建筑中庭空间的类型设计

通过对中庭空间这种具有庭院空间特色的建筑内部空间的探讨,归纳出中庭空间表现及运用的几种类型,并对此进行扩展,说明其在现代建筑设计方面的重要作用。     

Fouling Resistance on Chemically Etched Hydrophobic Surfaces in Nucleate Pool Boiling

Chemical etching, liquid phase deposition, and dipping techniques were utilized to fabricate highly hydrophobic micro‐ and nanoscale coating surfaces on stainless‐steel substrates. Heat transfer and fouling characteristics on these surfaces in pool boiling of deionized water and CaSO₄ solution were studied. High roughness and hydrophobicity of coated surfaces were obtained on chemically etched substrates. Compared to the polished stainless‐steel surface, the chemically etched coating surface provided a three times enhanced nucleate boiling coefficient at high heat flux. Obvious decrease of CaSO₄ fouling resistance was obtained on chemically etched surfaces due to the higher roughness and hydrophobicity before the fouling resistance reaches the asymptotic value. Slightly high asymptotic fouling resistance was observed compared with coating surfaces without chemical etching of substrates.     

Weighted Self-Adaptive Threshold Wavelets for Interpolation Point Selection Used in Interconnect MOR

超高膨胀比涡轮噪声控制技术研究

赵辛午，黄洪雁

（哈尔滨工业大学 能源科学与工程学院，哈尔滨 150001）

中文说明：

气动噪声控制是提高鱼雷隐身性能的关键技术之一。本文讨论了局部进气的超高膨胀比涡轮气动噪声产生机理。相邻喷嘴与流道之间形成的三角形非出气区域引起的尾迹、圆周局部进气设计引起的不稳定性、喷嘴和转子之间区域形成的复杂激波系是这类涡轮气动噪声产生的三种主要来源。因此，本文提出了两种气动噪声控制方法，增加转静子之间的轴向间距，喷嘴下俯、双侧修型和尾缘吹气。数值模拟结果表明：在对原涡轮气动性能影响不大的情况下，优化后涡轮的气动噪声下降10 dB以上。

关键词：超高膨胀比涡轮、气动噪声、流动特性、优化

     

Research on corrosion performance of 6061 aluminum alloy in salt spray environment

Salt spray corrosion test was carried out on 6061 aluminum alloy, and quasi-static tensile test at room temperature was carried out on the sample with universal testing machine. The effect of salt spray corrosion on the mechanical properties of 6061 aluminum alloy was studied by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and electrochemistry. The corrosion rate of 6061 aluminum alloy was quantitatively characterized by different corrosion parameters. It was found that local corrosion of 6061 aluminum alloy occurred in salt spray environment, mainly pitting corrosion and intergranular corrosion. With the increase of corrosion time, the polarization resistance of 6061 aluminum alloy decreases, and the corrosion rate significantly increases. The average corrosion rate and the maximum corrosion rate of 6061 aluminum alloy were characterized by corrosion weight loss and corrosion pit depth. And they can be transformed into each other. The mechanical properties of 6061 aluminum alloy were mainly affected by the depth of corrosion pit. With the increase of corrosion time, the tensile strength and fracture strain decreased, resulting in poor plasticity of the sample. At the same time, the change of elongation of 6061 aluminum alloy can be accurately predicted by the depth of corrosion pit.     

Highly efficient VLSI architecture for DWT with low-storage implementation

With the gradual increase in image resolution of the spacecraft camera, it is highly required to figure out the problem how to process a huge amount of image data on board at a high speed. As a solution, the CCSDS proposes a space-oriented image-coding standard. For the sake of high image-coding performance, it adopts wavelet transformation as a method of image data transformation. However, wavelet transformation contains multi-level data processing, which causes more computational time consumption and more memory utilization. In order to solve this problem, we propose a highly efficient VLSI architecture for DWT with low-storage. By revising the traditional lifting structure and employing time-multiplex data processing strategy to perform the second and third level of wavelet transformation by the same logic module, the usage of logic resource is reduced with no sacrifice on speed.Using a small amount of on-chip memory instead of off-chip memory to save certain parts of DWT coefficients and sending the coefficients in a specific sequence to entropy coder timely, the off-chip memory for storage of DWT coefficients is no longer required. The proposed VLSI architecture of DWT is already implemented on the Xilinx FPGA XC4VSX55, which can achieve a high performance, in terms of data throughput, reaching 95.91MPixels/s.     

