摘要：Pt based materials are the most efficient electrocatalysts for the oxygen reduction reaction(ORR)and methanol oxidation reaction(MOR)in fuel *** the utilization of Pt based materials by modulating their morphologies to expose more active sites is a fundamental objective for the practical application of fuel ***,we report a new class of hierarchically skeletal Pt-Ni nanocrystals(HSNs)with a multi-layered structure,prepared by an inorganic acid-induced solvothermal *** addition of H_(2)SO_(4)to the synthetic protocol provides a critical trigger for the successful growth of Pt-Ni nanocrystals with the desired *** Pt-Ni HSNs synthesized by this method exhibit enhanced mass activity of 1.25 A mgpt−1 at 0.9 V(versus the reversible hydrogen electrode)towards ORR in 0.1-M HClO_(4),which is superior to that of Pt-Ni multi-branched nanocrystals obtained by the same method in the absence of inorganic acid;it is additionally 8.9-fold higher than that of the commercial Pt/C ***,it displays enhanced stability,with only 21.6%mass activity loss after 10,000 cycles(0.6–1.0 V)for ***,the Pt-Ni HSNs show enhanced activity and anti-toxic ability in CO for *** superb activity of the Pt-Ni HSNs for ORR and MOR is fully attributed to an extensively exposed electrochemical surface area and high intrinsic activity,induced by strain effects,provided by the unique hierarchically skeletal alloy *** novel open and hierarchical structure of Pt-Ni alloy provides a promising approach for significant improvements of the activity of Pt based alloy electrocatalysts.

摘要：当今轮胎行业在设计新轮胎时普遍采用虚拟试验,因其能在节省大量开发时间的同时降低成本。虚拟试验除了模拟轮胎静态响应,还可以同时研究轮胎在道路上行驶的动态状况。这项工作可以进行不同条件下的轮胎试验,获取模型参数所需要的摩擦特征。其缺点就是无法控制的环境条件和轮胎结构会影响到试验结果。因此，在更多可控制条件下进行的小型试验更具有优势。胶料摩擦性能的试验特征因综合测量系统的必然性而有局限性。LATl00型实验室磨耗和滑动性能试验机（如图1所示，下称试验机）是针对轮胎行业的胶料测试而设计开发的，其利用特制摩擦盘模拟路况，测量直径为80mm小型滚动轮胎的湿滑、牵引力和磨耗，从而将结构复杂的轮胎简化为由一种胶料制造的实心轮胎，以研究滚动轮胎与道路之间的相互作用。

摘要：印刷机上的卷筒控制技术对于改善印刷品的性能来说是一个重要的议题。多色印刷机包含了多个印刷单元,每个印刷单元的原动力都是耦合的,而信号的传播总是有所滞后。本文介绍了一种针对三色印刷机的基于信号滞后的非线性控制方法。首先,为状态变量设计了一种非线性坐标变换,可描绘出压力的原动力和印刷缺陷。然后根据新坐标,绘制出基于滞后的反馈规律,这样封闭的循环系统归于零。最后,与传统的控制方法相对比,得出一些模拟结果。

摘要：本文研究了一个新柱型电动力转向(EPS-TT)系统。这种EPS-TT系统的显著特点是采用光隔离转矩传感器测量转向器转矩,它的辅助转矩控制方法是采用一个单向马达和两个离合器。因而它不需要一个复杂的马达驱动系统,该系统在作反向转动时要耗费大量的电能。为估算EPS-TT开发了一个完整的转向系统模型和一个简化了的模型。一个完整的车辆模型用来研究车辆的响应。为控制EPS-TT系统设计了线圈载体控制法和比例积分微分控制算法。分析了加于系列不同正弦输入和结果性能。结果表明用ESP-TT系统所达到的性能和常规的ESP系统通过的频率范围相似。整个转向系统模型结果和简化了的模型结果相似但车辆的响应稍稍不同。该线圈载体控制提供了好的性能不影响车辆的稳定性和可控性。

摘要：本文特别针对24V电池输入条件下的低电压,大电流特性,设计了一种新颖的PWM软开关DC-DC前向式功率变换器模型。在局部运行区域,利用了ZCS PWM DC-DC前向式功率变换器的附加控制模式来实现软开关。这种新型功率变换器在低负载条件下可支持PWM-PDM双模控制一疗式,研究结果征实,在ZCS 和有功电压钳位开关条件下,基于PWM-PDM双模控制的软开关前向式功率变换器可在较大的负载范围内改善运行效率。

摘要：To get an optimal product of orthopaedic implant or regenerative medicine needs to follow trialand-error analyses to investigate suitable product’s material,structure,mechanical properites *** whole process from in vivo tests to clinical trials is expensive and *** model is seen as a useful analysis tool to make the product development.A series of models for simulating tissue engineering process from cell attachment to tissue regeneration are *** challenging is that models for simulating tissue engineering processes are developed *** cell to tissue regeneration,it would go through blood injection after moving out the defect;to cell disperse and attach on the scaffold;to proliferation,migration and differentiation;and to the final part-becoming mature *** paper reviewed models that related to tissue engineering process,aiming to provide an opportunity for researchers to develop a mature model for whole tissue engineering *** article focuses on the model analysis methods of cell adhesion,nutrient transport and cell proliferation,differentiation and migration in tissue *** cell adhesion model,one of the most accurate method is to use discrete phase model to govern cell movement and use Stanton-Rutland model for simulating cell *** for nutrient transport model,numerical model coupling with volume of fluid model and species transport model together is suitable for predicting nutrient transport *** cell proliferation,differentiation and migration,finite element method with random-walk algorithm is one the most advanced way to simulate these *** of the model analysis methods require further experiments to verify the accuracy and *** to the lack of technology to detect the rate of nutrient diffusion,there are especially few researches on model analysis methods in the area of blood ***,there is still a lot of work to be done in the resea

