Langmuir

摘要： 氮氧化物NO_(x)(NO,NO_(2))是对人类健康有严重危害的大气污染物。近年来研究表明赤铁矿(α-Fe_(2)O_(3))可作为高效光催化剂去除大气中NO_(x),但NO_(x)气体在赤铁矿表面的吸附特性还未明确,阻碍了对其催化机理的进一步认识。基于密度泛函理论,采用包括电子强关联效应的PBE+U以及色散力修正的方法,对NO气体分子在α-Fe_(2)O_(3)(0001)晶面的吸附行为进行深入研究,发现基于PBE+U方法获得的吸附能(Ead=-0.64 eV)比PBE获得的Ead(-1.31 eV)低近50%。这是由于电子强关联项U的引入降低了表面铁原子d轨道对价带顶的贡献,抑制了其化学活性,而NO具有一个未成对的π*轨道电子,使得其对吸附基体的电子结构格外敏感。与+U不同,色散力修正不会显著改变体系的电子结构,只是使Ead略有增加(-0.18 eV)。采用统计力学的Langmuir公式计算NO在α-Fe_(2)O_(3)(0001)表面的热力学平衡占据数,发现基于+U的吸附能得到的平衡占据数与实验观测更为一致。这些结果揭示了电子强关联效应在α-Fe_(2)O_(3)表面化学中的重要作用,并为进一步研究NO_(x)在α-Fe_(2)O_(3)表面的光催化反应机理奠定了基础。

摘要： This study was based on the evaluation of the potential effectiveness of Moringa oleifera seeds biomass as a biosorbent in the removal of copper (Cu) in water which was justified by the level of toxicity, environmental unfriendliness and costly nature of chemical coagulants presently used. Fourier transform infrared (FTIR) analysis was used to identify the Moringa oleifera seeds biomass functional groups present in the adsorption of metal ions and found to be the carboxylic acid and amine functional groups (-COOH and -NH). The effects of contact time, adsorbent dosage, metal ion concentration and pH were studied. The maximum adsorption capacity at pH 5, room temperature and 0.8 g dosage was 70% for Cu(II). The adsorption data fitted better to the Langmuir than the Freundlich models as the sorption capacity (qm) of Moringa oleifera seeds biomass for Cu(II) was 3.64 mg/g. The separation factor (RL) was within the range of 0 and 1 which showed that the Cu(II) biosorption processes were favourable for Moringa oleifera biosorbent. The results showed that Moringa oleifera seed biomass is an effective adsorbent in the removal of the studied heavy metals in water. The effective pH for the Cu(II) removal was 5.0 as equilibrium was achieved practically in 35 min. The quantitative analysis of defatted Moringa oleifera should be studied in order to have a fair mixing ratio between Moringa oleifera seeds biomass and the adsorbate. There is also the ardent need to work on environmentally friendly disposal of adsorbent after saturation of adsorbent by analyte to avoid secondary pollution.

摘要： 基于广义Zakharov模型,结合斜入射等离子体的时域有限差分(FDTD)方法与双流体力学方程,通过由二维麦克斯韦方程等价转换的一维麦克斯韦方程,与等离子体流体力学方程建立了一个电磁波以不同角度入射电离层传播的数值模型.分析推导出TEz波在斜入射非线性电离层等离子体的支配方程,然后推导了适用于计算电离层电磁波传播特性的FDTD算法.通过仿真来证明该方法在较小倾角下,电磁波对电离层加热形成Langmuir扰动及其传播特性的准确性和有效性.结果表明,在小角度入射下,大功率高频电磁波在电离层等离子体中的O波反射点附近激发出了Langmuir波,同时波粒相互作用导致O波转换为Z波并向电离层更高区域传播.本文进一步研究了基于电离层等离子体的电磁波传播特性,为全面深入分析电离层Langmuir扰动对电离层电波传播特性影响奠定数值算法的基础.

