Accuracy Analysis of Assembly Success Rate with Monte Carlo Simulations

Monte Carlo simulation was applied to Assembly Success Bate (ASK) analyses. ASR of two peg-in-hole robot assemblies was used as an example by taking component parts' sizes, manufacturing tolerances and robot repeatability into account. A statistic arithmetic expression was proposed and deduced in this paper, which offers an alternative method of estimating the accuracy of ASR, without having to repeat the simulations. This statistic method also helps to choose a suitable sample size, if error reduction is desired. Monte Carlo simulation results demonstrated the feasibility of the method.

Drying-Mediated Self-Assembly of Graphene for Inkjet Printing of High-Rate Micro-supercapacitors

Scalable fabrication of high-rate micro-supercapacitors(MSCs)is highly desired for on-chip integration of energy storage components.By virtue of the special self-assembly behavior of 2D materials during drying thin films of their liquid dispersion,a new inkjet printing technique of passivated graphene micro-flakes is developed to directly print MSCs with 3D networked porous microstructure.The presence of macroscale through-thickness pores provides fast ion transport pathways and improves the rate capability of the devices even with solid-state electrolytes.During multiple-pass printing,the porous microstructure effectively absorbs the successively printed inks,allowing full printing of 3D structured MSCs comprising multiple vertically stacked cycles of current collectors,electrodes,and sold-state electrolytes.The all-solid-state heterogeneous 3D MSCs exhibit excellent vertical scalability and high areal energy density and power density,evidently outperforming the MSCs fabricated through general printing techniques.

Optimization of the Assembly Efficiency for Lidamycin Chromophore Bound to its Apoprotein:A Case Study using Orthogonal Array

Objective Lidamycin （LDM） can be dissociated to an apoprotein （LDP） and an active enediyne chromophore （AE）. The detached AE can reassemble with its LDP-containing fusion protein to endow the latter with potent antitumor activity. However, the reassembly of AE with LDP is affected by several factors. Our aim was to optimize the assembly efficiency of the AE with a LDP-containing fusion protein and investigate the influence of several factors on the assembly efficacy. Methods A method based on RP-HPLC was developed to analyze the assembly rate, and an orthogonal experimental design L9 （3^4） was used to investigate the effects of temperature, assembly time, pH and molecular ratio of LDP-containing fusion protein to AE on the assembly rate. Furthermore, the determined optimum conditions for the assembly rate of the LDP-containing fusion protein with AE were applied and evaluated. Results A calibration curve based on the LDM micromolar concentration against the peak-area of AE by HPLC was obtained. The order in which individual factors in the orthogonal experiment affected the assembly rate were temperature〉time〉pH〉molar ratio of AE to protein and all were statistically significant （P〈0.01）. The optimal assembly conditions were temperature at 10 ℃, time of 12 h, pH 7.0, and the molar ratio of AE： protein of 5：1. The assembly rate of AE with a LDP-containing fusion protein was improved by 23% after condition optimization. Conclusion The assembly rate of chromophore of lidamycin with its LDP-containing fusion protein was improved after condition optimization by orthogonal design, and the optimal conditions described herein should prove useful for the development of this type of LDP-containing fusion protein.

Reaction rates in blanket assemblies of a fusion-fission hybrid reactor

To validate neutronics calculation for the blanket design of fusion-fission hybrid reactor,experiments for measuring reaction rates inside two simulating assemblies are performed.Two benchmark assemblies were developed for the neutronics experiments.A D-T fusion neutron source is placed at the center of the setup.One of them consists of three layers of depleted uranium shells and two layers of polyethylene shells,and these shells are arranged alternatively.The ^(238)U capture reaction rates are measured using depleted uranium foils and an HPGe gamma spectrometer.The fission reaction rates are measured using a fission chamber coated with depleted uranium.The other assembly consists of depleted uranium and LiH shells.The tritium production rates are measured using the lithium glass scintillation detector which is placed in the LiH region of the assembly.The measured reaction rates are compared with the calculated ones predicted using MCNP code,and C/E values are obtained.