摘要：Multifunctional devices are of great interest for integration and miniaturization on the same platform, but simple addition of functionalities would lead to excessively large devices. Here, the photodetection and chemical sensing device is developed based on two-dimensional(2D) glassygraphene that meets similar property requirements for the two functionalities. An appropriate bandgap arising from the distorted lattice structure enables glassy graphene to exhibit comparable or even improved photodetection and chemical sensing capability, compared with pristine graphene. Due to strong interactions between glassy graphene and the ambient atmosphere, the devices are less sensitive to photoinduced desorption than the ones based on graphene. Consequently,the few-layer glassy graphene device delivers positive photoresponse, with a responsivity of 0.22 A W^(-1) and specific detectivity reaching ~10^(10) Jones under 405 nm ***, the intrinsic defects and strain in glassy graphene can enhance the adsorption of analytes, leading to high chemical sensing performance. Specifically, the extracted signalto-noise-ratio of the glassy graphene device for detecting acetone is 48, representing more than 50% improvement over the device based on graphene. Additionally, bias-voltage-and thickness-dependent volatile organic compound(VOC) sensing features are identified, indicating the few-layer glassy graphene is more sensitive. This study successfully demonstrates the potential of glassy graphene for integrated photodetection and chemical sensing, providing a promising solution for multifunctional applications further beyond.

摘要：轮胎模拟是当今轮胎行业技术研究的一项必要手段。汽车制造商、政府部门和消费者要求轮胎在任何情况下都具有更好的牵引性能和更低的磨耗，还要求轮胎有更低的噪声和滚动阻力。因此，在轮胎设计过程中采用有限元分析来解决这些互相制约的需求问题。轮胎有限元模拟可以深入了解轮胎的特殊性能，缩短开发时间，降低开发成本。评测轮胎操纵性能必须准确预测轮胎在道路上的静态变形和动态滚动响应。

摘要：The Giant Radio Array for Neutrino Detection(GRAND)is a planned large-scale observatory of ultra-high-energy(UHE)cosmic particles,with energies exceeding 10~8 Ge *** goal is to solve the long-standing mystery of the origin of UHE cosmic *** do this,GRAND will detect an unprecedented number of UHE cosmic rays and search for the undiscovered UHE neutrinos and gamma rays associated to them with unmatched *** will use large arrays of antennas to detect the radio emission coming from extensive air showers initiated by UHE particles in the *** design is modular:20 separate,independent sub-arrays,each of 10000 radio antennas deployed over 10000 km^2.A staged construction plan will validate key detection techniques while achieving important science goals *** we present the science goals,detection strategy,preliminary design,performance goals,and construction plans for GRAND.

摘要：CD8+T细胞主要通过T细胞表面受体(T cell recep tor,TCR)识别并与Ⅰ型主要组织性复合物提呈的抗原(pMHC-Ⅰ)相互作用[1]。TCR对刺激型抗原的识别在CD8+T细胞毒性和适应性免疫中发挥着关键作用。许多证据表明机械力可以延长TCR与刺激性pMHC作用的键合时间(bond lifetime)形成抗原特异性逆锁键(catch bond)[2],并且这种逆锁键对抗原识别非常重要。然而,机械力调控TCR抗原识别的具体结构机制仍不清楚。通过分子动力学模拟、单分子生物膜力学探针、磁镊、T细胞活化实验和动物模型对此问题展开了系统的研究[4]。发现作用在TCR-pMHC-Ⅰ复合体上的拉力可以作用在TCR-pMHC-Ⅰ复合体上的拉力可以打破MHC-I分子内部α1-α2和β2结构域间的相互作用,导致α1-α2结构域旋转并发生构象变化。力诱导的MHC-I构象变化可以进一步别构地调节TCR与刺激性抗原肽及α1-α2结构域的构象及相互作用,诱导产生新的氢键,增强TCR-pMHC-Ⅰ之间的键合时间,但并不能增强TCR与抑制性pMHC-Ⅰ之间的作用。当用点突变阻断这些新形成的氢键,或者α1-α2和β2结构域被二硫键锁住时,最佳力诱导的TCR-pMHC-Ⅰ作用的键合时间明显缩短并且T细胞的活化受到抑制。另外,在人TCR和HLA-A2相互作用中发现了类似机制,并且与肿瘤相关的HLA-A2点突变[3]可以通过限制HLA-A2α1--α2和β2结构域之间的构象打开减弱TCR对肿瘤抗原的识别及T细胞的功能。研究结果表明,机械力诱导的MHC-I构象变化对TCR抗原识别和T细胞活化非常重要,进一步地阐明了机械力调控TCR抗原识别机制,为临床肿瘤的免疫治疗和药物设计提供了新思路和新靶点。