扫描电镜-聚类分析研究广州地区气溶胶颗粒特征

本文主要针对广州地区冬夏两季气溶胶样品,应用扫描电镜/X射线能谱分析技术,对单个颗粒物进行形貌观察和组份分析;对于大量单颗粒的组份采用动态聚类法处理,广州气溶胶粗颗粒中的主要污染元素是Cu,Zn,Pb和Ag,Pb和Ag的存在是广州气溶胶的一个特征。     

操作X线探伤机防射线的最佳位置

操作Ｘ线探伤机防射线的最佳位置吴昌机械制造、化工、造船、建筑等行业都离不开焊接工艺。焊缝质量好坏关系到设备和产品的优劣，以及生产过程中的安全防护。目前，大多数企业都采用放射性探伤术检验焊接质量，其中又以利用Ｘ线拍片探伤最为广泛。这就提出了如何防止探伤...     

数字音频技术在楼宇对讲系统中的应用

现行二总线制楼宇呼叫对讲系统中,多数系统均采用数字信号进行呼叫、控制,而对讲则直接采用音频模拟信号,侧音大、易产生啸叫成为该类系统的通病.把数字音频技术引入二总线制楼宇呼叫对讲系统中,可设计出高音质、低成本、简单实用的楼宇对讲系统,完全解决了侧音大、易产生啸叫的问题.     

X射线底片缺陷特征提取与分析

1 现有X射线成像的处理手段 射线成像检测有两种方式：一种是以胶片形式存贮的离线检测．例如：在锅炉压力容器检测中大量使用的X光照片。拍摄好的底片图像放在扫描仪中．通过图像扫描仪把底片图像扫描数字化成为数字图像，送入到计算机内，由计算机对数字图像进行调整、滤波、增强、压缩和识别等处理．改善图像的清晰度，通过人机对话对底片图像缺陷进行评估．     

水泥散装工艺系统收尘改造保障职工身心健康

随着福建省推广散装水泥的力度不断加强,南平水泥股份有限公司散装水泥出厂量逐年提高,加重了发放散装水泥工艺线上的负荷,尤其是该系统的收尘装置,该公司散装系统采用的是1个散装库,2个下料点的双装车结构,水泥经螺旋输送机加入散装库时,为防止库顶扬尘,在库顶设置了仓顶式袋式除尘器和2台单机袋式除尘器.     

1960-2011 年东北地区热量资源时空变化特征

基于1961-2011 年东北地区88 个气象站逐日气温资料,采用Kendall-Theil 线性趋势估计等方法探讨了该地区热量资源的时空变化特征。结果表明,近50 多年东北地区稳定≥0 ℃积温以25～95 ℃·d/10 a 的趋势显著增加,三江平原的增加趋势明显大于东部山区。稳定≥0 ℃气温的起始期在东北北部和中部显著提前,终止期在北部基本显著延后,日平均气温稳定≥0℃的日数在北部和中部地区基本以2～4 d/10 a 的趋势显著增加。东北地区大部分站点终霜冻日期明显提前,初霜冻日期明显延后,无霜冻期基本以3～5 d/10 a 的趋势显著增加。稳定≥10 ℃积温以30～110 ℃·d/10 a 的趋势显著增加,稳定≥10 ℃气温的起始期北部地区显著提前,终止期南部地区显著延后,作物有效生长期在中部和北部地区基本以2～4 d/10 a 的趋势显著增加。     

Attenuation of arsenic in a karst subterranean stream and correlation with geochemical factors: A case study at Lihu, South China

Arsenic （As） pollutants generated by human activities in karst areas flow into subterranean streams and contaminate groundwater easily because of the unique hydrogeological characteristics of karst areas. To elucidate the reaction mechanisms of arsenic in karst subterranean streams, physical-chemical analysis was conducted by an inductively coupled plasma mass spectrometer and an X-ray fluorescence spectrometer. The results show that inorganic species account for most of the total arsenic, whereas organic arsenic is not detected or occurs in infinitesimal amounts. As（III） accounts for 51.0% ± 9.9% of the total inorganic arsenic. Arsenic attenuation occurs and the attenuation rates of total As, As（III） and As（V） in the Lihu subterranean stream are 51%, 36% and 59%, respectively. To fully explain the main geochemical factors influencing arsenic attenuation, SPSS 13.0 and CANOCO 4.5 bundled with CanoDraw for Windows were used for simple statistical analysis and redundancy analysis （RDA）. Eight main factors, i.e., sediment iron （SFe）, sediment aluminum （SAI）, sediment calcium （SCa）, sediment organic matter （SOM）, sediment manganese （SMn）, water calcium （WCa^2＋）, water magnesium （WMg^2＋）, and water bicarbonate ion （WILCOX） were extracted from thirteen indicators. Their impacts on arsenic content rank as： SFe〉SCa〉WCa^2＋〉SAl〉wHCO3^-〉SMn〉SOM〉WMg^2＋. Of these factors, SFe, SAl, SCa, SOM, SMn, WMg^2＋ and WCa＆2＋ promote arsenic attenuation, whereas WHCO3^- inhibits it. Further investigation revealed that the redox potential （Eh） and pH are adverse to arsenic removal. The dramatic distinction between karst and non-karst terrain is that calcium and bicarbonate are the primary factors influencing arsenic migration in karst areas due to the high calcium concentration and alkalinity of karst water.     

