Web Tension Regulation of Multispan Roll-to-Roll System using Integrated Active Dancer and Load Cells for Printed Electronics Applications

The mass production of primed 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.

Development and installation of bedload monitoring systems with submerged load cells

Bedload governs riverbed channel variations and morphology,it is necessary to determine bedload discharge through an arbitrary cross section in a mountain river.A new system with submerged load cells has been developed to directly measure bedload discharge.The system consists of:(1)an iron box which is 1 m long,0.5 m wide and 0.1 m in depth,(2) two submerged load cells 0.7 m apart,(3) a pressure sensor and,(4) an electromagnetic velocity meter.This system has been designed to exclude the effect of the hydraulic pressure of water on direct measurements of bedload particle weight.Initial tests in a laboratory were conducted to examine the accuracy of measurements with the system under aerial conditions.The system has been installed in the supercritical flume in Ashi-arai-dani River of the Hodaka Sedimentation Observatory of the Disaster Prevention Research Institute(DPRI) of KyotoUniversity to obtain bedload discharge under natural conditions.Flume tests were conducted in this channel by artificial supply of uniform sediment particles of several grain sizes.The average velocity of the sediment particles near the bed was estimated using cross-correlation functions for weight waves obtained by the two load cells.Bedload discharge calculations were based on time integration of the product of sediment velocity and sediment weight obtained by the two load cells.This study clarifies the reasons why bedload measurements are difficult,and provides some solutions using the monitoring systems with submerged load cells through the field measurements.Additionally,the applicability of bedload measurement with the submerged load cells is explained based on experimental artificial sediment supply data.

Load-Measuring Pot Bearing with Built-In Load Cell —Part II: Fatigue Performance and Experimental Temperature Correction

This paper presents the results of fatigue performance tests performed up to 10 million cycles on a load-measuring pot bearing with built-in load cell to verify its field applicability and proposes an empirical temperature correction formula. In Part I of this work, various measurement performances of the load-measuring pot bearing were evaluated through static and dynamic loading tests. Bridge bearings are subjected to the effect of fatigue caused by the repeated application of moving loads and exposed to harsh site conditions including cold and hot weathers differently to laboratory conditions. Accordingly, the durability of the load-measuring pot bearing with built-in load cell shall be secured and the environmental effects like temperature shall be minimized for its application on field. This study conducted fatigue tests up to 10 million cycles on a load-measuring pot bearing with the capacity of 1000 kN to examine eventual degradation of the measurement accuracy with respect to the number of fatigue loading cycles. In addition, the experimental temperature correction procedure is proposed to obtain the temperature correction formula enabling to correct the effect of temperature on the load measurement.

Load-Measuring Pot Bearing with Built-In Load Cell —Part I: Design and Performance

This paper presents the underlying principle and the results of various performance evaluations for a load-measuring pot bearing with built-in load cell. The pot bearing composed of a pot made of steel in which an elastomer disk is inserted is a bearing supporting larger loads than the elastomeric bearing and accommodating rotational movement. Owing to a Poisson’s ratio close to 0.5, elastomer withstands hydrostatic pressure when confined in a rigid body. Accounting for this principle, the vertical load applied on the pot bearing can be obtained by converting the pressure acting on the elastomer. Therefore, a load-measuring pot bearing is developed in this study by embedding a load cell exhibiting remarkable durability in the base plate of the bearing. The details for the insertion of the load cell in the base plate of the pot were improved through finite element analysis to secure sufficient measurement accuracy. The evaluation of the static performance of the pot bearing applying these improved details verified that the bearing exhibited sufficient accuracy for the intended measurement purpose. The dynamic performance evaluation results indicated that accurate measurement of the dynamic load was also achieved without time lag.

Errors Prediction for Vector-to-Raster Conversion Based on Map Load and Cell Size

Vector-to-raster conversion is a process accompanied with errors.The errors are classified into predicted errors before rasterization and actual errors after that.Accurate prediction of the errors is beneficial to developing reasonable rasterization technical schemes and to making products of high quality.Analyzing and establishing a quantitative relationship between the error and its affecting factors is the key to error prediction.In this study,land cover data of China at a scale of 1:250 000 were taken as an example for analyzing the relationship between rasterization errors and the density of arc length(DA),the density of polygon(DP) and the size of grid cells(SG).Significant correlations were found between the errors and DA,DP and SG.The correlation coefficient(R2) of a model established based on samples collected in a small region(Beijing) reaches 0.95,and the value of R2 is equal to 0.91 while the model was validated with samples from the whole nation.On the other hand,the R2 of a model established based on nationwide samples reaches 0.96,and R2 is equal to 0.91 while it was validated with the samples in Beijing.These models depict well the relationships between rasterization errors and their affecting factors(DA,DP and SG).The analyzing method established in this study can be applied to effectively predicting rasterization errors in other cases as well.

