自行体目标稳定跟踪技术研究

文章研究了非等间隔采样环境下自行体稳定跟踪目标方法,包括坐标转换、航迹点迹动态关联、航迹滤波和航迹动态预测。仿真分析结果表明,在变采样间隔环境下采用该技术,自行体能够提供稳定的目标航迹信息。

平滑导引跟踪技术在某自行体武器系统中的应用

本文通过分析研究导引跟踪技术,解决目前存在的自行体目标导引时的炮塔抖动问题。在分析某自行体武器系统存在的雷达导引跟踪问题的基础上,针对该问题建立教学模型,提出相应的解决方案。最后通过外场实验数据进行了仿真及验证,实验数据表明,该技术较好的解决了自行体目标导引时的炮塔抖动问题,且易于工程实现,具有广阔的应用背景。

自行体上稳定系统设计的有关分析

车体运动给跟踪系统带来了反电枢扰动、转速扰动、电流扰动、天线指向扰动 ,本文仔细分析了这些扰动产生的原因 。

Casting effect on compressive brittleness of bulk metallic glass

An interesting phenomenon of cooling-rate induced brittleness in Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass （BMG） was reported. It was found that the as-cast BMG specimens exhibited a brittle-ductile transition when the larger specimens were machined into smaller specimens through removing the cast-softening surface layer by layer. After compression tests, the as-machined small specimens, owing to the absence of the cast-softening surface, displayed highly dense and intersecting shear bands, and extensive plastic deformation. This is in contrast to the catastrophic failure and low deformability in the as-cast large specimens. More free volume was detected in the smaller as-fractured specimens, by differential scanning calorimetry, which may be attributed to the occurrence of strain softening and increased plasticity. Compared with the relatively smooth fracture surface in the smaller specimens, the larger specimens showed more diverse features on the fracture surface due to their graded structures.

秘技BBQ

提升你的8390的铃声大小和质量1、WAV格式的铃声网络上有很多,但因为标准问题,并不是都适用于90,参考了广大玩家意见后发现,Windows PCM应该是最适合90的格式,如果你手中的 WAV 铃声在90上无法使用,请用 Windows 自带的"录音机"进行"另存为"转换.个人建议采用"PCM 11.025kHz16位立体声43KB/秒",效果不错,如果不在乎文件大小,可以继续调整,如"44.100kHz……"建议大家不要使用"8位",质量差很多,另外这里的"立体声"选项是体积大小的关键,如果采用"单声道"文件会小很多,但质量就…具体情况大家可以自行体会.2、"耳机音量"[手机侧键调整]直接影响铃声大小,想要保证90的铃声洪亮,一定要记得让你的耳机音量处于最大值。3、使用过机器自带的"WMP 播放器"时,记得要将音量调到最大[手机上键]后再关闭,否则也会对音量造成影响。经过以上工序改造过的90,铃声(尤其是 WAV 格式)应该可以比以往进步很多哦!这里也只是一些个人经验之谈,希望可以抛砖引玉吧!

ROBUST FAULT DIAGNOSIS FOR HELICOPTER FCS BASED ON LINEAR PARAMETERVARYING ADAPTIVE OBSERVER

Based on the linear parameter-varying （LPV） adaptive observer, the robust fault diagnosis for a class of LPV systems with external disturbances is studied. Since the flight control system （FCS） is nonlinear and time-varying, the LPV technique is used for FCS. And then the adaptive fault estimation algorithm based on the LPV adaptive observer is proposed to estimate the fault. To minimize the effect of disturbances on the fault estimation, the H~ robust performance index is introduced to design the LPV adaptive fault diagnosis observer and the fault estimation algorithm. The result shows that the method has good estimation performance and is robust to external disturbances. The design method is presented in terms of linear matrix inequalities （LMIs）. Finally, a helicopter LPV FCS model with the actuator fault is used to illustrate the effectiveness of the proposed method.

Influence of compression on thermal and corrosion behavior of Fe_(78)Si_9B_(13) glassy alloy

The Fe78Si9B13 glassy ribbons were compressed at room temperature with different pressures. The thermal and corrosion behaviors were investigated using various experimental techniques. The X-ray diffraction （XRD） and dilatometer （DIL） results show that the Fe78Si9B13 ribbons are in full amorphous state after pressing and the amount of free volume increases monotonically with increasing pressure. The corrosion resistance of the glassy alloys in various solutions decreases after compression at 10 MPa, but increases after compression at 20 MPa. The non-monotonic change of corrosion resistance is consistent with the result of electrical resistivity, which can be explained by the combining action of free volume that is introduced by the compression and the segregation of Si atoms in the samples.

