A novel 4D resolution imaging method for low and medium atomic number objects at the centimeter scale by coincidence detection technique of cosmic-ray muon and its secondary particles

The muon radiography imaging technique for high-atomic-number objects(Z) and large-volume objects via muon transmission imaging and muon multiple scattering imaging remains a popular topic in the field of radiation detection imaging. However, few imaging studies have been reported on low and medium Z objects at the centimeter scale. This paper presents an imaging system that consists of three layers of a position-sensitive detector and four plastic scintillation detectors. It acquires data by co...     

Comparison between fluctuation of floating potential gradient and velocity of blob structure on HL-2A tokamak

Several results based on the Langmuir probes' data on the HL-2A tokamak are presented. The blob structures' radial and poloidal drift velocities, estimated by the gradient of floating potential and by time delay evaluation, are compared in different line-averaged density and electron cyclotron resonance heating conditions. A positive correlation is observed in the comparison between blobs' radial velocity estimated by the two methods mentioned above, regardless of the situation differences mentioned above. Correlation is also observed in the comparison between the blobs' poloidal velocity estimated by the two methods in different situations, while a shift due to the different line-averaged density is observed. These results imply that the radial gradient of floating potential may have some value as a reference during data analysis in low-parameter discharge.     

Optical design of the Lyman alpha based beam emission spectroscopy(LAB)diagnostic on the HL-2A tokamak

In this article, we present the optical design of a novel diagnostic on the HL-2 A tokamak, i.e. the20-channel edge Lyman-alpha beam emission spectroscopy, which is a promising solution for edge density turbulence research on tokamaks, as it offers the possibility of density fluctuation measurement with a 3.3 mm spatial resolution while maintains a high temporal resolution of1 μs. The optical path, including the reflective collection optics, the high-dispersion spectrometer, and the linear detector array, is carefully optimized to obtain a good image quality and a high throughput. The maximum root mean square radius of the collection optics is 64 μm.The detected photon flux is estimated to be about 10~(11) photons/s/channel.     

响应面法优化番木瓜籽蛋白质提取工艺

作为食用和工业生产的废弃物番木瓜籽,提高其蛋白质提取率,实现资源的回收利用和扩大副产品价值。以番木瓜籽为原料,使用响应面法优化碱溶酸沉法提取番木瓜籽蛋白质提取工艺。以番木瓜籽蛋白质提取率为指标,研究pH值、液料比、时间、温度对蛋白质提取率的影响。结果表明番木瓜籽蛋白质提取率最优条件为:pH 11.3、料液比1∶45(g/mL)、时间224 min、温度47.5℃,针对蛋白质提取率的模型显示失逆项不显著,R2值为94.26%,表明模型拟合良好。在此试验条件下,验证试验结果平均值为53.74%,与理论值55.21%接近。     

The Self-Assembling Growth of Copper Nanowires for Transparent Electrodes

Long(15-40 μm), thin(diameter of 20 ± 5 nm), and well-dispersed CuNWs Cu nanowires were prepared. The high-resolution TEM and selected area electron diffraction showed that the CuNWs were single-crystalline. To investigate the growth mechanism, we examined the microstructure of these CuNWs at different reaction time. It was found that the CuNWs were actually formed through the self-assembling of Cu nanoparticles along the [110] direction. The transparent electrodes fabricated using the CuNWs achieved a high transparency of 76 % at 31±5 Ω/□.     

Effect of Al2O3/CaO on the melting and mineral transformation of Ningdong coal ash

Coal ash melting characteristics has a direct impact on the smooth operation of entrained gasifier. Mineral conversion of coal ash is very significant to be investigated, because the mineral can affect the melting temperature and viscosity under high temperature conditions. In this paper, the effects of different Al₂O₃/CaO on the mineral conversion, melting temperature and viscosity of Ningdong coal ash are studied by the combination of experiment and simulation. The trend of melting temperature decreases firstly and rises with increasing Al₂O₃/CaO. The ash melting point reached to the lowest when the ratio is 1.23. XRD and Factsage software are used to analyze crystallization behavior of samples. The results show that the content of anorthite, albite and corundum increases and subsequently decreases, while the content of mullite decreases firstly and then rises with increasing Al₂O₃/CaO. High content with CaO can contribute to form albite and anorthite of low-melting. Besides, high content with Al₂O₃ can tend to produce mullite of high-melting. The results of experimental and simulation are basically the same, which lays a foundation for the melting characteristics of Ningdong coal ash and can provide technical support for the smooth operation of the entrained-gasifier.     

