Soil seismic analysis for 2D oblique incident waves using exact free-field responses by frequency-based finite/infinite element method

The seismic analysis of a viscoelastic half-space under two-dimensional (2D) oblique incident waves is carried out by the finite/infinite element method (FIEM). First, the frequency-domain exact solutions for the displacements and stresses of the free field are derived in general form for arbitrary incident P and SV waves. With the present formulation, no distinction needs to be made for SV waves with over-critical incident angles that make the reflected P waves disappear, while no critical angle exists for P waves. Next, the equivalent seismic forces of the earthquake (Taft Earthquake 1952) imposed on the near-field boundary are generated by combining the solutions for unit ground accelerations with the earthquake spectrum. Based on the asymmetric finite/infinite element model, the frequency-domain motion equations for seismic analysis are presented with the key parameters selected. The results obtained in frequency and time domain are verified against those of Wolf’s, Luco and de Barros’ and for inversely computed ground motions. The parametric study indicated that distinct phase difference exists between the horizontal and vertical responses for SV waves with over-critical incident angles, but not for under-critical incident angles. Other observations were also made for the numerical results inside the text.     

Radiosensitization of Human Leukemic HL-60 Cells by ATR Kinase Inhibitor (VE-821): Phosphoproteomic Analysis

DNA damaging agents such as ionizing radiation or chemotherapy are frequently used in oncology. DNA damage response (DDR)—triggered by radiation-induced double strand breaks—is orchestrated mainly by three Phosphatidylinositol 3-kinase-related kinases (PIKKs): Ataxia teleangiectasia mutated (ATM), DNA-dependent protein kinase (DNA-PK) and ATM and Rad3-related kinase (ATR). Their activation promotes cell-cycle arrest and facilitates DNA damage repair, resulting in radioresistance. Recently developed specific ATR inhibitor, VE-821 (3-amino-6-(4-(methylsulfonyl)phenyl)-N-phenylpyrazine-2-carboxamide), has been reported to have a significant radio- and chemo-sensitizing effect delimited to cancer cells (largely p53-deficient) without affecting normal cells. In this study, we employed SILAC-based quantitative phosphoproteomics to describe the mechanism of the radiosensitizing effect of VE-821 in human promyelocytic leukemic cells HL-60 (p53-negative). Hydrophilic interaction liquid chromatography (HILIC)-prefractionation with TiO₂-enrichment and nano-liquid chromatography—tandem mass spectrometry (LC-MS/MS) analysis revealed 9834 phosphorylation sites. Proteins with differentially up-/down-regulated phosphorylation were mostly localized in the nucleus and were involved in cellular processes such as DDR, all phases of the cell cycle, and cell division. Moreover, sequence motif analysis revealed significant changes in the activities of kinases involved in these processes. Taken together, our data indicates that ATR kinase has multiple roles in response to DNA damage throughout the cell cycle and that its inhibitor VE-821 is a potent radiosensitizing agent for p53-negative HL-60 cells.     

烯丙基酚氧树脂改性双马来酰亚胺体系的优化

通过环氧树脂与二烯丙基双酚A合成了一种烯丙基酚氧树脂,用以增韧双马来酰亚胺。在单因素试验的基础上,根据Box-Benhnken的中心组合试验设计原理,选取改性树脂体系组分为影响因子,应用响应面法进行3因素3水平的18组的设计试验,改性树脂性能(弯曲强度,冲击强度,热变形温度)为响应值,对改性树脂组分配比进行优化。结果表明,改性树脂组分配比BMI、DDS、APO、DABPA、DAP为2∶1∶0.2∶0.84∶0.1(物质的量比)时,综合2性能最好,此时改性双马树脂体系的冲击强度可达到21.4 k J/m,弯曲强度为200.5 MPa,热变形温度为195.8℃。     

Application of the Electrodiffusion Method to Measure Wall Shear Stress: Integrating Theory and Practice

The electrodiffusion method has been used in fluid dynamic research for the past 50 years. It allows the measurement of wall shear stress, a crucial parameter, e.g., for the cleaning of membrane modules used in water filtration. Various authors have published articles dealing with the theory behind this technique. But no paper collects all the knowledge assembled over five decades of application. Here, comprehensive summary of the theory of steady flow, unsteady flow, and transient voltage step experiments is given. Factors influencing the accuracy of the measurements are discussed. Furthermore, a new approach to calibrate the system from voltage step experiments is introduced, and practical issues related to its application in flow measurements are discussed for an exemplary signal response to a near‐wall flow.     

