氟掺杂钛酸锂纳米片的制备及其电化学性能

采用一步水热法合成了氟掺杂钛酸锂纳米片,通过扫描电镜、X射线衍射和X射线光电子能谱等手段对其进行表征,并研究其电化学性能.结果表明:氟的掺入对钛酸锂纳米片的结构没有影响,氟掺杂钛酸锂纳米片的倍率性能和循环稳定性优于钛酸锂纳米片;在5A·g~(-1)的电流密度下,F掺杂样品的比容量达101mA·h·g~(-1),在2A·g~(-1)的电流密度下循环1 000次后材料仍具有120mA·h·g~(-1)的比容量,容量保持率为86.2%.     

城市污水处理工艺对有机磷酸酯类化合物的去除

城市污水处理厂进水中有机磷酸酯类化合物(OPs)的总质量质量浓度为1106.5μg·L~(-1),经厌氧好氧工艺三级处理后降至511.7μg·L-1,去除率为53.8%。OPs的去除主要发生在厌氧和好氧环节,非氯代的OPs能够得到较好的去除,而氯代的OPs难以去除(磷酸三(1,3-二氯-2-丙基)酯除外).在污水处理厂剩余活性污泥(脱水污泥)中也检出较高质量质量浓度的OPs,总质量质量浓度为16.9~60.7(μg·kg~(-1)).OPs去除率与其辛醇-水分配系数对数值(logKow)具有较强的相关性(r~2=0.538 85),表明具有较大Kow值的OPs与剩余活性污泥具有较强的吸附作用,进而会影响其在污水处理过程中的去除.     

云南昭通燃煤型氟病区厨房和烤房空气中氟和SO_2污染特征

为评价云南省昭通市典型氟中毒区厨房和烤房空气中气态氟化物和SO2污染状况,在昭通市镇雄县余家湾村随机选取14户农户,测定厨房空气中气态氟化物和SO2含量;在镇雄县余家湾村和小龙洞乡小米村共选取27间烤房,测定烤房空气中气态氟化物和SO2含量。实验数据说明:1)通过降氟炉的使用,厨房空气中气态氟化物日均值含量为3.7μg·m-3,已达到参考值(10μg·m-3)之内;虽然厨房空气中SO21h均值含量为0.9mg·m-3,已有大幅降低(降幅达93.7%),但依然高于室内SO2质量标准值(0.5mg·m-3)。2)镇雄县芒部镇余家湾村和昭阳区小米村烤房空气中气态氟化物日均值含量分别为10.1,7.2μg·m-3,接近参考值(10μg·m-3)。镇雄县芒部镇余家湾村和昭阳区小米村烤房空气中SO21h均值含量分别为14.4,6.8mg·m-3,分别为室内SO2质量标准值的28.8倍和13.6倍。研究认为烤房空气中气态氟化物和SO2的污染程度严重,这会污染烤房中的玉米和辣椒,从而继续危害当地居民健康。因此,要解决昭通地区燃煤型氟中毒问题,必须降低烤房空气中气态氟化物的含量。     

蒙古扁桃油脂特性及抗氧化稳定性研究

对蒙古扁桃种仁油脂特性及抗氧化稳定进行研究.结果表明,蒙古扁桃油脂抗氧化稳定性很强.现提取蒙古扁桃种仁油脂的过氧化值为165.0μmol·kg~(-1),在4℃冰箱里放置6个月后油脂过氧化值、酸价和碘值分别为840.0μmol·kg~(-1),0.534mg·g~(-1)和111.73g·(100g)-1.用Schaal烘箱法在(60±1)℃高温处理21d后其酸价由0.295mg·g~(-1)增至0.685mg·g~(-1),过氧化值由0.165mmol·kg~(-1)增至15.620mmol·kg~(-1),碘值第8d后检测不出.蒙古扁桃油脂中δ-维生素E的含量最高,为57.1 mg·(100g)-1,其次是α-维生素E,为49.36mg·(100g)-1,γ-和β-维生素E含量分别为22.30mg·(100g)-1和28.65mg·(100g)-1,总量为157.4mg·(100g)-1.从蒙古扁桃油脂中检测出Cu、Zn、Fe、Ca、Mg等人体必需元素,其含量依次为ZnMgCuCaFe.     

