New topology for implementing bandpass,bandstop and allpass filters with CFAs

In this brief, a new filter topology based on current feedback amplifiers is presented and compared with its operational amplifier counterpart. The circuits arising from the new topology have the important advantage that access to the Z node of the current feedback amplifier is not required, as is the case with many existing current feedback amplifier filter circuits. The operation and requirements for each of the filters are described. Theoretical results and circuit limitations are discussed and verified with experimental results. In one experiment a bandpass filter with a calculated Q and centre frequency of 20 and 158.53 kHz, respectively was built using the OPA2607 dual CFAs IC. Measured results yielded a Q of 20.153 at a centre frequency of 148.62 kHz showing close agreement with theory.     

键合互连对微波多芯片组件相位特性的影响

对键合互连对微波多芯片组件的相位特性影响进行了理论分析,并通过仿真软件HFSS对金丝键合互连模型进行了仿真。给出了在8~18 GHz的频率范围内,由于金丝拱高和跨距装配误差带来的相位误差。仿真分析表明,当金丝跨距在0.4~0.8 mm范围内波动时,最大相位差值在11 GHz以上时会超过20°,而当拱高在0.1~0.4 mm范围内波动时,最大相位差值在10 GHz以上时会超过20°,在13 GHz以上频率会超过30°。     

Ride quality analysis of a tracked vehicle suspension with a preview control

The feasibility of a preview control is examined for tracked vehicle’s suspension systems to improve the performance of tracked vehicle systems. Numerical results are compared with LQ, robust H_∞, reference model tracking and hybrid preview control methods. The ride quality analysis is performed based on the vertical acceleration at the driver’s position. On the simulations, it is proven that the hybrid preview controller is the most efficient and practical method.     

Combinatorics on update digraphs in Boolean networks

Boolean networks have been used as models of gene regulation and other biological networks. One key element in these models is the update schedule, which indicates the order in which states have to be updated. In Aracena et al. (2009) [1], the authors define equivalence classes that relate deterministic update schedules that yield the same update digraph and thus the same dynamical behavior of the network. In this paper we study algorithmical and combinatorial aspects of update digraphs. We show a polynomial characterization of these digraphs, which enables us to characterize the corresponding equivalence classes. We prove that the update digraphs are exactly the projections, on the respective subgraphs, of a complete update digraph with the same number of vertices. Finally, the exact number of complete update digraphs is determined, which provides upper and lower bounds on the number of equivalence classes.     

Quality improvement vs. advertising support: Which strategy works better for a manufacturer?

We consider a marketing channel with a single manufacturer and a single retailer, where both advertising and quality improvement contribute to the build-up of goodwill. In a non-coop scenario, the retailer controls the advertising efforts while the manufacturer controls the quality improvements and wholesale price. Although improving quality positively contributes to goodwill, it also increases the production cost, thereby reducing the manufacturer’s profit. In a coop scenario, the manufacturer supports the retailer’s advertising while decreasing his investments in quality. We investigate the conditions under which a coop program is beneficial when such a trade-off occurs. Our results demonstrate that only when advertising significantly contributes to goodwill the manufacturer has an incentive to cooperate and a coop program turns out to be Pareto-improving. Conversely, the retailer is always better off with a coop program. Moreover, the channel is operational- and marketing-driven when quality effectiveness is high independent of advertising effectiveness or when both quality and advertising effectiveness are large. In all other cases, the channel is marketing-driven.     

傅里叶望远镜外场实验与结果分析

为了分析外场环境因素对傅里叶望远镜成像质量的影响和验证成像过程不受下行链路大气扰动影响的特点,开展了傅里叶望远镜外场实验研究.外场实验在室内实验的发射光学系统的基础上增加了主镜、次镜和会聚透镜组对目标散射光进行3次会聚仿真实际系统的成像过程,同时将目标与主镜、主镜与次镜分别拉开100 m距离验证成像系统不受下行链路大气...     

Reactions of 2-(trifluoromethyl)chromones with cyanoacetamides, ethyl cyanoacetate and diethyl malonate. Unexpected synthesis of benzo[c]coumarin derivatives

While 2-(trifluoromethyl)chromones react with cyanoacetamides in the presence of sodium ethoxide to produce 6-(2-hydroxyaryl)-4-(trifluoromethyl)-2-oxo-1,2-dihydropyridine-3-carbonitriles, their reactions with ethyl cyanoacetate and diethyl malonate under the same conditions took an entirely different course and gave novel functionalized derivatives of 6H-benzo[c]chromen-6-one.     

多巴胺第三受体蛋白三维结构及其活性位点氨基酸残基

基于牛视紫红质模板蛋白,同源模建多巴胺第三受体（D₃R）蛋白三维结构,在1-棕榈酰-2-油酰-卵磷脂（POPC）膜-水模型环境,开展300 ns分子动力学模拟提炼优化其结构,取得稳定的D₃R蛋白三维结构（2B08-D₃R）.在该蛋白基础上,采用MP2/6-31G（d,p）方法,计算多巴胺（Dop）与氨基酸残基相互作用的结合能,确定五个残基（Asp117、Ser208、His272、Phe269和Thr276）为活性位点.五个活性位点残基分别位于D₃R蛋白跨膜螺旋区TM3、TM5和TM6,组成活性空腔结构.多巴胺分子以其苯基平面与TM2-TM7包围的圆柱体空腔平行和非共价键结合方式保留在D₃R蛋白中,与D₃R蛋白结合能E_b为-97.8 kJ·mol^-1基于3PBL D₃R突变体晶体结构,构建了另外一个含有多巴胺分子的D₃R蛋白结构（Dop-3PBL-D₃R）,确定在该蛋白结构中,多巴胺的活性位点氨基酸是Asp83、His272、Phe269、Phe268和Trp265.在该蛋白结构中,多巴胺分子同样以其苯基平面与TM2-TM7包围的圆柱体空腔平行和非共价键方式结合,与该蛋白相互作用的结合能是-80.5 kJ·mol^-1.     

Dynamic Active Noise Control of Broadband Noise in Fighter Aircraft Pilot Helmet

This paper presents the development of a dynamic Active Noise Control (ANC) algorithm aimed towards reducing the broadband noise inside the helmet earcups of a fighter aircraft pilot helmet. The dynamic ANC involves a Variable Step-Size Griffiths (VSSG) FxLMS algorithm to attenuate noise entering directly through helmet, a LMS based adaptive noise canceller to attenuate noise entering through the pilot microphone, and energy detectors for failure protection and optimized battery power usage. The algorithms are implemented on Texas Instruments’ TMS320C6748 processor and are tested in a helmet ANC experimental setup.     

Wireless powered hybrid backscatter-active communications with hardware impairments

Wireless powered hybrid backscatter-active communication can full make use of the different tradeoff between power consumption and achievable rate of the active and backscatter communications, and thus achieving a better performance than wireless powered active or backscatter communications. In this paper, we design a throughput maximization-based resource allocation scheme for a wireless powered hybrid backscatter-active communication network, while considering the hardware impairments at all RF front ends of each transceiver. Towards this end, we formulate a problem by jointly optimizing the transmit power of the dedicated energy source, the time for pure energy harvesting, backscatter and active communications, the power reflection coefficient, and the transmit power of each IoT node during active communications. The formulated problem is non-convex and different to solve. Subsequently an iterative algorithm based on the block coordinated decent technology is proposed to address the above problem. Simulation results verify that our proposed iterative algorithm converges very fast and that the proposed scheme outperforms the baseline schemes in terms of the throughput.