Analysis and innovation of key technologies for autonomous underwater vehicles

As the mission needs of the autonomous underwater vehicles(AUV) have become increasingly varied and complex,the AUVs are developing in the direction of systematism, multifunction, and clustering technology, which promotes the progress of key technologies and proposes a series of technical problems. Therefore, it is necessary to make systemic analysis and in-depth study for the progress of AUV's key technologies and innovative applications. The multi-functional mission needs and its key technologies involved in complex sea conditions are pointed out through analyzing the domestic and foreign technical programs, functional characteristics and future development plans. Furthermore, the overall design of a multi-moving state AUV is proposed. Then, technical innovations of the key technologies, such as thrust vector, propeller design, kinematics and dynamics, navigation control, and ambient flow field characteristics, are made, combining with the structural characteristics and motion characteristics of the new multi-moving state AUV. The results verify the good performance of the multi-moving state AUV and provide a theoretical guidance and technical support for the design of new AUV in real complex sea conditions.

A PILOT TRIAL FOR SEVERE ,REFRACTORY SYSTEMIC AUTOIMMUNE DISEASE WITH STEM CELL TRANSPLANTATION

Objective To evaluate the feasibility, efficacy, and safety of high dose immunosuppressive therapy （HDIT） and autolognus hemopoietic stem cell transplantation （HSCT） with CD^34＋ cell selection in patients with severe, refractory autoim mune diseases. Methods Twenty-six patients with persistent systemic lupus erythematosus （SLE）, rheumatoid arthritis （RA）, primary Sjogren＇s syndrome （pSS）, or systemic sclerosis （SSc） who had been treated unsuccessfully with conventional treatment were enrolled in the trial in Peking Union Medical College Hospital from September 1999 to June 2004. The patients received HDIT with 200 mg/kg cyclophosphamide followed by an infusion of autologous stem cells that were CD34 selected. Disease acti- vity, adverse effect, hemopoietic and immune reconstitution, and time to recurrence of disease were monitored. Overall treatment related mortality was 7.7% （2/26） with 1 patient died of cytomegalovirus infection and an other of severe pneumonia. Relapse occurred in 3 SLE patients （17.6%） in 37, 26, and 19 months posttransplantation respectively, and 1 RA patient in 15 months posttransplantation. SLE Disease Activity Index （SLEDAI） scores of SLE survivors decreased significantly （P 〈 0.01）. RA patients recorded a drop of Disease Activity Score 28 （DAS 28）. The pSS patient remained symptoms free up to now, more than 50 months aider the transplantation. Conclusion HSCT can be performed relative safely in patients with severe autoimmune disease. Short-term effect of HSCT is promising. However treatment related mortality and relapse were observed in a subset of patients.

Conscious Entities in Superluminal Parallel Universe

Tachyons are theoretical superluminal particles, i.e., faster than light particles. The idea of existence of tachyons comes from Arnold Sommerfeld. Bilaniuk and Sudarshan （1969） published the article ＂Particles beyond the Light Barrier＂ in Physics Today magazine where they analyze the theoretical properties of tachyons. From the tachyon idea I have hypothesized the existence of a Superluminal Parallel Universe constituted by Superluminal Conscious Entities that, like the theoretical tachyons, only can exist at speeds greater than the speed of light. This hypothesis should be subject to scientific inquiry but also to philosophical speculation or spiritual imagination. Later I imagine that the Superluminal Parallel Universe is the Spiritual World thought by theologians and idealistic philosophers. I relate the Superluminal Conscious Entities with Spirits and the Superluminal Parallel Universe comprising infinity of Superluminal Conscious Entities with God, the Universal Spirit, thus being simultaneously Unity and Infinity given that superluminal speed implies non-local, instantaneous connections. I imagine that the material Universe might have emerged from that God, assuming that many Spirits could lose superluminality generating the two classes of substances of the Universe： the class of subluminal particles of matter and the class of luminal particles, like photons. I imagine a Soul as a quasi superluminal entity dropped from a Spirit to animate material entities. The substances of both Universes would have evolved in parallel, with life arising and evolving from the subluminal substance driven by companion Souls. Let＇s also imagine that the natural way of being of Spirits and free Souls is a state similar to conscious dreaming. In this imagination, we all, Souls, would have been a part of God and we all might be again. We all are makers of the Universe. We all might get connected with the Spirits in God to beg for and to receive inspiration.

