chloro-oxindole is also described. 相似文献
48.
Santosh K. Shrestha Heiko Timmers Aidan P. Byrne Wayne D. Hutchison Don H. Chaplin Rakesh Dogra 《Hyperfine Interactions》2004,158(1-4):407-411
A radioisotope ion implanter has been developed using a cesium-sputtering, negative ion source, which offers versatility and
sustained operation. Employing the molecular 111In16O− ion, μCi activities of the radioisotope probe 111In/Cd have been implanted into different material hosts. The implanted tracer activity has been shown to be sufficient for
LTNO, NMRON and PAC. A new NMRON resonance for 111InAg was observed at 75.08 MHz. In2O3 powder performed well as the radioisotope carrier in the ion source, with the ratio of radioisotope and parasitic ion current
being typically 4 × 10−4. 相似文献
49.
The thioridazine metabolites 7-hydroxythioridazine (2a) and 7-hydroxysulforidazine (2b) were synthesized. Commercial 4-chloro-3-nitrophenylmethylsulfone was converted to the corresponding 4-thiol through an intermediate xanthate ester. Subsequent zinc metal reduction provided the 3-amino thiolate. This salt was condensed with chloroquinone to yield 7-hydroxy-2-methylsulfonylphenothiazine which was then protected as the isopropyl ether. N-Alkylation with 2-(2-chloroethyl)-1-methylpiperidine using sodium hydroxide, then ether cleavage, afforded 2b . The N-alkylation followed by reduction with diisobutylaluminum hydride and deblocking yielded 2a . These reference standards will assist in an exploration of the potential role of meta-bolically formed 2a and 2b in the neuroleptic response to thioridazine. 相似文献
50.
Interfacial Engineering of CdO–CdSe 3D Microarchitectures with in situ Photopolymerized PEDOT for an Enhanced Photovoltaic Performance
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Iseul Lim Dipak V. Shinde Supriya A. Patil Do Young Ahn Wonjoo Lee Nabeen K. Shrestha Joong Kee Lee Sung‐Hwan Han 《Photochemistry and photobiology》2015,91(4):780-785
In the present work, porous 3D CdO‐microstructured electrode obtained by pyrolysis of 3D CdCO3 microstructures is self‐sensitized with CdSe using an ion exchange reaction. After sensitization, an interfacial treatment of the CdO–CdSe interface is performed by depositing a thin film of PEDOT using a photoinduce polymerization route. The microstructured electrode before and after interfacial treatment is characterized using field‐emission scanning microscope, energy dispersive X‐ray analyzer, contact angle measurement, UV–Visible absorption spectrophotometer and X‐ray photoelectron spectrometer. After constructing a liquid junction solar cell with a Pt counter electrode, the photovoltaic performance and interfacial charge transfer kinetics across the CdO–CdSe interface before and after PEDOT treatment are investigated. The results exhibit an improved interfacial charge‐transfer resistance after the PEDOT treatment, which leads to enhance the short‐circuit current by 15.81% and the power conversion efficiency by 19.82%. 相似文献