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A reduction scheme of PAPR in CO-OFDM system using time-delay neural networks

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Optoelectronics Letters 2025年

作者： TONG Zhengrong liu zhihong WANG Hao ZHANG Weihua ZHANG Tianhao JIA Qiqi Tianjin Key Laboratory of Thin Film Electronics and Communication Devices， Engineering Research Center for Optoelectronic Devices and Communication Technology of the Ministry of Education， School of Integrated Circuit Science and Engineering， Tianjin University of Technology

An iterative partial transmission sequence （IPTS） cascading time-delay neural network （TDNN） scheme is proposed to reduce peak-to-average power ratio （PAPR） in the coherent optical orthogonal frequency division multiplexing （CO-OFDM） systems. The IPTS algorithm further reduces computational complexity based on the partial transmission sequence （PTS） algorithm. TDNN is trained by the iterative clipping filtering （ICF） method. Simulation results show that the proposed scheme achieves a PAPR reduction of 5.84 dB when complementary cumulative distribution function （CCDF） is 10-4and an extra transmission distance of 200 km for 10-3bit error rate （BER） compared to the original signals.

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乙型肝炎功能性治愈新药:聚焦反义寡核苷酸和小干扰RNA

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临床肝胆病杂志 2025年第1期41卷 7-14页

作者：梁携儿刘智泓侯金林南方医科大学南方医院感染内科广州510515 广东省肝脏疾病研究所广州510515

在乙型肝炎治疗领域,现有的核苷(酸)类似物以及聚乙二醇干扰素在功能性治愈方面的疗效较为有限。最近,反义寡核苷酸与小干扰RNA等小核酸药物以全新的作用机制和令人瞩目的早期临床研究疗效,为乙型肝炎的功能性治愈带来了前所未有的突破... 详细信息

在乙型肝炎治疗领域,现有的核苷(酸)类似物以及聚乙二醇干扰素在功能性治愈方面的疗效较为有限。最近,反义寡核苷酸与小干扰RNA等小核酸药物以全新的作用机制和令人瞩目的早期临床研究疗效,为乙型肝炎的功能性治愈带来了前所未有的突破性进展。反义寡核苷酸和小干扰RNA等小核酸药物可降低HBsAg水平甚至HBsAg转阴。随着HBsAg的减少,可能部分恢复机体的乙型肝炎特异性免疫功能,并可能将单纯的HBsAg清除进一步转化为减少乙型肝炎相关肝脏事件等具有临床价值的硬终点。紧密结合新药背景下HBsAg的动态变化轨迹,进一步优化联合治疗的策略与方案,有望将乙型肝炎功能性治愈转化为提升患者生存率及显著改善其生活质量的最终目标。

关键词：乙型肝炎寡核苷酸类,反义 RNA,小分子干扰乙型肝炎表面抗原功能性治愈

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Transesterification of glyceryl tributyrate with methanol using strontium borate as the solid base catalyst

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Science China Chemistry 2013年第12期56卷 1727-1734页

作者： HUANG HongSheng liu zhihong Key Laboratory for Macromolecular Science of Shaanxi Province School of Chemistry and Chemical EngineeringShaanxi Normal University Department of Chemisitry and Chemical Engineering Ankang University

Four kinds of strontium borates were prepared and characterized by XRD, SEM, EDS, TG-DTA and Hammett titration method and their catalytic activities were examined in the transesterification of glyceryl tributyrate with methanol for the first time. The separate effects of the molar ratio of methanol to oil, the reaction time, and reusability were investigated. In addition, the catalytic activities of Sr（OH）2 and SrCO3 were also examined for the comparison. The results showed that the basicity and catalytic activity of these catalysts were decreased as the following order： Sr（OH）2 〉 SrB2O4·4H2O 〉 SrB6O10·5H2O 〉 SrB2O4 〉 SrB6O10 〉 SrCO3, and the reusability decreases as the following order： anhydrous strontium borates （SrBgO4, SrB6O10）〉 hydrated strontium borates （SrB2O4·4H2O, SrB6O10·5H2O）〉 Sr（OH）〉 The results indicate that the SrB2O4·4H2O with regular morphology, which was obtained at low temperature by a simple preparation method, might be as one kind of good potential alkaline earth salts catalyst for transesterification. Moreover, the possible reaction mechanism is proposed and analyzed.

