含硫套索冠醚的合成

将二氮杂１８－冠－６的乙腈溶液分别与２－氯乙基烷基硫醚、２－氯乙基烯丙基硫醚、［２－（２－ｒ氯乙基）硫乙基］烷基硫醚在无水碳酸钾存在下反应制得５种新型侧链上含硫原子的双臂套索冠醚和５种新型单臂套索冠醚。它们的收率分别为３７％－７２％和１３％－３７％。此法比其它制备单臂套索冠醚的方法操作简单。     

Phosphorus Co-Existing in Water: A New Mechanism to Boost Boron Removal by Calcined Oyster Shell Powder

The removal of boron (B) from water by co-precipitation with hydroxyapatite (HAP) has been extensively studied due to its low cost, ease of use and high efficiency. However, there is no explicit mechanism to express how resolved B was trapped by HAP. Thus, in this work, the process of removing B from water was studied using a low-cost calcium (Ca) precipitation agent derived from used waste oyster shells. The results showed that the removal rate of B in the simulated wastewater by calcined oyster shell (COS) in the presence of phosphorus (P) is up to more than 90%, as opposed to virtually no removal without phosphate. For B removal, the treated water needs to be an alkaline solution with a high pH above 12, where B is removed as [CaB(OH)₄]⁺ but is not molecular. Finally, the synergistic mechanism of co-precipitation between HAP and dissolved B, occlusion co-precipitation, was explained in detail. The proposed method discovered the relationship between Ca, P and B, and was aimed at removing B without secondary pollution through co-precipitation.     

电化学不对称合成进展

综述了电化学不对称合成的研究概况，按照诱导手性方式的不同分六类加以介绍，参考文献５８篇。     

An improved EEHEMT model for kink effect on AIGaN/GaN HEMT

In this paper, a new current expression based on both the direct currect （DC） characteristics of the A1GaN/GaN high election mobility transistor （HEMT） and the hyperbolic tangent function tanh is proposed, by which we can describe the kink effect of the A1GaN/GaN HEMT well. Then, an improved EEHEMT model including the proposed current expression is presented. The simulated and measured results of Ⅰ-Ⅴ, S-parameter, and radio frequency （RF） large-signal characteristics are compared for a self-developed on-wafer A1GaN/GaN HEMT with ten gate fingers each being 0.4-μm long and 125-p-m wide （Such an A1GaN/GaN HEMT is denoted as A1GaN/GaN HEMT （10 × 125 μm））. The improved large signal model simulates the Ⅰ-Ⅴ characteristic much more accurately than the original one, and its transconductance and RF characteristics are also in excellent agreement with the measured data.     

f(T) Non-linear Massive Gravity and the Cosmic Acceleration

Inspired by the f(R) non-linear massive gravity,we propose a new kind of modified gravity model,namely f(T) non-linear massive gravity,by adding the dRGT mass term reformulated in the vierbein formalism,to the f(T)theory.We then investigate the cosmological evolution of f(T) massive gravity,and constrain it by using the latest observational data.We find that it slightly favors a crossing of the phantom divide line from the quintessence-like phase(ω_(de) -1) to the phantom-like one(ω_(de) -1) as redshift decreases.     

Quantum Private Query Based on Stable Error Correcting Code in the Case of Noise

In order to protect the privacy of query users and databases, a quantum private query protocol under noisy conditions is proposed and studied. It is a one-way quantum protocol that not only protects user privacy, but also prevents eavesdropping. And in the protocol initialization phase, the identity is verified by the quantum entanglement pair. Through key distribution, a user only knows a part of the key, and the accuracy of the original key needs to be considered. Channel noise directly affects the transmission result of quantum bits and reduces the transmission accuracy. In addition, the presence of eavesdropper Eve may also affect the transmission of qubits. The receiver corrects the error by using quantum error correction technology, thereby improving the efficiency of protocol communication.

     

Syntheses and characterizations of 5-nitro-2-(3′,5′-di(trifluoromethyl)phenyl)pyridyl-containing iridium(III) complexes and the two-band white photoluminescence properties in solution

A derivative of 2-phenylpyridine (Hppy), 5-nitro-2-(3′,5′-di(trifluoromethyl)phenyl)pyridine (HL), is prepared. The L-containing cyclometalated iridium(III) complexes with mono- and bidentate ancillary ligands, [Ir(L)₂(PPh₃)Cl] (1) and [Ir(L)₂(pic)] (2, pic = picolinic acid), are synthesized and characterized. The photoluminescence (PL) spectra of 1 and 2 in CH₂Cl₂ solutions show emission maxima at 558 and 560 nm, corresponding to yellow light emission with the Commission Internationale de L’éclairage (CIE) coordinates of (0.45, 0.54) and (0.46, 0.52), respectively. However, the luminescence intensity of 2 with PL quantum yield of 0.71 is obviously stronger that of 1 with PLQY of 0.19. The two-band white PL properties of 2 and [Ir(dfppy)₂(PPh₃)(NCS)] (3, dfppy = 2-(4,6-difluorophenyl)pyridine) with efficient blue light emission are investigated. The CH₂Cl₂ solutions of 2 and 3 in the molar ratio of 1?:?5 show white light emission with the CIE coordinates of (0.33, 0.41).     

Characterizing variable for the critical point in momentum space

The possible experimentally observable signal in momentum space for the critical point, which is free from the contamination of statistical fluctuations, is discussed. It is shown that the higher order scaled moment of transverse momentum can serve as an appropriate signal for the critical point, provided the transverse momentum distribution has a sudden change when energy increases passing through this point. A 2-D percolation model with a linear temperature gradient is constructed to check this suggestion. A sudden change of third order scaled moment of transverse momentum is observed.     

Synthesis and biological evaluation of echinocystic acid derivatives as HCV entry inhibitors

A series of echinocystic acid (EA) 28-COOH derivatives was synthesized, and their anti-HCV entry activity was evaluated by HCVpp and VSVpp entry assay. It was found that some of them showed moderate anti-HCV entry activity, especially compound 12, and these modifications also removed the undesired hemolytic effect.     

CuCo/BNNSs纳米催化剂对固态储氢材料氨硼烷水解的催化性能

采用共还原法将CuCo双金属负载到通过聚乙烯吡咯烷酮(PVP)辅助离子插层法制备的少层氮化硼纳米片(BNNSs)上,获得了平均粒径为2.7 nm且高度分散的铜钴/氮化硼纳米片(CuCo/BNNSs)纳米催化剂。通过原子力显微镜(AFM)、X射线衍射(XRD)、傅里叶转换红外光谱(FTIR)、拉曼光谱(Raman)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)和高分辨率透射电镜(HRTEM)对载体及催化剂的结构及形貌进行表征,并研究了CuCo/BNNSs的催化性能。研究发现,由于Cu、Co、BNNSs和OH-之间高效的四重效应协同使得Cu0.5Co0.5/BNNSs纳米催化剂在室温、pH=14条件下对氨硼烷(AB,NH3BH3)水解释氢具有极高的催化活性。转化频率(TOF)值达到104.52 molH2·molmetal^-1·min^-1,且CuCo/BNNSs纳米催化剂具有良好的稳定性,6次循环利用后仍保持较高催化活性。