摘要： 以大薸(Pistia Stratiotes L.)为原料,在不同温度下烧制成大薸生物炭(BC),采用磁改性方法制得改性生物炭(MBC),研究两者对铜离子(Cu2+)的吸附性能,并采用准一级动力学、准二级动力学模型及Langmuir与Freundlich等温吸附模型对试验数据拟合.结果表明:未改性与改性大薸生物炭对Cu2+的平衡吸附浓度分别从55.49mg/g增加到74.01mg/g,58.87mg/g增加到75.20mg/g;随着烧制温度升高,生物炭比表面积增大,孔径变小,孔隙结构增加;生物炭吸附Cu2+过程更符合Langmuir模型与二级动力学模型,拟合系数R2均大于0.9;热解温度为500°C时,生物炭对Cu2+的吸附效果最佳,改性生物炭对Cu2+的吸附速率大于未改性生物炭.

摘要： Deterioration and loss of quality of vegetable oil is a big challenge in the food industry.This study investigated the synthesis of nickel ferrite(Ni Fe_(2)_(O4))via co-precipitation method and its use for the removal of free fatty acids(FFAs)in deteriorated vegetable oil.Ni Fe2 O4 was characterized using Fourier transformed infrared spectroscopy(FTIR),X-ray diffraction(XRD),thermogravimetric(TG)analysis,Brunauer–Emm ett–Teller(BET)surface area,transmission electron microscopy(TEM),scanning electron microscopy(SEM)and energy-dispersive X-ray spectroscopy(EDX).Synthesis of Ni Fe_(2)_(O4)was confirmed by characterization,which revealed a BET surface area of 16.30 m^(2)·g^(-1)and crystallite size of 29 nm.Ni Fe_(2)_(O4)exhibited an adsorption capacity of 145.20 L·kg^(-1)towards FFAs with an 80.69%removal in a process,which obeys Langmuir isotherm and can be described by the pseudo-second-order kinetic model.The process has enthalpy(DH)of 11.251 k Jámolà1 and entropy(DS)of 0.038 k J·mol^(-1)K^(-1)with negative free energy change(DG),which suggests the process to be spontaneous and endothermic.The quantum chemical computation analysis via density functional theory further revealed the sorption mechanism of FFAs by Ni Fe_(2)_(O4)occurred via donor–acceptor interaction,which may be described by the lowest unoccupied molecular orbital(LUMO)and the highest occupied molecular orbital(HOMO).The study showed Ni Fe_(2)_(O4)to be a potential means that can remove FFAs from deteriorated vegetable oil.

摘要： 为了研究不同等温吸附模型对等温吸附实验的模拟效果,更好地描述页岩甲烷吸附规律,对川东南PY1井的7块岩心样品开展了等温吸附实验.结果表明,最大过剩吸附量与有机质含量呈现明显正相关,相关系数最大为0.8594,而与黏土矿物呈现负相关.分别采用不同模型对实验结果进行了模拟分析,不同模型所得到的模拟结果差异较大,其中以Lang-muir模型拟合相关系数表现最好,而SDR模型所得到的最大过剩吸附量最大,其次为定密度修正的Langmuir模型.SDR模型和修正的Langmuir模型均对实验结果进行了过剩吸附量的修正,但修正结果表明,SDR模型所得到的吸附相密度最为合理.最后综合考虑认为定密度修正的Langmuir模型和SDR模型对页岩中甲烷的吸附规律描述更为精确,能够更好地指导页岩吸附气含量的计算.

摘要： Background:Maintaining the structural and functional integrity of membranes is essential for proper cells function.A recent proteomic study suggests that S100A16 and Annexin A4(ANXA4)proteins participate to maintain the membrane integrity in the outer segment of the photoreceptors in the eye.The protein S100A16,recently discovered,is one of the S100 family proteins for which no protein and membrane interaction has yet been identified.Furthermore,maintain of the membrane integrity is calcium sensitive process.The main objective consists of studying the membrane interactions of S100A16 and ANXA4 proteins to better understand their functions in maintaining membrane integrity.Specific objectives are:(I)to achieve the purification of these proteins,(II)to gather information on their membrane interactions,and(III)to study the influence of calcium on these interactions.Methods:The S100A16 protein is obtained by cleavage followed by purification on a His-Trap column.Membrane interactions are studied with the Langmuir monolayer model.After measurement of the saturating concentration,the protein binding parameters,that to say the maximum insertion pressure and synergy,will then be determined in the presence of several phospholipids representative of physiological membranes.Results:The S100A16 protein was obtained with a purity greater than 99%and its saturating concentration is 0.5μM.Biophysical studies with different phospholipids in monolayer are currently in progress.Conclusions:Obtaining the S100A16 protein with a high purity allows carrying out the biophysical study in order to understand its membrane interactions.The purification of ANXA4 and the biophysical study with different phospholipids of this protein alone and in complex with the S100A16 protein will allow a better understanding of the membrane behavior of these proteins,as well as their roles in the maintenance of membrane integrity.