Characteristics of Dynamic Load Response of a Fuel Cell with a Dead-ended Anode

The dynamic load characteristics of a proton exchange membrane fuel cell（PEMFC） with a dead-ended anode were studied. In a 70 h experiment, the effects of anode pressure, operating temperature, and relative humidity of the cathode on the performances of the fuel cell were investigated. The obtained results show that, with different relative humidity of the cathode at 65 ℃, dynamic loading has little effect on the performances of fuel cell and the electrochemically active surface area（ECSA）. However, the fuel cell operating under dynamic load is unstable when the relative humidity is 50%, and at 50 ℃ with 100% relative humidity, applying a dynamic load has a significant influence on the fuel cell performances. Scanning electron microscopy（SEM） showed that both the upstream and middle catalyst layers of the cell were unchanged, whereas the downstream cathode catalyst layer thinned as a response to dynamic load.

Dental pulp stem cells express tendon markers under mechanical loading and are a potential cell source for tissue engineering of tendon-like tissue

Postnatal mesenchymal stem cells have the capacity to differentiate into multiple cell lineages. This study explored the possibility of dental pulp stem cells （DPSCs） for potential application in tendon tissue engineering. The expression of tendon- related markers such as scleraxis, tenascin-C, tenomodulin, eye absent homologue 2, collagens I and VI was detected in dental pulp tissue. Interestingly, under mechanical stimulation, these tendon-related markers were significantly enhanced when DPSCs were seeded in aligned polyglycolic acid （PGA） fibre scaffolds. Furthermore, mature tendon-like tissue was formed after transplantation of DPSC-PGA constructs under mechanical loading conditions in a mouse model. This study demonstrates that DPSCs could be a ootential stem cell source for tissue enEineerin~ of tendon-like tissue.

Nomograms based on HPV load for predicting survival in cervical squamous cell carcinoma: An observational study with a longterm follow-up

Objective: To investigate the prognostic value of pretreatment human papillomavirus(HPV) viral load for cervical cancer, and to develop nomograms based on HPV load and other clinicopathological factors for long-term survival.Methods: We conducted a prospective study on cervical squamous cell carcinoma(SCC) patients diagnosed between January 2003 and December 2008. Cervical samples were tested for HPV viral load by the Hybrid Capture II(HCII) assay before treatment and 6 months after treatment. Clinical characteristics and follow-up information were also collected. A multivariable Cox proportional hazards model was used to adjust covariates in both the radical hysterectomy(RH) treatment group and concurrent chemoradiotherapy(CCRT) treatment group to identify relevant covariates, and then nomograms were constructed and used for internal validation.Results: A total of 520 SCC patients enrolled in this study with a median follow-up of 127 months, 360 patients received RH, whereas 160 patients received CCRT. The median HPV viral load in RH and CCRT groups was356.10 and 294.29, respectively. Tumor size was positively correlated with high pretreatment HPV load in both groups. In CCRT group, the advanced International Federation of Gynecology and Obstetrics(FIGO) stage and enlarged retroperitoneal lymph node status determined by computed tomography(LNSCT) were correlated with low HPV load group. Initial HPV viral load, FIGO stage and lymph node metastasis were prognostic factors for RH group, whereas HPV viral load, squamous cell carcinoma antigen(SCC-Ag) level and LNSCT were identified as prognostic factors for CCRT group. Nomograms incorporating these predictors for 10-year progression-free survival(PFS) were constructed [concordance index(C-index): 0.756, 0.749].Conclusions: A low pretreatment HPV viral load is an independent prognostic factor for poor prognosis of cervical SCC and is related to other clinicopathological factors. The survival nomogram based on HPV viral load could predict the long-term prognosis.

A Uniaxial Loading Device for Studying Mechanoresponses of Single Plant Cell

A system which consists of a loading chamber unit, displacement sensor, data collector and processor, and a feedback control, was established for applying mechanical forces to single plant cells. The method works by compressing an agar cell-suspension block between parallel surfaces through using a force-feedback control circuit coupled to a microchip, delivering the pre-defined. The actual controlled stimulus is achieved whilst measuring the force being imposed on the cell, and its deformation. TheArabidopsisprotoplasts were utilized to test the system. It provides an experimental approach to investigate the mechanoresponses of plant cellsin vitroconditions.

