激光片光前向散射法测量烟雾颗粒尺寸分布

提出了一种利用激光片光CCD成像测量火灾烟雾颗粒粒径的方法，结合Mie散射理论确定了采取前向散射成像的方法测量烟雾颗粒尺寸分布，针对摄影测量过程中的成像形变，给出了结合数字摄影测量DLT技术进行数字校正的方法，并对实验方法和结果进行了分析与讨论。     

Degradation of a Terephthalate-containing Polyester by a Thermophilic Microbial Consortium

Biomax^® is an aliphatic-aromatic polyester. The biodegradability of Biomax^® was studied at 58 °C using a laboratory scale bioreactor. The bioreactor was inoculated with bacteria derived from compost and supplemented with powdered Biomax^® and an additional energy source. After a period of acclimation, the microorganisms in the bioreactor were capable of metabolizing the major components of the polymer, i.e., TPA and ethylene glycol. TPA and ethylene glycol were detected in the bioreactor only when they were added. Degradation and disintegration of the powdered Biomax^® was monitored by laser diffraction. The particle size distribution of the powdered polymer progressively shifted toward smaller sizes until the diameters of the polymer particles were indistinguishable from bacteria. The types of microbes in the bioreactor were determined by analyzing 16S rRNA gene sequences. The bacteria belonged to 35 different groups, and the majority of the bacteria appeared to represent new species.     

Mineralogy and chemistry of urinary stones: patients from North Jordan

Urinary stone diseases are increasing in the Middle East. The majority of urinary stone cases are found in the northern part of the country. Stone samples taken from patients living in the Irbid area were collected from Princess Basma Hospital. The present study concentrates on the mineralogical and chemical composition of the urinary stones and on the effective environmental factors that assist in developing the different types of urinary stones. Using X-ray diffraction techniques, the mineralogical composition of the urinary stones was found to be as follows: oxalate, cholesten, and uric acid, with cystine stones occuring more frequently than the others. Cholesten and calcium oxalate stones are the most dominant types of stones. Calcium oxalate is the most common type of oxalate stone. Calcium oxalate is represented in: whewellite, wheddellite, and calcium carbonate oxalate hydrate minerals, in addition to other minerals such as brushite, ammonium phosphate, vaterite, valleriite, and bobierrite from other types of stones. Bobierrite (phosphate group) is a new mineral reported in urinary stones, and this has not been determined in any previous study worldwide. Apatite (calcium phosphate) is deduced using scanning electron microscope (SEM) images. The SEM technique determined crystal forms and systems, shapes, morphological features, and the names of the minerals forming urine stones, while optical properties are studied by polarizing microscope. X-ray fluorescence technique determined the concentrations of major and some trace elements. It revealed that Ca is the main constituent of the urinary stones, especially those composed of calcium oxalate and calcium phosphate. The concentration of trace elements was Ba = 1.57, P = 3.61, Fe = 1.78, S = 2.08, Zr = 4.63, Mo = 3.92, Cu = 1.89, Co = 1.56, and F = 4.2% and was higher in the urinary stones of Jordanian patients than in foreigners in the country. Questionnaires completed by patients suggest that the most significant factors directly effecting the formation of stones are water, climate conditions, food rich in protein and rich in different chemicals. Moreover, some drugs and diseases might also help in developing other stones.     

Examination of the influence of phenyltrimethylammonium chloride (PTMA) concentration on acetochlor adsorption by modified montmorillonite

The results presented in this paper show an impact of the concentration of the aromatic organic cation on the adsorption of acetochlor on the surface of the organic-modified montmorillonite. Natural montmorillonite from Bogovina (Boljevac municipality, Serbia) was used for organic modification in this experiment. Cation exchange capacity of this montmorillonite (86 mmol 100 g^?1 of clay) was determined using the methylene blue method. In pretreatment, montmorillonite was modified with NaCl. For the purpose of organic modification, three different concentrations of phenyltrimethylammonium chloride (PTMA) have been selected, based on calculated CEC value: 43 mmol 100 g^?1 of clay (0.5 CEC), 86 mmol 100 g^?1 of clay (1 CEC) and 129 mmol 100 g^?1 of clay (1.5 CEC). The changes in the properties of the inorganic and organic modified montmorillonite were examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and batch equilibrium method. Freundlich coefficients show higher uptake of the herbicide by montmorillonite modified with PTMA, compared to inorganic-modified montmorillonite. The results also indicate the influence of the organic cation concentration on the adsorption of the selected herbicide.     

