CoS_(2) is considered to be a promising electrocatalyst for hydrogen evolution reaction(HER).However,its further widespread applications are hampered by the unsatisfactory activity due to relatively high chemisorption...CoS_(2) is considered to be a promising electrocatalyst for hydrogen evolution reaction(HER).However,its further widespread applications are hampered by the unsatisfactory activity due to relatively high chemisorption energy for hydrogen atom.Herein,theoretical predictions of first-principles calculations reveal that the introduction of a Cl-terminated MXenes-Ti_(3)CNCl_(2) can significantly reduce the HER potential of CoS_(2)-based materials and the Ti_(3)CNCl_(2)@CoS_(2) core–shell nanostructure has Gibbs free energy of hydrogen adsorption(|ΔGH|)close to zero,much lower than that of the pristine CoS_(2) and Ti_(3)CNCl_(2).Inspired by the theoretical predictions,we have successfully fabricated a unique Ti_(3)CNCl_(2)@CoS_(2) core–shell nanostructure by ingeniously coupling CoS_(2) with a Cl-terminated MXenes-Ti_(3)CNCl_(2).Interface-charge transfer between CoS_(2) and Ti_(3)CNCl_(2) results in a higher degree of electronic localization and a formation of chemical bonding.Thus,the Ti_(3)CNCl_(2)@CoS_(2) core–shell nanostructure achieves a significant enhancement in HER activity compared to pristine CoS_(2) and Ti_(3)CNCl_(2).Theoretical calculations further confirm that the partial density of states of CoS_(2) after hybridization becomes more non-localized,and easier to interact with hydrogen ions,thus boosting HER performance.In this work,the success of oriented experimental fabrication of high-efficiency Ti_(3)CNCl_(2)@CoS_(2) electrocatalysts guided by theoretical predictions provides a powerful lead for the further strategic design and fabrication of efficient HER electrocatalysts.展开更多
In view of the non-local phenomena appearing in the rock and concrete-like materials, the non-local damage and fracture model of rock and concrete-like materials was established through non-local method of Gaussian we...In view of the non-local phenomena appearing in the rock and concrete-like materials, the non-local damage and fracture model of rock and concrete-like materials was established through non-local method of Gaussian weighting function. The result indicates that, the stress of one point in the material is correlated not only to its strain history, but also to the interaction of the points in its certain adjacent region of the material. Based on the established non-local model, the numerical simulation of notch containing three-point bending beam was carried out. The results show that the grid sensitivities have been avoided and the fracture direction of the material has not been influenced by the grid shape, and the model proposed can be used to better simulate the damage developing process of the rock and concrete-like materials.展开更多
考虑线性软化模型不能反映材料软化变形复杂性的不足,选取高斯正态分布函数作为非局部理论的权函数,同时采用指数型应力衰减模式考虑软化的非线性特征,进一步地将这种非线性非局部理论与采用L ap lace算子考虑塑性应变梯度效应的塑性梯...考虑线性软化模型不能反映材料软化变形复杂性的不足,选取高斯正态分布函数作为非局部理论的权函数,同时采用指数型应力衰减模式考虑软化的非线性特征,进一步地将这种非线性非局部理论与采用L ap lace算子考虑塑性应变梯度效应的塑性梯度理论相结合,建议了一种非线性非局部应变梯度模型,并据此针对各向同性单向拉伸杆的力学响应进行了分析,将计算结果与线性软化模型进行了对比.结果表明:在非线性软化模型中,尽管塑性应变分布形式与线性软化模型的相同,但塑性应变同时依赖于应力降与破坏极限应变,两者最大应变是不同的.展开更多
为了解决无线定位精度与复杂测距之间的矛盾,提出一种基于接收信号强度比较的非测距定位算法,接收信号强度比较(Received signal strength compare,RSSC)定位算法。为了满足认知无线电网络中主用户的非合作特性,RSSC算法不需要主用户与...为了解决无线定位精度与复杂测距之间的矛盾,提出一种基于接收信号强度比较的非测距定位算法,接收信号强度比较(Received signal strength compare,RSSC)定位算法。为了满足认知无线电网络中主用户的非合作特性,RSSC算法不需要主用户与认知用户合作。通过比较认知用户所测量到的接收信号强度,逐步确定主用户所在的区域,取区域的质心作为主用户的位置估计。根据认知用户密度、用户密度和信噪比3种参数,对RSSC算法的性能进行了分析。实验结果表明,RSSC算法与其他非测距定位算法相比,能够明显提高定位精度。展开更多
