葡萄糖修饰的水溶性荧光锌离子化学传感器

设计合成了一个氨基葡萄糖修饰的水溶性锌离子荧光增强型化学传感器,并借助核磁共振谱和质谱对其结构进行了表征,利用荧光光谱法研究了该传感器对不同金属离子的荧光响应。结果显示,在4-羟乙基哌嗪乙磺酸(HEPES)缓冲溶液中,该传感器能与Zn2+配位且在发射波长490 nm处荧光显著增强,除Cu2+、Ni2+、Co2+和Cr3+对此配合物荧光强度有不同程度猝灭外,其他金属离子的加入均没有引起其明显变化,说明传感器对Zn2+有较好的选择性;同时,Job曲线表明二者形成了结合比为2∶1的稳定配合物。     

乌石北江大桥主塔测量控制技术

结合乌石北江大桥工程实例,对大桥主塔测量控制技术进行了研究,介绍了塔柱各节段位置复核方法与索道管的精密定位方式,分析了锚管平面定位及高程定位的精度,保证了大桥的施工质量。     

气体辅助注射成型数值模拟技术研究概述与展望

在介绍气体辅助注射成型数值模拟技术及其重要性的基础上,对气体辅助注射成型数值模拟技术的国内外研究现状进行了概述,并且对气体辅助注射成型数值模拟技术研究发展方向进行了展望。     

INFLUENCES OF TRACE ADDITIONS OF STRONTIUM AND PHOSPHORUS ON ELECTRICAL RESISTIVITY AND VISCOSITY OF LIQUID Al-Si ALLOYS

ＩＮＦＬＵＥＮＣＥＳＯＦＴＲＡＣＥＡＤＤＩＴＩＯＮＳＯＦＳＴＲＯＮＴＩＵＭＡＮＤＰＨＯＳＰＨＯＲＵＳＯＮＥＬＥＣＴＲＩＣＡＬＲＥＳＩＳＴＩＶＩＴＹＡＮＤＶＩＳＣＯＳＩＴＹＯＦＬＩＱＵＩＤＡｌＳｉＡＬＬＯＹＳ①ＧｕｉＭａｎｃｈａｎｇ，ＪｉａＪｕｎ，...     

Preparation technique of SiCp reinforced Al matrix composite

The advancement of modern technology in the areas of aerospace and automotive industries has generated demand for new engineering materials, leading to a rapid development of metal matrix composites (MMCs) [1]. These composites can be tailored to have outstanding mechanical and physical properties such as high specific strength and stiffness, increased wear resistance, enhanced high-temperature performance and better thermal, mechanical fatigue and creep resistance than those of monolithic mat…     

EFFECT OF Ti-ADDITION ON MECHANICAL ALLOYING OF NiAl

Mechanical alloying(MA)of Ni_(50)Ai_(45)Ti_5(atomic per cent)is studied by.situ thermalanalyses,XRD.and metallography.The results showed that the alloying process ofNi_(50)Al_(45)Ti_5 is similar to that of Ni_(500Al_(50).The addition of 5 at.%Ti prolongs the millingtime of alloy prior to the explosive reaction in the alloy.The final product.is nanocrystallineβ-phase NiAl(Ti)(B2 structure ).The addition of 5 at.% Ti shows little effect on the lattice parameter of β-phase.     

Sound absorption property of open-pore aluminum foams

This paper presents a study on sound absorption property of aluminum foam by evaluating its sound absorption coefficients using standing wave tube method. Experimental results showed that the average values of sound absorption coefficients (over the test frequency range) are all above 0.4, which indicate very good sound absorption property of the aluminum foams. The sound absorption coefficient is affected by frequency and pore structure, and reaches its maximum value at around 1 000 Hz. With the increase of porosity and decrease of cell diameter, the sound absorption coefficient values increase.     

Numerical simulation for mold-filling of thin-walled aluminum alloy castings in traveling magnetic field

1 .IntrOdUction High一strength,light一weight and large一size alumimimalloy eastings are widely used in aviation,astronavigation,gUided missile and 50 on.With the develoPment of neweasting teehnology,it 15 imPortant     

INFLUENCE OF STRESS STATE IN EARING PREDICTION (Ⅱ) CRYSTALLOGRAPHIC ANALYSIS OF BCC METALS

ＩＮＦＬＵＥＮＣＥＯＦＳＴＲＥＳＳＳＴＡＴＥＩＮＥＡＲＩＮＧＰＲＥＤＩＣＴＩＯＮ（Ⅱ）ＣＲＹＳＴＡＬＬＯＧＲＡＰＨＩＣＡＮＡＬＹＳＩＳＯＦＢＣＣＭＥＴＡＬＳ①ＬｉＳａｉｙｉ，ＺｈａｎｇＸｉｎｍｉｎｇ，ＬｉＬｕｏｘｉｎｇＤｅｐａｒｔｍｅｎｔｏｆＭａｔ...     

Low-temperature superplasticity of ZK40 magnesium alloy processed using equal channel angular pressing

Microstructure evolution and superplastic behaviors of ZK40 magnesium alloy were investigated in the temperature range of 473～623 K. Transmission electron microscopy (TEM) was used to study the microstructure changes, twinning occurred significantly after being processed by equal channel angular pressing (ECAP) for one pass through the die, the mean grain size was 5.6μm. Finer grains can be obtained after further processing through ECAP, the average grain size of the alloy processed by ECAP for three passes was as low as 0.8 μ_m; this alloy exhibited low temperature superplasticity at 473～523 K, elongations obtained at the same initial strain rate of 1×10~(-3) s~(-1) were 260％ at 473 K and 612％ at 523 K, respectively. Corresponding values for the ZK40 alloy processed by ECAP for only one pass were 124％ at 473 K and 212％ at 523 K, respectively; poor superplastic behavior of this material was related to the long-range stresses associated with the non-equilibrium grain boundaries within the coarse grains. The incompatibility between fine and coarse grains was thought to be unfavorable to the improvement of superplasticity.