Analytical synthesis of general high-order voltage/current transfer functions using CCIIs

This paper proposes two circuit structures to realize general high-order voltage and current transfer functions using second-generation current conveyors (CCIIs). The proposed general high-order voltage/current-mode circuit structures are designed based on an analytical synthesis method. The nth-order voltage-mode transfer function requires 2n+1 CCIIs, 2n+2 grounded resistors and n grounded capacitors. The nth-order current-mode transfer function requires 2n+2 CCIIs, 2n+2 grounded resistors and n grounded capacitors. The voltage-mode third-order allpass, lowpass and highpass filters and the current-mode third-order notch, lowpass and highpass filters that are derived out from the proposed high-order voltage and current-mode circuit structures are simulated to verify the synthesis methods.     

Failure modes and effects analysis for high-power GaN-based light-emitting diodes package technology

In this study, nondestructive test is developed to analyze the structure failure of LED package. The relationship between thermal resistance analysis and LED package failure structure is build with T3Ster thermal transient tester and scanning electron microscope (SEM). The failure LED device with defect in the attaching layer and gap between LED chip and copper are designed advisedly. The failure factors of LED package have been measured with thermal resistance analysis and SEM cross-section images. The thermal dissipation performance of LED with defect in the attaching layer is indicated by thermal resistance analysis combined with SEM cross-section images. The blister in attaching layer results in 4.4 K/W additional thermal resistance. The gap between LED chip and copper also makes high additional thermal resistance with 8.6 K/W. Different failures of LED packages are indicated obviously using thermal transfer analysis. The LED package failure structure such as interface defect between solder and cup-shaped copper is able to forecast without destructive measurement.     

High Input Impedance Voltage-Mode Universal Biquadratic Filter with Three Inputs and Six Outputs Using Three DDCCs

A new high input impedance voltage-mode universal biquadratic filter with three input terminals and six output terminals is presented. The proposed circuit uses three plus-type differential difference current conveyors (DDCCs), three resistors, and two grounded capacitors. The proposed circuit can realize all the standard filter functions, namely, lowpass, bandpass, highpass, notch, and allpass, simultaneously, without component matching conditions. The proposed circuit still offers the features of high input impedance, using only grounded capacitors, and orthogonal controllability of resonance angular frequency and quality factor.     

SmartMote: An Adaptive Update Mechanism for Wireless Ad-Hoc Sensor Network

This paper describes a novel update mechanism for large wireless ad-hoc sensor networks (WASNs). In wireless sensor networks, the nodes may have to be reprogrammed, especially for design-implement-test iterations. Manually reprogramming is a very cumbersome work, and may be infeasible if nodes of the network are unreachable. In addition, replacing the executed application on a node by transmitting the complete program image is inefficient for small changes in the code either. It consumes a lot of bandwidth and time. Therefore, an on-the-fly update mechanism is required. This paper exploits programmable packets to update sensor behaviors. To reduce the code transferred and power consumption, a group management architecture is developed. This architecture helps reduce power consumption and increase node number that control by Leader Node in WASNs. The proposed update mechanism, SmartMote, has been implemented on the Tmote-based Octopus II sensor node. Performance evaluation as well as measurement is conducted in the paper to illustrate the significance of the proposed mechanism.     

Heterogeneous Vehicle Navigation Platform Combined with Mobile RFID Using MIMO System

In a mobile Radio Frequency Identification (RFID) system, the RFID tag is attached to a mobile object such as a vehicle, a human etc. The information is more difficult to detect than in the case where the tag is attached to a stationary object. The RFID reader and back-end database both help to automatically record and store the vehicle driver information and real time status of a tracked geographic information system (GIS), and they cooperate to synchronize the information flow and monitor. In this paper, the Kalman filter (KF) has been implemented as the primary integration scheme of the global positioning system (GPS) and inertial navigation systems (INS) for many land vehicle navigation and positioning applications. It also includes estimating the state of dynamic systems, almost all systems have some dynamic component, and determine how to best use a given set of vehicle sensors for modeling a high performance analysis by using the KF algorithm.     

A new authentication based cheating prevention scheme in Naor–Shamir’s visual cryptography

Visual cryptography (VC), first presented by Naor and Shamir, is a variant of secret sharing, thus it also called visual secret sharing. It can be widely used in many applications such as encrypting large data efficiently. In the literature, the problem of cheating is under consideration in secret sharing. Recently, Horng et al. pointed out that cheating is possible in k-out-of-n VC schemes, and presented two kinds of the cheating prevention schemes for protecting honest participants. One of them is the authentication based cheating prevention scheme. In this paper, we analyze the definition of cheating prevention and propose a new authentication based cheating prevention scheme. This scheme is constructed with Naor–Shamir’s VC scheme. Finally, we give the security analysis to prove that the proposed scheme is immune to cheating.     

