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排序方式: 共有74条查询结果,搜索用时 15 毫秒
1.
Jorge Segovia Chen Chen Ian C. Cloët Craig D. Roberts Sebastian M. Schmidt Shaolong Wan 《Few-Body Systems》2014,55(1):1-33
Predictions obtained with a confining, symmetry-preserving treatment of a vector ? vector contact interaction at leading-order in a widely used truncation of QCD’s Dyson–Schwinger equations are presented for Δ and Ω baryon elastic form factors and the γN → Δ transition form factors. This simple framework produces results that are practically indistinguishable from the best otherwise available, an outcome which highlights that the key to describing many features of baryons and unifying them with the properties of mesons is a veracious expression of dynamical chiral symmetry breaking in the hadron bound-state problem. The following specific results are of particular interest. The Δ elastic form factors are very sensitive to m Δ. Hence, given that the parameters which define extant simulations of lattice-regularised QCD produce Δ-resonance masses that are very large, the form factors obtained therewith are a poor guide to properties of the Δ(1232). Considering the Δ-baryon’s quadrupole moment, whilst all computations produce a negative value, the conflict between theoretical predictions entails that it is currently impossible to reach a sound conclusion on the nature of the Δ-baryon’s deformation in the infinite momentum frame. Results for analogous properties of the Ω baryon are less contentious. In connection with the N → Δ transition, the Ash-convention magnetic transition form factor falls faster than the neutron’s magnetic form factor and nonzero values for the associated quadrupole ratios reveal the impact of quark orbital angular momentum within the nucleon and Δ; and, furthermore, these quadrupole ratios do slowly approach their anticipated asymptotic limits. 相似文献
2.
Optimizing Optoelectronic Properties of Pyrimidine‐Based TADF Emitters by Changing the Substituent for Organic Light‐Emitting Diodes with External Quantum Efficiency Close to 25 % and Slow Efficiency Roll‐Off 下载免费PDF全文
Kailong Wu Tao Zhang Lisi Zhan Dr. Cheng Zhong Prof. Shaolong Gong Prof. Nan Jiang Prof. Zheng‐Hong Lu Prof. Chuluo Yang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(31):10860-10866
A series of green butterfly‐shaped thermally activated delayed fluorescence (TADF) emitters, namely PXZPM , PXZMePM , and PXZPhPM , are developed by integrating an electron‐donor (D) phenoxazine unit and electron‐acceptor (A) 2‐substituted pyrimidine moiety into one molecule via a phenyl‐bridge π linkage to form a D –π–A–π–D configuration. Changing the substituent at pyrimidine unit in these emitters can finely tune their emissive characteristics, thermal properties, and energy gaps between the singlet and triplet states while maintaining frontier molecular orbital levels, and thereby optimizing their optoelectronic properties. Employing these TADF emitters results in a green fluorescent organic light‐emitting diode (OLED) that exhibits a peak forward‐viewing external quantum efficiency (EQE) close to 25 % and a slow efficiency roll‐off characteristic at high luminance. 相似文献
3.
为了说明V82A和L90M变异对蛋白酶(PR)和茚地那韦(IDV)复合物的影响,进行了5.5ns的MD模拟.用MM-PBSA方法计算了体系的结合自由能,计算和实验结果一致.分解自由能为不同能量项说明,这两个变异引起熵的贡献变化大于焓的贡献变化.分解自由能到每个残基说明Wild,V82A和L90M具有相似的结合模式,结合能的贡献主要来源于A28/A28',I50/I50'和I84/I84'这六个残基组,详细分析了Wild和IDV的结合模式,对比分析了V82A和L90M变异引起结合模式的细小变化.V82A变异引起结合模式的变化是由于变异后位阻减小导致的.L90M变异引起D25和L90间的作用增强并引起结合模式的细小变化.研究结果有助于更好地理解变异对抑制剂和HIV-1PR结合模式的影响,并可以用来帮助设计更高效的PR抑制剂. 相似文献
4.
FKBP12 (FK506-binding protein-12)是一种具有神经保护和促神经再生作用的蛋白. 采用分子动力学模拟取样, 运用MM-GBSA方法计算了FKBP12和3个抑制剂(GPI-1046, 308和107)的绝对结合自由能, GPI-1046的结合能最小, 308小于107的结合能. 通过能量分解的方法考察了FKBP12蛋白的主要残基与抑制剂之间的相互作用和识别, 计算结果表明: 3个抑制剂具有相似的结合模式, Ile56和Tyr82主要表现为氢键作用, Tyr26, Phe46, Val55, Ile56, Trp59, Tyr82, Tyr87和Phe99形成疏水作用区. 计算结果和实验结果吻合. 相似文献
5.
