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51.
目前,混合动力汽车(HEV)、插电式混合动力汽车(PHEV)和纯电动汽车(EV)的开发工作与锂离子(Li-ion)电池的使用密不可分,许多OEM、电子设备供应商和电池制造商探讨的重点都集中在如何构建最佳的电池监控和管理系统.这些系统当然需要一个主监控器,它通常是一个与微控制器或电池管理单元(BMU)接口的模数转换器(ADC),用来提供精确的测量数据并执行电池平衡(确保充电前所有电池处于同一电平).  相似文献   
52.
Mechanistic links have been suggested between repolarization alternans (RPA) and the onset of ventricular tachycardia (VT) and/or fibrillation. Endocardial detection of RPA may, therefore, be an important step in future device-based treatments of arrhythmias. Here, we investigate if RPA could be detected during acute ischemia using an implantable cardioverter defibrillator (ICD) lead (tip to distal coil) located in the right ventricular apex. In 18 pigs, the right coronary (n = 10) or left anterior descending coronary (n = 8) artery was occluded for 10 min using a balloon catheter, followed by reperfusion for 30 min, and re-occlusion for 30 min. RPA magnitude, computed using the modified moving average (MMA) method, showed a sharp increase in all 18 animals, from a mean baseline level of 1.9 +/- 1.3 mV to 3.0 +/- 1.3 mV during first occlusion (p < 0.001). RPA magnitude showed a prominent increase in 10 animals during re-occlusion, from a mean baseline level of 1.7 +/- 1.0 mV to 3.3 +/- 1.5 mV (p < 0.001). The protocol was terminated during the first two stages of occlusion and reperfusion for the remaining 8 animals due to the occurrence of ventricular fibrillation (VF). These results confirm that RPA increases under ischemic conditions and that it is possible to detect and track RPA dynamics with an ICD lead that is positioned in a clinically realistic location. Such an approach may be useful in formulating improved arrhythmia detection and control algorithms.  相似文献   
53.
身处市场领先地位的SoC(系统单芯片)设计团队认为,“惯常的业务”已不复重现,强大的技术与商务力量(似乎独立于EDA供应商的路线图),都在将SoC设计方法重新塑造为新的形式,并与仅仅几年前的最佳实践有非常大的差异。  相似文献   
54.
Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is investigated as a transparent cathode to replace indium tin oxide (ITO) in inverted polymer solar cells. Increasing the thickness of the PEDOT:PSS electrode leads to a reduction in transparency and sheet resistance which lowers the photocurrent but increases the fill factor of the solar cells. The offset of photocurrent and fill factor as the thickness is increased leads to a saturation of the power conversion efficiency to 3%. These electrodes were applied to flexible substrates showing similar device performance to glass based devices. Cyclic bending test of these flexible polymer electrodes show improved conversion efficiency retention (92%) when compared to flexible ITO based electrodes (50%) after 300 bend cycles. In addition to using PEDOT:PSS as a cathode replacement for ITO in inverted solar cells, its use as a semi-transparent anode replacement to Ag is also examined. Semi-transparent inverted solar cells fabricated with ITO as the cathode and PEDOT:PSS as the top anode electrode were demonstrated showing efficiencies of 2.51% while replacement of both ITO and Ag with PEDOT:PSS as both the cathode and anode show efficiencies of 0.47%.  相似文献   
55.
The nuclear spin quantum computer proposed by Kane [Nature 393 (1998) 133] exploits as a qubit array 31P dopants embedded within a silicon matrix. Single-qubit operations are controlled by the application of electrostatic potentials via a set of metallic ‘A’ gates, situated above the donors, on the silicon surface, that tune the resonance frequency of individual nuclear spins, and a globally applied RF magnetic field that flips spins at resonance. Coupling between qubits is controlled by the application of potentials via a set of ‘J’ gates, between the donors, that induce an electron-mediated coupling between nuclear spins. We report the results of the study of the electric field and potential profiles arising within the Kane device from typical gate operations. The extent to which a single nuclear spin can be tuned independently of its neighbours, by operation of an associated A-gate, is examined and key design parameters in the Kane architecture are addressed. Implications for current fabrication strategies involving the implantation of 31P atoms are discussed. Solution of the Poisson equation has been carried out by simulation using a TCAD modelling package (Integrated Systems Engineering AG).  相似文献   
56.