反演同化技术在激光雷达中的应用研究

为增强模式预报准确性,提高激光雷达数据在化学模式中的应用水平,建立激光雷达同化系统,将激光雷达数据引入模式,利用WRF-Chem模拟2016年12月6日～10日一次污染过程,将激光雷达监测的气溶胶光学深度(AOD)反演成近地面PM2.5浓度,通过三维变分同化技术订正模式原始场,调整模式预报结果.实验对比发现,反演同化后...     

Monitoring and assessment of toxic metals in Gulf War oil spill contaminated soil using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) was applied for the detection of toxic metals in oil spill contaminated soil (OSCS). The OSCS samples were collected from Khursania Saudi Arabia along the coast of Persian Gulf exposed to oil spills in 1991 Gulf war. Environmentally important elements like Aluminum Magnesium, Calcium, Chromium, Titanium, Strontium, Iron, Barium, Sodium, potassium, Zirconium and Vanadium from the contaminated soil have been detected. Optimal experimental conditions for analysis were investigated. The LIBS system was calibrated using standard samples containing these trace elements. The results obtained using Laser-Induced Breakdown Spectroscopy (LIBS) were compared with the results obtained using Inductively Coupled Plasma Emission Spectroscopy (ICP). The concentrations of some elements (Ba and Cr) were found higher than permissible safe limits. Health risks associated with exposure to such toxic elements are also discussed.     

Safety management by use of laser mass spectrometry of polychlorinated biphenyls (PCBs) in the processed gas and work environment of a PCB disposal plant

This study demonstrates the applicability of laser mass spectrometry for safety management of the processed gas and the work environment in a polychlorinated biphenyl (PCB) disposal plant. By utilization of laser ionization/ion trapping storage/time-of-flight mass spectrometry (LI-IT-TOFMS), we analyzed gaseous PCBs from scrap capacitors with on-line detection. It was confirmed that few contaminants were detected in the spectrum. By the effect of laser-induced selective ionization, it was considered that there was little interference with the mass range of PCBs. The accuracy of LI-IT-TOFMS when analyzing environmental gas was almost the same as that for the PCB standard gas. It was possible to perform on-line analysis of the work environment for over 2000 h (120 000 data points). LI-IT-TOFMS was thus shown to be a very useful method for ensuring the safety of the work environment in disposal plants for PCBs.     

高炉渣调质作为矿渣纤维原料

以铁矿废石和粉煤灰的混合物为添加剂对高炉渣进行调质,调质后的矿渣作为制备矿渣纤维的原料,并对影响机理进行分析。结果表明,随着添加剂比例升高,矿渣的酸度系数M_k和粘度系数M_η升高,氢离子指数pH降低,矿渣纤维的稳定性逐渐增加,矿渣粘度较小,其主晶相为黄长石。配加添加剂比例较高时熔渣凝固后无矿物析出,形成均匀的无限固溶体。矿渣更加适合制备矿渣棉纤维。     

震后某工号建渣及土壤样品中铀的分析测定

采用激光荧光法对"5.12"地震后某工号建筑垃圾和土壤样品进行了铀的测定。方法检出下限D.L≤3×10-11g/mL,相对标准偏差RSD为7.4%,回收率达到86%~109%。对实验数据进行了分析和初步评价,结果表明,该工号所测样品铀含量基本处于天然本底水平。     

用于应力腐蚀试验的飞机铝合金装配模拟件内部应力无损测定

目的 减少或避免服役飞机机体的应力腐蚀和腐蚀疲劳开裂.方法 采用短波长特征X射线衍射技术和仪器无损检测飞机铝合金装配模拟件的内部残余应力和装配应力的分布.结果 0.5 mm矩形间隙使下缘条根部上表层产生高达110 MPa及以上的拉应力;0.3 mm矩形间隙使下缘条根部上表层产生约80 MPa的拉应力;0.5 mm楔形间隙使下缘条根部上表层产生的拉应力平均值约55 MPa.结论 利用短波长特征X射线衍射技术能够无损测定和表征铝合金装配件内部应力及其分布,装配间隙使下缘条根部上表层产生较大拉应力,这与服役飞机机身螺接件出现较多非典型裂纹的部位吻合.矩形间隙装配件下缘条根部上表层的拉应力大于相同间隙值的楔形间隙装配件下缘条根部上表层的拉应力,并且,装配间隙越小,产生的拉应力越小.减小螺母靠根部处的装配间隙与螺母靠根部处到壁板距离的比值,将减小装配件的拉应力,减少或避免SCC&CFC的发生,以及非典型裂纹的产生.