The central trinomial coefficient T_(n)denotes the coefficient of x^(n)in the expansion of(1+x+x^(2))^(n).We prove a congruence related to the sums of the central trinomial coefficient and the central binomial coeffic...The central trinomial coefficient T_(n)denotes the coefficient of x^(n)in the expansion of(1+x+x^(2))^(n).We prove a congruence related to the sums of the central trinomial coefficient and the central binomial coefficient,which was conjectured by Z.-W.Sun.展开更多
The Underwater Communication Link(UCL)is a crucial component of Underwater Wireless Optical Communication(UWOC)systems,requiring optimised design to mitigate the high power attenuation inherent in seawater.To ensure t...The Underwater Communication Link(UCL)is a crucial component of Underwater Wireless Optical Communication(UWOC)systems,requiring optimised design to mitigate the high power attenuation inherent in seawater.To ensure the reliability of an optimal UCL design,it is essential to account for the three primary scattering regimes:forward scattering(FSC),backward scattering(BSC),and isotropic scattering(ISC)in seawater channels.This study introduces a new photon-tracking model based on a discrete equation,facilitating Monte Carlo Simulation(MCS)to evaluate how different scattering regimes influence received photon distribution.Three distinct Scattering Regime Contribution Weight(SRCW)probability sets were employed,each representing different UCL operational configurations dominated by specific scattering regimes.The proposed modeling approach enables a comprehensive assessment of the temporal characteristics of received optical pulses,channel loss,and time spread-ultimately defining the optimal UCL design parameters.The key findings of this study include:(1)Enhancing the FSC regime dominance leads to a quasi-light waveguide effect over link spans and small Fields of View(FOV)<25°,significantly improving channel performance in Harbor seawater compared to Coastal seawater.(2)A well-designed UCL with a small FOV(<25°)can minimise channel loss and time spread,ensuring high capacity and efficient performance in both Coastal and Harbor seawaters.(3)When BSC and ISC contributions exceed FSC dominance,the received optical pulse undergoes significant temporal broadening,particularly for larger FOV angles(>25°)and extended link spans.(4)The developed novel MCS-based discrete equation provides a simple yet robust model for simulating photon propagation in both homogeneous and inhomogeneous underwater channels.These insights contribute to developing more efficient and reliable UCL designs with military standards by enhancing UWOC system performance over a longer linkspan for a given limited optical power across various underwater environments.展开更多
在单因素试验基础上,通过Plackett-Burman试验筛选及中心组合设计试验优化超声时间、超声温度和混酸用量三个因素对超声辅助提取人发中铅的影响。由响应面法建立二次回归模型得到最佳超声条件为:超声时间16 min,超声温度56℃,混酸体积6....在单因素试验基础上,通过Plackett-Burman试验筛选及中心组合设计试验优化超声时间、超声温度和混酸用量三个因素对超声辅助提取人发中铅的影响。由响应面法建立二次回归模型得到最佳超声条件为:超声时间16 min,超声温度56℃,混酸体积6.50 m L。方法的相对标准偏差(RSD)为3.18%。检出限为0.80μg·L^(-1),定量限为2.7μg·L^(-1)。t检验结果表明超声提取法和湿消解法之间无显著性差异,因此用超声波辅助-原子吸收光谱法测定人发中的铅方法可行,且超声提取法耗时短、试剂用量少。展开更多
目的探讨5F鞘组在经外周静脉穿刺置入中心静脉导管(peripherally inserted central catheter,PICC)中临床应用的效果。方法回顾性分析并总结2012年12月至2013年2月哈尔滨医科大学附属第一医院收治的应用5F鞘组10例行PICC患者的临床资料...目的探讨5F鞘组在经外周静脉穿刺置入中心静脉导管(peripherally inserted central catheter,PICC)中临床应用的效果。方法回顾性分析并总结2012年12月至2013年2月哈尔滨医科大学附属第一医院收治的应用5F鞘组10例行PICC患者的临床资料。结果 10例患者均顺利完成PICC,有2例患者术后出现静脉炎,其余患者均未发生严重的并发症。结论静脉穿刺条件差的患者应用5F鞘组行PICC导管有利于提高置管成功率。展开更多
金枪鱼渔业区域性管理组织主要有大西洋金枪鱼养护国际委员会（International Commission for the Conservation of Atlantic Tunas-ICCAT）,印度洋金枪鱼委员会（Indian Ocean Tuna Commission -IOTC）, 中西太平洋渔业委员会（Western...金枪鱼渔业区域性管理组织主要有大西洋金枪鱼养护国际委员会（International Commission for the Conservation of Atlantic Tunas-ICCAT）,印度洋金枪鱼委员会（Indian Ocean Tuna Commission -IOTC）, 中西太平洋渔业委员会（Western and Central Pacific Fisheries Commission -WCPFC）,南方蓝鳍金枪鱼养护委员会（Commission for the Conservation of Southern Blue-fin Tuna- CCSBT）等5个。展开更多
The feasibility of copper smelter slag processing by ammonia solution treatment was investigated. The central composite rotatable design(CCRD) and approximation method were used to determine the optimum conditions of ...The feasibility of copper smelter slag processing by ammonia solution treatment was investigated. The central composite rotatable design(CCRD) and approximation method were used to determine the optimum conditions of zinc and copper recovery to a solution. The experimental design was done at five levels of the four operating parameters which were the initial concentration of NH–3, the initial Cl ions concentration, leaching time and solid/liquid ratio. Two mathematical models describing dependence of metal recovery on the operating parameters were obtained. The models are successful in predicting the responses. It was found that optimal parameters for zinc and copper recovery are as follows(values for copper are given in brackets): initial CNH3 17.1%(19.9%), initial CCl– 160 g/L(160 g/L), leaching process duration 4.56 h(4.13 h), solid/liquid ratio 0.39(0.53). The maximum Zn and Cu recoveries to solution, obtained experimentally under the conditions, are 81.16% and 56.48%, respectively.展开更多
基金National Natural Science Foundation of China(11971222,12071208)Jiangsu Qinglan ProjectProject of Guangzhou Huashang College(2022HSDS27)。
文摘The central trinomial coefficient T_(n)denotes the coefficient of x^(n)in the expansion of(1+x+x^(2))^(n).We prove a congruence related to the sums of the central trinomial coefficient and the central binomial coefficient,which was conjectured by Z.-W.Sun.
