网上黑客工具——木马探讨（续一）

5木马的危害 木马的危害主要表现在远程控制方面。木马连接建立后，控制端端口和木马端口之间将会出现一条通道。     

最小均方误差检测器对扩频系统中窄带干扰的抑制性能分析

本文首先说明当码元间隔内的码片数目与扩频序列周期相等时,直接序列扩频(DSSS)系统中最小均方误差(MMSE)意义下的最优滤波器也是最小误码率意义下的最优滤波器,因而能很好地抑制大多数干扰样式。本文具体分析了最小均方误差检测器对音频干扰以及自回归干扰的抑制性能,给出了详细的推导过程以及结论。     

PCB上串扰的耦合机理和优化分析模型

本文从频域与时域两个方面分析了PCB上的串扰的耦合机理,探究了耦合电容以及近端和远端电阻的影响。针对2-π串扰电路模型所提出的时域上的数学优化模型,明确了信号上升沿对干扰输出的影响。并且利用Hyperlynx软件包进行仿真,比较了耦合电容、耦合长度等的作用结果,仿真结果证明了理论分析的正确性。     

Optimization of transient feeding to parallel-plate transmission lines from coaxial line

The transient feeding to parallel-plate transmission lines from coaxial line is optimized by using the Finite-Difference Time-Domain (FDTD) method and a simple FDTD feed model. Observing the reflected voltages, this letter presents the optimal feeding position and ratio of width to height for a given input impedance of the coaxial line.     

恶性骨肿瘤血清的吸收光谱研究

运用分光光度计对正常与恶性骨肿瘤患者的血清进行光谱检测,把这些光谱数据进行 统计与分析,发现两者的差异,为医生快速确诊恶性骨肿瘤又提供了一种新的途径。     

双机拖动系统的鲁棒调节器的设计

在线性系统设计中,需要设计一种调节器使系统具有闭环系统稳定且达到无差调节的性质,在系统参数发生微小扰动时,仍然要求保持这两种性质。设计具有这种性质的调节器的问题,称为鲁棒调节器问题。本文以双机拖动调速系统为例,说明鲁棒调节器的结构及设计方法,这种方法在鲁棒调节器设计中起着重要作用。     

用阳极溶出伏安法测定啤酒中铜与铅的含量

本文主要介绍了阳极溶出伏安法在啤酒成分中痕量铜铅离子的分析方法,用玻碳电极为工作电极,以醋酸—醋酸钠缓冲液为底液,对铜铅离子进行了本方法的条件试验,选择了理想的电解电位、电积时间、扫描速率等条件。酒样用标准加入法,所测铜铅的实验数据有较好的重现性,铜铅测定范围可达10—360 ppb,回收率在90—110%之内,变异系数<±10%。     

Transition Metal Oxide Work Functions: The Influence of Cation Oxidation State and Oxygen Vacancies

Transition metal oxides are capable of a wide range of work functions. This quality allows them to be used in many applications that involve charge transfer with adsorbed molecules, for example as heterogeneous catalysts, as charge‐injection layers in organic electronics, and as electrodes in fuel cells. Chemical and structural factors can alter transition‐metal oxide work functions, often making their work functions difficult to control. Little is known about the effects of the cation oxidation state and point defects on the oxide work function. It is necessary to understand how such chemical and structural factors affect work functions in order to controllably tune transition metal oxides for desired applications. Here, a correlation between the oxide work function and cation oxidation state is demonstrated. This correlation is attributed to the change in cation electronegativity with oxidation state. A model is presented that relates the work function to the oxygen deficiency for d⁰ oxides in the limit of dilute oxygen vacancies. It is proposed that the rapid initial decrease in work function, observed for d⁰ oxides, is caused by an increase in the density of donor‐like defect states. It is also shown that oxides tend to have decreased work functions near a metal/metal‐oxide interface as a consequence of the relationship between defects and work function. These insights provide guidelines for tuning transition metal oxide work functions.     

Metallic Zinc Anode Working at 50 and 50 mAh cm−2 with High Depth of Discharge via Electrical Double Layer Reconstruction

Achieving high-rate and high-areal-capacity Zn anode with high depth of discharge (DOD) offers a bright future for large-scale aqueous batteries. However, Zn deposition suffers from severe dendrite growth and side reactions, which compromises achievable lifetime. Herein, an electrical double layer (EDL) reconstruction strategy is proposed by employing acetone as electrolyte additive to fully address these issues. Experimental and theoretical simulation results reveal that the adsorption priority of acetone to water on Zn creates a water-poor inner Helmholtz layer. Meanwhile, the intense hydrogen bonding effect between acetone and water confines the activity of free water and weakens the Zn²⁺ solvation in the outer Helmholtz layer and diffusion layer. Such ion/molecule rearrangement in EDL suppresses hydrogen evolution, facilitates the desolvation process, and promotes the Zn²⁺ diffusion kinetics, which guides homogeneous Zn nucleation and uniform growth, even in extreme situations. At both ultrahigh current density of 50 mA cm⁻² and areal capacity of 50 mAh cm⁻², the addition of 20 v/v% acetone in 2 m ZnSO₄ extends the lifespan of Zn//Zn symmetric cells from 12 to 800 h, with a high DOD of 73.5%. The effectiveness of this strategy is further demonstrated in the Zn-MnO₂ full batteries at wide temperature range from −30 to 40 °C.     

Ultraefficient Non-Doped Deep Blue Fluorescent OLED: Achieving a High EQE of 10.17% at 1000 cd m−2 with CIEy<0.08

The pursuit for efficient deep blue material is an ever-increasing issue in organic optoelectronics field. It is a long-standing challenge to achieve high external quantum efficiency (EQE) exceed 10% at brightness of 1000 cd m⁻² with a Commission International de L'Eclairage (CIE_y) <0.08 in non-doped organic light-emitting diodes (OLEDs). Herein, this study reports a deep blue luminogen, PPITPh, by bonding phenanthro[9,10-d]imidazole moiety with m-terphenyl group via benzene bridge. The non-doped OLED based on PPITPh exhibits an exceptionally high EQE of 11.83% with a CIE coordinate of (0.15, 0.07). The EQE still maintains 10.17% at the brightness of 1000 cd m⁻², and even at a brightness as high as 10000 cd m⁻², an EQE of 7.5% is still remained, representing the record-high result among non-doped deep-blue OLEDs at 1000 cd m⁻². The unprecedented device performance is attributed to the reversed intersystem crossing process through hot exciton mechanism. Besides, the maximum EQE of orange phosphorescent OLED with PPITPh as host is 32.02%, and remains 31.17% at the brightness of 1000 cd m⁻². Such minimal efficiency roll-off demonstrates that PPITPh is also an excellent phosphorescent host material. The result offers a new design strategy for the enrichment of high-efficiency deep blue luminogen.