科创中国

Pneumatic actuators and electric actuators have almost been applied to all manufacturing industries.The two kinds of actuators can replace each other in most fields,such as the point to point transmission occasion and some rotating occasions.However,there are very few research results about the advantages and disadvantages of two kinds of actuators under the same working conditions so far.In this paper,a novel comprehensive assessment method,named as overall life cycle comprehensive assessment(OLCCA),is proposed for comparison and assessment of pneumatic and electric actuators.OLCCA contains mechanical properties evaluation(MPE),life cycle cost analysis based on users(LCCABOU)and life cycle environmental impact analysis(LCEIA)algorithm in order to solve three difficult problems:mechanical properties assessment,cost analysis and environmental impact assessment about actuators.The mechanical properties evaluation of actuators is a multi-objective optimization problem.The fuzzy data quantification and information entropy methods are combined to establish MPE algorithm of actuators.Two kinds of pneumatic actuators and electric actuators with similar bearing capacity and similar work stroke were taken for example to verify the correctness of MPE algorithm.The case study of MPE algorithm for actuators verified its correctness.LCCABOU for actuators is also set up.Considering cost complex structure of pneumatic actuators,public device cost even method(PDCEM)is firstly presented to solve cost division of public devices such as compressors,aftercooler,receivers,etc.LCCABOU method is also effective and verified by the three groups of pneumatic actuators and electric actuators.Finally,LCEIA model of actuators is established for the environmental impact assessment of actuators.LCEIA data collection method and model establishment procedure for actuators are also put forward.With Simapro 7,LCEIA comparison results of six actuators can be obtained:Fossil fuels are the major environmental factor of pneumatic and electric actuators;Environmental impact of electric actuator is large than one of pneumatic actuator under the similar mechanical properties and working conditions of pneumatic and electric actuators.The results are correct and correspond with the actual mechanical properties of actuators.This paper proposes a comprehensive evaluation method of the actuators,which can solve the critical problem that similar electromechanical products are very difficult to be compared with each other from the angle of performance,cost and environment impact.

Objective To detect the cell viability and the expressions of stem cell surface markers after chemotherapeutic drug treatment.Methods We observed the cytotoxic effects of three chemotherapeutic agents[epirubicin(Epi),fluorouracil(5-FU)and cyclophosphamide(Cyc)]in three cell lines,and the cell viabilities after removed these chemotherapeutic agents.Expressions of stem cell surface markers CD44,CD24,CD90,CD14 and aldehyde dehydrogenase1(ALDH1)in breast cancer cells were analyzed by real-time PCR.The post hoc analysis(Tukey's tests)in conjunction with one-way ANOVA was used for statistical analysis.Results The initial cytotoxic efficacy was most notable.After the treatment of the same therapeutic agents,cell viability was decreased by 64.8%35.14%,32.25%in BT-483 cells,66.4%,22.94%and 45.88%in MDA-MB-231 cells,97.1%,99.5%and 76.4%in MCF cells.The difference was significant compared with that before treatment(P=0.000).However,the inhibitory effects were diminished after chemotherapeutic agent withdrawal.Cell viabilities were increased to 167.9%,212.04%and 188.66%in MDA-MB-231 cells at48 h after withdrawal.At 72 h after withdrawal,cell viability was increased with a significant difference in three cell lines(all P values=0.000).Expressions of CD44 and ALDH1 were most prevalent for MDA-MB-231,BT-483 and MCF-7 cells.ALDH1 mRNA level was significant higher in BT-483(HER-2 overexpression cell line)than MDA-MB-231(triple negative cell line)(P=0.012).CD14 mRNA level in MCF-7 cells were significantly lower than that in MDA-MB-231 and BT-483(P=0.003,0.001).BT-483 showed significantly higher level of CD44 than MDA-MB-231 and MCF-7 cell line(P=0.013,0.020),and no significant difference was detected between MDA-MB-231 and MCF-7 breast cancer cells(P=0.955).CD90 mRNA expressions were detected in MDA-MB-231 cells and MCF-7 cells,but not in BT-483 cells.Conclusion Some malignant cells could survive in vitro and begin to proliferate again between cycles of chemotherapy.

The remanufacturing blanks with cracks were considered as irreparable. With utilization of detour effect and Joule heating of pulsed current, a technique to arrest the crack in martensitic stainless steel FV520B is developed. According to finite element theory, the finite element(FE) model of the cracked rectangular specimen is established firstly. Then, based on electro-thermo-structure coupled theory, the distributions of current density, temperature field, and stress field are calculated for the instant of energizing. Furthermore, the simulation results are verified by some corresponding experiments performed on high pulsed current discharge device of type HCPD-I. Morphology and microstructure around the crack tip before and after electro pulsing treatment are observed by optical microscope(OM) and scanning electron microscope(SEM), and then the diameters of fusion zone and heat affected zone(HAZ) are measured in order to contrast with numerical calculation results. Element distribution, nano-indentation hardness and residual stress in the vicinity of the crack tip are surveyed by energy dispersive spectrometer(EDS), scanning probe microscopy(SPM) and X-ray stress gauge, respectively. The results show that the obvious partition and refined grain around the crack tip can be observed due to the violent temperature change. The contents of carbon and oxygen in fusion zone and HAZ are higher than those in matrix, and however the hardness around the crack tip decreases. Large residual compressive stress is induced in the vicinity of the crack tip and it has the same order of magnitude for measured results and numerical calculation results that is 100 MPa. The relational curves between discharge energies and diameters of the fusion zone and HAZ are obtained by experiments. The difference of diameter of fusion zone between measured and calculated results is less than 18.3%. Numerical calculation is very useful to define the experimental parameters. An effective method to prevent further extension of the crack is presented and can provide a reference for the compressor rotor blade remanufacturing.

