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关键词： Sediment-based biochar   Nitrate removal   Biological response   Surface functional group   Electron transfer capacity   Application potential  

摘要： Biological removal of the nitrate, a highly concerning contaminant in rivers, is limited due to the low activity of denitrifying community. Biochar is extensively used in facilitating the nitrate removal because of its unique physicochemical properties which enhance the denitrifying performance in aqueous environment. However, the physicochemical properties of biochar and its potential strengthening mechanism in denitrification process remains unknown. Herein, the sediment-based biochar was prepared for strengthening denitrification for the first time. The biochar was prepared at 400-1100 degrees C, with its conductivity increasing from 0.21 to 310.11 S m(-1) while nitrogen (oxygen) content decreasing from 5.81% (20.30%) to 3.79% (16.63%). A maximum total nitrogen (TN) removal rate of 21.67 +/- 0.66 g N m(-3) d(-1) with a nitrate nitrogen (NO3--N) removal rate of 22.43 +/- 0.62 g N m(-3) d(-1) was obtained when biochar at pyrolysis temperature of 800 degrees C (SBC800) was added, which were 11.6 and 5.0-fold higher than that without biochar, indicating an ameliorative denitrification performance. The nitrogen-containing functional groups were correlated significantly with electron donating capacity (EDC, r = 0.898, p < 0.05) and electron accepting capacity (EAC, r = 0.911, p < 0.05) of biochar, further increased the abundance of denitrifying species to 75.9% by gaining high correlation with NO3--N removal (r = 0.903, p < 0.05). Overall, this study provides a low-cost and sustainable way to efficiently remove nitrogen from fluvial systems using sediment-based biochar.

关键词： 物理化学   粒度级配   炸药油墨   CL-20   黏度   非牛顿指数  

摘要： 为了研究粒度级配对CL-20基炸药油墨流变性能的影响,制备了粒径分别为400nm和4μm的CL-20样品,以及7种不同粒度级配的CL-20基炸药油墨;采用博勒飞(CPS)流变仪对炸药油墨进行了黏度测试,得到了相应的流变数据,并计算出非牛顿指数、屈服值和触变指数。结果表明,炸药颗粒的粒度级配对炸药油墨的流变性能有着十分明显的影响;随着粒径为4μm的CL-20含量的增多,炸药油墨表观黏度出现先减小后增大的现象;同时,非牛顿指数出现先增大后减小的现象,屈服值和触变指数总体上呈现先减小后增大的现象;当炸药油墨中粒径分别为400nm和4μm的CL-20质量比为1∶2时,炸药油墨的非牛顿指数为最大值0.41,屈服值和触变指数均达到最小值,分别为26.73和8.74,表明在该粒度级配条件下,炸药油墨具有更好的流变性能。

关键词： 药学   物理化学   C-PBL教学法  

摘要： "物理化学"是药学专业的一门专业基础主干课程,与多门后续药学专业课联系密切,同时也是最难掌握的课程之一。将C-PBL教学法运用于"物理化学"热力学部分的理论教学中,通过设置情境及相关开放性问题,有效地调动了学生学习的积极性和主动性,取得了良好的教学效果。

关键词： Sequential extraction   CISED   Chemometrics   BCR CRM 701   Airborne particulate matter   Inductively coupled plasma mass spectrometry  

摘要： Two non-specific sequential extraction methods utilising chemometric data processing (chemometric identification of substrates and element distribution, CISED) have been developed and used to determine the physicochemical partitioning of potentially harmful elements (PHE) in certified reference material BCR CRM 701 (lake sediment). A miniaturized centrifugation method in which the sample was extracted on a filter insert in a polypropylene centrifuging tube, and a quasi-flow through method in which the sample was supported on a TX40 filter in a 47 mm in-line polycarbonate filter holder, gave similar results. The CISED data processing identified nine components. Seven of these were of geochemical origin - two carbonate components, an Al/Fe oxide/hydroxide component, three Fe-dominated components and one Si-dominated component - while the others represented the TX40 filter blank. The overall extraction capabilities of the methods were similar to that of the well established BCR sequential extraction (Sigma steps 1-3). However, whilst the BCR extraction is operationally defined, the CISED provides information on associations between PHE and the geochemical components identified. The flow through CISED procedure has potential applications in investigating the chemical speciation of PHE associated with urban airborne particular matter.

