太赫兹(THz)波在物质检测方面发挥着巨大的作用,是一种非常有潜力的生化传感工具。但是传统的太赫兹时域光谱系统(TDS)结构复杂,系统的集成度低,占用空间较大。所以,如何对THz波进行有效引导、实现集成化传输并得到高质量光谱就成为太...太赫兹(THz)波在物质检测方面发挥着巨大的作用,是一种非常有潜力的生化传感工具。但是传统的太赫兹时域光谱系统(TDS)结构复杂,系统的集成度低,占用空间较大。所以,如何对THz波进行有效引导、实现集成化传输并得到高质量光谱就成为太赫兹光谱系统的研究热点。太赫兹片上系统是将THz的产生、传输以及探测都集成到同一芯片上,然后通过相干探测的方法获得THz时域光谱。它可以实现对多种样品的检测,尤其在对难于取样的微量样品探测方面具有广泛的应用价值。它无需光路准直,操作简便,成品率高。两个研究工作都是基于低温砷化镓(LT-GaAs)外延片开展的。首先将一根直径为200μm的铜线固定在LT-GaAs外延片的上方,通过真空蒸镀的方法制备出天线电极,同时得到天线间隙,研制出基于LT-GaAs外延片的THz天线。利用波长为800 nm的飞秒激光对其进行测试,得到了质量较高的THz信号,验证了天线的实用性。然后在另一外延片上利用光刻微加工工艺制作出传输线和微电极,得到了集成的THz片上系统。使用波长为1550 n m的飞秒激光分别激发片上系统的太赫兹产生天线和探测天线,天线产生的太赫兹波在传输线上传播,在探测端同样得到了质量较高的THz时域信号,证实了THz片上系统的可行性。该方法省去了腐蚀牺牲层以及LT-GaAs薄膜的转移、键合等步骤,极大地提高了片上系统的成品率,避免了薄膜转移过程中易破碎及腐蚀液存在毒性的问题。最后,研究了外加电压对从片上系统中获得的THz波性能的影响,结果为电压越高,THz波的信号强度越强;另外,通过在传输线上方垂直放置铜箔的方法验证了THz波沿着传输线传播的事实。该研究中采用的基于LT-GaAs外延片的片上系统的制备方法简单,制作周期短,制作过程安全,应用领域广泛,这为将来与微流控芯片相结合实现对液体样品的探测打下了基础。展开更多
At present, many chaos-based image encryption algorithms have proved to be unsafe, few encryption schemes permute the plain images as three-dimensional（3D） bit matrices, and thus bits cannot move to any position, th...At present, many chaos-based image encryption algorithms have proved to be unsafe, few encryption schemes permute the plain images as three-dimensional（3D） bit matrices, and thus bits cannot move to any position, the movement range of bits are limited, and based on them, in this paper we present a novel image encryption algorithm based on 3D Brownian motion and chaotic systems. The architecture of confusion and diffusion is adopted. Firstly, the plain image is converted into a 3D bit matrix and split into sub blocks. Secondly, block confusion based on 3D Brownian motion（BCB3DBM）is proposed to permute the position of the bits within the sub blocks, and the direction of particle movement is generated by logistic-tent system（LTS）. Furthermore, block confusion based on position sequence group（BCBPSG） is introduced, a four-order memristive chaotic system is utilized to give random chaotic sequences, and the chaotic sequences are sorted and a position sequence group is chosen based on the plain image, then the sub blocks are confused. The proposed confusion strategy can change the positions of the bits and modify their weights, and effectively improve the statistical performance of the algorithm. Finally, a pixel level confusion is employed to enhance the encryption effect. The initial values and parameters of chaotic systems are produced by the SHA 256 hash function of the plain image. Simulation results and security analyses illustrate that our algorithm has excellent encryption performance in terms of security and speed.展开更多
Systemic lupus erythematosus（SLE） is a typical autoimmune disease. Lymphotoxin β receptor（LTβR） signaling plays an important role in autoimmune inflammations. LTβR-Ig fusion protein, LTβR blocking agent, has b...Systemic lupus erythematosus（SLE） is a typical autoimmune disease. Lymphotoxin β receptor（LTβR） signaling plays an important role in autoimmune inflammations. LTβR-Ig fusion protein, LTβR blocking agent, has been used to treat SLE, while its mechanism remains to be fully elucidated. In this study, to investigate the expression of LTβR in the T cells of SLE patients and its roles in the pathogenesis of SLE, we isolated the peripheral blood T cells of SLE patients and normal controls to detect expression of LTβR by flow cytometry and RNA assay. T cells were also stimulated with LIGHT, a ligand of LTβR, and then detected for their LTβR expressions and apoptosis by flow cytometry. Also, their expressions of inflammatory factors and receptors were determined by RNA assay. The