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Numerical Simulation and Experimental Investigation on A Thermoacoustic Engine with Tapered Resonance Tube A symmetrical standing-wave thermoacoustic engine with tapered resonance tube has been numerically simulated with liner thermoacoustics. The simulation shows that using tapered resonance tube in thermoacoustic engine could decrease the velocity amplitude and lower the total acoustic power loss in the resonance tube. The experimental results indicate that the harmonic was suppressed effectively by using the tapered resonance tube, and the pressure ratio was improved.

采用锥形谐振管的热声发动机的数值模拟和实验研究利用线性热声理论，对一台采用锥形谐振管的驻波型热声发动机进行了数值模拟，发现采用锥形谐振管可有效降低工质气体的速度振幅，进而减小在谐振管中声功率的损失；与一台在相同频率下工作的采用等直径圆柱谐振管的驻波型热声发动机进行了实验对比，结果表明，在使用锥形管作为谐振管的热声发动机系统中，谐振管中的非线性效应得到了明显的抑制，热声发动机在基频模式下稳定运行，压比增大而加热温度降低。

Domelike decompression can increase APDC, IFD, ELD and CSAC significantly, especially for CSAC, which is an effective way for lumbar stenosis.

弯顶形椎管扩大成形术可明显扩大腰椎管的矢径、上关节突内缘间距、椎板间距和椎管截面积，尤其是椎管截面积扩大更为明显，是一种治疗腰椎管狭窄症有效的方法。

Although the SWNTs are higheractive, their price is great higher than that of MWNTs, so we try to functionalize theMWNTs with the same method.

尽管单壁碳纳米管的活性高于多壁碳纳米管，但其制备成本远高于多壁碳纳米管，因此我们也尝试了用沉淀聚合方法改性多壁碳纳米管。

CNTs were first pre-treated using acid solution (HNO3) to obtain CNTs functionalized with carboxylic groups. Subsequently, the stearyl alcohol was grafted onto CNT with the assistance of dehydrating agent, N,N'-dicyclohexyl-carbodiimide. Excellent dispersion in organic solvents such as acetone, THF, and chloroform was found for the modified CNTs (CNT-C18). In addition, the PBS/CNTs nanocomposites were then prepared through simple melt-blending. Mechanical properties, thermal behavior, conductivity of resultant polymer/CNT composites were investigated. The results show that excellent dispersion of nanotubes in the PBS matrices was achieved.

为了增加多壁奈米碳管在复合材料中的分散性，将碳管表面进行化学修饰，首先将多壁奈米碳管浸入HNO3溶液中，进行酸化，使碳管表面带有羧酸的官能基，然后再加入十八烷醇，在温和的条件下，藉由N，N'-二环己基碳二亚胺(N，N'-dicyclohexyl- carbodiimide，DCC)脱水剂脱水，使碳管和十八烷醇之间产生酯基的化学键结，改质后的碳管可以分散在acetone、THF、chloroform…等有机溶剂中，结果显示成功的利用DCC脱水剂完成碳管的改质。

objective the aim of this study is to investigate the expression and the distribution of the nerve growth factor during the period of neural tube development of human embryo.method early development of neural tube was studied in human embryos about 35 gestational days by using immunocytochemical abc technique.result there were ngf immuno-positive substances in the cytoplasm and nuclei of neuroepithelial cells in the ventricular zones of neural tube.in the intermediate zone of neural tube,ngf immunoreactivity was detected in the nuclei of some neurons,or the processes of other neurons which contained no ngf-immunoreactive substances in their nuclei;the expression pattern of ngf in the marginal zone of neural tube was similar to that of the intermediate zone.the density of ngf-immunorecative particles was higher on the rostrum side of neural tube than on the caudal side.the ngf immuno-positive cells were also observed among the somites of embryo under the neural tube.conclusion these results suggest that ngf was an important signal molecule to induce neural tube differentiation,and that ngf may play a significant role in regulation of the biological function of neurons in developing neural tube.

目的 研究捷安肽素的抗真菌作用机理。方法采用形态学方法和同位素标记法。显微形态观察经捷安肽素处理后的供试真菌的形态学变化。进一步采用14c同位素标记的特异底物&尿苷二磷酸-（14c）-葡萄糖&示踪，研究捷安肽素对真菌(1，3)-β-d-葡聚糖合成酶活性反应的影响。结果研究神经生长因子在早期人胚神经管发育过程中的定位表达。方法采用免疫细胞化学 abc法染色，研究35天人胚的发育情况。结果在人胚神经管的室管带中，神经元的细胞质和细胞核ngf免疫反应阳性；在中间带，一部分神经元的细胞核ngf免疫反应阳性，另外一部分神经元的细胞核ngf免疫反应阴性，而其突起ngf免疫反应阳性；在边缘带ngf的表达与中间带相似。在神经管的头侧ngf阳性反应较强，神经管的尾侧ngf阳性反应较弱。结论 ngf在人胚神经管免疫反应阳性，表明ngf可能是诱导神经管分化发育的重要信号分子，提示ngf可能在人胚神经管的发育中具有十分重要的作用。神经生长因子；人胚；神经管；发育