The competition of surface and subsurface crack initiation induced failure is critical to understand very high cycle fatigue(VHCF)behavior,which necessitates the elucidation of the underlying mechanisms for the transition of crack initiation from surface to interior defects.Crack initiation potential in materials containing defects is investigated numerically by focusing on defect types,size,shape,location,and residual stress influences.Results show that the crack initiation potency is higher in case of serious property mismatching between matrix and defects,and higher strength materials are more sensitive to soft inclusions(elastic modulus lower than the matrix).The stress localization around inclusions are correlated to interior crack initiation mechanisms in the VHCF regime such as inclusion-matrix debonding at soft inclusions and inclusion-cracking for hard inclusions(elastic modulus higher than the matrix).It is easier to emanate cracks from the subsurface pores with the depth 0.7 times as large as their diameter.There exists an inclusion size independent region for crack incubation,outside which crack initiation will transfer from the subsurface soft inclusion to the interior larger one.As for elliptical inclusions,reducing the short-axis length can decrease the crack nucleation potential and promote the interior crack formation,whereas the long-axis length controls the site of peak stress concentration.The compressive residual stress at surface is helpful to shift crack initiation from surface to interior inclusions.Some relaxation of residual stress can not change the inherent crack initiation from interior inclusions in the VHCF regime.The work reveals the crack initiation potential and the transition among various defects under the influences of both intrinsic and extrinsic factors in the VHCF regime,and is helpful to understand the failure mechanism of materials containing defects under long-term cyclic loadings.

报告1例透明细胞汗腺瘤.患者女,22岁.3年前无意中发现左下腹一核桃大褐色半透明状实性肿块,逐渐增大,现约3.2cm*1.6cm*1.3cm,有蒂,表面光滑,质地中等,无压痛感.

针对传统图像阈值降噪不足,本文提出了无需对噪声方差进行评估的基于主分量分析(Principal Component Analysis,PCA)的第二代Curvelet变换的图像降噪算法,并利用Cycle Spinning技术进行优化.PCA对Curvelet域中的噪声能量进行估计以实现对放射状条纹以及伪吉布斯等不良现象能够有效抑制.仿真试验结果表明,利用本文提出的算法对含噪图像进行降噪,降噪后图像的峰值信噪比得到了显著提高,且视觉效果也得到了明显地改善.因此,本文算法在图像处理领域具有广阔的应用前景.

中国宏观经济数据表明,存货总投资对解释GDP波动具有非常重要的作用.进一步利用采购经理人指数(PMI)数据对产成品存货投资和原材料存货投资进行研究,本文发现前者具有逆周期性,而后者表现出顺周期性.本文构建了一个具有产成品和原材料两种存货的动态宏观模型.利用贝叶斯动态方法,对模型进行了整体估计.结果表明,模型动态很好地解释了数据中的经验事实;两类存货投资的周期性特征主要源于最终需求冲击,该结论印证了2008年金融危机中,需求大幅回落是造成中国经济波动的最主要因素.

目的利用AAV介导的体细胞基因敲除技术,在人大肠癌细胞系HCTll6中对靶基因Sirt1进行敲除,达到基因沉默的目的.方法构建Sirtl打靶载体,通过病毒包装、感染、药物筛选、PCR鉴定、Westernblotting鉴定等步骤获得Sirt1基因敲除的细胞株.结果经过筛选和鉴定后获得两个Sirtl-/-阳性克隆,成功构建HCTll6Sirtl.一细胞系.结论通过体细胞敲除技术,我们成功地获得Sirtl敲除肠癌细胞株.

The mass production of printed electronics can be achieved by roll-to-roll(R2R) printing system, so highly accurate web tension is required that can minimize the register error and keep the thickness and roughness of printed devices in limits. The web tension of a R2R system is regulated by the use of integrated load cells and active dancer system for printed electronics applications using decentralized multi-input-single-output(MISO) regularized variable learning rate backpropagation artificial neural networks. The active dancer system is used before printing system to reduce disturbances in the web tension of process span. The classical PID control result in tension spikes with the change in roll diameter of winder and unwinder rolls. The presence of dancer in R2R system shows that improved web tension control in printing span and the web tension can be enhanced from 3.75 N to 4.75 N. The overshoot of system is less than ±2.5 N and steady state error is within ±1 N where load cells have a signal noise of ±0.7 N. The integration of load cells and active dancer with self-adapting neural network control provide a solution to the web tension control of multispan roll-to-roll system.