A Potential Flow Based Flight Simulator for an Underwater Glider

Underwater gliders are recent innovative types of autonomous underwater vehicles （AUVs） used in ocean exploration and observation. They adjust their buoyancy to dive and to return to the ocean surface. During the change of altitude, they use the hydrodynamic forces developed by their wings to move forward. Their flights are controlled by changing the position of their centers of gravity and their buoyancy to adjust their trim and heel angles. For better flight control, the understanding of the hydrodynamic behavior and the flight mechanics of the underwater glider is necessary. A 6-DOF motion simulator is coupled with an unsteady potential flow model for this purpose. In some specific cases, the numerical study demonstrates that an inappropriate stabilizer dimension can cause counter-steering behavior. The simulator can be used to improve the automatic flight control. It can also be used for the hydrodynamic design optimization of the devices.

Feasibility and safety of autologous bone marrow mononuclear cell transplantation in patients with advanced chronic liver disease

AIM： To evaluate the safety and feasibility of bone marrow cell （BMC） transplantation in patients with chronic liver disease on the waiting list for liver transplantation. METHODS： Ten patients （eight males） with chronic liver disease were enrolled to receive infusion of autologous bone marrow-derived cells. Seven patients were classified as Child-Pugh B and three as Child-Pugh C. Baseline assessment included complete clinical and laboratory evaluation and abdominal MRI. Approximately 50 mL of bone marrow aspirate was prepared by centrifugation in a ficoll-hypaque gradient. At least of 100 millions of mononuclear-enriched BMCs were infused into the hepatic artery using the routine technique for arterial chemoembolization for liver tumors. Patients were followed up for adverse events up to 4 mo. RESULTS： The median age of the patients was 52 years （range 24-70 years）. All patients were discharged 48 h after BMC infusion. Two patients complained ofmild pain at the bone marrow needle puncture site. No other complications or specific side effects related to the procedure were observed. Bilirubin levels were lower at 1 （2.19 ± 0.9） and 4 mo （2.10 ± 1.0） after cell transplantation that baseline levels （238 ± 1.2）. Albumin levels 4 mo after BMC infusion （3.73 ± 0.5） were higher than baseline levels （3.47 ± 0.5）. International normalized ratio （INR） decreased from 1.48 （SD = 0.23） to 1.43 （SD = 0.23） one month after cell transplantation. CONCLUSION： BMC infusion into hepatic artery of patients with advanced chronic liver disease is safe and feasible. In addition, a decrease in mean serum bilirubin and INR levels and an increase in albumin levels are observed. Our data warrant further studies in order to evaluate the effect of BMC transplantation in patients with advanced chronic liver disease.

Study of Electronic Density of States: Zintl Alloys

In the present work the electronic density of states of liquid,viz.,Zintli alloys,have been studied only at the composition of their maximum resistivity to have an elementary idea about the behaviors of the alloys with respect to nearly free electron behavior.The study reveals that the anomalous electronic behavior of liquid Li-Pb,Na-Pb,Li-Sn,and Na-Sn can be attributed to the preferential ordering of unlike atoms.

Mechanical Design and Students＇ Creativity ＂Think outside the Box＂

A design project was used in junior level mechanical design course to challenge the students＇ creativity skills. Beside the theoretical foundation of the course subject, the students were introduced to several professional skills such as： decision making tools, technical review meetings, interaction with customers, and teamwork skills. The design challenge was to develop a bike rack to meet a list of technical and marketing constraints. Details of the project requirements are presented with a brief overview of the main project mentoring tools. Students＇ creativity is discussed through two samples of the student work. It was noticed that, the basic creativity skills of the students can be improved by using some of the training tools, however, the students vary in their response to this training.

Freedom of Speech and Newspaper Excesses

Press has been found to have an impact on the outcome of electoral political campaigns. Press can distort the electorate＇s perception of an objective reality to fulfill the political orientation of its editorial line. This can be achieved in propaganda and in the rhetoric of excess. Within the framework of Critical Discourse Analysis （CDA）, this paper has conducted a thematic content analysis to study the rhetoric of excess in the construction of political identity and relations in 100 articles pertaining to two different ideologically oriented Tunisian newspapers, namely Le Maghreb and El Dhamir. The study covered the period from December 26, 2011 to December 26, 2012. Results have shown a low level of impartiality violating Gricean maxims of quality and quantity. This tendency could culminate in violence and undermine the public＇s confidence in the media. Proactive measures of media management are recommended.

