一种有效的振动信号分离算法

振动信号包含随机成分与周期成分 ,其中的随机成分占据了很宽的频域 ,其能量极易引起其它设备特别是电子设备的共振 ,从而导致设备失效。为评估随机成分对设备的影响 ,需要将周期成分从振动信号中去除。为此 ,首先使用ARMA建模法对振动信号中周期成分出现的频率位置进行估计 ,然后设计阻带带宽极窄 (小于 0 .5Hz)的V型滤波器来完成相应的滤波。实验表明本文中的方法能有效地去除振动信号中的周期成分 ,而完整地保留随机成分     

羰基铁类随机混合吸波材料等效电磁参数的计算

本文为计及多重散射偶极子间的相互作用，引入参量εｈ和μｈ，导得一组公式。它不仅能计算铁氧体类也能计算羰基铁类的随机混合吸波材料的等效电磁参数，均与实验结果吻合良好。     

全20CrMnTi表面激光重熔的组织与性能研究

本文对激光重熔20CrMnTi材料表明改性层显微组织分布特征、表面硬度分布规律以及残余应力状态作了研究,结果表明,表面改性层由熔融层、相变硬化层及过渡层组成,且材料表面显微硬度得到大幅度提高,表面硬度达到HV841,约提高4倍。硬化层深度约1mm。残余应力测试得出最大残余应力出现在熔凝带中心,表现为压应力。随着离中心距离的增大,残余应力逐步降低,到熔化带边缘,表现为低幅值压应力;而熔池的外边缘应力在热影响区则转变为拉应力状态。     

Predicting posttraumatic growth in breast cancer survivors.

Wide variability exists with respect to how breast cancer survivors respond to common psychological and psychosocial challenges of their disease, ranging from posttraumatic stress disorder to posttraumatic growth. This cross-sectional study examined contextual, disease-related, and intraindividual predictors of posttraumatic growth in 224 randomly selected breast cancer survivors. A series of hierarchical regression analyses found that age at diagnosis, marital status, employment, education, perceived intensity of disease, and active coping accounted for 34%, 35%, and 28% of the variance in growth in relationships with others, new possibilities, and appreciation for life. These findings suggest that a more comprehensive model of growth will be helpful in understanding the various factors that play a role in breast cancer survivors' perception of psychological and psychosocial growth. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Treatment of Posttraumatic Stress Disorder in Military and Veteran Populations.

While concerns about the psychological effects of war are not new, only recently has systematic attention been paid to such problems among past and present military personnel. There is increasing recognition that mental health has serious implications for operational performance, retention, and compensation. Although little controlled research exists with this population, preliminary evidence suggests that psychological treatments for posttraumatic stress disorder may be beneficial, albeit less so than for civilian populations. This article reviews evidence for each of several psychological treatment stages: stabilization and engagement, psychoeducation, symptom management, prolonged exposure, cognitive restructuring, and relapse prevention, with particular reference to the clinical issues raised by military personnel. Possible explanations for reduced treatment effects in this population compared with civilians are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

应用地应力模拟技术研究断块区剩余油分布

应力场数值模拟不仅能够重塑出不同阶段地应力场，而且还可以定量一半定量地预测破裂的发生、裂缝的方向和密度，进一步探讨时间和空间上油气运移的规律，为油田勘探、开发提供必要的依据。本文以大庆萨北开发区北二西断层区为研究对象，通过应力场数值模拟研究了流体运移势场与剩余油分布的关系、流体运移与构造应力的关系、裂缝形成与剩余油分布的关系，确定了剩余油分布的有利区域，为油田注采系统的设计、部署和油田开发及措施调整提供了依据。     

New accurate two-noded shear-flexible curved beam elements

 There are two purposes of this work. One is to present two accurate two-noded finite elements which are derived from the potential energy principle and the Hellinger–Reissner functional principle respectively. The second is to show the successful application of the internal displacement parameters in developing a high-order related displacement-rotation interpolation field. Because the derived interpolation field is capable of accurately modeling deformation modes in extreme thin curved beams and nearly straight beams, both shear locking and membrane shocking are avoided. Several standard numerical tests display superior behaviors of the present elements. Received: 5 February 2002 / Accepted: 16 September 2002     

Neutron Stress Measurement of W‐Fiber Reinforced Cu Composite

Stress measurement methods using neutron and X‐ray diffraction were examined by comparing the surface stresses with internal stresses in the continuous tungsten‐fiber reinforced copper‐matrix composite. Surface stresses were measured by X‐ray stress measurement with the sin²ψ method. Furthermore, the sin²ψ method and the most common triaxal measurement method using Hooke's equation were employed for internal stress measurement by neutron diffraction. On the other hand, microstress distributions developed by the difference in the thermal expansion coefficients between these two phases were calculated by FEM. The weighted average strains and stresses were compared with the experimental results. The FEM results agreed with the experimental results qualitatively and confirmed the importance of the triaxial stress analysis in the neutron stress measurement.     

Stress Concentration Factors for a Circular Hole in Curved Beams Under Bending Loads

Abstract: As a contribution to the field of stress concentration studies, the case of circular hole in curved bar elements under bending is hereby studied. Trend values of stress concentration factors (SCF) are presented based on selected variables of the problem for two critical hole locations. The results will help to identify an SCF law for practical use by applying the statistical method of regression analysis. Two approximations obtained by means of computational methods are compared with those obtained by photoelastic experimental method.     

A Closer Examination of the Structured Written Disclosure Procedure.

The current study examined psychological and physical health outcomes of the written disclosure paradigm and the hypothesis that the principles of therapeutic exposure account for the beneficial effects of the paradigm. Participants were randomly assigned to either a written disclosure condition or a control condition. Reactivity to the writing sessions was examined using both subjective and physiological measures. Measures of psychological and physical health were completed before and 1 month after the sessions. Participants assigned to the disclosure condition reported fewer psychological and physical symptoms at follow-up compared with control participants, though reductions were clinically significant for only 1 outcome measure. Physiological activation to the 1st disclosure session was associated with reduced psychological symptoms at follow-up for disclosure participants. Subjective reports of emotional responding corresponded with physiological reactivity. Implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)