高效液相色谱法测定食醋中乳酸的不确定度评定

摘 要： 目的 建立高效液相色谱法测定食醋中乳酸的不确定度的数学模型。方法 根据JJF1059.1-2012《测量不确定度评定与表示》,从测量过程各步骤分析不确定度来源,并对已识别来源的不确定度影响进行评价和分析。结果 测量结果不确定度主演来源于乳酸标准溶液、试样溶液配制和液相色谱仪的定量重复性。当食醋中乳酸含量为48.49mg/g时,其扩展不确定度为1.34mg（k=2）。结论 该研究可为实验室评定食醋中乳酸含量的测定结果质量提供参考。     

顶空固相微萃取-气质联用技术检测油菜籽中 挥发性成分

目的 采用气相色谱-质谱(GC-MS) 技术对正常油菜籽与霉变油菜籽中挥发性成分进行鉴定和分类分析。方法 采用顶空固相微萃取(HS-SPME)技术对油菜籽中的挥发性成分进行萃取,优化顶空固相微萃取的微萃取头、萃取温度、萃取时间和解析时间等条件,并结合气相色谱-质谱(GC-MS) 技术对正常油菜籽与霉变油菜籽中挥发性成分进行测定。结果 顶空固相微萃取的最佳条件为固相萃取头30/50 μm DVB/CAR/PDMS,萃取温度60 ℃,萃取时间60 min,解吸时间3 min。在最佳实验条件下,GC-MS鉴定出油菜籽中挥发性成分主要有醛类、酮类、醇类、烃类、少量酸、酯类物质及杂环类等多种组分,其中烃类含量最高; 3-辛酮、苯乙酮、苯乙醛、苯乙醇、以及十九烷 、二十一烷等烷烃类化合物仅在霉变油菜籽中检出。结论 该方法可较好区分正常油菜籽与霉变油菜籽。     

贻贝中微塑料检测的消解方法比较

目的 比较双壳贝类中微塑料检测常用的酸消解、碱消解、氧化消解和酶消解等方法,推荐适用于贝类中微塑料检测的通用型消解方式。方法 以常用的指示性双壳贝类贻贝作为研究对象,确定食品样品检测通用的消解条件。在这些条件下对聚苯乙烯（polystyrene,PS）、聚丙烯（polypropylene,PP）、聚碳酸酯（polycarbonate,PC）、聚乙烯（polyethylene,PE）、聚对苯二甲酸乙二醇酯（polyethylene terephthalate,PET）、聚酰胺6（polyamide,PA6）和聚酰胺66（polyamide,PA66）七种微塑料进行消解,考察不同条件下微塑料粒子消解前后重量、红外光谱、粒径分布和形貌特征的变化。结果 采用不同的消解方式对不同的微塑料影响不同,其中重量受影响较大的是PA6和PA66,在硝酸-高氯酸混合溶液和高氯酸-双氧水混合溶液中完全溶解损失,PC和PET在氢氧化钾溶液中损失严重。通过结构表征,PE、PA6和PC的粒径增加,PC的形貌结构发生彻底改变。结论 微塑料含量甚微的双壳贝类样品进行检测,推荐采用胃蛋白酶溶液和胰蛋白酶溶液进行消解;如需缩短消解时间,推荐采用双氧水在高温下消解。     

热裂解-气相色谱-质谱法快速筛查和定量分析乳与乳制品中的4种微塑料

目的 建立热裂解-气相色谱-质谱法（pyrolysis-gas chromatography mass spectrometry, PY-GC-MS）快速筛查和定量分析乳与乳制品中的4种微塑料（microplastics, MPs）,防止原料、生产工艺、包装等过程带入微塑料残留。乳与乳制品中微塑料（microplastics, MPs）检测的热裂解-气相色谱质谱联用技术（pyrolysis-gas chromatography mass spectrometry, PY-GC-MS）。方法 以聚碳酸酯（polycarbonate, PC）、聚对苯二甲酸乙二醇酯（polyethylene terephthalate, PET）、聚酰胺6（polyamide 6, PA6）和聚酰胺66（polyamide 66, PA66） 4种微塑料粒子为例,采用红外光谱和粒度分析对微塑料形貌进行表征。考察了进样模式、裂解温度对裂解效果的影响,并对四种微塑料的特征定量峰进行比较并对4种微塑料的特征定量峰进行比较 ,最终选择单击式裂解模式,裂解温度600℃,4种微塑料的特征物质分别为双酚A、对苯二甲酸-2-苯甲酰氧基乙酯乙烯酯、己内酰胺和环戊酮。验证了裂解方法的稳定性和特异性,利用高温裂解产生的特征碎片离子进行定量分析。结果 本方法对四种微塑料检测的线性范围为本方法对4种微塑料检测的线性范围为2 μg ~64 μg ,检出限0.1 μg~1.2 μg,定量限0.3 μg~4.0 μg,平均加标回收率79.5%~96.0%,精密度1.74%~10.8%。结论 本方法适用于乳与乳制品中微塑料的检测,也可以进一步优化条件应用到其他类型的微塑料检测过程,作为微塑料浓度检测标准制定的参考方法。