Applications of carbonic acid solution for developing conversion coatings on Mg alloy

Works on exploring an environmentally clean method for producing an Mg,Al-hydrotalcite(Mg6Al2(OH) 16CO3·4H2O) layer and/or calcium carbonate(CaCO3) layer on Mg alloy in a carbonic acid solution system(aqueous HCO3-/CO3 2-or Ca 2+ /HCO3-) at 50℃ were reviewed.Conversion treatment for the Mg,Al-hydrotalcite conversion coating was as follows.Mg alloy was treated first in acidic HCO3-/CO3 2-aqueous for precursor layer formation on Mg alloy surface and then in alkaline HCO3-/CO3 2-aqueous to form a crystallized Mg,Al-hydrotalcite coating.Duration of an Mg,Al-hydrotalcite coating on Mg alloy surface was reduced from 12 h to 4 h by the conversion treatment.On the other hand,for reducing the formation time of CaCO3 coating on Mg alloy,the aqueous Ca 2+ /HCO3-with a saturated Ca 2+ content was employed for developing a CaCO3 coating on Mg alloy.A dense CaCO3 coating could yield on Mg alloy surface in 2 h.Corrosion rate(corrosion current density,Jcorr) of the Mg,Al-hydrotalcite-coated sample and CaCO3-coated AZ91D sample was 7-10μA/cm 2,roughly two orders less than the Jcorr of the as-diecast sample(about 200μA/cm 2) . No corrosion spot on the Mg,Al-hydrotalcite-coated sample and CaCO3-coated sample was observed after 72 h and 192 h salt spray test,respectively.

A transceiver frequency conversion module based on 3D micropackaging technology

The idea of Ku-band transceiver frequency conversion module design based on 3D micropackaging technology is proposed. By using the double frequency conversion technology,the dual transceiver circuit from Ku-band to L-band is realized by combining with the local oscillator and the power control circuit to complete functions such as amplification, filtering and gain. In order to achieve the performance optimization and a high level of integration of the Ku-band monolithic microwave integrated circuits(MMIC) operating chip, the 3 D vertical interconnection micro-assembly technology is used. By stacking solder balls on the printed circuit board(PCB), the technology decreases the volume of the original transceiver to a miniaturized module. The module has a good electromagnetic compatibility through special structure designs. This module has the characteristics of miniaturization, low power consumption and high density, which is suitable for popularization in practical application.

Transcription factor-based gene therapy to treat glioblastoma through direct neuronal conversion

Objective:Glioblastoma(GBM)is the most prevalent and aggressive adult primary cancer in the central nervous system.Therapeutic approaches for GBM treatment are under intense investigation,including the use of emerging immunotherapies.Here,we propose an alternative approach to treat GBM through reprogramming proliferative GBM cells into non-proliferative neurons.Methods:Retroviruses were used to target highly proliferative human GBM cells through overexpression of neural transcription factors.Immunostaining,electrophysiological recording,and bulk RNA-seq were performed to investigate the mechanisms underlying the neuronal conversion of human GBM cells.An in vivo intracranial xenograft mouse model was used to examine the neuronal conversion of human GBM cells.Results:We report efficient neuronal conversion from human GBM cells by overexpressing single neural transcription factor Neurogenic differentiation 1(Neuro D1),Neurogenin-2(Neurog2),or Achaete-scute homolog 1(Ascl1).Subtype characterization showed that the majority of Neurog2-and Neuro D1-converted neurons were glutamatergic,while Ascl1 favored GABAergic neuron generation.The GBM cell-converted neurons not only showed pan-neuronal markers but also exhibited neuron-specific electrophysiological activities.Transcriptome analyses revealed that neuronal genes were activated in glioma cells after overexpression of neural transcription factors,and different signaling pathways were activated by different neural transcription factors.Importantly,the neuronal conversion of GBM cells was accompanied by significant inhibition of GBM cell proliferation in both in vitro and in vivo models.Conclusions:These results suggest that GBM cells can be reprogrammed into different subtypes of neurons,leading to a potential alternative approach to treat brain tumors using in vivo cell conversion technology.

