A Status Graph Based Control Allocation Algorithm of Digital Micro-Thruster Array for Micro/Nano-Satellites Orbit Control Application

Digital micro-thruster arrays can be used for special missions of micro/nano-satellites with the requirements of high precision and small impulse.This paper presents a novel control allocation algorithm for the digital micro-thruster array,namely status graph based control allocation(SGBCA)algorithm,which aims at finding the optimal micro thrusters combination scheme to realize the sequential control synthesis for micro/nano-satellite during real-time orbit control tasks.A mathematical model is set up for the control allocation of this multivariate over-actuated system.Through dividing thrusters into disjoint segments by offline calculation and combining segments dynamically online to provide a sequence of the required impulse for the micro/nano-satellite,the time complexity of the control allocation algorithm decreases significantly.All levels of impulse can be generated by the digital micro thruster arrays and the service life of the arrays can be extended using the segment converting strategy proposed in this paper.The simulation indicates that the algorithm can satisfy the requirements of real-time orbit control for micro/nano-satellites.

Maskless Microscopic Lithography through Shaping Ultraviolet Laser with Digital Micro-mirror Device

Laser shaping was introduced to maskless projection soft lithography by using digital micro-mirror device (DMD). The predesigned intensity pattern was imprinted onto the DMD and the input laser beam with a Gaussian or quasi-Gaussian distribution will carry the pattern on DMD to etch the resin. It provides a method of precise control of laser beam shapes and?photon-induced curing behavior of resin. This technology provides an accurate micro-fabrication of microstructures used for micro-systems. As a virtual mask generator and a binary-amplitude spatial light modulator, DMD is equivalent to the masks in the conventional exposure system. As the virtual masks and shaped laser beam can be achieved flexibly, it is a good method of precision soft lithography for 2D/3D microstructures.

Full-field mapping of internal strain distribution in red sandstone specimen under compression using digital volumetric speckle photography and X-ray computed tomography

It is always desirable to know the interior deformation pattern when a rock is subjected to mechanicalload. Few experimental techniques exist that can represent full-field three-dimensional （3D） straindistribution inside a rock specimen. And yet it is crucial that this information is available for fully understandingthe failure mechanism of rocks or other geomaterials. In this study, by using the newlydeveloped digital volumetric speckle photography （DVSP） technique in conjunction with X-ray computedtomography （CT） and taking advantage of natural 3D speckles formed inside the rock due to materialimpurities and voids, we can probe the interior of a rock to map its deformation pattern under load andshed light on its failure mechanism. We apply this technique to the analysis of a red sandstone specimenunder increasing uniaxial compressive load applied incrementally. The full-field 3D displacement fieldsare obtained in the specimen as a function of the load, from which both the volumetric and the deviatoricstrain fields are calculated. Strain localization zones which lead to the eventual failure of the rock areidentified. The results indicate that both shear and tension are contributing factors to the failuremechanism. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.

Digital arc welding power supply based on real-time operating system

A digital arc welding power supply was designed with the advanced reduced instruction set computer machine （ARM） and embedded real-time multi-task operating system micro C/OS- Ⅱ. The ARM, with its powerful calculating speed and complete peripheral equipments, is very suitable to work as the controller of the digital power supply. The micro C/OS- Ⅱ transplanted in ARM, helps to improve the respondent speed against various welding signals, as well as the reliability of the controlling software. The welding process consists of nine tasks. The tasks of great significance on reliability of the welder, for example, the A/D conversion of current and voltage, enjoy top priority. To avoid simultaneous-sharing on A/D converter and LCD module, two semaphores are introduced in to ensure the smooth performance of the welding power supply. Proven by experiments ,the ARM and the micro C/OS- Ⅱ can greatly improve both the respondent speed and the reliability of the digital welder.