基金The Deanship of Scientific Research(DSR)at King Abdulaziz University(KAU),Jeddah,Saudi Arabia,has funded this project under Grant No.(KEP-PhD:72-130-1443).
文摘The Underwater Communication Link(UCL)is a crucial component of Underwater Wireless Optical Communication(UWOC)systems,requiring optimised design to mitigate the high power attenuation inherent in seawater.To ensure the reliability of an optimal UCL design,it is essential to account for the three primary scattering regimes:forward scattering(FSC),backward scattering(BSC),and isotropic scattering(ISC)in seawater channels.This study introduces a new photon-tracking model based on a discrete equation,facilitating Monte Carlo Simulation(MCS)to evaluate how different scattering regimes influence received photon distribution.Three distinct Scattering Regime Contribution Weight(SRCW)probability sets were employed,each representing different UCL operational configurations dominated by specific scattering regimes.The proposed modeling approach enables a comprehensive assessment of the temporal characteristics of received optical pulses,channel loss,and time spread-ultimately defining the optimal UCL design parameters.The key findings of this study include:(1)Enhancing the FSC regime dominance leads to a quasi-light waveguide effect over link spans and small Fields of View(FOV)<25°,significantly improving channel performance in Harbor seawater compared to Coastal seawater.(2)A well-designed UCL with a small FOV(<25°)can minimise channel loss and time spread,ensuring high capacity and efficient performance in both Coastal and Harbor seawaters.(3)When BSC and ISC contributions exceed FSC dominance,the received optical pulse undergoes significant temporal broadening,particularly for larger FOV angles(>25°)and extended link spans.(4)The developed novel MCS-based discrete equation provides a simple yet robust model for simulating photon propagation in both homogeneous and inhomogeneous underwater channels.These insights contribute to developing more efficient and reliable UCL designs with military standards by enhancing UWOC system performance over a longer linkspan for a given limited optical power across various underwater environments.
文摘在单因素试验基础上,通过Plackett-Burman试验筛选及中心组合设计试验优化超声时间、超声温度和混酸用量三个因素对超声辅助提取人发中铅的影响。由响应面法建立二次回归模型得到最佳超声条件为:超声时间16 min,超声温度56℃,混酸体积6.50 m L。方法的相对标准偏差(RSD)为3.18%。检出限为0.80μg·L^(-1),定量限为2.7μg·L^(-1)。t检验结果表明超声提取法和湿消解法之间无显著性差异,因此用超声波辅助-原子吸收光谱法测定人发中的铅方法可行,且超声提取法耗时短、试剂用量少。
文摘目的探讨5F鞘组在经外周静脉穿刺置入中心静脉导管(peripherally inserted central catheter,PICC)中临床应用的效果。方法回顾性分析并总结2012年12月至2013年2月哈尔滨医科大学附属第一医院收治的应用5F鞘组10例行PICC患者的临床资料。结果 10例患者均顺利完成PICC,有2例患者术后出现静脉炎,其余患者均未发生严重的并发症。结论静脉穿刺条件差的患者应用5F鞘组行PICC导管有利于提高置管成功率。
文摘金枪鱼渔业区域性管理组织主要有大西洋金枪鱼养护国际委员会（International Commission for the Conservation of Atlantic Tunas-ICCAT）,印度洋金枪鱼委员会（Indian Ocean Tuna Commission -IOTC）, 中西太平洋渔业委员会（Western and Central Pacific Fisheries Commission -WCPFC）,南方蓝鳍金枪鱼养护委员会（Commission for the Conservation of Southern Blue-fin Tuna- CCSBT）等5个。
文摘The feasibility of copper smelter slag processing by ammonia solution treatment was investigated. The central composite rotatable design(CCRD) and approximation method were used to determine the optimum conditions of zinc and copper recovery to a solution. The experimental design was done at five levels of the four operating parameters which were the initial concentration of NH–3, the initial Cl ions concentration, leaching time and solid/liquid ratio. Two mathematical models describing dependence of metal recovery on the operating parameters were obtained. The models are successful in predicting the responses. It was found that optimal parameters for zinc and copper recovery are as follows(values for copper are given in brackets): initial CNH3 17.1%(19.9%), initial CCl– 160 g/L(160 g/L), leaching process duration 4.56 h(4.13 h), solid/liquid ratio 0.39(0.53). The maximum Zn and Cu recoveries to solution, obtained experimentally under the conditions, are 81.16% and 56.48%, respectively.