Force Feedback Coupling with Dynamics for Physical Simulation of Product Assembly and Operation Performance

Most existing force feedback methods are still difficult to meet the requirements of real-time force calculation in virtual assembly and operation with complex objects. In addition, there is often an assumption that the controlled objects are completely flee and the target object is only completely fixed or flee, thus, the dynamics of the kinematic chain where the controlled objects are located are neglected during the physical simulation of the product manipulation with force feedback interaction. This paper proposes a physical simulation method of product assembly and operation manipulation based on statistically learned contact force prediction model and the coupling of force feedback and dynamics. In the proposed method, based on hidden Markov model （HMM） and local weighting learning （LWL）, contact force prediction model is constructed, which can estimate the contact force in real time during interaction. Based on computational load balance model, the computing resources are dynamically assigned and the dynamics integral step is optimized. In addition, smoothing process is performed to the force feedback on the synchronization points. Consequently, we can solve the coupling and synchronization problems of high-frequency feedback force servo. low-frequency dynamics solver servo and scene rendering servo, and realize highly stable and accurate force feedback in the physical simulation of product assembly and operation manipulation. This research proposes a physical simulation method of product assembly and operation manipulation.

Polymer-Based Micro Flow Sensor with Alternative Electronic Signal Interfaces for Low and High Flow Rates

The qualitative and quantitative assessment of gas flow has become increasingly relevant in the use of everyday systems. The micro flow sensor, developed by Innovative Sensor Technology AG （Switzerland）, is by principle a calorimetric flow sensor produced as a micro system on a glass substrate by means of photolithography and glass etching technology. These structures are arranged as a platinum micro heater and sensor in a Wheatstone bridge. The subsequent etching process produces an exposed area of polyimide membrane that is only a few microns thick and includes the resistive sensor structure as the active area. In addition, the RTD （resistance temperature detector） technology included on the sensor allows for the implementation of a variety of electronic biasing and signal processing modes. Since the sensor can be powered and the bridge can be measured in both CTA （constant temperature anemometer） and calorimetric mode, new possibilities are presented for both low and high flow rates with regard to temperature compensation, self-calibration and self-monitoring.

A multi-shot target wheel assembly for high-repetition-rate, laser-driven proton acceleration

A multi-shot target assembly and automatic alignment procedure for laser–plasma proton acceleration at high repetition rate are introduced.The assembly is based on a multi-target rotating wheel capable of hosting more than 5000 targets,mounted on a 3D motorized stage to allow rapid replenishment and alignment of the target material between laser irradiations.The automatic alignment procedure consists of a detailed mapping of the impact positions at the target surface prior to the irradiation that ensures stable operation of the target,which alongside the purpose-built design of the target wheel,enables operation at rates up to 10 Hz.Stable and continuous laser-driven proton acceleration at 10 Hz is demonstrated,with observed cut-off energy stability about 15%.

拼装湿地循环处理对城市水体水质改善的效果

近年来,降雨径流造成城市水体有机物和氨氮浓度超标的微污染问题较为突出,影响城市人居与生态环境,亟需开发绿色高效的原位处理技术以满足微污染城市水体水质改善需求。选取城市雨水提升泵站前池为处理水体,在水体内原位设置由动力模块和高效模块组成的循环拼装湿地,通过泵站前池水体循环处理方式,去除水体污染物和提升水体自净能力;通过对拼装湿地不同模块运行水质参数〔化学需氧量(COD)、氨氮、浊度〕的连续监测及水体不同区域耗氧速率和氨氮消除速率测定,探究拼装湿地循环处理对城市微污染水体水质改善的影响。结果表明:1)拼装湿地能够稳定去除约85%的COD和87%的氨氮,水体COD和氨氮浓度分别稳定在2~3和0.2~0.3 mg/L;2)拼装湿地循环处理作用下,泵站前池水体的耗氧速率提升3~10倍,氨氮去除速率提升2~3倍;3)拼装湿地填料表面形成了具有高效脱氮除碳功能的微生物种群,保证了拼装湿地良好的污染物去除性能。拼装湿地循环处理方式不仅借助设备本身的过滤、植物吸收和微生物降解等过程去除污染物,还通过强化气液传质、提升溶解氧水平和提高生化反应速率等方式提升了所处理水体的自净能力。拼装湿地循环处理技术在净化城市河湖水体、改善水体微生态等方面具有推广应用的潜力。