Response of framed buildings to excavation-induced movements

This paper presents a study of the influence of frame action on the response of buildings to deformations induced by deep excavations in soft clay. Using the finite element method, a building was modelled as a framed structure adjacent to a multi-propped excavation, firstly as a frame with continuous footings and then as a frame with individual footings. The geometry, location, and structural elements forming the frame models were varied to investigate the response of various frames. Using a structural analysis, parameters representing the stiffness of the frames in reducing deflection ratios and horizontal strains were derived. The influence of the frame action on the building stiffness can be quantified using the results from the finite element models. This makes it possible to estimate building modification factors from the relevant design charts so that induced deflection ratios and horizontal strains, caused by adjacent excavation and tunnelling activities, can be calculated. The approach gives a more realistic estimate of the tensile strains for assessing the potential damage caused to buildings.     

The effects of etching and deposition on the performance and stress evolution of open through silicon vias

The effects of silicon etching using the Bosch process and LPCVD oxide deposition on the performance of open TSVs are analyzed through simulation. Using an in-house process simulator, a structure is generated which contains scalloped sidewalls as a result of the Bosch etch process. During the LPCVD deposition step, oxide is expected to be thinner at the trench bottom when compared to the top; however, additional localized thinning is observed around each scallop. The scalloped structure is compared to a structure where the etching step is not performed, but rather a flat trench profile is assumed. Both structures are imported into a finite element tool in order to analyze the effects of processing on device performance. The scalloped structure is shown to have an increased resistance and capacitance when compared to the flat TSV. Additionally, the scalloped TSV does not perform as well at high frequencies, where the signal loss is shown to increase. However, the scallops allow the TSV to respond better to an applied stress. This is due to the scallops’ enhanced range of motion and displacement, meaning they can compensate for the stress along the entire sidewall and not only on the TSV top, as in the flat structure.     

智能识别技术在安防系统中的应用

在现代安防系统中,身份的识别和确认是整个安防系统第一道关卡,也是最关键步骤。传统的身份识别易复制、易丢失等不安全因素,促进了更高要求的识别技术诞生。论文从安防系统的角度出发,对部分智能识别技术的基本概念及其应用进行阐述。     

Low-Power Design of Ethernet Data Transmission

For the reliability and power consumption issues of Ethernet data transmission based on the field programmable gate array （FPGA）, a low-power consumption design method is proposed, which is suitable for FPGA implementation. To reduce the dynamic power consumption of integrated circuit （IC） design, the proposed method adopts the dynamic control of the clock frequency. For most of the time, when the port is in the idle state or lower-rate state, users can reduce or even turn off the reading clock frequency and reduce the clock flip frequency in order to reduce the dynamic power consumption. When the receiving rate is high, the reading clock frequency will be improved timely to ensure that no data will lost. Simulated and verified by Modelsim, the proposed method can dynamically control the clock frequency, including the dynamic switching of high-speed and low-speed clock flip rates, or stop of the clock flip.     

Impact of Material on Crankshaft Torsional Vibrations

In this study, it shows how the main indicators of torsional vibrations of the crankshaft change when its materials change. In the study, the crankshaft of diesel engine with four cylinders in line was taken, in which the material is changing from steel to cast iron, due to the technological possibilities of production. For study of torsional vibration of crankshaft system, the construction of equivalent reduced scheme is carried. Reduced inertia moments of discs are determined for each crank of crankshaft, by receiving the impact of piston group and rod mass. Reduced rigidities of crank are determined by experimental method. The results show that the rigidity of crank for the same crankshaft varies up to 6%, while the change between crankshafts goes up 10%. At the end, frequency and vibration forms are calculated using Tole-Holxer method. From calculations, it results that the frequencies are 19% smaller, while the vibration forms varies slightly. In this case, the change of the materials leads to the first frequency in the area of engine rotations and it can worsen the level of torsional vibration, therefore, it should check the resonance areas and vibration amplitude.     

主动密封旋转防喷器胶心油压响应规律研究

确定主动密封旋转防喷器胶心的油压响应对整个装备的研制至关重要。运用有限元软件建立了胶心模型,在内胶心上、下两端全约束的情况下计算胶心的Von Mises应力分布,对胶心内置铁块的数量、形状及安放位置进行计算和设计,得到了注油压力与最大接触压力的估算式,通过样机的密封压力试验对估算式进行验证。研究结果表明,主动密封胶心完全采用橡胶材料其刚度无法满足设计要求;主动密封胶心需要内置8块铁块,铁块外弧10°,内弧13°,径向长度确定为105 mm,轴向高度为90 mm;胶心与钻杆的接触压力比施加在胶心上的油压小5 MPa。