EFFECT OF COLD ROLLING ON THE KINETICS OF δ PHASE PRECIPITATION IN INCONEL 718

采用Ｘ射线衍射测定了冷轧Ｉｎｃｏｎｅｌ７１８合金在不同加热条件下的δ相含量,了冷轧变形对δ相析出动力学影响。结果表明,δ相析出的质量民时间的关系符合Ａｖｒａｍｉ方程,在加热温度为９６０℃时,冷轧变形量对时间指数和δ相析出速率的影响不大;低于９１０℃,随冷轧变形量的增加和加热温度的提高,ｎ值减小而α值增加,δ相的析出速率与加热温度的关系符合Ａｒｒｈｅｎｉｕｓ方程,随冷轧变形量增加,δ相析出激活能降低     

基于数值模拟的20A钢棒材热连轧晶粒尺寸的预测

通过Deform-3D有限元分析软件及正交实验,模拟并优化了20A钢棒材热连轧过程的工艺参数,并对该热轧工艺条件下的20A钢棒材的晶粒组织的有限元数值模拟以及物理实验验证进行探索。对比数值模拟值与物理实验值,研究结果表明:在最佳工艺参数条件下,数值模拟的20A钢棒材平均晶粒尺寸为45.8 mm,而物理实验中的平均晶粒尺寸为47.56 mm,二者数值均满足技术要求,且误差仅为3.7%,通过有限元模拟能够成功地预测热轧变形过程晶粒尺寸大小。     

家用微波炉磁控管用碳化La2O3-Mo阴极

研究了家用微波炉磁控管碳化La2 O3 Mo阴极 ,参照碳化ThO2 W阴极磁控管的制作工艺 ,成功实现了La2 O3 Mo阴极的碳化以及碳化La2 O3 Mo阴极磁控管的去气、激活。碳化La2 O3 Mo阴极的微波能量输出功率为 5 0 0W ,而同类型的碳化ThO2 W阴极磁控管的额定微波能量输出为 90 0W。通过分析认为 ,碳化La2 O3 Mo阴极磁控管微波输出能量不足的主要原因在于碳化La2 O3 Mo阴极材料本身的电子发射能力不足。     

稀土氧化物对中高碳钢堆焊金属中夹杂物的变质作用

采用电镜和金相等手段，对加稀土氧化物和不加稀土氧化物的堆焊金属中的夹杂物进行了研究，结果表明，稀土氧化物能细化堆焊金属中的夹杂物，减少了尺寸大的夹杂物数量，使其尺寸分布在8μm以下，同时，稀土氧化物能够改善夹杂物的形状，减少了形状系数大的长条状夹杂物数量，使形状系数接近为1的夹杂物较多。稀土氧化物还能变质堆焊金属中夹杂物的属性，可以形成铝、硅、镧的氧化物夹杂和铝、硅、镧的硫氧化物夹杂，并且减少了有害的硫化锰和铝、锰、钛复合夹杂物在堆焊金属中的存在。     

基于二维位移传感器的砂轮表面形貌测量

砂轮表面的三维形貌对保证其磨削质量有重要意义。采用高精度二维位移传感器在线测量砂轮的表面形貌,再通过建立的砂轮三维形貌基准平面和数字滤波方法,用测量数据计算得到砂轮表面的三维形貌评价参数。结果表明:该评价参数与Zeta自动三维测量系统的测量结果基本相同,验证了该评价方法的有效性和实用性,可为砂轮修整及其磨削加工提供参考指标。      

天津地区灰霾特征初步研究

利用2001～2004年天津市有代表性站点的气象观测资料及市区主要污染物排放资料和温风探空资料来分析天津地区灰霾特征,得出天津地区灰霾总体状况.天津市灰霾受地理环境影响较大,年灰霾日数呈现市区》山区》海滨;灰霾日数年分布市区峰值出现在8月,蓟县(山区)和塘沽(海滨)分别出现在7月和10月,三站谷值都出现在春季,市区出现在4月,蓟县(山区)和塘沽(海滨)集中在3月;天津市灰霾日污染普遍重于非灰霾日,灰霾日污染物监测浓度高于或接近污染物监测浓度月均值;灰霾日边界层明显特征是存在较强近地逆温层.     

大气颗粒物对城市污染的危害与预防

本文主要讲述了大气颗粒物对人体健康、大气能见度、温度、降水等的影响和对它的防御措施。     

Production and isolation of chitosan from Aspergillus terreus and application in tin(II) adsorption

Fed‐batch fermentation was used for biomass and fungal chitosan production by Aspergillus terreus (BCRC 32068) grown in a potato dextrose agar medium. The polysaccharides were extracted by an alkali–acid treatment, and structural investigations by X‐ray diffraction, Fourier transform infrared analysis, and viscosity and thermal analysis were done. A high level of chitosan was extracted from A. terreus; this implied that it was feasible to produce chitosan from industrial waste mycelia. Fungal chitosan derived from A. terreus showed the highest adsorption capacity for Sn(II). The order of Sn(II) adsorption capacity for these chitosanaceous materials was Fungal chitosan > Chitin > Biomass. Fungal chitosan derived from A. terreus was well correlated with Langmuir's isotherm model. The maximum capacity for Sn(II) sorption deduced from the use of the Langmuir isotherm equation was 303 mg/g; this was significantly higher than that of A. terreus. Fungal chitosan is an easy and cost‐effective material for the abatement of pollution. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40436.     

菜心中残留毒死蜱的去除方法研究

针对我国当前蔬菜生产中由于农药的不合理使用而导致的农药残留超标的问题,开展了在对蔬菜农药的残留去除方法的研究。设计了以菜心为材料,以有机磷农药毒死蜱为研究对象,在不同时间、不同温度、不同清洗剂(清水、淘米水、洗洁精、加热、Na2CO3溶液以及Na Cl溶液等)以及不同的浓度下对菜心中毒死蜱残留去除效果的研究探讨。实验结果表明,对菜心中残留毒死蜱的去除效果是:淘米水Na2CO3洗洁精NaCl清水。     

CdS quantum dot-sensitized solar cells based on nano-branched TiO2 arrays

Nano-branched rutile TiO₂ nanorod arrays were grown on F:SnO₂ conductive glass (FTO) by a facile, two-step wet chemical synthesis process at low temperature. The length of the nanobranches was tailored by controlling the growth time, after which CdS quantum dots were deposited on the nano-branched TiO₂ arrays using the successive ionic layer adsorption and reaction method to make a photoanode for quantum dot-sensitized solar cells (QDSCs). The photovoltaic properties of the CdS-sensitized nano-branched TiO₂ solar cells were studied systematically. A short-circuit current intensity of approximately 7 mA/cm² and a light-to-electricity conversion efficiency of 0.95% were recorded for cells based on optimized nano-branched TiO₂ arrays, indicating an increase of 138% compared to those based on unbranched TiO₂ nanorod arrays. The improved performance is attributed to a markedly enlarged surface area provided by the nanobranches and better electron conductivity in the one-dimensional, well-aligned TiO₂ nanorod trunks.