摘要： Sandy soils have poor physical properties, which cause them to drain quickly and not hold water well;however, with the addition of cattle manure, sandy soil can be improved. Therefore, experiments were conducted to investigate the characterization and impact of different particle sizes of cattle manure (CMS) on improving some physical properties of sandy soil and thus the yield of lettuce. Cattle manure was ground to powder and was sieved with three different Particle sizes 4.76-2 (CMS1), 2-0.8 (CMS2), 0.8-0.4 (CMS3) mm. Some physical properties were measured for different Particle sizes of manure. A batch of sorption experiments was carried out to study the role of different Particle sizes of manure on adsorption of N, P and K from aqueous solution. Two experiments were carried out on sandy soil (pots and field) to study the impact of adding CMS (5 ton/fed) to enhance some physical properties of sandy soil. The results indicated that the physical properties of cattle manure changed based on particle size fractionation, where Bulk density and saturated water holding capacity increased as particle size decreased, while porosity reduced as particle size decreased. The results of the sorption parameters of N, P and K on different particle sizes of manure indicated that maximum sorption occurred on CMS 3 for both P and K according to Langmuir and Freundlich sorption models. Two experiments showed that CMS had affected significantly the total porosity (TP), bulk density (Bd), slowly drainable pores (SDP), water holding pores and (WHP) available water (AW) in comparison to control. The CMS had a slight effect on Quickly-drainable pores (QDP) and fine capillary pores (FCP) as compared to the control in both experiments. Fresh weight, dry weight and number of leaf lettuce increased significantly with decreasing particle sizes of cattle manure as compared to control.

摘要： 芦丁是一类具有广泛药理作用的黄酮类化合物,为了从大豆异黄酮的粗提液中选择性的提取芦丁,根据分子识别技术原理,以芦丁为模板分子,能和芦丁分子中的酚羟基反应的氨丙基三乙氧基硅烷为功能单体,正硅酸乙酯为偶联剂制备出对芦丁具有高选择性的硅质吸附剂,同时制备了空白吸附剂.对此吸附剂进行了静态吸附试验和选择性试验,在70°C进行了等温吸附试验并采用langmuir等温吸附机理进行了回归.结果表明,此硅质吸附剂与空白吸附剂相比,有较高的吸附量和选择性;吸附复合langmuir等温吸附机理.

摘要： 本发明公开了一种用于等离子体诊断的圆柱形Langmuir探针，属于等离子体诊断技术领域。本发明使用直径为0.3mm的钨丝作为探针材料，钨丝外面包覆两层耐高温氧化铝(Al

摘要： 本发明公开了一种用于等离子体诊断的Langmuir多探针控制电路，属于等离子体诊断技术领域。控制电路整体位于等离子体装置之外，包括三个Langmuir单探针、交流锯齿波供电电压发生装置、直流供电电压发生装置、双刀双掷开关、反向开关、第一双刀三掷开关、第二双刀三掷开关、第一单刀单掷开关、第二单刀单掷开关和转换电阻，通过切换控制电路中的开关来进行Langmuir单探针、双探针和三探针不同诊断电路之间的选择，并提供清洗电路实现对探针的清洗操作。本发明利用了三种探针诊断方法在实验设备上的相同点，可以节约实验成本。结合三种诊断方法的不同点，通过转换控制电路切换不同方法，方便快捷，大大缩短实验周期；可以在实验过程中对探针进行清洗，使实验结果更加准确。