Radiopaque polyurethanes with flexible iodine‐containing chain extender

Iodinated polyurethanes (IPUs) with radiopaque property were prepared using poly(oxytetramethylene) glycol, 4,4′‐diphenylmethane diisocyanate, and a novel chain extender. The chain extender, described as N‐(1,3‐dihydroxypropan‐2‐yl)‐2,3,5‐triiodobenzamide, was synthesized in two steps from 2‐aminopropane‐1,3‐diol and 2,3,5‐triiodobenzoic acid with a high yield. A thorough study on the chemical structure, mechanical properties, radiopacity, and physiological properties of the IPUs was conducted. It is revealed that with increasing content of chain extender, the molecular weights of IPUs decreased slightly while the tensile modulus and breaking strength of IPUs increased significantly, illustrating an excellent comprehensive performance. With iodine content high to about 16 wt %, the IPU sample is equal to the aluminum plate with the same thickness in X‐ray radiopacity, meaning that the synthesized polyurethanes are promising as radiopaque materials. The oxidative degradation and cytotoxicity tests illustrated a good performance of stability and biocompatibility for the IPUs. It confirmed that the as‐synthesized IPUs are promising for biomedicine applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42693.     

基于MIMO的可见光通信中的信道均衡

针对基于多输入多输出(MIMO)的室内可见光通信(Visible-Light Communication,VLC)系统中存在的码间串扰(ISI)问题进行了分析,并提出了适用于MIMO可见光通信系统的信道均衡方案及实现方法.仿真实验结果表明,该方法可以有效降低MIMO可见光通信系统中的码间串扰的影响.     

精细线路板面粗糙度分析及验证

线路板进一步向高密度发展,线宽线间距不断缩小,对板面粗糙度的要求也随之提升。文章主要分析了精细线路印制板板面粗糙度原理,并验证了"砂带+不织布"磨板的板面粗糙度效果。实验表明,使用1000#砂带+600#不织布磨板可获得最佳板面粗糙度,板厚≥1.0mm时,才建议使用此类磨板方法制作。     

一种降低微震定位误差的偏振分析方法

目前微地震监测技术已成为地球物理界的热门技术之一。对于微地震震源定位,主流的初至时差分析方法由于方程组局部极值、初至拾取困难以及波速恒定假设等问题,极易产生超定或欠定的误差,而且未考虑有效数据不足的情况。为此,利用所测量的检波器姿态信息,计算出参考校正角,并将垂直、径向和切向分量数据校正为标准的三分量数据,以此提取同型波来计算偏振角,所获取的偏振角数据一方面可进行定位求解,另一方面也可对三分量数据进行进一步的校正,以提高时差分析中初至拾取的准确性;综合偏振角极化分析与初至时差分析两种方法建立了最小误差优化模型,实现了更为复杂地质条件下的联合定位,降低了定位误差。最后对数值模拟实验和野外实验结果进行了统计分析,结果表明:最优化联合定位方法能够大大降低定位误差且在有效数据不足的情况下仍能保证较好的定位效果,有效数据在9组以上时的定位误差小于7 m。     

四川盆地高磨地区龙王庙组储层岩石流体概率识别技术

四川盆地高石梯—磨溪地区下寒武统龙王庙组气藏储层的岩性与流体性质地震识别难度较大,主要原因是不同岩性、不同流体性质地层的岩石物理参数往往存在着较大的重叠空间,由此增加了识别的不确定性与多解性。为破解上述难题,采用岩石流体概率识别技术进行了尝试。该方法首先依据岩石物理参数分析结果建立各种岩性、流体性质的概率分布函数,再根据联合求解来确定储层的岩性及流体性质的概率,以此开展岩性、流体性质识别。应用结果表明:较之于一般的叠前反演方法,该方法通过多弹性参数对的联合概率求解,既提高了对储层岩性、流体性质识别的精度,又为提高储层岩性、流体性质识别的可靠程度提供了量化依据,可以为油气藏勘探开发井位部署决策等提供更充足的量化参考指标和依据。