Load Balancing for Hex-Cell Interconnection Network

The hex-cell is one of the interconnection networks used for parallel systems. The main idea of the hex-cell is that there are hexagon cells that construct the network;each one of those cells has six nodes. The performance of the network is affected by many factors one of the factors as load balancing. Until the moment of writing of this paper, there is no load balancing algorithm for this network. The proposed algorithm for dynamic load balancing on hex-cell is based on Tree Walking Algorithm (TWA) for load balancing on tree interconnection network and the ring all to all broadcast.

Mechanical loading of adipose derived stromal cells causes cell alignment

Osteoarthritis is a debilitating disease that affects hundreds of millions of people worldwide. Current research involving growth and characterization of adipose derived stromal cells (ADSC) in vitro offers a potential solution for the treatment of cartilage de-fects that will allow patients to return to the physical activities they were involved in. Studies have shown that fibroblast cells grown in vitro respond to cyclic mechanical stretching by orienting in a direction perpendicular to the direction of stretch. ADSCs were isolated from human peripatellar adipose tissue discards. Cells were cultured until confluent and seeded at a density of approximately 105 cells in silicone wells pretreated with ProNectin-F Plus. After stret-ching, relative alignment of the cells was ascertained using imaging software. Stretching cells for 3, 4, 8 and 12 hours resulted in noticeable cellular alignment of approximately 60? relative to the direction of loading. Cell alignment is crucial for developing tis-sue-engineered cartilage that has similar mechanical properties to native cartilage. Mechanically loading cells is one method to achieve cell alignment. Since cell differentiation will be initiated after alignment, the resulting chondrocytes will be aligned, leading to organized collagen formation and resulting in a hya-line-like cartilage structure.

Higher Viral Load and Prolonged Viral Shedding Period is Associated with Impaired Th17 Cell Response in Patients with H1N1 Influenza A

Objective To explore whether age,disease severity,cytokines and lymphocytes in H1N1 influenza A patients correlate with viral load and clearance.Methods Total of 70 mild and 16 severe patients infected with H1N1 influenza A virus were enrolled in this study.Results It was found that the patients under 14 years old and severe patients displayed significantly higher viral loads and prolonged viral shedding periods compared with the patients over 14 years old and mild patients,respectively(P < 0.05).Moreover,the patients under 14 years old and severe patients displayed significantly lower Th17 cell frequency than the patients over 14 years old and mild patients(P < 0.01).The viral shedding period inversely correlated with the frequency of IL-17+IFN-γ-CD4+ T cells.Additionally,the decreased concentration of serum TGF-β correlated with the decreased frequency of IL-17+IFN-γ-CD4+ T cells.Conclusions Both younger and severe patients are associated with higher viral loads and longer viral shedding periods,which may partially be attributed to the impaired Th17 cell response.