A New Design Method for Variable Digital Filter Based on Field Programmable Gate Array(FPGA)

In order to obtain variable characteristics,the digital filter's type,number of taps and coefficients should be changed constantly such that the desired frequency-domain characteristics can be obtained.This paper proposes a method for self-programmable variable digital filter(VDF) design based on field programmable gate array(FPGA).We implement a digital filter system by using custom embedded micro-processor,programmable finite impulse response(P-FIR) macro module,coefficient-loader,clock manager and analog/digital(A/D) or digital/analog(D/A) controller and other modules.The self-programmable VDF can provide the best solution for realization of digital filter algorithms,which are the low-pass,high-pass,band-pass and band-stop filter algorithms with variable frequency domain characteristics.The design examples with minimum 1 to maximum 32 taps FIR filter,based on Modelsim post-routed simulation and onboard running on XUPV5-LX110T,are provided to demonstrate the effectiveness of the proposed method.

The Design of Digital Excitation Regulator

The digital excitation regulator is very popular in the small electric plant. This kind of regulator can im- prove the working condition of generator and its working efficiency. It is on the base of the 80C51 Micro-con- troller. The regulator can automatically finish some functions through the combination of software and hard- ware. Through the experiment we can know it is more intellectual than the traditional analog excitation regu- lator.

基于Micro-CT扫描技术的低渗砂岩储层微观孔喉特征研究

以Micro-CT扫描技术为基础的储层微观孔隙特征研究是油藏精细描述的首要内容,也是孔隙尺度提高采收率的必然选择。以Micro-CT扫描获取的全尺寸岩心三维数字图像为基础,通过高级图像处理算法,得出岩心切面孔隙率随切片位置的变化规律,整体考察了低渗砂岩储层天然岩心的宏观非均质性。为了详细描述岩心内部微观孔喉特征,对钻取的2 mm岩样精细扫描,利用最大球算法提取真实孔隙结构相等价的球棍模型,定量考察了孔喉半径、表面积、拓扑结构、有效孔隙度等的分布规律,形象展示了孤立孔隙、连通孔隙的空间分布。该研究可为数字岩石物理实验的应用提供思路。

MicroStation在摄影测量数字化生产中的应用

介绍了在 APS解析测图仪上使用 Micro Station进行大比例尺测图时 ,对工作单位、种子文件、层等基础信息进行设置需要注意的一些问题 ,以及在应用过程中根据需要扩展地图符号库的方法。

Capacitance Sensing and Software-Realized Lock-in Amplifier for the Electromagnetically Levitated Micro Gyroscope

In the novel prototype of micro-gyroscope structure,the new configured capacitance sensing scheme for the micro gyroscope was analyzed and the virtual instrument based detection scheme was implemented.The digital lock-in amplifier was employed in the capacitance detection to restrain the noise interference.The capacitance analysis shows that 1 fF capacitance variation corresponds to 0.1 degree of the turn angle.The differential capacitance bridge and the charge integral amplifier were used as the front signal input interface.In the implementation of digital lock-in amplifier,a new routine which warranted the exactly matching of the reference phase to signal phase was proposed.The result of the experiment shows that digital lock-in amplifier can greatly eliminate the noise in the output signal.The non linearity of the turn angle output is 2.3% and the minimum resolution of turn angle is 0.04 degrees.The application of the software demodulation in the signal detection of micro-electro-mechanical-system(MEMS)device is a new attempt,and it shows the prospective for a high-performance application.

The Quantification of Micro-structural Damage of Weak Muddy Intercalation in Dry-wet Cycles Combining in-situ SEM and DIP

In order to reflect truly the damage evolution mechanism of weak muddy intercalation in dry-wet cycles, two typical weak muddy intercalations were selected for dry-wet cycles. The mineral changes of specimens were analyzed via X-ray diffraction after dry-wet cycles. By combining in-situ SEM and digital image processing(DIP), the damage evolution process and damage characteristic parameters of each stage were obtained. The experimental results indicate that the hydration and dissolution of minerals can not be a determinant factor in structure damage. The micro-structural damage is due to disintegration of mineral aggregates, leading to changes in the number and size of cracks and pores. The damage degree of specimens is related to its initial structure, and the micro-structural damage intensifies and finally tends to stabilize with cycle times increased.