results showed that LTβR positive cells were 22.75%±6.98% in CD3~＋ cells of SLE patients, while there were almost no LTβR positive cells in CD3~＋ cells of normal persons. Moreover, LTβR expression was remarkably higher in CD3,CD4 and CD8 positive T cells of active SLE patients than non/low active patients（all P〈0.05）, and positively correlated with increased Ig level, decreased complement level and renal damage. Moreover, the stimulation of SLE T cells with LIGHT promoted higher expression of LTβR, IL-23 R and IL-17 A, and apoptosis of T cells. In conclusion,we demonstrated a high expression of LTβR in the T cells of SLE patients which may be associated with pathogenesis of SLE.展开更多
A number of experiments regarding hydrodynamics have been carried out in the open turbine rotating disc contactor using quartz particles as solid phase, tap water and kerosene as liquid phase. Flooding phenomenon has ...A number of experiments regarding hydrodynamics have been carried out in the open turbine rotating disc contactor using quartz particles as solid phase, tap water and kerosene as liquid phase. Flooding phenomenon has been observed. The variables studied include the rotor speed, compartment height, stator ring opening, column diameter and the superficial velocity of each phase. Correlations for predicting the solid phase holdup and characteristic velocity have been developed. In comparison with liquid-liquid system, the presence of solid particles will result in higher dispersed phase holdup but lower characteristic velocity and total throughput.展开更多
随着嵌入式计算机系统应用的不断扩展,嵌入式系统的可靠性引起了学术界和工业界的广泛关注,也提出了很多增进可靠性的方法和技术.然而,现有的方法和技术在测试套生成方面论述不多,所以在处理大批量嵌入式系统测试工作中遇到了挑战.讨论...随着嵌入式计算机系统应用的不断扩展,嵌入式系统的可靠性引起了学术界和工业界的广泛关注,也提出了很多增进可靠性的方法和技术.然而,现有的方法和技术在测试套生成方面论述不多,所以在处理大批量嵌入式系统测试工作中遇到了挑战.讨论抽象测试套生成方法和适配技术,提出了LTS(labeled transition system)到BT(behavior tree)的转换算法,从而使TTCN(test and testing control notation)测试套可以通过转换嵌入式软件的LTS描述产生.还介绍了基于上述转换算法的嵌入式软件测试工具包,以及一个嵌入式物联网识读器测试案例研究.展开更多
文摘太赫兹(THz)波在物质检测方面发挥着巨大的作用,是一种非常有潜力的生化传感工具。但是传统的太赫兹时域光谱系统(TDS)结构复杂,系统的集成度低,占用空间较大。所以,如何对THz波进行有效引导、实现集成化传输并得到高质量光谱就成为太赫兹光谱系统的研究热点。太赫兹片上系统是将THz的产生、传输以及探测都集成到同一芯片上,然后通过相干探测的方法获得THz时域光谱。它可以实现对多种样品的检测,尤其在对难于取样的微量样品探测方面具有广泛的应用价值。它无需光路准直,操作简便,成品率高。两个研究工作都是基于低温砷化镓(LT-GaAs)外延片开展的。首先将一根直径为200μm的铜线固定在LT-GaAs外延片的上方,通过真空蒸镀的方法制备出天线电极,同时得到天线间隙,研制出基于LT-GaAs外延片的THz天线。利用波长为800 nm的飞秒激光对其进行测试,得到了质量较高的THz信号,验证了天线的实用性。然后在另一外延片上利用光刻微加工工艺制作出传输线和微电极,得到了集成的THz片上系统。使用波长为1550 n m的飞秒激光分别激发片上系统的太赫兹产生天线和探测天线,天线产生的太赫兹波在传输线上传播,在探测端同样得到了质量较高的THz时域信号,证实了THz片上系统的可行性。该方法省去了腐蚀牺牲层以及LT-GaAs薄膜的转移、键合等步骤,极大地提高了片上系统的成品率,避免了薄膜转移过程中易破碎及腐蚀液存在毒性的问题。最后,研究了外加电压对从片上系统中获得的THz波性能的影响,结果为电压越高,THz波的信号强度越强;另外,通过在传输线上方垂直放置铜箔的方法验证了THz波沿着传输线传播的事实。该研究中采用的基于LT-GaAs外延片的片上系统的制备方法简单,制作周期短,制作过程安全,应用领域广泛,这为将来与微流控芯片相结合实现对液体样品的探测打下了基础。
基金Project supported by the National Natural Science Foundation of China(Grant Nos.41571417 and 61305042)the National Science Foundation of the United States(Grant Nos.CNS-1253424 and ECCS-1202225)+4 种基金the Science and Technology Foundation of Henan Province,China(Grant No.152102210048)the Foundation and Frontier Project of Henan Province,China(Grant No.162300410196)China Postdoctoral Science Foundation(Grant No.2016M602235)the Natural Science Foundation of Educational Committee of Henan Province,China(Grant No.14A413015)the Research Foundation of Henan University,China(Grant No.xxjc20140006)