The experimental and analytical results show that the axial rigidity of the corrugated pipe is 23.0 percent of the bare pipe with the same thickness and diameter,and the thermal compensation performance of the former is 2.27 times the latter's under equal-stress condition.By using corrugated pipe bundle instead of the bare pipe bundle with the same stiffness as its tube sheet,the axial thermal compensation can be increased by 40.4 percent,and the corresponding pulling-out force is 53.2 percent of that of the bare pipe bundle.

研究结果表明，波节换热管单管的刚度为相应光管的23.4%；在最大应力相同的条件下，波节换热管的轴向热补偿量为相应光管的2.27倍；在光管管束与壳体等刚度条件下，用波节管管束代替光管管束，轴向热补偿量可提高40.4%，相应的拉脱力为光管管束的53.2%。

METHODS: 8 curved artificial root canals were prepared with stainless steel K files by the step-back technique, the root canals were digitally photographed, the images were analysed by the software Image-Pro Plus, the shapes and positions of the root canals were measured and analysed. SPSS10.0 software package was used for statistical analysis, paired-samples t test was used to compare the difference of the means among sample groups.

使用手用不锈钢K锉，按逐步后退法预备8个弯曲人工根管，根管预备过程中对根管及根尖孔进行微距摄影，用图像分析软件Image-Pro Plus对根管的形态与位置变化进行测量、分析；实验数据采用SPSS10.0统计软件包进行统计学分析，选用配对t检验比较组间差异。

The results showed that the CNTs have outer diameters of about 60 nm~90 nm and a length of 8 μm, showing straight tubular and chain structures.

结果显示：合成的碳纳米管为多壁碳管；碳纳米管直径60nm~90nm，长度约8μm；碳纳米管展现出中空管状和链状两种结构；碳纳米管的生长采取催化剂底端生长模式。

Some special features ofthe static mixer tube are demonstrated.4 An evaluation method of velocity-based disturbance effect of fluid field wasproposed. Qualitative results are obtained by using this method in fluid fielddesign and structure optimization of disturbing elements.5 Experimental models are made efficiently and accurately by RPM method.

主要内容包括： 1、总结了化工过程强化技术的现状和强化研究的途径，提出了紧凑式工业炉的概念，确定用静态混合式炉管进行局部强化。2、提出了静态混合式炉管应用的虚拟工程放大研究方法，指出研究中提高效率的关键是计算模型快速生成技术和实验模型的快速原型制造。3、对工业炉的关键部位——炉管，从材料成分、强度、制造等方面对静态混合式炉管的设计、制造进行了分析，与常规炉管对比，说明了静态混合式炉管的独特性和要求。4、应用快速原型方法，迅速、准确地得到了符合精度、强度要求的静态混合式炉管模型，产品的精度和强度完全符合要求，提高了模型制造效率。5、应用计算流体动力学方法，进行静态混合式炉管的工程放大研究。

The state-of-the-art of chemical process and equipment intensificationtechniques is reviewed. A novel concept of compact industrial furnace isproposed, in which tube with static mixer for partly intensification is determined. 2 A virtual engineering scale-up approach is put forward. The key points toimprove the scaling-up efficiency include two tools: one is rapid generationtechniques for computational models in which a re-use library is built, the otheris rapid prototyping manufacturing, employed for rapid generation forexperimental models.3 The tube is the key component for industrial furnace. Material microstructure,high temperature strength, and casting process of the tube with static mixer arediscussed as compared with those of traditional tube. Some special features ofthe static mixer tube are demonstrated.4 An evaluation method of velocity-based disturbance effect of fluid field wasproposed.

主要内容包括： 1、总结了化工过程强化技术的现状和强化研究的途径，提出了紧凑式工业炉的概念，确定用静态混合式炉管进行局部强化。2、提出了静态混合式炉管应用的虚拟工程放大研究方法，指出研究中提高效率的关键是计算模型快速生成技术和实验模型的快速原型制造。3、对工业炉的关键部位——炉管，从材料成分、强度、制造等方面对静态混合式炉管的设计、制造进行了分析，与常规炉管对比，说明了静态混合式炉管的独特性和要求。4、应用快速原型方法，迅速、准确地得到了符合精度、强度要求的静态混合式炉管模型，产品的精度和强度完全符合要求，提高了模型制造效率。5、应用计算流体动力学方法，进行静态混合式炉管的工程放大研究。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。