银行数字化转型对小微企业自主创新的影响——兼论数字金融的协同作用

银行数字化转型提高了金融服务质量与效率,这能否缓解实体经济融资约束,助力小微企业牵住自主创新的“牛鼻子”?本文构建理论模型刻画银行数字化转型对小微企业自主创新的影响,并采用爬虫技术获得超过18万条有关商业银行报道的新闻文本,创新地构造了地级市层面的银行数字化转型指数,将中国小微企业调查(CM ES)数据和银行数字化转型指数相匹配,实证检验银行数字化转型对小微企业自主创新的影响及其机制,并据此分析银行数字化转型与数字金融的协同作用。研究发现,银行数字化转型通过缓解企业融资约束的中介机制,显著驱动了小微企业自主创新。进一步研究发现,银行数字化转型与数字金融在驱动小微企业自主创新方面具有协同效应,数字金融水平越高,银行数字化转型的创新驱动效应越强。本文将制度环境划分为产权保护、产研结合、政策环境,通过异质性分析发现,在知识产权保护环境较好、社会平台协作度较高及经济政策不确定性较小的地区,银行数字化转型对小微企业自主创新的驱动作用更为显著。本研究为赋能银行数字化转型战略提供了支持证据,也为解决实体经济融资难问题、驱动自主创新、促进经济高质量发展提供了解决方案。

数字普惠金融服务小微企业融资研究--以全国首个小微企业数字征信实验区为例

数字普惠金融将数字技术与普惠金融深度融合,为纾解小微企业融资困境提供了可行的新路。根据对全国首个小微企业数字征信实验区的案例剖析和区内588家小微企业的问卷调查结果,小微企业融资行为符合普惠金融“短、小、频、急”的典型特征,融资方式以信用贷款为主,资金用途多样,但是信息和信用不对称制约其融资可得性。实验区以服务小微企业为中心,构建综合金融服务体系、全国首个区块链数字征信平台、金融科技创新监管试点“三位一体”的运行模式,充分发挥了数字普惠金融的赋能效应。但是,要复制、推广实验区的建设经验,仍面临一些制约因素,因此要完善相关法律法规,稳步扩大金融科技创新监管试点,深化数字技术和数据要素融合应用,探索构建全国互联互通的数字征信平台和数字普惠金融“元宇宙”,以期在更大范围更好地服务小微企业融资和实体经济高质量发展。

论新质生产力研究的经济学思维

“新质生产力”思维概念,基于历史唯物主义发展观的理论范式,将马克思主义的“生产力-生产关系”理论范式,运用于对新时代新现象的观察和研究。在新质生产力的经济学理论范式中,对于“人”的概化具有特别重要的认识论和逻辑自洽性意义。“人”的概化,不仅包含人与自然的关系,也包含人与人的关系,即马克思所说的人的本质是“社会关系的总和”。新质生产力经济学思维所概化的“人”,从“经济人”“组织人”演化产生了“智能机器人”。当新质生产力研究接受数字化人工智能的经济学思维时,主流经济学将发生颠覆性的范式变革。对生产力的“质态”关切,超越对生产力的“量态”关切,是新质生产力重要的经济学属性。经济学的范式变革,须将长期性、未来性、存量性、多元性等因素也纳入观察研究体系,这是域观经济学与新质生产力相契合的逻辑基础,可以引导现代经济学的“微观-宏观”范式体系,更科学地研究新时代、新世界所产生的新现象。

数字政府建设促进小微企业创业了吗?——来自浙江省中小企业公共服务平台的证据

数字政府建设是优化营商环境、激发市场活力的重要手段,在促进中小企业创业中发挥重要作用。政府数字化企业服务平台是应用最广的数字政府建设载体之一。本文以浙江省中小企业公共服务平台建成运营为准自然实验,结合浙江省小微企业注册数据,对数字政府建设的创业促进效应进行实证估计。结果发现,通过提供市场信息和匹配服务需求,浙江省中小企业公共服务平台建设降低了市场进入壁垒,促进了小微企业创业,且该创业促进效应在创业环境差的地区更显著。