Preparation of in-plane anisotropy Ni80Co20/Bi multifilms

A series of Au/[Ni Co/Bi]x/Au(x = 2, 3) films were fabricated by pulsed laser deposition method. In order to induce the in-plane uniaxial magnetic anisotropy(IPUMA) of the multifilms, multiple layers and different oblique angles ranging from 0° to 30° for the substrate are applied during the deposition. The microstructures of the nanofilms were investigated by using X-ray diffraction(XRD) and transmission electronic microscope(TEM).And their magnetic properties were measured by an alternating gradient magnetometer. For the multicycle systems,using the method that with more periodic structures of Ni Co/Bi film is easier for inducing IPUMA than the less or the samples located with various angles.     

Rational design and synthesis of upconversion luminescence-based optomagnetic multifunctional nanorattles for drug delivery

Optomagnetic multifunctional composite based on upconversion luminescence nanomaterial is regarded as a promising strategy for bioimaging,disease diagnosis and targeted delivery of drugs.To explore a mesoporous nanostructure with excellent water dispersibility and high drug-loading capacity,a novel nanorattle-structured Fe3O4@SiO2@NaYF4∶Yb,Er magnetic upconversion nanorattle (MUCNR) was suc-cessfully designed by using Fe3O4 as core and NaYF4∶Yb,Er nanocrystals as shell.The microstructures and crystal phase of the as-prepared MUCNRs were evaluated by transmission electron microscopy,X-ray powder diffraction and N2 adsorption/desorption isotherms.The Kirkendall effect was adapted to explain the formation mechanism of the MUCNRs.The loading content and encapsulation efficiency of doxorubicin hydrochloride (DOX) could reach as high as 18.2％ and 60.7％,respectively.Moreover,the DOX loading MUCNR (DOX-MUCNR) system showed excellent sustained drug release and strong pH-dependent performance,which was conducive to drug release at the slightly acidic microenvironment of tumor.Microcalorimetry was used to quantify the interactions between the carrier structure and drug release rate directly.The heat release rates in the heat-flow diagrams are basically consistent with the DOX release rate,thereby showing that microcalorimetry assay not only provides a unique thermody-namic explanation for the structure-activity relationship of Fe3O4@SiO2@NaYF4∶Yb,Er MUCNRs but also provides powerful guidance to avoid the blind selection or design of drug carriers.Therefore,our work firmly provided a comprehensive perspective for using Fe3O4@SiO2@NaYF4∶Yb,Er MUCNRs as a remark-able magnetic targeted drug carrier.     

Performance evaluation of a bubble generator and a bubble separator designed for the gas removal system of a small thorium molten salt reactor

In the present study, a bubble generator and a bubble separator were designed and evaluated for an independent off-gas removal system of a small thorium molten salt reactor(TMSR) with reference to the design of the Oak Ridge National Laboratory(ONRL). The bubble generator employed a Venturi tube as its main body owing to its simplicity and highly reliable structure. A centrifugal separator was used as the bubble separator, taking advantage of the kinetic energy of fluid to create a centrifugal force to separate gas bubbles from the mixture flow. Both the bubble generator and the separator were demonstrated to have good potential to meet the performance requirements of an off-gas removal system for a small TMSR. With water and air as the working fluids, for the final designs of the two key pieces of equipment, a liquid flow rate exceeding 15 m~3·h~(-1) can essentially make their performance meet the requirements of the off-gas removal system in terms of the average size of the generated bubbles and gas separation efficiency.     

基于互连线插值的时间数字转换器结构设计

全数字锁相环(All-digital Phase Locked Loop,ADPLL)中时间数字转换器(Time-to-Digital Converter,TDC)用于测量数控振荡器(Digitally Controlled Oscillator,DCO)输出时钟和参考时钟之间分数相位差,其分辨率越高,环路的相位噪声特性越好。为了提升TDC的测量分辨率,提出了一种对工艺偏差不敏感的环形互连线插值的TDC结构。本文首先给出了基于互连线插值TDC的系统结构,然后提出了一种工艺偏差不敏感的互连线结构实现等延时方法,并给出了环形的版图布局方案,最后利用仿真对提出的等延时实现方法进行验证。实验结果表明:该方法即使是在0.18μm CMOS工艺下也能将TDC的分辨率提高至皮秒级。