基于薯类收获机的装配式设计可行性分析

以进一步提升薯类收获机的综合作业效率为目标,从产品设计最优化角度入手,针对其结构装配及作业控制展开研究。考虑薯类收获机的作业对象特点及设计指标要求,采用机械装配式设计的实现机理,搭建用于薯类收获机装配式设计的精确处理模型,进行核心零部件的设计装配,通过执行过程的控制监测,完成薯类收获机的装配式设计整机呈现。进行挖掘马铃薯的作业试验,结果表明:基于薯类收获机的装配式设计正确可行,整机装配精度可达97.58%,各项作业指标良好,破损率可降低至2.78%;当作业速度为0.8 m/s、振动转速为90 r/min时,明薯率可达96.70%,优于薯类收获的设计指标要求,具有较高的适用性与可靠性。

预制装配率对装配式建筑工程造价的影响分析

针对装配式建筑相较于传统现浇式建筑工程造价增加问题,依据相关计算规则,在满足规范预制装配率的前提下,对不同类型装配式建筑、不同预制装配率的混凝土小高层住宅及不同预制构件类型的工程造价进行对比分析,探讨预制装配式建筑与传统现浇式建筑间的成本差异,并从经济角度出发,对预制构件、部品及技术的优先选择进行排序,以期为优化PC深化设计,探究投资最少、成本最低的预制装配率方案提供参考。

基于PS球自组装技术的GaN纳米柱阵列ICP刻蚀工艺研究

选用蓝宝石衬底上生长的P型氮化镓为材料,通过自组装技术制备的PS球为掩膜,采用感应耦合等离子体(ICP)干法刻蚀的方法来制备形状规则、周期均匀的纳米结构。在制备过程中,氮化镓纳米结构的形貌受诸多因素的影响,例如胶体球掩膜自组装的形貌,ICP刻蚀所通入的气体类型、气体比例、刻蚀功率源、刻蚀时间等。系统地研究了刻蚀过程中通入的气体类型、气体比例和刻蚀功率源、刻蚀时间对氮化镓纳米结构形貌的影响,并进行调整优化。利用扫描电子显微镜(SEM)对氮化镓进行的形貌分析表明:(1)随着刻蚀功率源和刻蚀时间的增大,掩膜层PS球的尺寸会随之减小使得刻蚀得到的纳米结构直径减小;(2)氮化镓纳米结构的形貌、刻蚀速率受到刻蚀通入的气体类型和比例影响,在Ar和CF_(4)或SF_(6)的组合气体作用下刻蚀速率相对非常缓慢,最高为15 nm/min,而Cl_(2)和BCl_(3)的组合气体作用速率可达到150 nm/min。

装配式建筑评价标准研究

研究以西安市某装配式建筑项目为例,应用各省市评价标准进行了装配率测算,并对计算结果进行了对比分析。根据长期工程实践,剖析了各省市装配式建筑评价标准当前存在的主要问题,并针对性地提出了评价标准发展建议,指出科学合理的评价体系和评价方法是装配式建筑产业健康可持续发展的关键。

