In this paper, We show that the simple K\-3-groups can be characterized by the orders of their maximal abelian subgroups. That is, we have Theorem Let G be a finite group and M a simple K \-3-group. Then ...In this paper, We show that the simple K\-3-groups can be characterized by the orders of their maximal abelian subgroups. That is, we have Theorem Let G be a finite group and M a simple K \-3-group. Then G is isomorphic to M if and only if the set of the orders of the maximal abelian subgoups of G is the same as that of M .展开更多
Plant roots are widely known to provide mechanical reinforcement to soils against shearing and further increase slope stability.However,whether roots provide reinforcement to loess cyclic re-sistance and how various f...Plant roots are widely known to provide mechanical reinforcement to soils against shearing and further increase slope stability.However,whether roots provide reinforcement to loess cyclic re-sistance and how various factors affect roots reinforcement during seismic loading have rarely been studied.The objective is to conduct a series of cyclic direct simple shear tests and DEM numerical simulation to investigate the cyclic behaviour of rooted loess.The effects of initial static shear stress and loading frequency on the cyclic resistance of root-soil composites were first investigated.After that,cyclic direct simple shear simulations at constant volume were carried out based on the discrete element method(PFC^(3D))to investigate the effects of root geome-try,mechanical traits and root-soil bond strength on the cyclic strength of rooted loess.It was discovered that the roots could effectively improve the cyclic resistance of loess.The cyclic resistance of the root-soil composite decreases with the increase of the initial shear stress,then increases,and improves with the increase of the frequency.The simulation result show that increases in root elastic modulus and root-soil interfacial bond strength can all enhance the cyclic resistance of root-soil composites,and the maximum cyclic resistance of the root-soil composite was obtained when the initial inclination angle of the root system was 90°.展开更多
We demonstrate a simple and fast post-deposition treatment with high process compatibility on the hole transport material（HTM） Spiro-MeOTAD in vapor-assisted solution processed methylammonium lead triiodide（CH3NH3P...We demonstrate a simple and fast post-deposition treatment with high process compatibility on the hole transport material（HTM） Spiro-MeOTAD in vapor-assisted solution processed methylammonium lead triiodide（CH3NH3PbI3）-based solar cells. The prepared Co-doped p-type Spiro-MeOTAD films are treated by O3 at room temperature for 5 min,10 min, and 20 min, respectively, prior to the deposition of the metal electrodes. Compared with the traditional oxidation of Spiro-MeOTAD films overnight in dry air, our fast O3 treatment of HTM at room temperature only needs just 10 min,and a relative 40.3% increment in the power conversion efficiency is observed with respect to the result of without-treated perovskite solar cells. This improvement of efficiency is mainly attributed to the obvious increase of the fill factor and short-circuit current density, despite a slight decrease in the open-circuit voltage. Ultraviolet photoelectron spectroscopy（UPS） and Hall effect measurement method are employed in our study to determine the changes of properties after O3 treatment in HTM. It is found that after the HTM is exposed to O3, its p-type doping level is enhanced. The enhancement of conductivity and Hall mobility of the film, resulting from the improvement in p-doping level of HTM, leads to better performances of perovskite solar cells. Best power conversion efficiencies（PCEs） of 13.05% and 16.39% are achieved with most properly optimized HTM via CH3NH3I vapor-assisted method and traditional single-step method respectively.展开更多
In the SU（3） simple group model, the new neutral gauge boson Z＇ couples to pairs of SM fermions with couplings fixed in terms of the SM gauge couplings and depending only on the choice of the fermion embedding. In ...In the SU（3） simple group model, the new neutral gauge boson Z＇ couples to pairs of SM fermions with couplings fixed in terms of the SM gauge couplings and depending only on the choice of the fermion embedding. In this paper, we calculate the contributions of this new particle to the processes e^＋e^-→l^＋l^-, bb^-, and cc^- and study the possibility of detecting this new particle via these processes in the future high-energy linear e^＋e^- collider（LC） experiments with √s= 500 GeV and ￡int= 340 fb^-1. We find that the new gauge boson Z＇ is most sensitive to the process e^＋e^-→b^＋b^-. As long as Mz,≤2 TeV , the absolute values of the relative correction parameter are larger than 5%. We calculate the forward-backward asymmetries and left-right asymmetries for the process e^＋e^-→c^＋c^-, with both the universal and anomaly-free fermion embeddings. Bounds on Z＇ masses are also estimated within 95% confidence level.展开更多