PRP联合ADSCs负载藻酸钙凝胶修复软骨缺损的效果研究

目的探讨富血小板血浆(PRP)联合脂肪间充质干细胞(ADSCs)负载藻酸钙凝胶修复软骨缺损的效果。方法取新西兰大白兔皮下脂肪分离培养ADSCs,制造兔关节软骨缺损模型,然后将ADSCs种植到负载PRP的藻酸钙凝胶上,构建组织工程软骨并移植到缺损处。实验分为3组:对照组、PRP组和PRP-ADSCs-藻酸钙凝胶组,每组10只。术后观察细胞形态和生长情况,甲苯胺蓝染色和Ⅱ型胶原免疫组化染色等方法检测成软骨特性,CCK-8法检测ADSCs增殖活性,RT-PCR检测Ⅱ型胶原mRNA和蛋白多糖mRNA表达。结果在倒置相差显微镜下,ADSCs呈现典型的间充质干细胞形态,即梭形或椭圆形,细胞质丰富,核形规则。随着培养时间的延长,ADSCs逐渐呈现出良好的生长状态,细胞数量增多,细胞间连接紧密,形态规则。对照组软骨缺损区未见明显修复,染色呈浅蓝,ADSCs数量多;PRP组软骨缺损区部分修复,染色呈蓝色,ADSCs数量较对照组多;PRP-ADSCs-藻酸钙凝胶组软骨缺损区修复效果最好,染色呈深蓝色,ADSCs数量较PRP组多。诱导14 d后,ADSCs甲苯胺蓝异染阳性,胞浆及细胞周围出现紫红色异染。Ⅱ型胶原免疫组化染色显示,PRP-ADSCs-藻酸钙凝胶组ADSCs平均灰度值明显高于其他组(P<0.05);阳性细胞胞浆内可见棕黄色颗粒,细胞周围黄染。CCK-8检测显示,PRP-ADSCs-藻酸钙凝胶组ADSCs第2天进入指数生长,对照组第3天才开始进入指数生长状态。在观察期间内,PRP-ADSCs-藻酸钙凝胶组软骨诱导后ADSCs OD值显著高于其他组(P<0.05)。PRP-ADSCs-藻酸钙凝胶组Ⅱ型胶原mRNA表达明显高于其他组(P<0.05)。3组ADSCs的蛋白多糖mRNA表达随时间增加而递增,第14、21天PRPADSCs-藻酸钙凝胶组ADSCs的蛋白多糖mRNA表达明显高于其他组(P<0.05)。结论利用PRP、ADSCs、藻酸钙凝胶形成的复合体初步构建组织工程软骨对缺损关节软骨进行修复,可提高ADSCs增殖活性及Ⅱ型胶原和蛋白多糖mRNA表达水平,使缺损的关节软骨得到明显修复。

计及热负荷柔性的户用氢能系统运行优化研究

针对风电/光伏出力的随机性和间歇性给户用氢能系统热电联供可靠性带来的挑战,提出基于热负荷柔性松弛运行约束的户用氢能系统热电联供优化策略。首先,搭建包含不同模块的户用氢能系统基础架构,并详细说明该系统的运行原理;其次,建立系统中关键环节的数学模型,确定电解槽平均氢/热比和燃料电池在不同温度下电/热比的范围;然后,为了兼顾用户的舒适度和热负荷的灵活性,根据热感觉平均标度预测指标对户用氢能系统的热负荷需求进行调整;最后,综合考虑储氢罐的容量限制、氢能设备的电/热功率和用户侧柔性热能需求等约束条件,以总投资成本最少和新能源弃电率最低为目标,建立户用氢能系统优化运行模型。仿真结果表明:引入柔性热负荷进行运行调节时,不仅增强了可再生能源的消纳能力,还显著降低了系统的运行成本。

A comparative crashworthiness analysis of multi-cell polygonal tubes under axial and oblique loads

In order to investigate the energy absorption characteristics of multi-cell polygonal tubes with different cross-sectional configurations,firstly,the theoretical formulae of the mean crushing force under axial load for four multi-cell polygonal tubes were derived by combining the Super Folding Element theory with Zhang’s research results.These formulae can be used to validate the numerical model and quickly evaluate the energy absorption ability of multi-cell polygonal tubes.Furthermore,a comparative study on the energy absorption performance of eight multi-cell polygonal tubes under axial and oblique loads was conducted.The results show that all tubes have a stable mixed deformation mode under axial load.The multi-cell decagon tube has better energy-absorption ability compared with other tubes.Whenθis less than 10°,all the tubes maintain a stable deformation mode,and the multi-cell decagon tube also has the biggest crushing force efficiency and specific energy absorption among these eight tubes;meanwhile compared with the results atθ=0°,the specific energy absorption of all tubes decreases by about 8%-21%,while the crushing force efficiency increases by 20%-56%.However,at large angles 20°and 30°,all of the tubes collapse in bending modes and lose their effectiveness at energy absorption.

网状孔壁碳化硅基多孔陶瓷的制备及其颗粒物过滤研究

为了提高碳化硅基多孔陶瓷的过滤性能,以碳化硅粉体、氧化铝粉体、聚醚多元醇、多亚甲基多苯基异氰酸酯、二月桂酸二丁基锡、三乙烯二胺、稳泡剂硅油(阿拉丁)为原料,通过聚氨酯发泡技术,研制了三维(3D)网状孔壁结构的碳化硅基多孔陶瓷试样,并探索了料浆固含量(固相质量分数分别为45%、50%、55%和60%)对试样显微结构、物理性能和颗粒物过滤性能的影响。结果表明:1)随着固含量的升高,试样体积密度和常温耐压强度提高,显气孔率降低;2)聚氨酯发泡过程中产生的微孔会分布在陶瓷孔壁上形成网状孔壁结构,增大颗粒物与孔壁碰撞概率,提高试样的过滤效率;同时,网状孔壁结构还可以提高试样气孔贯通性,降低其压降;3)当固含量为55%(w)时,试样体积密度约为0.57 g·cm^(-3),显气孔率为79.2%,常温耐压强度为3.7 MPa;且对颗粒物的去除率高达91.2%,具有良好的再生性能。