Construction of 2D Zn‐MOF/BiVO_(4)S‐scheme heterojunction for efficient photocatalytic CO_(2) conversion under visible light irradiation

The construction of S‐scheme heterojunction photocatalysts has been regarded as an effective avenue to facilitate the conversion of solar energy to fuel.However,there are still considerable challenges with regard to efficient charge transfer,the abundance of catalytic sites,and extended light absorption.Herein,an S‐scheme heterojunction of 2D/2D zinc porphyrin‐based metal‐organic frameworks/BiVO_(4)nanosheets(Zn‐MOF/BVON)was fabricated for efficient photocatalytic CO_(2)conversion.The optimal one shows a 22‐fold photoactivity enhancement when compared to the previously reported BiVO4 nanoflake(ca.15 nm),and even exhibits~2‐time improvement than the traditional g‐C3N4/BiVO4 heterojunction.The excellent photoactivities are ascribed to the strengthened S‐scheme charge transfer and separation,promoted CO_(2)activation by the well‐dispersed metal nodes Zn_(2)(COO)_(4)in the Zn‐MOF,and extended visible light response range based on the results of the electrochemical reduction,electron paramagnetic resonance,and in‐situ diffuse reflectance infrared Fourier transform spectroscopy.The dimension‐matched Zn‐MOF/BVON S‐scheme heterojunction endowed with highly efficient charge separation and abundant catalytic active sites contributed to the superior CO2 conversion.This study offers a facile strategy for constructing S‐scheme heterojunctions involving porphyrin‐based MOFs for solar fuel production.

Design of a 20-Gsps 12-bit time-interleaved analog-to-digital conversion system

The time-interleaved analog-to-digital conversion(TIADC)technique is an effective method for increasing the sampling rate in a waveform digitization system.In this study,a 20-Gsps TIADC system was designed.A wide-bandwidth performance was achieved by optimizing the analog circuits,and a sufficient effective number of bits(ENOB)performance guaranteed using the perfect reconstruction algorithm for mismatch error correction.The proposed system was verified by tests,and the results indicated that a-3 dB bandwidth of 6 GHz and the ENOB performance of 8.7 bits at 1 GHz and 7.6 bits at6 GHz were successfully achieved.

A new method to create depth information based on lighting analysis for 2D/3D conversion

A new method creating depth information for 2D/3D conversion was proposed. The distance between objects is determined by the distances between objects and light source position which is estimated by the analysis of the image. The estimated lighting value is used to normalize the image. A threshold value is determined by some weighted operation between the original image and the normalized image. By applying the threshold value to the original image, background area is removed. Depth information of interested area is calculated from the lighting changes. The final 3D images converted with the proposed method are used to verify its effectiveness.

A Universal Atomic Substitution Conversion Strategy Towards Synthesis of Large‑Size Ultrathin Nonlayered Two‑Dimensional Materials

Nonlayered two-dimensional(2D)materials have attracted increasing attention,due to novel physical properties,unique surface structure,and high compatibility with microfabrication technique.However,owing to the inherent strong covalent bonds,the direct synthesis of 2D planar structure from nonlayered materials,especially for the realization of large-size ultrathin 2D nonlayered materials,is still a huge challenge.Here,a general atomic substitution conversion strategy is proposed to synthesize large-size,ultrathin nonlayered 2D materials.Taking nonlayered CdS as a typical example,large-size ultrathin nonlayered CdS single-crystalline flakes are successfully achieved via a facile low-temperature chemical sulfurization method,where pre-grown layered CdI2 flakes are employed as the precursor via a simple hot plate assisted vertical vapor deposition method.The size and thickness of CdS flakes can be controlled by the CdI2 precursor.The growth mechanism is ascribed to the chemical substitution reaction from I to S atoms between CdI2 and CdS,which has been evidenced by experiments and theoretical calculations.The atomic substitution conversion strategy demonstrates that the existing 2D layered materials can serve as the precursor for difficult-to-synthesize nonlayered 2D materials,providing a bridge between layered and nonlayered materials,meanwhile realizing the fabrication of large-size ultrathin nonlayered 2D materials.