(CH_3OCH_2CH_2C_5H_4)_2LnI(Ln=La,Nd)complexes have been synthesized by the reaction between NaI and[(CH_3OCH_2CH_2C_5H_4)_2LnCl]2 in THF;A single crystal X-ray study has shown that the lanthanum complex is an unsolvat...(CH_3OCH_2CH_2C_5H_4)_2LnI(Ln=La,Nd)complexes have been synthesized by the reaction between NaI and[(CH_3OCH_2CH_2C_5H_4)_2LnCl]2 in THF;A single crystal X-ray study has shown that the lanthanum complex is an unsolvated monomer with lanthanum(Ⅲ)in a trigonal bipyramidal coordination geometry if the cyclopentadienyl ring is regarded as occupying a single polyhedral vertex.展开更多
Three-party password authenticated key exchange (3PAKE) protocol plays a significant role in the history of secure communication area in which two clients agree a robust session key in an authentic manner based on pas...Three-party password authenticated key exchange (3PAKE) protocol plays a significant role in the history of secure communication area in which two clients agree a robust session key in an authentic manner based on passwords. In recent years, researchers focused on developing simple 3PAKE (S-3PAKE) protocol to gain system e?ciency while preserving security robustness for the system. In this study, we first demonstrate how an undetectable on-line dictionary attack can be successfully applied over three existing S-3PAKE schemes. An error correction code (ECC) based S-3PAKE protocol is then introduced to eliminate the identified authentication weakness.展开更多
The simple model for 4f-5d transitions of lanthanide ions in crystals was extended to deal with the case of the octahedral crystal field,where for the t_(2)component of 5d orbitals the spin-orbit interaction could not...The simple model for 4f-5d transitions of lanthanide ions in crystals was extended to deal with the case of the octahedral crystal field,where for the t_(2)component of 5d orbitals the spin-orbit interaction could not be neglected due to incomplete quenching of the 5d orbital angular momentum.The energy levels for the 4f^(N-1)5d configuration and the relative line strengths for the 4f^(N)\4f^(N-1)5d transition were calculated in detail.The result was applied to the interpretation of the low-temperature 4f-5d excitation spectrum of Cs_(2)NaYCl_(6)∶Tb^(3+).展开更多
针对室外街道的行人检测与跟踪,提出一种改进YOLOv3与简单在线实时跟踪(simple online and real-time tracking,SORT)算法相结合的检测及跟踪方法。首先,引入距离和比例交并比(distance and proportional-IOU,DPIOU)损失,将原有的损失...针对室外街道的行人检测与跟踪,提出一种改进YOLOv3与简单在线实时跟踪(simple online and real-time tracking,SORT)算法相结合的检测及跟踪方法。首先,引入距离和比例交并比(distance and proportional-IOU,DPIOU)损失,将原有的损失函数中的均方误差(mean square error,MSE)部分进行变化,从而得到更精确的检测框;其次,将网络结构中的RestNet进行优化,改变下采样区域,增加池化层,进而减少特征信息的丢失;最后将检测结果输入SORT算法进行建模和匹配。实验结果表明,在室外街道的场景下,改进的算法与YOLOv3相比较,损失值收敛更快,平均准确率高出4.85%,跟踪准确率上升3.4%,同时,模型的速度有所提高,最快可达14.39 FPS。展开更多
电子邮件是Internet上应用最多和最广的服务项目,SMTP(Simple Mail Transport protocol)和POP3(Post office protocol)是在电子邮件服务中分别负责收信和发信的两种协议。本文介绍了电子邮件系统的工作原理及相关协议,并基于这些协议设...电子邮件是Internet上应用最多和最广的服务项目,SMTP(Simple Mail Transport protocol)和POP3(Post office protocol)是在电子邮件服务中分别负责收信和发信的两种协议。本文介绍了电子邮件系统的工作原理及相关协议,并基于这些协议设计和开发了一个实用的邮件系统。展开更多
文摘In this paper, We show that the simple K\-3-groups can be characterized by the orders of their maximal abelian subgroups. That is, we have Theorem Let G be a finite group and M a simple K \-3-group. Then G is isomorphic to M if and only if the set of the orders of the maximal abelian subgoups of G is the same as that of M .
文摘Plant roots are widely known to provide mechanical reinforcement to soils against shearing and further increase slope stability.However,whether roots provide reinforcement to loess cyclic re-sistance and how various factors affect roots reinforcement during seismic loading have rarely been studied.The objective is to conduct a series of cyclic direct simple shear tests and DEM numerical simulation to investigate the cyclic behaviour of rooted loess.The effects of initial static shear stress and loading frequency on the cyclic resistance of root-soil composites were first investigated.After that,cyclic direct simple shear simulations at constant volume were carried out based on the discrete element method(PFC^(3D))to investigate the effects of root geome-try,mechanical traits and root-soil bond strength on the cyclic strength of rooted loess.It was discovered that the roots could effectively improve the cyclic resistance of loess.The cyclic resistance of the root-soil composite decreases with the increase of the initial shear stress,then increases,and improves with the increase of the frequency.The simulation result show that increases in root elastic modulus and root-soil interfacial bond strength can all enhance the cyclic resistance of root-soil composites,and the maximum cyclic resistance of the root-soil composite was obtained when the initial inclination angle of the root system was 90°.