关键词： strontium borate solid base catalyst transesterification glyceryl tributyrate

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语音声特征的互相关贝叶斯块稀疏化方法

机械设计与制造 2025年第1期407卷 226-230页

作者：马鸣刘志红李超赵化良青岛理工大学山东青岛266000 工业流体节能与污染控制教育部重点实验室山东青岛266000

为解决语音声信号稀疏化表示中稀疏度确定难和稀疏化程度低的问题,提出一种互相关块稀疏贝叶斯学习方法。该方法基于稀疏贝叶斯学习理论,利用语音声信号的块稀疏性和时间相关性特征,构建了语音声信号稀疏解的互相关块稀疏空间结构,使其... 详细信息

为解决语音声信号稀疏化表示中稀疏度确定难和稀疏化程度低的问题,提出一种互相关块稀疏贝叶斯学习方法。该方法基于稀疏贝叶斯学习理论,利用语音声信号的块稀疏性和时间相关性特征,构建了语音声信号稀疏解的互相关块稀疏空间结构,使其在特征空间内展现更充分的稀疏性。该方法可有效提高语音声信号的稀疏表示。经数值仿真验证构建的声特征惩罚矩阵D对稀疏解x的约束作用显著提高,x中相邻的数据块密切相关,单一的噪声峰值被抑制,说明能得到最优稀疏解,并且提高了稀疏化程度。

关键词：稀疏化稀疏贝叶斯块稀疏互相关

Influence of PEG 6000 on gallium oxide(Ga_2O_3) polymorphs and photocatalytic properties

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Science China Chemistry 2015年第3期58卷 532-538页

作者： Xiaohui Chai zhihong liu Yingping Huang Key Laboratory of Analytical Chemistry for Biology and Medicine Ministry of Education College of Chemistry and Molecular Sciences Wuhan University Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region Ministry of Education China Three Gorges University Collaborative Innovation Center for Geo-Hazards and Eco-Environment in Three Gorges Area Hubei Province China Three Gorges University

Three different nanorod-like gallium oxides with mono/poly-crystalline nature(α, β, and α/β-Ga2O3) were prepared by regulating the amount of polyethylene glycol(PEG) 6000 in the range of 0.2–0.8 g proportionally via a hydrothermal method combined with further calcination. The bandgap of the products, given by UV-Vis diffuse reflectance spectra(UV-Vis DRS), was in the order of α-Ga2O3 > α/β-Ga2O3 > β-Ga2O3. To further investigate the photocatalysis performance of the catalysts, the decomposition of rhodamine B(Rh B) by Ga2O3 under UV light illumination(λ < 387 nm) was presented and complete degradation could be achieved within 30 min, a result that showed the highest efficiency. The photocatalytic oxidation mechanism is further discussed and prominently related to the active species: hydroxyl radical(·OH) and superoxide radical(O·-2), which were confirmed by electron paramagnetic resonance(EPR).

关键词： gallium oxides photocatalysis UV light hydroxyl radical superoxide radical

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DOA估计的稀疏线阵双迭代傅里叶优化方法

噪声与振动控制 2025年第1期45卷 97-104页

作者：徐希鑫赵化良刘志红张开业孙琪青岛理工大学机械与汽车工程学院山东青岛266520 青岛理工大学工业流体节能与污染控制教育部重点实验室山东青岛266520

针对稀疏线阵波达方向估计精度较低问题,提出一种稀疏线阵双迭代傅里叶优化方法。基于阵列孔径原理,利用阵列因子与阵元激励间的傅里叶变换关系,构建稀疏线阵构型优化目标函数;提出双迭代傅里叶变换算法,制定合理的旁瓣阈值和旁瓣约束条... 详细信息

针对稀疏线阵波达方向估计精度较低问题,提出一种稀疏线阵双迭代傅里叶优化方法。基于阵列孔径原理,利用阵列因子与阵元激励间的傅里叶变换关系,构建稀疏线阵构型优化目标函数;提出双迭代傅里叶变换算法,制定合理的旁瓣阈值和旁瓣约束条件,依据稀疏率和阵元数将孔径自适应分区,以阵列峰值旁瓣和孔径为约束,由双层嵌套循环迭代优化阵列麦克风数量和位置,获得更低的阵列峰值旁瓣电平。数值仿真和实验结果表明,根据该方法获得的49.5λ孔径、23%稀疏率的稀疏阵列峰值旁瓣电平为-21.59 dB,主瓣宽度为1.03°,角度分辨率为1°,估计误差小于0.01。与其他方法对比,峰值旁瓣低1 d B,优化效率提升50%,由此可证明该方法的有效性和快速性。

关键词：信号处理稀疏线阵波达方向估计双迭代傅里叶变换旁瓣阈值旁瓣约束条件

Step-Directed Deposition of Au Nanostructures By Electron Beam Evaporation

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Journal of Rare Earths 2004年第z2期22卷 141-144页

