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921.
Yumin Wang Dr. Xuemiao Yin Prof. Junfeng Chen Prof. Yaxing Wang Prof. Zhifang Chai Prof. Shuao Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(9):1900-1905
Scintillators are a unique class of luminescent materials with specific applications towards radiation detection. The emitters within state-of-the-art scintillators are mostly limited to bismuth, cerium, europium, thallium, lead, tungsten, etc. A shared feature of these elements is the relatively high atomic number, which is responsible for high radiation stopping power and radiation-induced luminescence. Searching for new scintillating materials is an essential target aiming at specific applications. In this Concept article, we will discuss our recent works on the topic of “uranyl-bearing scintillators”. As a virgin territory in this field, uranyl-bearing scintillators show intrinsic merits for designing new materials with X-ray detection capability, that is, the large photoelectric cross-section, high X-ray attenuation efficiency, and high crystal density. In addition, we also present challenges in the further development of the uranyl-bearing scintillators. 相似文献
922.
Nonlinear Dynamics - Visually meaningful image encryption may keep the data security and appearance security of the digital images. However, there are still security and efficiency shortcomings... 相似文献
923.
Amir Lashgari Caroline K. Williams Jenna L. Glover Yueshen Wu Dr. Jingchao Chai Prof. Jianbing “Jimmy” Jiang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(70):16774-16781
The control of the second coordination sphere in a coordination complex plays an important role in improving catalytic efficiency. Herein, we report a zinc porphyrin complex ZnPor8T with multiple flexible triazole units comprising the second coordination sphere, as an electrocatalyst for the highly selective electrochemical reduction of carbon dioxide (CO2) to carbon monoxide (CO). This electrocatalyst converted CO2 to CO with a Faradaic efficiency of 99 % and a current density of −6.2 mA cm−2 at −2.4 V vs. Fc/Fc+ in N,N-dimethylformamide using water as the proton source. Structure-function relationship studies were carried out on ZnPor8T analogs containing different numbers of triazole units and distinct triazole geometries; these unveiled that the triazole units function cooperatively to stabilize the CO2-catalyst adduct in order to facilitate intramolecular proton transfer. Our findings demonstrate that incorporating triazole units that function in a cooperative manner is a versatile strategy to enhance the activity of electrocatalytic CO2 conversion. 相似文献
924.
Coal and gangue (black-gray solid wastes in coal) recognition is vital to avoid waste of resources and pollution of the environment during the coal production. Considering their color/temperature is very close to each other, the traditional visible image and infrared image analyzing method is hard to obtain satisfied recognition efficiency. Therefore, a new idea of the ‘liquid intervention + infrared monitoring’ method was proposed to improve the recognition efficiency. In this article, the coal/gangue recognition experiments with different water temperatures were conducted, and the infrared thermal imager was used to record temperature variation after water intervention. The results show that when the water temperature is lower than the ambient temperature, the temperature difference between coal and gangue reaches the maximum value within 10 s, which is five times that without water intervention. The mean value of temperature difference between coal and gangue shows an approximate linear downward trend with the increasing of water temperature. The results indicate that under the condition of water intervention, it is recommended to choose water with a temperature below the ambient air, which may be a new approach to improve the coal/gangue recognition efficiency under different complex environments in underground coal mines. 相似文献
925.
Liu Y. Zheng Z. Deng H. Ren Q. Zhou Z. Zhao C. Chai H. 《Journal of Structural Chemistry》2021,62(8):1285-1292
Journal of Structural Chemistry - Quinazolinones and their derivatives are an important class of broad-spectrum pharmacodynamic groups with a wide range of pharmacological activities. We designed... 相似文献
926.
Yaojiang Li Prof. Junying Wu Lijun Yang Deshen Geng Manzoor Sultan Lang Chen 《ChemistryOpen》2020,9(4):470-479
4-amino-3-aminopyrazole-8-trinitropyrazolo-[5, 1-c] [1, 2, 4]triazine (PTX, C5H2N8O6) has good detonation performance, thermal stability and low mechanical sensitivity, which endow it with good development prospects in insensitive ammunition applications. To study the effects of polymerization on the decomposition of PTX, the reaction processes of PTX at different conditions were simulated by quantum chemistry and molecular dynamics methods. In this paper, the effects of polymerization on the decomposition of PTX were studied in terms of species information, reaction path of PTX, bond formation and bond cleavage, evolution of small molecules and clusters, and kinetic parameters at different stages. The results show that under the high-temperature and high-pressure conditions, the initial reaction path of unimolecular PTX in the thermal decomposition is mainly the cleavage of C−NO2 bonds. At the same time, there are many polymerization reactions in thermal decomposition process, which may greatly affect the reaction rate and path. The higher the degree of polymerization, the larger equilibrium value of potential energy, the less energy release of thermal decomposition. Compared with the activation energy of other explosives, the activation energy of PTX is higher than that of β-HMX and lower than that of TNT. 相似文献
927.
A novel phase-shifted long-period fiber grating(PS-LPFG)for the simultaneous measurement of torsion and temperature is described and experimentally demonstrated.The PS-LPFG is fabricated by inserting a pretwisted structure into the long-period fiber grating(LPFG)written in single-mode fiber(SMF).Experimental results show that the torsion sensitivities of the two dips are?0.114 nm/(rad/m)and?0.069 nm/(rad/m)in the clockwise direction,and?0.087 nm/(rad/m)and?0.048 nm/(rad/m)in the counterclockwise direction,respectively.The temperature sensitivities of the two dips are 0.057 nm/℃ and 0.051 nm/℃,respectively.The two dips of the PS-LPFG exhibit different responses to torsion and temperature.Simultaneous measurement of torsion and temperature can be implemented using a sensor.The feasibility and stabilization of simultaneous torsion and temperature measurement have been confirmed,and hence this novel PS-LPFG demonstrates potential for fiber sensing and engineering applications. 相似文献
928.
929.
本文报导了多孔硅的拉曼散射和光致发光的研究。给出了多孔硅的拉曼和光致发光谱之间的对应关系,根据拉曼峰的移动,估算了多孔硅量子线横截面的平均尺度为2.1~4.2nm。 相似文献
930.
Some practical research topics on tunable fiber gratings in author's group are presented, including tuning speed, tuning range, tuning characteristics of gratings in HB fiber, and the tunability of the line-width. The applications of fiber gratings in communication and sensing are also discussed. 相似文献