A Distributed 2D-to-3D Video Conversion System

2D-to-3D video conversion is a feasible way to generate 3D programs for the current 3DTV industry. However, for large-scale 3D video production, current systems are no longer adequate in terms of the time and labor required for conversion. In this paper, we introduce a distributed 2D-to-3D video conversion system that includes a 2D-to-3D video conversion module, architecture of the parallel computation on the cloud, and 3D video coding in the system. The system enables cooperation among multiple users in the simultaneous completion of their conversion tasks so that the conversion efficiency is greatly promoted. In the experiments, we evaluate the system based on criteria related to both time consumption and video coding performance.

Organic-magnesium complex conversion coating on AZ91D magnesium alloy

An organic-magnesium complex conversion(OMCC)coating on AZ91D magnesium alloy was obtained by treating in a solution containing organic compounds.SEM,FESEM and XPS were used to examine the surface morphology,thickness and structure of the conversion coatings.The results show that the continuous and uniform conversion coating is deposited on AZ91D alloy and the main component of the coatings is organic compound containing benzene ring,which forms a chemical bond with magnesium.The polarization measurement and salt spray test show that the corrosion resistance of the conversion coating is much higher than that of traditional chromate conversion coating.

Precise conversion between virtual world and real world in stereoscopic imaging

A method for precise conversion between virtual world and real world is put forward in this paper. The method aims to precisely establish the connection between the virtual coordinates and the real coordinates with OpenGL. In the virtual world, two virtual cameras are set to capture the left and right perspective planar images, and coordinates of the planar images can be calculated by the perspective projection model. With coordinates of planar images, coordinates of the stereo- scopic image synthesized in the real world can be calculated by the binocular observation model. Therefore, the corresponding connection between the two systems is established. Experimental re- suits match data from this method well. Therefore, this method can precisely realize the conversion and the interactivity, laying a solid foundation for further study.

Method to Increase Micro-controller A/D Conversion Speed

The speed and cost of A/D conversion are conflict to each other. As micro-controller speed is increasing and its internal function is improving, full utilization of its internal resource can dramatically increase A/D conversion speed and without compromising conversion quality. MSP430F11x1 series micro-controller is exploited to increase A/D conversion speed.

Optical Analog-to-digital Conversion Scheme Based on Tunable Fabry-Perot Resonator

Proposed is an interference type of optical analog-to-digital conversion(ADC). The refractive index of Fabry-Perot cavity changes with different voltages. The Fabry-Perot resonator converts electronic intensity into light wavelength through selecting lights of different wavelengthes. The parameters of the scheme are acquired with the transmission matrix of optical element and the time of steady-state light field. The maximum sampling speedes of 4-bit, 6-bit, 7-bit, 8-bit and 9-bit(ADC) are 1.695×1010 count/s, 4.33×109 count/s, 2.38×109 count/s, 1.24×109 count/s and 5.9×108 count/s, respectively.

Conversion of U-238 and Th-232 Using a Fusion Neutron Source

This article proposes a general framework for the conversion of U-238 and Th-232 utilizing fusion-produced neutrons. This recognizes that emerging fusion technologies may not produce sufficient net energy output to justify stand-alone applications, yet may be commercially viable for breeder transmutation or hybrid fusion-fission reactor concepts proposed herein to dispose of nuclear wastes and long life high radioactive fission products remaining in shutdown nuclear power plants. Results show that this could be achievable within a decade, given an appropriate fusion source. However, if 20% beryllium of nuclei density is added to the convertor blanket, the efficiency of the conversion process can be significantly increased. Also, the neutron energy spectrum resulting from dense D-D plasma core fusion is much softer than D-T fusion neutron source, hence the probability of (n, p) (n, α) backward decay reaction paths will be smaller and the conversion efficiency will be elevated.