基金supported by the National Natural Science Foundation of China(Grant Nos.51472016 and 51272015)
文摘We demonstrate a simple and fast post-deposition treatment with high process compatibility on the hole transport material（HTM） Spiro-MeOTAD in vapor-assisted solution processed methylammonium lead triiodide（CH3NH3PbI3）-based solar cells. The prepared Co-doped p-type Spiro-MeOTAD films are treated by O3 at room temperature for 5 min,10 min, and 20 min, respectively, prior to the deposition of the metal electrodes. Compared with the traditional oxidation of Spiro-MeOTAD films overnight in dry air, our fast O3 treatment of HTM at room temperature only needs just 10 min,and a relative 40.3% increment in the power conversion efficiency is observed with respect to the result of without-treated perovskite solar cells. This improvement of efficiency is mainly attributed to the obvious increase of the fill factor and short-circuit current density, despite a slight decrease in the open-circuit voltage. Ultraviolet photoelectron spectroscopy（UPS） and Hall effect measurement method are employed in our study to determine the changes of properties after O3 treatment in HTM. It is found that after the HTM is exposed to O3, its p-type doping level is enhanced. The enhancement of conductivity and Hall mobility of the film, resulting from the improvement in p-doping level of HTM, leads to better performances of perovskite solar cells. Best power conversion efficiencies（PCEs） of 13.05% and 16.39% are achieved with most properly optimized HTM via CH3NH3I vapor-assisted method and traditional single-step method respectively.
基金supported in part by a grant from Henan Institute of Science and Technology under Grant No.06040
文摘In the SU（3） simple group model, the new neutral gauge boson Z＇ couples to pairs of SM fermions with couplings fixed in terms of the SM gauge couplings and depending only on the choice of the fermion embedding. In this paper, we calculate the contributions of this new particle to the processes e^＋e^-→l^＋l^-, bb^-, and cc^- and study the possibility of detecting this new particle via these processes in the future high-energy linear e^＋e^- collider（LC） experiments with √s= 500 GeV and ￡int= 340 fb^-1. We find that the new gauge boson Z＇ is most sensitive to the process e^＋e^-→b^＋b^-. As long as Mz,≤2 TeV , the absolute values of the relative correction parameter are larger than 5%. We calculate the forward-backward asymmetries and left-right asymmetries for the process e^＋e^-→c^＋c^-, with both the universal and anomaly-free fermion embeddings. Bounds on Z＇ masses are also estimated within 95% confidence level.
文摘(CH_3OCH_2CH_2C_5H_4)_2LnI(Ln=La,Nd)complexes have been synthesized by the reaction between NaI and[(CH_3OCH_2CH_2C_5H_4)_2LnCl]2 in THF;A single crystal X-ray study has shown that the lanthanum complex is an unsolvated monomer with lanthanum(Ⅲ)in a trigonal bipyramidal coordination geometry if the cyclopentadienyl ring is regarded as occupying a single polyhedral vertex.
基金the National Science Council (Nos. NSC 99-2218-E-011-014 and NSC 100-2219-E-011-002)
文摘Three-party password authenticated key exchange (3PAKE) protocol plays a significant role in the history of secure communication area in which two clients agree a robust session key in an authentic manner based on passwords. In recent years, researchers focused on developing simple 3PAKE (S-3PAKE) protocol to gain system e?ciency while preserving security robustness for the system. In this study, we first demonstrate how an undetectable on-line dictionary attack can be successfully applied over three existing S-3PAKE schemes. An error correction code (ECC) based S-3PAKE protocol is then introduced to eliminate the identified authentication weakness.
基金the National Natural Science Foundation of China(NSFC10474092,50332050)the City University of Hong Kong Research Grant(9360123)
文摘The simple model for 4f-5d transitions of lanthanide ions in crystals was extended to deal with the case of the octahedral crystal field,where for the t_(2)component of 5d orbitals the spin-orbit interaction could not be neglected due to incomplete quenching of the 5d orbital angular momentum.The energy levels for the 4f^(N-1)5d configuration and the relative line strengths for the 4f^(N)\4f^(N-1)5d transition were calculated in detail.The result was applied to the interpretation of the low-temperature 4f-5d excitation spectrum of Cs_(2)NaYCl_(6)∶Tb^(3+).
文摘针对室外街道的行人检测与跟踪,提出一种改进YOLOv3与简单在线实时跟踪(simple online and real-time tracking,SORT)算法相结合的检测及跟踪方法。首先,引入距离和比例交并比(distance and proportional-IOU,DPIOU)损失,将原有的损失函数中的均方误差(mean square error,MSE)部分进行变化,从而得到更精确的检测框;其次,将网络结构中的RestNet进行优化,改变下采样区域,增加池化层,进而减少特征信息的丢失;最后将检测结果输入SORT算法进行建模和匹配。实验结果表明,在室外街道的场景下,改进的算法与YOLOv3相比较,损失值收敛更快,平均准确率高出4.85%,跟踪准确率上升3.4%,同时,模型的速度有所提高,最快可达14.39 FPS。
文摘电子邮件是Internet上应用最多和最广的服务项目,SMTP(Simple Mail Transport protocol)和POP3(Post office protocol)是在电子邮件服务中分别负责收信和发信的两种协议。本文介绍了电子邮件系统的工作原理及相关协议,并基于这些协议设计和开发了一个实用的邮件系统。