To use non X ray comprehensive measurement for accurate localization of sublabio septo sphenoidal approach for shortening operating duration, decreasing hemorrhage, and increasing the success rate of operation Me...To use non X ray comprehensive measurement for accurate localization of sublabio septo sphenoidal approach for shortening operating duration, decreasing hemorrhage, and increasing the success rate of operation Methods Operations in 122 patients suffering from tumors in the sella turcica region used non X ray localizations including localization by the angle formed by the glalella, anterior nasal spina and anterior nasal spina sella turcica; localization by the angle formed by the upper incisors, anterior nasal spina and anterior nasal spina sella turcica; and localization by anatomical markers (determination of the midline by the nasoseptum and vomer; determination of the anterior wall of the sphenoidal sinus by the foramen of the sphenoidal sinus and vomer body; correction of the site by septum of the sphenoidal sinus; location of the center of saddle by the shape of the floor of the sella and determination of the approach direction by the damaged area in the sella turcica region) were comprehensively employed Additionally, X ray localization was used to correct its accuracy Results Non X ray comprehensive localization was applied to 40 patients for determining the site and depth of the floor of the sella, and the preciseness of the measurement was confirmed with X ray Operating duration averages 2 2 hours Non X ray localization was directly applied to 82 patients for comprehensively measuring the floor of the sella, and operations were successful Operating duration averages 1 5 hours and blood transfusion averages 200?ml No deaths and severe complications occurred Conclusion Non X ray comprehensive measurement can be directly applied for precisely localizing the floor of the sella展开更多
基金supported by the National Natural Science Foundation of China(No.62004143)the Central Government Guided Local Science and Technology Development Special Fund Project(No.2020ZYYD033)+3 种基金the Natural Science Foundation of Hubei Province(No.2021CFB133)the Opening Fund of Key Laboratory of Rare Mineral,Ministry of Natural Resources(No.KLRM-KF 202005)the Opening Fund of Key Laboratory for Green Chemical Process of Ministry of Education of Wuhan Institute of Technology(No.GCP202101)the Innovation Project of Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education(No.LCX2021003).
文摘CoS_(2) is considered to be a promising electrocatalyst for hydrogen evolution reaction(HER).However,its further widespread applications are hampered by the unsatisfactory activity due to relatively high chemisorption energy for hydrogen atom.Herein,theoretical predictions of first-principles calculations reveal that the introduction of a Cl-terminated MXenes-Ti_(3)CNCl_(2) can significantly reduce the HER potential of CoS_(2)-based materials and the Ti_(3)CNCl_(2)@CoS_(2) core–shell nanostructure has Gibbs free energy of hydrogen adsorption(|ΔGH|)close to zero,much lower than that of the pristine CoS_(2) and Ti_(3)CNCl_(2).Inspired by the theoretical predictions,we have successfully fabricated a unique Ti_(3)CNCl_(2)@CoS_(2) core–shell nanostructure by ingeniously coupling CoS_(2) with a Cl-terminated MXenes-Ti_(3)CNCl_(2).Interface-charge transfer between CoS_(2) and Ti_(3)CNCl_(2) results in a higher degree of electronic localization and a formation of chemical bonding.Thus,the Ti_(3)CNCl_(2)@CoS_(2) core–shell nanostructure achieves a significant enhancement in HER activity compared to pristine CoS_(2) and Ti_(3)CNCl_(2).Theoretical calculations further confirm that the partial density of states of CoS_(2) after hybridization becomes more non-localized,and easier to interact with hydrogen ions,thus boosting HER performance.In this work,the success of oriented experimental fabrication of high-efficiency Ti_(3)CNCl_(2)@CoS_(2) electrocatalysts guided by theoretical predictions provides a powerful lead for the further strategic design and fabrication of efficient HER electrocatalysts.
