质子治疗装置动态电源控制系统研发

针对质子治疗装置中主环动态电源多平台能量的引出需求,研制了基于开源平台的高速实时动态电源控制系统,该控制系统以开源平台Beaglebone作为顶层硬件接口,以现场可编程逻辑门阵列(FPGA)为核心的控制器作为底层硬件接口,采用分布式的实验物理及工业控制系统(EPICS)进行远程控制。该系统可实时传输任意动态电源的输出参考电流波形数据,并结合定时系统与联锁系统,控制动态电源按预设电流波形进行输出,并实现多平台能量的引出。实验结果显示该控制系统能实现每秒最高十万条指令传输,百万次数据传输零误码率。同时,该系统结构灵活、扩展性强,可作为通用控制平台。     

Chaos in a tethered satellite system induced by atmospheric drag and Earth’s oblateness

Nonlinear Dynamics - This paper describes the chaos behavior of an in-plane tethered satellite system induced by atmospheric drag and the Earth’s oblateness. A commonly used model, the...     

激光雷达辅助驾驶道路参数计算方法研究

针对特定场景辅助驾驶的需求，构建道路场景车载激光雷达三维扫描系统，并设计基于三维激光点云的道路参数提取与计算方法，包括路面宽度、横杆或桥梁或隧道限高、拐弯半径等等，为辅助判断道路的可通过性提供决策依据。测试和对比实验表明，所设计算法效果稳定、精度良好，在效率和自动化程度上有一定优势，可为辅助驾驶提供非常有益的决策参数。     

Electron Configuration Modulation of Nickel Single Atoms for Elevated Photocatalytic Hydrogen Evolution

The emerging metal single‐atom catalyst has aroused extensive attention in multiple fields, such as clean energy, environmental protection, and biomedicine. Unfortunately, though it has been shown to be highly active, the origins of the activity of the single‐atom sites remain unrevealed to date owing to the lack of deep insight on electronic level. Now, partially oxidized Ni single‐atom sites were constructed in polymeric carbon nitride (CN), which elevates the photocatalytic performance by over 30‐fold. The 3d orbital of the partially oxidized Ni single‐atom sites is filled with unpaired d‐electrons, which are ready to be excited under irradiation. Such an electron configuration results in elevated light response, conductivity, charge separation, and mobility of the photocatalyst concurrently, thus largely augmenting the photocatalytic performance.     

Chiral Phosphoric Acid Catalyzed Atroposelective C−H Amination of Arenes

N‐arylcarbazole structures are important because of their prevalence in natural products and functional OLED materials. C?H amination of arenes has been widely recognized as the most efficient approach to access these structures. Conventional strategies involving transition‐metal catalysts suffer from confined substrate generality and the requirement of exogenous oxidants. Organocatalytic enantioselective C–N chiral axis construction remains elusive. Presented here is the first organocatalytic strategy for the synthesis of novel axially chiral N‐arylcarbazole frameworks by the assembly of azonaphthalenes and carbazoles. This reaction accommodates broad substrate scope and gives atropisomeric N‐arylcarbazoles in good yields with excellent enantiocontrol. This approach not only offers an alternative to metal‐catalyzed C–N cross‐coupling, but also brings about opportunities for the exploitation of structurally diverse N‐aryl atropisomers and OLED materials.     

Numerical Modeling of Momentum Dispersion in Porous Media Based on the Pore Scale Prevalence Hypothesis

Transport in Porous Media - A macroscopic model that accounts for the effect of momentum dispersion on flows in porous media is proposed. The model is based on the pore scale prevalence hypothesis...     

Zeolitic Imidazolate Framework 8‐Derived Au@ZnO for Efficient and Robust Photocatalytic Degradation of Tetracycline

Tetracycline (TC) and other antibiotics accumulated in groundwater and soil pollute ecological environment and threaten human health. Gold nanoparticles doped on photocatalysts are able to enhance the photodegradation efficiency during removing these antibiotics, but preparation of Au nanoparticles of well‐dispersion on photocatalysts remains challenging. In this work, zeolite imidazolate (ZIF‐8) was employed as the precursor to prepare Au@ZnO photocatalyst via impregnation and in‐situ reduction method to efficiently degrade the tetracycline in the aqueous solution. Au nanoparticles are of 10 nm in size and uniformly dispersed on the surfaces of ZnO microstructures. The as‐prepared Au@ZnO is able to remove 85.5% of TC of 0.010 mg/mL within 2 h, presenting higher photocatalytic activity than pure ZnO catalyst. Most importantly, the catalyst shows its superior stability after five cycles without structure and activity changing. The mechanism of the photocatalytic degradation was discussed in detail.     

Influence of neodymium on mitochondrial metabolism: a thermokinetic perspective

Journal of Thermal Analysis and Calorimetry - Nd compounds have been widely used for the promotion of growth of plant due to their excellent biophysical and biochemical properties. Mitochondria are...