湿空气在全尺寸压水堆燃料组件中的自然循环特性试验及理论研究

为开发一种不依赖于计算流体力学(Computational Fluid Dynamics,CFD)结果的燃料组件自然循环特性分析模型,以研究乏燃料水池在发生冷却剂丧失事故后的自然循环特性,本研究基于全尺寸压水堆燃料组件压降实验结果对Darcy-Forchheimer模型进行了修正,以预测湿空气流过燃料组件的压降,然后建立了燃料组件自然循环流量和峰值包壳温度的分析预测模型,并考虑了空气的相对湿度对模型计算结果的影响。结果表明:该模型可较为准确地预测不同加热功率下燃料组件的自然循环流量和峰值包壳温度,与实验测量值相比误差分别在25%和20%以内。并利用该模型研究了总加热功率、环境温度和相对湿度对燃料组件自然循环流量和峰值包壳温度的影响。因此,本研究所开发的模型可用于压水堆全尺寸燃料组件的自然循环特性研究。

基于AHP的高品质住宅高装配率部品技术研究

为解决装配式建筑建造中的限制因素,文章通过对装配式建筑技术的分析,以高品质住宅为研究对象,探究合肥市特色的装配式建造模式,结合工程案例,重点研究在65%高装配率下非结构部品部件技术的实施策略。通过AHP层次分析法综合评价分析,采用非结构多部品与装配式新技术应用组合方案在高装配率项目中具有显著优势。证明在装配式建筑项目中,通过综合运用高装配率部品技术、装配式智能高新技术,可推动装配式建筑智能建造模式的实现。

Gyroscope Dynamic Balance Counterweight Prediction Based on Multi-Head ResGAT Networks

The dynamic balance assessment during the assembly of the coordinator gyroscope significantly impacts the guidance accuracy of precision-guided equipment.In dynamic balance debugging,reliance on rudimentary counterweight empirical formulas persists,resulting in suboptimal debugging accuracy and an increased repetition rate.To mitigate this challenge,we present a multi-head residual graph attention network(ResGAT)model,designed to predict dynamic balance counterweights with high precision.In this research,we employ graph neural networks for interaction feature extraction from assembly graph data.An SDAE-GPC model is designed for the assembly condition classification to derive graph data inputs for the ResGAT regression model,which is capable of predicting gyroscope counterweights under small-sample conditions.The results of our experiments demonstrate the effectiveness of the proposed approach in predicting dynamic gyroscope counterweight in its assembly process.Our approach surpasses current methods in mitigating repetition rates and enhancing the assembly efficiency of gyroscopes.

Spatiotemporal evolution and assembly processes of ammonia-oxidizing prokaryotic communities in 1 000-year-old coastal reclaimed soils

Coastal marshes are transitional areas between terrestrial and aquatic ecosystems.They are sensitive to climate change and anthropogenic activities.In recent decades,the reclamation of coastal marshes has greatly increased,and its effects on microbial communities in coastal marshes have been studied with great interest.Most of these studies have explained the short-term spatiotemporal variation in soil microbial community dynamics.However,the impact of reclamation on the community composition and assembly processes of functional microbes(e.g.,ammonia-oxidizing prokaryotes)is often ignored.In this study,using quantitative polymerase chain reaction and the Ion S5™XL sequencing platform,we investigated the spatiotemporal dynamics,assembly processes,and diversity patterns of ammonia-oxidizing prokaryotes in 1000-year-old reclaimed coastal salt marshes.The taxonomic and phylogenetic diversity and composition of ammonia oxidizers showed apparent spatiotemporal variations with soil reclamation.Phylogenetic null modelling-based analysis showed that across all sites,the archaeal ammonia-oxidizing community was assembled by a deterministic process(84.71%),and deterministic processes were also dominant(55.2%)for ammonia-oxidizing bacterial communities except for communities at 60 years of reclamation.The assembly process and nitrification activity in reclaimed soils were positively correlated.The abundance of the amoA gene and changes in ammonia-oxidizing archaeal and bacterial diversities significantly affected the nitrification activity in reclaimed soils.These findings suggest that long-term coastal salt marsh reclamation affects nitrification by modulating the activities of ammonia-oxidizing microorganisms and regulating their community structures and assembly processes.These results provide a better understanding of the effects of long-term land reclamation on soil nitrogen-cycling microbial communities.