基金Project(50904036) supported by the National Natural Science Foundation of ChinaProject (20090450421) supported China Postdoctoral Science Foundation
文摘In view of the non-local phenomena appearing in the rock and concrete-like materials, the non-local damage and fracture model of rock and concrete-like materials was established through non-local method of Gaussian weighting function. The result indicates that, the stress of one point in the material is correlated not only to its strain history, but also to the interaction of the points in its certain adjacent region of the material. Based on the established non-local model, the numerical simulation of notch containing three-point bending beam was carried out. The results show that the grid sensitivities have been avoided and the fracture direction of the material has not been influenced by the grid shape, and the model proposed can be used to better simulate the damage developing process of the rock and concrete-like materials.
文摘考虑线性软化模型不能反映材料软化变形复杂性的不足,选取高斯正态分布函数作为非局部理论的权函数,同时采用指数型应力衰减模式考虑软化的非线性特征,进一步地将这种非线性非局部理论与采用L ap lace算子考虑塑性应变梯度效应的塑性梯度理论相结合,建议了一种非线性非局部应变梯度模型,并据此针对各向同性单向拉伸杆的力学响应进行了分析,将计算结果与线性软化模型进行了对比.结果表明:在非线性软化模型中,尽管塑性应变分布形式与线性软化模型的相同,但塑性应变同时依赖于应力降与破坏极限应变,两者最大应变是不同的.
文摘为了解决无线定位精度与复杂测距之间的矛盾,提出一种基于接收信号强度比较的非测距定位算法,接收信号强度比较(Received signal strength compare,RSSC)定位算法。为了满足认知无线电网络中主用户的非合作特性,RSSC算法不需要主用户与认知用户合作。通过比较认知用户所测量到的接收信号强度,逐步确定主用户所在的区域,取区域的质心作为主用户的位置估计。根据认知用户密度、用户密度和信噪比3种参数,对RSSC算法的性能进行了分析。实验结果表明,RSSC算法与其他非测距定位算法相比,能够明显提高定位精度。
文摘To use non X ray comprehensive measurement for accurate localization of sublabio septo sphenoidal approach for shortening operating duration, decreasing hemorrhage, and increasing the success rate of operation Methods Operations in 122 patients suffering from tumors in the sella turcica region used non X ray localizations including localization by the angle formed by the glalella, anterior nasal spina and anterior nasal spina sella turcica; localization by the angle formed by the upper incisors, anterior nasal spina and anterior nasal spina sella turcica; and localization by anatomical markers (determination of the midline by the nasoseptum and vomer; determination of the anterior wall of the sphenoidal sinus by the foramen of the sphenoidal sinus and vomer body; correction of the site by septum of the sphenoidal sinus; location of the center of saddle by the shape of the floor of the sella and determination of the approach direction by the damaged area in the sella turcica region) were comprehensively employed Additionally, X ray localization was used to correct its accuracy Results Non X ray comprehensive localization was applied to 40 patients for determining the site and depth of the floor of the sella, and the preciseness of the measurement was confirmed with X ray Operating duration averages 2 2 hours Non X ray localization was directly applied to 82 patients for comprehensively measuring the floor of the sella, and operations were successful Operating duration averages 1 5 hours and blood transfusion averages 200?ml No deaths and severe complications occurred Conclusion Non X ray comprehensive measurement can be directly applied for precisely localizing the floor of the sella