Comparing dynamical systems concepts and techniques for biomechanical analysis

Traditional biomechanical analyses of human movement are generally derived from linear mathematics.While these methods can be useful in many situations,they do not describe behaviors in human systems that are predominately nonlinear.For this reason,nonlinear analysis methods based on a dynamical systems approach have become more prevalent in recent literature.These analysis techniques have provided new insights into how systems(1) maintain pattern stability,(2) transition into new states,and(3) are governed by short-and long-term(fractal) correlational processes at different spatio-temporal scales.These different aspects of system dynamics are typically investigated using concepts related to variability,stability,complexity,and adaptability.The purpose of this paper is to compare and contrast these different concepts and demonstrate that,although related,these terms represent fundamentally different aspects of system dynamics.In particular,we argue that variability should not uniformly be equated with stability or complexity of movement.In addition,current dynamic stability measures based on nonlinear analysis methods(such as the finite maximal Lyapunov exponent) can reveal local instabilities in movement dynamics,but the degree to which these local instabilities relate to global postural and gait stability and the ability to resist external perturbations remains to be explored.Finally,systematic studies are needed to relate observed reductions in complexity with aging and disease to the adaptive capabilities of the movement system and how complexity changes as a function of different task constraints.

Numerical computation and analysis of high-speed autonomous underwater vehicle (AUV) moving in head sea based on dynamic mesh

Autonomous underwater vehicles （AUVs） navigating on the sea surface are usually required to complete the communication tasks in complex sea conditions. The movement forms and flow field characteristics of a multi-moving state AUV navigating in head sea at high speed were studied. The mathematical model on longitudinal motion of the high-speed AUV in head sea was established with considering the hydrodynamic lift based on strip theory, which was solved to get the heave and pitch of the AUV by Gaussian elimination method. Based on this, computational fluid dynamics （CFD） method was used to establish the mathematical model of the unsteady viscous flow around the AUV with considering free surface effort by using the Reynolds-averaged Navier-Stokes （RANS） equations, shear-stress transport （SST） k-w model and volume of fluid （VOF） model. The three-dimensional numerical wave in the computational field was realized through defining the unsteady inlet boundary condition. The motion forms of the AUV navigating in head sea at high speed were carried out by the program source code of user-defined function （UDF） based on dynamic mesh. The hydrodynamic parameters of the AUV such as drag, lift, pitch torque, velocity, pressure and wave profile were got, which reflect well the real ambient flow field of the AUV navigating in head sea at high speed. The computational wave profile agrees well with the experimental phenomenon of a wave-piercing surface vehicle. The force law of the AUV under the impacts of waves was analyzed qualitatively and quantitatively, which provides an effective theoretical guidance and technical support for the dynamics research and shape design of the AUV in real complex environnaent.

Novel function of perforin in negatively regulating CD4^＋ T cell activation by affecting calcium signaling

Perforin is a pore-forming protein engaged mainly in mediating target T cell death and is employed by cytotoxic T lymphocytes （CTLs） and natural killer cells. However, whether it also plays a role in conventional CD4^＋ T cell function remains unclear. Here we report that in perforin-deficient （PKO） mice, CD4^＋ T cells are hyperproliferative in response to T cell receptor （TCR） stimulation. This feature of hyperproliferation is accompanied by the enhancement both in cell division and in IL-2 secretion. It seems that the perforin deficiency does not influence T cell development in thymus spleen and lymph node. In vivo, perforin deficiency results in increased antigen-specific T cell proliferation and antibody production. Furthermore, PKO mice are more susceptible to experimental autoimmune uveitis. To address the molecular mechanism, we found that after TCR stimulation, CD4^＋ T cells from PKO mice display an increased intracellular calcium flux and subsequently enhance activation of transcription factor NFAT1. Our results indicate that perforin plays a negative role in regulating CD4^＋ T cell activation and immune response by affecting TCR-dependent Ca^2＋ signaling.

Hydrodynamics of Supercavitating Bodies at an Angle of Attacks under Conditions of Considerable Effect of Fluid Weightiness and Closeness of Free Border

We present the results of theoretical and experimental studies of flow processes of extended axisymmetric cavitators during motion near a free surface taking into account a considerable effect of fluid weightiness. The main objective of work is to study ways of reduction of fluid weightiness effect using lift at cavitator and other body （hull） elements within a cavity, in order to apply this way of drag reduction for a range of considerably lower motion speeds.