基于HRV的受限空间内装配人员作业疲劳研究

为了解受限空间内装配人员作业过程疲劳特征,避免疲劳累积,设计并组织扳手旋紧螺栓试验。招募10名男大学生进行试验,测量不同作业高度(120cm、140cm)和不同工作面(侧面、顶面、正面)下装配人员心率变异性数据(HRV),并记录主观疲劳评分。然后,利用统计学方法分析装配过程中作业人员疲劳特征。结果表明,作业高度显著影响NNMean、RMSSD、HF%和LF/HF以及主观疲劳评分,但工作面影响不显著,且无二阶效应。受限空间内装配人员旋紧螺丝作业中,不同工作面下疲劳发展差异不显著,140cm作业高度下疲劳累积明显高于120cm高度。

基于三方博弈理论对装配式住宅持续发展影响

相较于现砌建筑,装配式施工方式被认为是提高建筑行业环境绩效和可持续发展的有效途径。但现今装配式住宅的发展依旧存在障碍,消费者和政府这两个主要因素直接影响装配式住宅企业的决策。对其发展起着主导作用。然而,现有的研究大多为实证研究或只关注政府的某些激励行为缺乏不同参与方视角的分析以及相互作用产生的影响。所以对政府、消费者、建筑企业三大利益相关者之间动态关系及其动态行为策略。建立三方博弈模型,对不同情景进行数据分析来说明三方的决策行为,为此提供理论和实践依据,从而为如今装配式住宅可持续发展提供见解。

基于延时微分的旋转导向工具造斜率预测方法研究

【目的】旋转导向工具造斜率的准确预测是实现工具精准控制的前提,为掌握旋转导向底部钻具组合造斜率变化规律。【方法】根据工具结构特点,采用欧拉-伯努利梁方程法对复合式旋转导向工具底部钻具组合进行受力分析。通过结合底部钻具几何关系,得到各节工具转角与钻头预钻进偏角计算方法,并将旋转导向工具各节点与钻头间距离作为空间延时周期,最终建立基于延时微分的旋转导向底部钻具组合的造斜率预测模型。该模型综合考虑了工具本身几何尺寸与结构、与地层有关的钻头切削各向异性、钻压以及工具材料及内外径有关的抗弯刚度等参数对造斜率的定量影响。【结果和结论】研究表明:(1)该模型预测结果与斯伦贝谢成熟应用的基于有限元分析的钻具造斜率预测软件仿真结果具有良好的吻合度,预测结果差值均保持在0.5(°)/30 m以内,符合工程要求。(2)同时该方法还可在钻具姿态测量短节的实际测量数据基础上补偿钻头与测量单元间距带来的测量误差问题,为解决测量盲区提供一种新的途径。基于空间延时微分的造斜率预测方法为旋转导向系统底部钻具组合的结构优化及钻井参数优选提供理论依据和快速分析手段。建立的模型易于仿真和移植,在实际工程应用中可获取较好的实时响应,为基于数字孪生的旋转导向工具研发提供准确的钻具运动模型基础。

船海工程大型模块建造预组装技术

为通过优化建造技术加快船海工程类工艺模块的建造进度,降低生产成本,结合目前万吨级模块的建造实践,对模块甲板片在总装阶段的预组装建造工艺进行分析。先在地面对各甲板片进行预合拢,再对甲板片底部的结构支撑、电仪支撑和管线等进行预组装,最后对甲板片进行吊装合拢,从而提高其在地面的预组装率,加快模块总装速度,减少高风险作业,节省人工和机械成本,缩短模块建造周期,达到降本增效的目的,为后续类似大型工艺模块的建造提供参考。