Sulfur evolution in chemical looping combustion of coal with MnFe2O4 oxygen carrier

Chemical looping combustion （CLC） of coal has gained increasing attention as a novel combustion technology for its advantages in CO2 capture. Sulfur evolution from coal causes great harm from either the CLC operational or environmental perspective. In this research, a combined MnFe2O4 oxygen carrier （OC） was synthesized and its reaction with a typical Chinese high sulfur coal, Liuzhi （LZ） bituminous coal, was performed in a thermogravimetric analyzer （TGA）-Fourier transform infrared （FT-IR） spectrometer. Evolution of sulfur species during reaction of LZ coal with MnFeaO40C was systematically investigated through experimental means combined with thermodynamic simulation. TGA-FTIR analysis of the LZ reaction with MnFe2O4 indicated MnFe2O4 exhibited the desired superior reactivity compared to the single reference oxides Mn304 or Fe203, and SO2 produced was mainly related to oxidization of H2S by MnFe2O4. Experimental analysis of the LZ coal reaction with MnFe2O4, including X-ray diffraction and X-ray photoelectron spectroscopy analysis, verified that the main reduced counterparts of MnFe2O4 were Fe304 and MnO, in good agreement with the related thermodynamic simulation. The obtained MnO was beneficial to stabilize the reduced MnFe2O4 and avoid serious sintering, although the oxygen in MnO was not fully utilized. Meanwhile, most sulfur present in LZ coal was converted to solid MnS during LZ reaction with MnFe2O4, which was further oxidized to MnSO4. Finally, the formation of both MnS and such manganese silicates as Mn2SiO4 and MnSiO3 should be addressed to ensure the full regeneration of the reduced MnFe2O4.     

Photocatalytic degradation of Rhodamine B bymicrowave-assisted hydrothermal synthesized N-doped titanate nanotubes

Microwave-induced nitrogen-doped titanate nanotubes（NTNTs） were characterized by transmission electron microscopy（TEM）, X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, Fourier transform infrared spectroscopy（FT-IR）, Zeta potential analysis,specific surface area（SBET）, and UV-Visible spectroscopy. TEM results indicate that NTNTs retain a tubular structure with a crystalline multiwall and have a length of several hundred nanometers after nitrogen doping. XRD findings demonstrate that the crystalline structure of NTNTs was dominated by anatase, which is favored for photocatalytic application. The Ti-O-N linkage observed in the XPS N 1s spectrum is mainly responsible for narrowing the band gap and eventually enhancing the visible light photoactivity. FT-IR results demonstrated the existence of H3O＋, which could be excited by photo-generated holes to form hydroxyl radicals and degrade environmental pollutants. After sintering at 350°C, the UV-Vis absorbance edges of NTNTs significantly shift to the visible-light region, which indicates N atom doping into the nanotubes. Photocatalytic degradation of Rhodamine B（RhB） via NTNTs show good efficiency, with pseudo first-order kinetic model rate constants of 3.7 × 10-3, 2.4 × 10-3and 8.0 × 10-4sec-1at pH 3, 7, and 11, respectively.     

高压静电分选Ag与PET的实验研究

为了提高高压静电分选Ag与聚对苯二甲酸乙二醇酯(polyethylene terephthalate,简称PET)的效率,寻求可产生较佳分选效率的电压、转速、极间距和电晕线角度。采用自制的线辊式静电分选机,通过单因素实验和部分因子实验,研究了不同条件下Ag与PET的分选效率。结果表明:将Ag与PET从二者混合物中有效分选出来的电压为25~30k V、转速为60~75 r/min、极间距为60~70 mm、电晕极角度为50~60°;当电压为30 k V、转速为75 r/min、电晕极距离为70 mm和电晕极角度为60°时,Ag的分选效率达到了最大值为99.60%,PET的分选效率也达到了最大值为99.98%,为线辊式静电分选机结构设计与参数优化提供了参考。