文摘At present, many chaos-based image encryption algorithms have proved to be unsafe, few encryption schemes permute the plain images as three-dimensional（3D） bit matrices, and thus bits cannot move to any position, the movement range of bits are limited, and based on them, in this paper we present a novel image encryption algorithm based on 3D Brownian motion and chaotic systems. The architecture of confusion and diffusion is adopted. Firstly, the plain image is converted into a 3D bit matrix and split into sub blocks. Secondly, block confusion based on 3D Brownian motion（BCB3DBM）is proposed to permute the position of the bits within the sub blocks, and the direction of particle movement is generated by logistic-tent system（LTS）. Furthermore, block confusion based on position sequence group（BCBPSG） is introduced, a four-order memristive chaotic system is utilized to give random chaotic sequences, and the chaotic sequences are sorted and a position sequence group is chosen based on the plain image, then the sub blocks are confused. The proposed confusion strategy can change the positions of the bits and modify their weights, and effectively improve the statistical performance of the algorithm. Finally, a pixel level confusion is employed to enhance the encryption effect. The initial values and parameters of chaotic systems are produced by the SHA 256 hash function of the plain image. Simulation results and security analyses illustrate that our algorithm has excellent encryption performance in terms of security and speed.
文摘Systemic lupus erythematosus（SLE） is a typical autoimmune disease. Lymphotoxin β receptor（LTβR） signaling plays an important role in autoimmune inflammations. LTβR-Ig fusion protein, LTβR blocking agent, has been used to treat SLE, while its mechanism remains to be fully elucidated. In this study, to investigate the expression of LTβR in the T cells of SLE patients and its roles in the pathogenesis of SLE, we isolated the peripheral blood T cells of SLE patients and normal controls to detect expression of LTβR by flow cytometry and RNA assay. T cells were also stimulated with LIGHT, a ligand of LTβR, and then detected for their LTβR expressions and apoptosis by flow cytometry. Also, their expressions of inflammatory factors and receptors were determined by RNA assay. The results showed that LTβR positive cells were 22.75%±6.98% in CD3~＋ cells of SLE patients, while there were almost no LTβR positive cells in CD3~＋ cells of normal persons. Moreover, LTβR expression was remarkably higher in CD3,CD4 and CD8 positive T cells of active SLE patients than non/low active patients（all P〈0.05）, and positively correlated with increased Ig level, decreased complement level and renal damage. Moreover, the stimulation of SLE T cells with LIGHT promoted higher expression of LTβR, IL-23 R and IL-17 A, and apoptosis of T cells. In conclusion,we demonstrated a high expression of LTβR in the T cells of SLE patients which may be associated with pathogenesis of SLE.
文摘A number of experiments regarding hydrodynamics have been carried out in the open turbine rotating disc contactor using quartz particles as solid phase, tap water and kerosene as liquid phase. Flooding phenomenon has been observed. The variables studied include the rotor speed, compartment height, stator ring opening, column diameter and the superficial velocity of each phase. Correlations for predicting the solid phase holdup and characteristic velocity have been developed. In comparison with liquid-liquid system, the presence of solid particles will result in higher dispersed phase holdup but lower characteristic velocity and total throughput.
文摘随着嵌入式计算机系统应用的不断扩展,嵌入式系统的可靠性引起了学术界和工业界的广泛关注,也提出了很多增进可靠性的方法和技术.然而,现有的方法和技术在测试套生成方面论述不多,所以在处理大批量嵌入式系统测试工作中遇到了挑战.讨论抽象测试套生成方法和适配技术,提出了LTS(labeled transition system)到BT(behavior tree)的转换算法,从而使TTCN(test and testing control notation)测试套可以通过转换嵌入式软件的LTS描述产生.还介绍了基于上述转换算法的嵌入式软件测试工具包,以及一个嵌入式物联网识读器测试案例研究.