基于节点网元的韧性配电网时-空调度序列协同优化负荷恢复策略

为提升配电网的韧性,在更大的时间尺度和空间范围内确保新型电力系统下灵活、高效的电力供应,提出一种新颖的基于节点网元的韧性配电网时-空调度序列协同优化负荷恢复策略,获取配电网灾后场景下的最优负荷恢复序列方案及其调度时刻表。在多智能体代理系统架构下提出节点网元的概念,制定负荷恢复序列方案,通过邻近节点间局部信息的交互获取全局参数信息,作为灾后信息网络受损下负荷恢复优化模型的输入。对灾后负荷恢复模型中的混合整数线性规划问题进行求解,获取负荷恢复路径及修复时刻表,形成由多个分布式电源组成的节点网元以恢复停电负荷,实现检修人员调度和操作人员调度间的协同优化。最后,通过改进IEEE 37节点和IEEE 123节点系统验证了所提协同调度优化模型的有效性。

进气相对湿度对变载工况下PEMFC电堆性能的影响

为了探究进气相对湿度对质子交换膜燃料电池电堆变载工况性能的影响,设计了一个动态循环工况,包括电流密度从0.10到0.35 A/cm^(2)、从0.10到1.00 A/cm^(2)的2种阶跃工况和电流密度分别为0.10、0.35、1.00 A/cm^(2)的稳定工况,进行了相对湿度分别为20%、30%、50%、70%、80%的5组试验.结果表明:恒流状态时,电堆在不同电流密度下对相对湿度的敏感性不同,在大电流密度下相对湿度对电堆性能影响较大;变载过程中,电堆电压出现下冲和过冲现象,加载过程的电压下冲量与变载幅度和相对湿度有关,电堆单电池电压一致性变差,电压一致性与进气相对湿度有关.

太阳能电池电路的负载特性研究

在关于太阳能电池的文献中,一般都会给出输出电流-输出电压关系曲线和输出功率-输出电压关系曲线。但很少见到关于太阳能电池的输出电压-负载电阻关系曲线、输出电流-负载电阻关系曲线,以及输出功率-负载电阻关系曲线。本文从实验和理论两方面研究了这些关系曲线,实验测试和理论计算的结果相当一致,二者均表明,对确定的太阳能电池电路,随着负载电阻的增大,输出电压单调增大,输出电流单调减小,但输出功率不是单调变化的,而是存在一个最佳功率值,这个最佳功率值对应一个最佳负载电阻值。此外,我们也研究了入射光强对太阳能电池输出电压、输出电流,以及输出功率的影响,发现这些输出量均随光强的增大而增大。这些研究结果在太阳能电池电路的设计和应用中具有重要的意义。

基线CD_(4)^(+)T细胞数和病毒载量对整合酶抑制剂方案疗效影响的Meta分析

目的评价HIV感染者基线CD4+T淋巴细胞(CD4细胞)计数和病毒载量对含整合酶抑制剂治疗方案疗效的影响。方法检索知网、万方、维普、PubMed以及Web of Science数据库,对符合纳入标准文献进行质量评价和原始数据提取,对基线CD4细胞计数(<200/μL vs.≥200/μL)和HIV病毒载量(>10^(5)拷贝/mL vs.≤10^(5)拷贝/mL)进行亚组分析,评估各亚组治疗失败风险,采用R软件进行Meta分析。结果共纳入29篇文献。Meta分析结果显示,与基线CD4细胞计数≥200/μL组相比,<200/μL组治疗48周(OR=1.93,95%Cl:1.47~2.53,P=0.01)和96周(OR=1.53,95%Cl:1.13~2.09,P<0.01)的治疗失败风险更高;与基线病毒载量≤10^(5)拷贝/mL的HIV感染者相比,>10^(5)拷贝/mL的HIV感染者治疗48周后治疗失败风险更高(OR=1.82,95%Cl:1.37~2.42,P<0.01)。结论HIV感染者基线CD4细胞计数和病毒载量是影响含整合酶抑制剂治疗方案疗效的重要因素,应积极推行“发现即治疗”政策,促进HIV感染者的早检测、早诊断及早治疗。