Paper Jamz是一款玩具电吉他,它与真正的电吉他非常相似,电源为三颗AAA电池,靠一个内置的11/2英寸扬声器来发出声音。它的名称及25美元的低价都暗示着该吉他是采用印刷电极和信号线。这可以当作一个研究的案例,即如何用强大的微控制器和一些电容触控感应输入,做出复杂的产品。  相似文献   
57.
Protected Working Capacity Envelope (PWCE) has been proposed to simplify resource management and traffic control for survivable WDM networks. In a PWCE-based network, part of the link capacity is reserved for accommodating working routes, and the remaining capacity is reserved for backup routes. The shortest path routing is applied in PWCE-based networks. An arrival call is accepted only when each link along the shortest path has a free working channel. Such a working path routing scheme greatly simplifies the call admission control process for dynamic traffic, and it is especially suitable for implementation in a distributed manner among network nodes. In this article, we investigate two protection strategies: Bundle Protection (BP) and Individual Protection (IDP). In BP, only one backup path can be used to protect a failure component, whereas multiple backup paths can be used in IDP. We formulate four mixed integer non-linear programming (MINLP) problems using BP and IDP strategies for single link and single node failure protection. Each model is designed to determine link metrics for shortest working path routing, working and backup channel assignments, and backup path planning. Our objective is to minimize call-blocking probability on the bottleneck link. Since these models are highly non-linear and non-convex, it is difficult to obtain exact global optimal solutions. We propose a Simulated Annealing-based Heuristic (SAH) algorithm to obtain near optimal solutions. This SAH adopts the concepts of simulated annealing as well as the bi-section technique to minimize call-blocking probabilities. To evaluate the performance, we made simulation comparisons between SAH and the unity link weight assignment scheme. The results indicate that SAH can greatly reduce call-blocking probabilities on benchmark and the randomly generated networks.  相似文献   
58.
The exact analysis of second order bandpassDelta-Sigma modulator with sinusoidal inputs isperformed. The results indicate that quantization erroris neither uniformly distributed nor white. Thequantization error spectrum is purely discrete andsymmetric with one forth of sampling frequency, and thelocations of these discrete frequency components arestrongly dependent on input amplitudes. Similar resultsare also observed for passband communication signals,such as quadrature amplitude modulation. From theanalysis, crosscorrelation between quantization error andsinusoidal input was shown to exist but can be cancelledout by proper design of the noise shaping function. Crosscorrelation can degrade the performance of thedelta-sigma system. Hence, the exact analysis is anothermethod to enable design for high performance.  相似文献   
59.
Blood product transfusion is a financial concern for hospitals and patients. Efficient utilization of this dwindling resource is a critical problem if hospitals are to maximize patient care while minimizing costs. Traditional statistical models do not perform well in this domain. An additional concern is the speed with which transfusion decisions and planning can be made. Rapid assessment in the emergency room (ER) necessarily limits the amount of usable information available (with respect to independent variables available). This study evaluates the efficacy of using artificial neural networks (ANNs) to predict the transfusion requirements of trauma patients using readily available information. A total of 1016 patient records are used to train and test a backpropagation neural network for predicting the transfusion requirements of these patients during the first 2, 2-6, and 6-24 h, and for total transfusions. Sensitivity and specificity analysis are used along with the mean absolute difference between blood units predicted and units transfused to demonstrate that ANNs can accurately predict most ER patient transfusion requirements, while only using information available at the time of entry into the ER.  相似文献   
60.
目前的第一代无线局域网(WLAN)仅仅用来简单地取代有线,即只是用来消除主要家庭娱乐系统或办公设备部署采用过多线缆所引起的混乱.而实际上,无线通信的优势远远不止这一点.摆脱线缆的束缚之后,设备间可能的连接方式将大量增加.  相似文献   
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