作者： Xu Xiangdong liu zhihong Wang Yinchuan liu Zhongfan Institute of Microelectronics Tsinghua UniversityBeijing 100084China Institute of MicroelectronicsTsinghua UniversityBeijing 100084China Center for Nanoscale Science & TechnologyCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Center for Nanoscale Science & TechnologyCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Au atoms were vaporized by electron beam evaporation, and their subsequent growths on Si (111 ) and highly ordered pyrolytic graphite (HOPG) substrates were studied using atomic force microscopy. Results show that Au nanoparticles tend to nucleate and grow regularly along the step edges of HOPG, however, nanoparticles are distributed homogeneously over the whole Si substrate. The possibility of controlled growth of Au in ultrahigh vacuum with peculiar surface structures was preseuted.

关键词： electron beam evaporation HOPG Au controlled growth ultrahigh vacuum

Improving multi-target cooperative tracking guidance for UAV swarms using multi-agent reinforcement learning

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Chinese Journal of Aeronautics 2022年第7期35卷 100-112页

作者： Wenhong ZHOU Jie LI zhihong liu Lincheng SHEN College of Intelligence Science and Technology National University of Defense TechnologyChangsha 410073China

Multi-Target Tracking Guidance(MTTG)in unknown environments has great potential values in applications for Unmanned Aerial Vehicle(UAV)*** Multi-Agent Deep Reinforcement Learning(MADRL)is a promising technique for learning cooperation,most of the existing methods cannot scale well to decentralized UAV swarms due to their computational complexity or global information *** paper proposes a decentralized MADRL method using the maximum reciprocal reward to learn cooperative tracking policies for UAV *** method reshapes each UAV’s reward with a regularization term that is defined as the dot product of the reward vector of all neighbor UAVs and the corresponding dependency vector between the UAV and the *** the dependence between UAVs can be directly captured by the Pointwise Mutual Information(PMI)neural network without complicated aggregation ***,the experience sharing Reciprocal Reward Multi-Agent Actor-Critic(MAAC-R)algorithm is proposed to learn the cooperative sharing policy for all homogeneous *** demonstrate that the proposed algorithm can improve the UAVs’cooperation more effectively than the baseline algorithms,and can stimulate a rich form of cooperative tracking behaviors of UAV ***,the learned policy can better scale to other scenarios with more UAVs and targets.

关键词： Decentralized cooperation Maximum reciprocal reward Multi-agent actor-critic Pointwise mutual information Reinforcement learning

Activity coefficient of NiO in SiO_(2)-saturated MnO–SiO_(2)slag and Al_(2)O_(3)-saturated MnO–SiO_(2)–Al_(2)O_(3)slag at 1623 K

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International Journal of Minerals,Metallurgy and Materials 2022年第2期29卷 248-255页

作者： Guoxing Ren Songwen Xiao Caibin Liao zhihong liu School of Metallurgy and Environment Central South UniversityChangsha 410083China Changsha Research Institute of Mining&Metallurgy Co. LtdChangsha 410012China

As a part of the fundamental study related to the reduction smelting of spent lithium-ion batteries and ocean polymetallic nodules based on MnO–SiO_(2)slags,this work investigated the activity coefficient of NiO in SiO_(2)-saturated Mn O–Si O_(2)slag and Al_(2)O_(3)-saturated Mn O–SiO_(2)–Al_(2)O_(3)slag at 1623 K with controlled oxygen partial pressure levels of 10^(-7),10^(-6),and 10^(-5)*** showed that the solubility of nickel oxide in the slags increased with increasing oxygen partial *** nickel in the Mn O–Si O_(2)slag and Mn O–Si O_(2)–Al_(2)O_(3)slag existed as Ni O under experimental *** addition of Al_(2)O_(3)in the Mn O–Si O_(2)slag decreased the dissolution of nickel in the slag and increased the activity coefficient of Ni ***,the activity coefficient of Ni O(γN_(i O)),which is solid Ni O,in the Si O_(2)saturated Mn O–Si O_(2)slag and Al_(2)O_(3)saturated Mn O–Si O_(2)–Al_(2)O_(3)slag at 1623 K can be respectively calculated asγN_(i O)=8.58w(Ni O)+3.18 andγN_(i O)=11.06w(Ni O)+4.07,respectively,where w(Ni O)is the Ni O mass fraction in the slag.

关键词： nickel equilibrium MnO–SiO_(2)slag MnO–SiO_(2)–Al_(2)O_(3)slag activity coefficient spent lithium-ion batteries recovery polymetallic nodules