Prof. Dr. Suning Wang Deng‐Tao Yang Jiasheng Lu Hiroyuki Shimogawa Prof. Dr. Shaolong Gong Xiang Wang Soren K. Mellerup Prof. Dr. Atsushi Wakamiya Dr. Yi‐Lu Chang Prof. Dr. Chuluo Yang Prof. Dr. Zheng‐Hong Lu 《Angewandte Chemie (International ed. in English)》2015,54(50):15074-15078
New BN‐heterocyclic compounds have been found to undergo double arene photoelimination, forming rare yellow fluorescent BN‐pyrenes that contain two B? N units. Most significant is the discovery that the double arene elimination can also be driven by excitons generated electrically within electroluminescent (EL) devices, enabling the in situ solid‐state conversion of BN‐heterocycles to BN‐pyrenes and the use of BN‐pyrenes as emitters for EL devices. The in situ exciton‐driven elimination (EDE) phenomenon has also been observed for other BN‐heterocycles. 相似文献
6.
In this paper, we consider the short-pulse equation (SPE) by using the dynamical system theory. The periodic solutions of the SPE are investigated. The solutions are characterized by two parameters. The periodic waves existent conditions are found, and explicit parametric expressions of all periodic solutions are given. 相似文献
7.
以苯并噻唑为荧光团, 氰基乙酸乙酯为识别基团, 设计合成了对水合肼和亚硫酸氢盐具有双重检测能力的荧光探针3-(2-羟基-苯并噻唑)-2-氰基-丙烯酸乙酯(HBT-CN). 在二甲基亚砜/磷酸盐(体积比为1:4)的缓冲液中, 探针对水合肼和亚硫酸氢盐具有良好的选择性, 且荧光强度分别增强了5.6倍(500 nm)和7.5倍(458 nm). 结果表明, 在检测过程中, HTB-CN与水合肼发生了还原-缩合反应, 生成了醛腙, 在波长500 nm处发出黄绿色的荧光信号; HBT-CN与亚硫酸氢盐发生了亲核加成反应, 在波长458 nm处发出蓝色的荧光信号, 从而实现了对水合肼和亚硫酸氢盐的差异性定性与定量检测. 相似文献
8.
Dr. Yuxuan Hu Dr. Jingsheng Miao Dr. Cheng Zhong Yang Zeng Prof. Shaolong Gong Dr. Xiaosong Cao Xue Zhou Dr. Yu Gu Prof. Chuluo Yang 《Angewandte Chemie (International ed. in English)》2023,62(19):e202302478
Heavy-atom integration into thermally activated delayed fluorescence (TADF) molecule could significantly promote the reverse intersystem crossing (RISC) process. However, simultaneously achieving high efficiency, small roll-off, narrowband emission and good operational lifetime remains a big challenge for the corresponding organic light-emitting diodes (OLEDs). Herein, we report a pure green multi-resonance TADF molecule BN-STO by introducing a peripheral heavy atom selenium onto the parent BN-Cz molecule. The organic light-emitting diode device based on BN-STO exhibited state-of-the-art performance with a maximum external quantum efficiency (EQE) of 40.1 %, power efficiency (PE) of 176.9 lm W−1, well-suppressed efficiency roll-off and pure green gamut. This work reveals a feasible strategy to reach a balance between fast RISC process and narrow full width at half maximum (FWHM) of MR-TADF by heavy atom effect. 相似文献
9.
Based on Emin's idea of deformation potential in deformable continuum, a bipolaron Hamiltonian is generalized to two-dimensional deformable electron-phonon system with the assumption of localized deformation potential of δ function. The dynamic properties of bipolaron are studied in the framework of Davydov's soliton theory, and a nonlinear Schrodinger equation is derived using the principle of least action. By function-series method, an exact two-dimensional (2D) soliton solution is obtained. We find that the center-of-mass motion of bipolaron is shown in a solitary wave form, and its relative motion is a harmonic one. 相似文献
10.
建立了以凝胶渗透色谱(GPC)和固相萃取(SPE)净化、气相色谱-质谱(GC-MS)法同时测定紫皮石斛中10种有机磷农药残留的方法。样品用乙腈超声提取,提取液经GPC去除类脂杂质和大分子物质,后经Envi-Carb/NH2固相萃取柱净化,选择离子(SIM)监测模式检测,外标法定量。在26min内10种农药得到很好的分离,农药残留量在0.02~0.5μg/mL,方法的线性良好,相关系数为0.997 3~0.999 9,农药加标浓度为0.05mg/kg和0.2mg/kg时,加标回收率在70.4%~115.8%,相对标准偏差在2.8%~9.6%,满足国家标准要求,检出限为0.005 2~0.011mg/kg。方法简便、快速、灵敏、准确,能够运用于石斛中多组分有机磷农药残留的定性和定量分析。 相似文献