民营小微外贸企业数字化转型升级的内在逻辑和实现途径——以社交媒体赋能促进新质生产力形成视角

企业规模门槛效应阻碍了小微企业数字化转型升级中新质生产力的形成,尤其是民营小微外贸企业受规模限制普遍对数字化转型升级抱有“用不起、不会用、不愿用”的消极态度。近年来,国外消费者通过社交媒体进行购物的新消费模式正在形成。社交媒体具有低成本、高覆盖和精准定位的特点,易于改造成为跨境信息传播、营销推广的重要平台,为民营小微外贸企业数字化转型升级带来了新视野,提供了新机遇。本文针对民营小微外贸企业“两大、四缺乏”的现状,揭示了数字化转型升级带来的“四升一降”效应,并提出利用信息获取与反馈、市场拓展与推广、跨境交流与合作等机制,企业通过建立专业化团队、制定清晰策略、优化线上渠道、加强客户沟通等路径,创新出“社交媒体数字营销+小微外贸企业生产”深度融合的外贸新模式,培育新质生产力,促进传统产业转型升级和高质量发展。

An Effective Method for Improving Silicon Micro-resonator System Performance

The working principle of silicon micro-resonator system was firstly introduced. An intelligent silicon micro-resonator system design and realization was presented in focus. There are two steps working flows for roughness and fine searching. Meanwhile the digital interface technology was analyzed in detail. Combined with experimental data and sweeping curve, two different searching results came out in different vacuum circumstance and its working performance was well evaluated.

微认证:重塑教师数字素养的新引擎--来自美国的个案分析

教师数字素养是推动我国教育数字化转型的关键软实力,其培训与评价应指向实践取向、循证决策,然而目前现实情况却不容乐观。微认证体现了工作场景和实践能力指向的发展性评价理念,耦合了教师专业发展的复杂实践性和自我反思性的特征。本研究以美国“数字承诺”平台开发的教师数字素养微认证项目为例,深入剖析项目运行的内在逻辑,按照明确参与主体、培训谁、为什么培训、怎样培训、如何保证持续有效的递进关系,总结出微认证促进教师数字素养提升的实践路径:“分工明确、各司其职”“基于角色、微观设计”“需求导向、能力为本”“依据规范、坚持循证”“系统规划、绩效管理”,以期为我国开展教师数字素养培训与评价提供启示和借鉴。

VR技术在微课实施过程中的应用——以企业纳税实务微课开发为例

微课是一种现代教育模式,在微课中利用VR等现代科技和信息化手段,能够让学生获得更丰富的学习体验。以企业纳税实务微课开发为例,在分析目前VR技术在微课中应用现状的基础上,探究VR技术应用到微课的基本策略,从而提高学习效果,有效推动教育的数字化建设,为今后相关微课的开发提供可借鉴的经验。

数智时代高职院校思政课教师的数字素养要求及提升路径

数智时代,教育的数字化转型已成必然趋势,这对思政课教师提出了数字素养要求。基于对杭州和绍兴两地高职院校思政课教师开展的问卷调查发现:高职院校虽然已为思政课教师提供了必要的数字化软硬件配套设施,但思政课教师数字素养的培育却仍然面临着自身数字化意识不强、内外部驱动力不足以及保障机制不健全的现实困境。对此,为进一步提升高职院校思政课教师的数字素养,使其在数字化时代的思政教育教学中有更好的适应性和创新性,一要强化教师数字化意识,二要完善数字素养考评认证机制,三要提升培训针对性。

教师数字分身在微课教学中的运用分析

随着数字人在各行各业的广泛应用,其表现出巨大的发展潜力和价值。为了发挥教师数字分身在微课教学中的优势,提高微课制作效率,降低微课制作成本,推进其在微课教学中的应用,实现个性化、规模化等教学,文章分析了教师数字分身的概念及制作方法及其在微课制作及教学中的应用优势,并指出了教师数字分身应用于微课教学中的问题。给出了相应的建议和对策,旨在推进教师数字分身在教育教学中的规范应用,推动数字技术与教育教学的深度融合。