摘要： 本发明涉及一种基于Langmuir‑Blodgett (LB)技术在分子水平涂层碳纤维的方法，包括：（1）氧化石墨烯铺展溶液的制备；（2）氧化石墨烯在水面单分子层的铺展；（3）利用LB技术，制备氧化石墨烯单分子层涂层的碳纤维。本发明实现了氧化石墨烯在碳纤维表面的分子水平的调控、排列、组装和修饰，实现了对碳纤维表面分子水平的修饰改性，可广泛应用于碳纤维增强体、功能材料等领域，有着很好的实用价值与潜在价值。

摘要： 本发明公开了一种用于等离子体空间电位诊断的Langmuir发射探针，包括探针主体与探针支撑。探针主体中，使用直径为0.1mm，含量2％的钍钨丝作为发射探针材料，钍钨丝弯曲成U型，钍钨丝尾部与铜导线焊接，铜导线尾部与屏蔽同轴电缆线的中心信号线焊接在一起，屏蔽同轴电缆线的中心信号线作为信号传输线并包覆以多层绝缘隔热防护材料。探针主体通过弯折成倒L形状的管状探针支撑进行支撑，支撑结构螺纹连接在空间定位装置上。本发明提供的探针结构体积小、传输信号的信噪比高、耐热性高、稳定性好、空间定位便捷、重复定位误差小，适用于多种等离子体环境下等离子体特性参数空间分布的快速、准确测量，广泛适用于等离子体的科学研究及工业应用。

摘要： 本发明公开了一种用于等离子体诊断的Langmuir多探针控制电路，属于等离子体诊断技术领域。控制电路整体位于等离子体装置之外，包括三个Langmuir单探针、交流锯齿波供电电压发生装置、直流供电电压发生装置、双刀双掷开关、反向开关、第一双刀三掷开关、第二双刀三掷开关、第一单刀单掷开关、第二单刀单掷开关和转换电阻，通过切换控制电路中的开关来进行Langmuir单探针、双探针和三探针不同诊断电路之间的选择，并提供清洗电路实现对探针的清洗操作。本发明利用了三种探针诊断方法在实验设备上的相同点，可以节约实验成本。结合三种诊断方法的不同点，通过转换控制电路切换不同方法，方便快捷，大大缩短实验周期；可以在实验过程中对探针进行清洗，使实验结果更加准确。

摘要： 本发明公开了一种用于等离子体诊断的圆柱形Langmuir探针，属于等离子体诊断技术领域。本发明使用直径为0.3mm的钨丝作为探针材料，钨丝外面包覆两层耐高温氧化铝(Al

摘要： 本实用新型涉及一种用于大型真空舱的射频Langmuir探针系统，在采用Mike Hopkins探针杆结构的前提下，引入滤波电路保护腔体，通过密封管路将密封腔体与真空舱上的供气接头连通，并给腔体充入保护气体，使射频滤波电路被保护在常压环境下。将金属密封腔通过铜编织线接地，屏蔽了射频电磁干扰的同时解决了大型真空舱中探针测量位置缺乏导电地的问题。探针的探测信号经过射频滤波电路滤波后，通过屏蔽线将探测信号输入到射频Langmuir探针的信号处理单元中。本实用新型克服现有技术的不足之处，提供大型真空舱中的射频Langmuir探针结构，从而解决了由于真空环境体积过大，射频滤波电路难于接入的问题。

摘要： 本发明公开了一种计算非定常Langmuir环流的动态模拟方法：(1)采用近岸海浪模式计算某一时间范围内的波浪场，输出波浪参数；(2)将得到的波浪参数输入Stokes漂移速度计算模型，计算得到stokes漂移速度；(3)改进普林斯顿海洋模式，使普林斯顿海洋模式包含非定常Langmuir环流的参数化计算方法；(4)将得到的stokes漂移速度输入改进后的普林斯顿海洋模式，实时模拟包含非定常Langmuir环流的海洋动态过程，得到包含非定常Langmuir环流物理过程影响的海洋温度、盐度和流速场。本发明在海洋环流模型的湍动能参数化计算方法中加入非定常langmuir环流的作用，可以动态地模拟非定常Langmuir环流对海洋要素的影响，可以完善海洋数值模式的物理过程，得到更加精准的海洋预报模型。