关键词： 物理化学课程教学   求真务实思政元素   辩证唯物主义  

摘要： 为了提高学生的道德素养,文章首先阐述了求真务实思政元素融入物理化学课程教学的理论基础和求真务实思政元素融入物理化学课程教学的实践逻辑,然后论述了求真务实思政元素融入物理化学课程教学的实践。

关键词： 物理化学   熔铸炸药   3,4-二硝基吡唑(DNP)   流变性能   表观黏度  

摘要： 为了解3,4-二硝基吡唑(DNP)/HMX悬浮液在不同影响因素下的流变行为,采用Brookfield R/S Plus流变仪对其流变性能进行测试,分析了HMX含量、粒度、颗粒级配、体系温度以及不同添加剂对悬浮液流变性能的影响。结果表明,DNP单质为牛顿流体,表观黏度约为16.4mPa·s,比TNT高82%,比DNAN高140%;同一剪切速率下,DNP/HMX悬浮液表观黏度随固含量的增加而增加,当HMX质量分数为30%时,悬浮液近似牛顿流体;HMX质量分数高于30%时,表观黏度随剪切速率的增加呈指数型下降的趋势愈发明显;悬浮液表观黏度随颗粒粒径的增大和温度的增加而降低,当温度从95℃升到105℃时,黏流活化能(E)从29211J/mol增至38458J/mol;固含量为60%时,平均粒径(d50)分别为16.6μm和575.6μm的HMX颗粒的最佳质量比为1∶5,此时悬浮液表观黏度最小。N-甲基-4-硝基苯胺(MNA)降低了悬浮液的表观黏度,乙酸丁酸纤维素(CAB)和微晶蜡-80(MV80)增加了悬浮液的表观黏度。

关键词： 铁电材料   极化反转   磁性调控   电子性质   气敏应用   光解水  

摘要： 铁电材料作为一种重要的功能材料具有内在的自发极化和外电场可控极化反转特性.这种电极化不仅使得铁电材料产生内部电场;极化反转以及双稳极化态这一特性可以用于构建非易失性电子器件.本文从铁电调控磁性、电子性质、气敏应用以及光催化水分解4个方面介绍二维铁电材料在物理性质调控和化学领域的应用研究进展.最后,展望了二维铁电材料在电子器件、能源转化方面的应用前景.

关键词： Commercial biografts   Crystal size   Organic material   Crystalline structure   Bio-hydroxyapatite  

摘要： This article focused on the comparative study of the physicochemical properties of bovine and human bio hydroxyapatites with commercial samples used in dental implants. Raw and defatted bovine bone was calcined at 560 degrees C, while commercial samples were analyzed without any processing (RTR, Novabone (R), and Nukbone (R) granules). Transmission Electron Microscopy and Scanning Electron Microscopy were used to study their crystal size and morphology. Thermogravimetric analysis was used to study the decomposition and transformation of the organic and inorganic phases. The crystalline phases and Full Width at Half Maximum were determined by Xray. Infrared and Raman spectroscopies were used to determine the presence of organic materials. Results showed the presence of organic material in some commercial samples, which means that these biografts could have immunological reactions with the patient.

关键词： 工科院校   《物理化学》   课程思政   教改探讨  

摘要： 《物理化学》是工科院校本科生的重要的专业基础课,它在连接基础课和专业课过程中起着重要的作用。如何通过教改将授专业知识与育人“无缝对接”?文中立足本专业课程特点,针对该课程中存在的问题进行了归纳总结,并制定该课程在思政背景下的专业课程的培养目标,通过课程案例式等教学方法,就所进行的改革实践进行了探讨。