应用Converse3D设计和实现虚拟校园

高等院校合理运用虚拟校园系统,不仅立体展示校园实景信息和校园文化,而且可以更有效地进行学校的组织管理,同时能够提高学校的知名度、增强学校的竞争力。本文以安庆职业技术学院校园为基础,建立三维实景模型,利用Converse3D虚拟漫游平台,建立虚拟校园系统,实现实时交互式漫游。

基于RFID的医疗设备远程管理系统设计

为提高医院内设备定位精度,设计基于RFID的医疗设备远程管理系统。通过阅读器、电子标签和处理器组成RFID节点,引入AS3992芯片作为核心芯片,实现数据处理和编码,执行远程指令。采用自由空间传播模型计算路径损耗产生值,通过三角定位数学方法计算待定标签位置,采用RFID定位方法确定标签的最近邻居,实现医疗设备的远程定位。实验结果表明,在没有障碍物的情况下,所提系统设备定位误差少于1 m,在有障碍物的情况下,定位误差在2 m左右,证明所提出系统定位准确性较高,满足系统的设计需求。

“6D法则”在住院医师规范化培训院级师资培训中的探索和运用——以教学查房培训为例

目的在住院医师规范化培训(简称住培)院级师资培训中引入“6 D法则”,推进师资培训的“三个转化”,即住培师资岗位需求的转化、培训内容的转化、师资内在的素质和能力的转化。方法以院级教学查房培训为例,将培训设计为准备、培训、转化和评估4个阶段,实现培训后的转化以及培训质量的改善。结果基于“6 D法则”的教学查房培训过后,以教学督导的形式进行总结性评估。接受过教学查房培训的师资平均得分为90.00分,未接受过教学查房培训的师资平均得分为84.93分,培训达到了预期目标。结论“6 D法则”采用系统化思维方式,注重学习转化和绩效的改善,将以终为始的理念贯穿整个培训过程,有利于培训取得实效。

全细胞转化生产D-阿洛酮糖条件优化

全细胞体系制备D-阿洛酮糖因成本低、工艺简单受到人们的关注,研究全细胞转化D-果糖为D-阿洛酮糖的较适条件对促进D-阿洛酮糖的产业化具有重要意义。该文探究了全细胞酶的储藏稳定性并对全细胞制备D-阿洛酮糖的条件(培养时间、细胞浓度、转化初始pH、转化温度、金属离子)进行了优化与验证。结果表明:全细胞酶具有较强的储藏稳定性,40℃放置48 h催化效果未明显降低;在500 g/L D-果糖底物浓度下,适用于生产的全细胞转化较适条件为细胞浓度10 g/L、转化温度70℃、转化初始pH为自然pH、转化率为31.55%,较优化前转化率提高约3%,转化周期缩短至4 h,生产工序简化、生产效率提高、生产成本降低。该研究旨在为D-阿洛酮糖工业化生产提供实验基础,满足大规模生产的需求。

基于DSP的FIR数字滤波综合实验设计

为了提供一种融合数字信号处理、Matlab仿真与DSP技术3门课程相关内容且贴近实际应用的综合性实验,设计了一种基于DSP的FIR数字滤波综合实验。该实验包含了数字信号处理从理论到设计、再到最后调试实现的完整实践训练过程,为学生提供了一种进行数字信号处理设计与实现的综合性实践训练。

基于DSP和FIFO的多路高速数据采集系统在PFN中的应用

提出了一种基于罗氏线圈、FIFO和DSP的多路高速数据采集系统,将其成功应用于脉冲成形网络(PFN)脉冲放电电流的检测。系统数据采集频率高,采样精度可达到5‰以内,实现了对多路PFN电流的实时检测及对PFN运行状况的快速监测。

我国地区R&D效率及其影响因素探究——基于“科研产出—成果转化”视角

基于"科研产出—成果转化"视角,以2000～2008年的面板数据为基础,运用随机前沿分析方法研究了我国各地区R&D效率及其影响因素。研究结果表明:东部地区科研产出和成果转化效率皆高于中西部地区,中部地区科研产出效率高于西部地区,成果转化效率低于西部地区;科研产出的提高呈明显的资金推动型;政府支持力度和企业R&D投入力度对科研产出效率的提高有促进作用但不显著,外资吸纳能力能显著促进科研产出效率的提高,高新技术产业规模反而抑制科研产出效率的提高;政府支持力度、高新技术产业规模以及企业R&D投入力度对我国科研成果转化效率的提高有显著促进作用,外资吸纳能力抑制成果转化效率但不显著。