吸附法去除饮用水中的氟化物

利用活性氧化铝吸附去除饮用水中的氟化物,在进水氟化物2.66mg/L时,出水氟化物≤0.7mg/L,出水水质稳定,达到了《生活饮用水卫生标准》(GB5749-85)中的要求。该项目为类似水中氟化物去除提供了实际参考。     

氯化镁盐改性煤渣的制备和吸附F~-研究

为了回收再利用工业废弃物煤渣,本文利用负载法制备了氯化镁改性的煤渣除氟吸附剂(MgMC),通过扫描电镜(SEM)和粉末X射线衍射(PXRD)对其结构进行了表征,考察了吸附剂投加量和溶液pH对Mg MC吸附F~-性能的影响.与未改性煤渣和氯化钙改性煤渣除氟吸附剂(CaMC)相比,Mg MC对F~-有更好的去除效果.研究结构表明,当选择F~-溶液的初始浓度为30 mg·L~(-1)和吸附剂投加量为30 g·L~(-1)时,在pH=2~11的范围内Mg MC吸附F~-的效率均达到90%以上.在最佳条件下,当F~-的浓度较低时,F~-出水浓度达到了国家饮用水标准;当F~-的浓度较高时,F~-出水浓度达到了国家废水排放的标准.在不同浓度下,MgMC对F~-的吸附过程可以用表观二级动力学模型和Langmuir吸附等温方程来描述,在303 K时MgMC的吸附量达到最大值63.694 mg·g~(-1).     

制备焙烧Mg/Al水滑石及同时去除水中氟和硬度

通过共沉淀法制备焙烧Mg/Al水滑石(HTCs-400-MgAl),利用X射线衍射(XRD)和傅里叶变换红外线光谱(FTIR)对材料进行表征,研究焙烧水滑石投加的质量浓度、温度、溶液初始pH值、吸附动力学和等温吸附等对吸附效果的影响.结果表明:当焙烧水滑石在最佳投加质量浓度为6g·L~(-1)时,其在4h内对初始质量浓度为10mg·L~(-1)的氟离子和500mg·L~(-1)的硬度(以CaCO_3的质量浓度计算)的吸附量分别为1.57,47.50mg·g~(-1);焙烧水滑石吸附氟离子的过程更符合拟二级动力学模型和Langmuir等温吸附模型,其去除机理为结构重建;焙烧水滑石吸附硬度的过程更符合拟二级动力学模型和Freundlich等温吸附模型,其去除机理包括表面吸附和生成沉淀去除.     

大薸对不同质量浓度畜禽废水的净化作用及生物学效应

实验以自然湿地中采集的大薸为研究对象,在室内模拟条件下首次研究了大薸在低质量浓度至高质量浓度畜禽废水条件下的净化作用及植物生理变化。并探讨了湿地植物大薸对废水的净化作用与生物学效应之间的相关性。研究结果表明：大薸对畜禽废水的CODcr、氨氮、总磷最高去除率分别达到82.33%、69.21% 和45.88%。大薸在不同质量浓度畜禽废水胁迫8 d后,大薸抗氧化系统酶活性总体呈下降趋势,畜禽废水质量浓度越高,植物损伤情况越明显。大薸叶片中起主要保护作用的酶是POD,变化幅度最明显,对畜禽废水胁迫的敏感性、应激性最强。大薸对畜禽废水的净化作用与大薸的生物学效应相关性较强。     

磁性水热炭对水体中砷、氟的吸附特性

利用水热法合成磁性水热炭(m-HTC)吸附剂,经X-射线衍射仪(XRD)、Zeta电位分析仪对吸附剂进行表征,通过试验探究吸附剂对水体中砷、氟的吸附特性.结果表明:投加量为2 g·L~(-1)时,对砷、氟去除率达85%左右;去除率随pH变化而变化,随离子强度I_s,吸附质初始质量浓度C_0的增加而下降;不同温度下的等温线数据更符合Langmuir模型,温度升高有利于吸附,单独体系下砷、氟的最大吸附量q_m分别为26.06和15.64 mg·g~(-1),共存体系下对砷、氟的q_m分别为20.42和13.62 mg·g~(-1),砷、氟存在相互抑制的作用;动力学试验数据更符合准二级动力学方程,经5次循环,去除率下降,但从实际角度,具有可取性.     

高容量锂离子电池SiO/SnO_x复合负极材料研究

通过高能球磨和惰性气氛保护烧结两步法制得SiO/SnO_x复合材料.高能球磨后的SiO和SnO_2均是无定形结构,随着烧结温度的增加,部分SnO_2被还原成Sn单质,这一过程伴随有SiO_2的生成.在700℃烧结处理的样品表现出最优异的电化学性能,在0.1A·g(~-1)电流密度下,循环90次容量保持在920mA·h·g~(-1),且在不同电流密度下复合材料均表现出优异的倍率性能,在2A·g~(-1)的大电流密度下容量达到380mA·h·g~(-1).     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that