基于卷积神经网络判定方法的激光微透镜阵列微米级加工工艺

在MLA曝光工艺中,曝光点的数量庞大,通过高倍率显微镜配合人工目检来判定曝光质量耗时耗力,造成工艺成本偏高。为了解决这个问题,设计了一种便于检测的圆环形图案并引入深度学习中的目标检测Yolov5模型,一定程度上能够取代人工目检,完成对曝光质量的快速判定。基于上述方法,分析了不同光刻胶厚度之下,线能量密度的最优区间与光刻胶的剖面倾角。并在同等线能量密度下通过圆度判定曝光图案失真情况。在本研究的MLA曝光工艺中,选取光刻胶厚度、激光曝光功率以及加工平台移动速度作为自变量,评价曝光合格率、光刻胶剖面倾角以及曝光圆度等加工质量参数具有重要的工程意义。

肝炎肝衰竭和妊娠期急性脂肪肝肝衰竭的母婴结局分析

目的比较肝炎肝衰竭和妊娠期急性脂肪肝(acute fatty liver of pregnancy,AFLP)肝衰竭的母婴结局。方法收集中山大学附属第三医院及分院妊娠合并肝衰竭的病例28例,其中肝炎引起的肝衰竭10例(肝炎组),AFLP引起的肝衰竭18例(AFLP组),分别对两组母婴结局进行分析比较。结果肝炎组中产后凝血功能完全恢复正常需要的时间[(19.0±11.9)d]是AFLP组[(9.8d±5.9)d]的2倍,最高总胆红素[(294.3±136.9)μmol/L]和最高直接胆红素[(214.7±95.4)μmol/L]均高于AFLP组[(192.6±109.7)μmol/L、(139.9±81.8)μmol/L],肝炎组平均住院时间明显长于AFLP组[(26.2±14.7)d vs(17.1±7.9)d],但肝炎组中发生产后出血率10%明显低于AFLP组的50%,以上两组间差异均具有统计学意义(P<0.05)。两组新生儿的新生儿转科率、窒息率、早产率及严重并发症率差异均无统计学意义(P>0.05)。结论及时终止妊娠后,两种肝衰竭的新生儿结局无差异,但肝炎肝衰竭产妇产后恢复时间明显延长。

包装印刷全生命周期绿色评价与管理体系研发

随着全社会绿色发展理念和政策不断推进落实,包装印刷生命周期全过程造成的较大资源环境影响受到广泛重视。本研究以纸塑铝包装的生命周期评价(Life Cycle Assessment, LCA)为例,介绍了LCA的基本方法,尤其是包装再生循环方面的分析结果。基于LCA方法,本研究提出了包装印刷全生命周期绿色评价与管理体系研发的设想,包括评价标准体系、原料数据库建设、互联网平台开发等。该体系可以为包装印刷行业大规模开展全生命周期绿色评价与管理,为行业可持续发展提供技术支持。

产品生命周期可得性水足迹计算方法

水足迹方法试图量化评价人类活动对水资源可得性的影响,从而为水资源可持续利用提供科学的依据.水足迹的评价方法尚未统一,目前全球应用最为广泛的是WFN(water footprint network,水足迹协作网络)水足迹计算方法.基于LCA(life cycle assessment,生命周期评价)方法的基本框架,围绕水资源可得性的水量、水质和空间分布3个因素,在分析现有水足迹计算公式的基础上,指出了WFN水足迹计算方法的不足.根据国际水足迹标准(ISO 14046)的原则和要求,改进了WFN的水足迹计算公式,提出了产品生命周期WAF(water availability footprint,可得性水足迹)定义和评价方法,其中包括单元过程数据计算、背景过程数据处理和生命周期汇总.通过方法对比和案例研究得到:WAF方法统一了水消耗量与水污染量定义中的水质基准,可以明确区分水污染和水净化两类过程,还可以反映区域水资源稀缺程度的影响;采用WAF方法,在现有LCA数据库和软件的支持下可以更为规范地完成生命周期水足迹建模与计算但目前单元过程数据计算中各种污染物的基准浓度选取有不可避免的主观性,将直接影响到水足迹计算结果及其客观性,有待进一步研究.

CT/^(99m)Tc-GSA SPECT fusion images demonstrate functional differences between the liver lobes

AIM: To evaluate the functional differences between the 2 liver lobes in non-cirrhotic patients by using computed tomography/99mTc-galactosyl human serum albumin (CT/99mTc-GSA) single-photon emission computed tomography (SPECT) fusion images. METHODS: Between December 2008 and March 2012, 264 non-cirrhotic patients underwent preoperative liver function assessment using CT/99mTc-GSA SPECT fusion images. Of these, 30 patients, in whom the influence of a tumor on the liver parenchyma was estimated to be negligible, were selected. Specifically, the selected patients were required to meet either of the following criteria: (1) the presence of an extrahepatic tumor; or (2) presence of a single small intrahepatic tumor. These 30 patients were retrospectively analyzed to calculate the percentage volume (%Volume) and the percentage function (%Function) of each lobe. The ratio between the %Function and %Volume (function-to-volume ratio) of each lobe was also calculated, and the ratios were compared between the 2 lobes. Furthermore, the correlations between the function-to-volume ratio and each of 2 liver parameters [lobe volume and diameter ratio of the left portal vein to the right portal vein (LPV-to-RPV diameter ratio)] were investigated. RESULTS: The median values of %Volume and %Function were 62.6% and 67.1% in the right lobe, with %Function being significantly higher than %Volume (P < 0.01). The median values of %Volume and %Function were 31.0% and 28.7% in the left lobe, with %Function being significantly lower than %Volume (P < 0.01). The function-to-volume ratios of the right lobe (1.04-1.14) were significantly higher than those of the left lobe (0.74-0.99) (P < 0.01). The function-to-volume ratio showed no significant correlation between the lobe volume in either lobe. In contrast, the function-to-volume ratio showed significant correlations with the LPV-to-RPV diameter ratio in both lobes (right lobe: negative correlation, rs = -0.37, P = 0.048; left lobe: positive correlation, r s = 0.71, P < 0.001). The function-to-volume ratio in the left lobe tended to be higher, and that in the right lobe tended to be lower, in accordance with the increase in the LPV-to-RPV diameter ratio. CONCLUSION: CT/99mTc-GSA SPECT fusion images demonstrated that the function of the left lobe was significantly decreased compared with that of the right lobe in non-cirrhotic livers.

Trend analysis and comparison of basic parameters for tunnel blast design models

One of the most important factors influencing on a tunnel blast efficiency is the proper design of blasting pattern. Among blasting parameters, blasthole diameter and tunnel face area are more significant so that any change in these parameters could finally affect on specific charge and specific drilling. There are mainly two groups of methods for tunnel blast design categorized based on the parallel cuts and angular cuts. In this research, a software for tunnel blast design was developed to analyze the effect and sensitiveness of blasthole diameter and the tunnel face area on blasting results in different blast design models. Using the software, it is quickly possible to determine specific charge, specific drilling and number of blastholes for each blast design model. The relations between both of blasthole diameters and the tunnel face area with the above parameters in different blast design models were then investigated to yield a set of equations with the highest correlations to compare the methods. The results showed that angular method requires more blasthole numbers than parallel method in similar condition(blasthole diameter and tunnel face area). Moreover, the specific charge values yielded by the two methods are approximately the same and very close together.

90 years of thermal analysis as a control tool in the melting of cast iron

Since its first literature mention in conjunction with cast iron in 1931 by Esser and Lautenbusch,thermal analysis(TA)has journeyed a long way.Today it is an accepted and widely used tool for process control for all types of cast irons.This paper reviews the latest progress in the development of equipment and analysis methods that make TA successful in applications such as the estimation of chemical composition,graphitization potential,and the shape and number of graphite aggregates.The potential and limitations of the prediction of shrinkage defects propensity are analyzed in some details.Examples of attempts at prediction of mechanical properties and shrinkage propensity are also discussed.Several graphs showing the data scattering are presented to convey the reader a better sense of the accuracy of various predictions.

Tribological Performance of Different Concentrations of Al_(2)O_(3)Nanofluids on Minimum Quantity Lubrication Milling

Nanofluid minimum quantity lubrication(NMQL)is a green processing technology.Cottonseed oil is suitable as base oil because of excellent lubrication performance,low freezing temperature,and high yield.Al_(2)O_(3)nanoparticles improve not only the heat transfer capacity but also the lubrication performance.The physical and chemical proper-ties of nanofluid change when Al_(2)O_(3)nanoparticles are added.However,the effects of the concentration of nanofluid on lubrication performance remain unknown.Furthermore,the mechanisms of interaction between Al_(2)O_(3)nanoparti-cles and cottonseed oil are unclear.In this research,nanofluid is prepared by adding different mass concentrations of Al_(2)O_(3)nanoparticles(0,0.2%,0.5%,1%,1.5%,and 2%wt)to cottonseed oil during minimum quantity lubrication(MQL)milling 45 steel.The tribological properties of nanofluid with different concentrations at the tool/workpiece interface are studied through macro-evaluation parameters(milling force,specific energy)and micro-evaluation parameters(surface roughness,micro morphology,contact angle).The result show that the specific energy is at the minimum(114 J/mm^(3)),and the roughness value is the lowest(1.63μm)when the concentration is 0.5 wt%.The surfaces of the chip and workpiece are the smoothest,and the contact angle is the lowest,indicating that the tribological proper-ties are the best under 0.5 wt%.This research investigates the intercoupling mechanisms of Al_(2)O_(3)nanoparticles and cottonseed base oil,and acquires the optimal Al_(2)O_(3)nanofluid concentration to receive satisfactory tribological properties.

铸铁熔炼热分析技术发展九十年

自从1931年Esser和Lautenbusch第一次在铸铁文献中谈及热分析以来,铸铁的热分析技术已经走过了漫长的道路。目前,热分析已被广泛应用于各种铸铁的过程控制。文中综述了热分析在设备和分析方法方面的最新进展,正是这些技术进步使得热分析得以成功应用于评估化学成分、石墨化潜能、石墨形状和数量等。详细分析了热分析技术在预测收缩缺陷倾向方面的潜力和局限性,讨论了预测力学性能和收缩倾向的实例。为了让读者更好地了解各种预测的准确性,文中给出了一些数据和图表。

Performance Calibration of Articulated Arm Coordinate Measuring Machine

This paper presents the method for the performance calibration of AACMM （articulated arm coordinate measuring machines） according to ASME B89.4.22 Standard. The growing use of this class of measurement equipment has been accompanied by an absence of authorized laboratories to provide calibration certificates for its performance. Due to ASME B89.4.22 and VD12617-9 are nowadays the unique standards in the field of AACMM verification, IK4 Tekniker has compared both of them in order to develop internal test procedures to yield reliable performance calibration results. As a result, IK4 Tekniker has been recognized by the Spanish Accreditation Body （ENAC） in the field of AACMM calibration. Internal test procedures and uncertainty evaluation analysis have been developed as well as ENAC certificated reference test equipments have been acquired to ensure a suitable AACMM calibration process.

Some paradoxical observations about spheroidal graphite degeneracy

Differential thermal analysis experiments have been performed on samples machined from Y2-blocks cast with different high-silicon spheroidal graphite irons. Depending on magnesium, silicon, cerium and antimony content, the as-cast microstructure showed various levels of chunky graphite in the central part of the blocks. In contrast, the microstructure of the materials after remelting and resolidification during differential thermal analysis consisted of lamellar or compacted graphite. The formation of chunky graphite in the as-cast microstructure is rationalized using an index or silicon equivalent that has been recently suggested. The differences in the microstructures after differential thermal analysis are discussed in terms of available free magnesium. Emphasis is finally put on the striking differences in characteristic size of the microstructures made of compacted graphite as compared to lamellar graphite and chunky graphite. This leads to tentative conclusions about growth of compacted and chunky graphite which would be worthy of further experimental investigations.

Experimental and Modeling Studies on the Chemical Vapor Infiltration with Respect to the Effects of Thermal Gradient and Other Operating Parameters

Effects of operating parameters in the thermal gradient chemical vapor infiltration of propane such as thermal gradient, diffusion, infiltrations time, and concentration of propane were studied by focusing on the visualizations of the intrinsic effects of these parameters. A uniform deposition in the preform was obtained with a gradually increasing temperature along the gas flow. The uniformity of deposition through the preform got improved with increasing deposition time. Results of numerical modeling estimated the experimental data very well when the pre-exponential factor of the overall rate of carbon deposition from propane reported by Vaidyaraman[1] was multiplied by 4. The average density of a preform increased by about 3 times from 0.38 to 1.15 g/cm3 after 60 hr deposition with a thermal gradient under the conditions of 3% propane in nitrogen and 840 to 900 ℃.

Electrostatic atomization minimum quantity lubrication machining:from mechanism to application

Metal cutting fluids(MCFs)under flood conditions do not meet the urgent needs of reducing carbon emission.Biolubricant-based minimum quantity lubrication(MQL)is an effective alternative to flood lubrication.However,pneumatic atomization MQL has poor atomization properties,which is detrimental to occupational health.Therefore,electrostatic atomization MQL requires preliminary exploratory studies.However,systematic reviews are lacking in terms of capturing the current research status and development direction of this technology.This study aims to provide a comprehensive review and critical assessment of the existing understanding of electrostatic atomization MQL.This research can be used by scientists to gain insights into the action mechanism,theoretical basis,machining performance,and development direction of this technology.First,the critical equipment,eco-friendly atomization media(biolubricants),and empowering mechanisms of electrostatic atomization MQL are presented.Second,the advanced lubrication and heat transfer mechanisms of biolubricants are revealed by quantitatively comparing MQL with MCF-based wet machining.Third,the distinctive wetting and infiltration mechanisms of electrostatic atomization MQL,combined with its unique empowering mechanism and atomization method,are compared with those of pneumatic atomization MQL.Previous experiments have shown that electrostatic atomization MQL can reduce tool wear by 42.4%in metal cutting and improve the machined surface Ra by 47%compared with pneumatic atomization MQL.Finally,future development directions,including the improvement of the coordination parameters and equipment integration aspects,are proposed.

Biological Stability of Water-Based Cutting Fluids:Progress and Application

The application of cutting fluid in the field of engineering manufacturing has a history of hundreds of years,and it plays a vital role in the processing efficiency and surface quality of parts.Among them,water-based cutting fluid accounts for more than 90%of the consumption of cutting fluid.However,long-term recycling of water-based cutting fluid could easily cause deterioration,and the breeding of bacteria could cause the cutting fluid to fail,increase manufacturing costs,and even endanger the health of workers.Traditional bactericides could improve the biological stability of cutting fluids,but they are toxic to the environment and do not conform to the development trend of low-carbon manufacturing.Low-carbon manufacturing is inevitable and the direction of sustainable manufacturing.The use of nanomaterials,transition metal complexes,and physical sterilization methods on the bacterial cell membrane and genetic material could effectively solve this problem.In this article,the mechanism of action of additives and microbial metabolites was first analyzed.Then,the denaturation mechanism of traditional bactericides on the target protein and the effect of sterilization efficiency were summarized.Further,the mechanism of nanomaterials disrupting cell membrane potential was discussed.The effects of lipophilicity and the atomic number of transition metal complexes on cell membrane penetration were also summarized,and the effects of ultraviolet rays and ozone on the destruction of bacterial genetic material were reviewed.In other words,the bactericidal performance,hazard,degradability,and economics of various sterilization methods were comprehensively evaluated,and the potential development direction of improving the biological stability of cutting fluid was proposed.

企业组织管理创新与经济运行质量提升

围绕企业经营活动中的"组织管理创新",对于转变发展方式、迈向高质量发展轨道开展探讨。企业的组织创新是在约束条件变化的情况下,通过对可利用资源组合的重新整合和配置,适应环境并保持和提升组织分工效率和协调能力,实现组织持续生存和组织目标的重要手段。在对企业组织创新的特征加以讨论的基础上,分析了企业组织创新活动可能采取的几种具体形式、组织创新有助于调整完善企业与市场、企业内部的分工和合作关系,并促成企业管理体系和管理模式的创新,带来企业运行质量的提升。

生产性规模的铝合金化学镀镍

目前,在所有工业铝合金上化学镀镍已不存在重大的技术问题。所得到的复合材料具有特殊的功能特性。本文将讨论用这种合金制作的工件如何以生产规模化学镀镍并取得良好的经济效益。所列举的、在各个技术领域中应用的实例,将会对铝合金化学镀镍这种多功能的复合系统开辟新的用途。

The Drosophila adult neuromuscular junction as a model for unravelling amyloid peptide influence on synapse dynamics

Amyloid peptide（Aβ）oligomers are considered one of the primary causal factors for the synaptic loss characteristic of Alzheimer’s disease（AD）（Karran and De Strooper,2016）.However,Aβis generated in normal brains and accumulates at synaptic sites,which raises the question whether Aβplays a physiological role in synapses.

Heterogeneous Fenton Catalyst for the Efficient Removal of Azo Dyes in Water

Heterogeneous Fenton/photo Fenton type processes using a Fe-exchanged zeolite of Y-type have been applied for the degradation of a model textile synthetic water based on Black B azodye. Research work has been directed to compare process efficiency and to establish their advantages over corresponding homogenous Fenton type processes. By optimizing the amount of reactants and process conditions, a complete decolorization of the effluent and a reduction greater than 80 per cent in the total organic carbon content is achieved. The influence of solar radiation on the heterogeneous process has been also studied. Homogeneous and heterogeneous Fenton processes yielded similar decolorization and mineralization, but the concentration of Fe ions in the bulk after the treatment was not significant in the latter case. Moreover, the catalyst support can be reused in successive cycles without significant loss of effectiveness. The use of solar radiation as a source of energy for operating the process accelerates the decomposition of azodye, making the process economical and environmentally sustainable.

Optimal Positioning of Mobile Platforms for Accurate Manipulation Operations

Many mobile robotics applications, especially in industrial environments, require the robot to perform safe navigation and then reach the goal with a high precision. In this research work, the objective is to analyze the appropriateness of autonomous natural navigation strategies for mobile manipulation tasks. The system must position itself in a realistic map, follow a path closely and then achieve an accurate positioning in the destination point in order to be able to perform the manipulation, inspection or pick task efficiently. Autonomous navigation is not able to fulfill the accuracy required by some of the jobs so that a second positioning system using vision is proposed in this paper. The experiments show that localization systems have, on average, an error greater than a decimetre and how an additional positioning system can reduce it to a few millimetres.