借助信息技术优化物理复习教学——《液体密度》一课的探索

在“互联网+”时代,高速发展的信息技术早已融入学科教学中。教学苏科版初中物理八年级下册《液体密度》复习课时,借助信息技术,优化课堂教学:运用自制微课,重回学习现场;运用虚拟实验,简化实验过程;运用电子白板,显化思维过程;运用在线评价工具,及时、精准反馈。

对JJG667-2010《液体容积式流量计》中若干修订内容的解释与说明

JJG667-1997《液体容积式流量计》检定规程（以下简称＂旧规程＂）在对液体容积式流量计的检定工作中起了很积极的作用。但随着国内计量管理手段的不断完善和细化．不断出现新的产品．液体容积式流量计的应用也越来越广泛．这样也对该流量计的检定工作（包括新产品的型式评价）提出了新的要求．这种现状导致旧规程部分不能适应目前的检定工作。

《液体》教学设计

[授课对象]高二学生[教材]人民教育出版社高中课程标准实验教科书物理选修3-3第九章第2节[课时安排]1课时(45分钟)一、教材分析1.普通高中物理课程标准(2017年版)要求3.1.5观察液体的表面张力现象。了解表面张力产生的原因。知道毛细现象。

《液体和气体怎样传热》导入一法

材上的导入部分实验装配操作难度大,如用这种方法,花去20分钟时间,重点部分学生没有充足时间研究。我是这样设计的:给每组学生准备两个试管,一个装水。

“液体沸点与压强关系”实验的改进

"液体沸点与压强关系"实验是中学物理中一个重要的实验,但教材中介绍的实验使用实验器材多,操作麻烦,因此较费时,而且效果也不理想,教学实践中我们作了如下改进.

浅议容积式流量计检定误差与黏度的关系——兼谈JJG667-1997《液体容积式流量计》检定规程修订建议

在石油化工等工矿企业里,使用着大量的容积式流量计（如刮板流量计、罗茨流量计、椭圆齿轮流量计、双转子流量计等）。这类流量计据其测量原理和结构特点,在机加工等制造技术较强的今天,比较容易制造出较高准确度的流量计。但是由于测量介质不同,所造成的误差也不一样。如用水标定的流量计去测量重油的流量,其测量值要上升10%左右。这主要是被测介质的黏度不同所致。

In situ electrochemical synthesis of MOF-5 and its application in improving photocatalytic activity of BiOBr

Metal-organic frameworks（MOFs） are important functional materials. MOF-5（IL）（Zn4O（BDC）3（BDC=1,4-benzenedicarboxylate） was in situ synthesized by the electrochemical method using a tunable ionic liquid（IL）, 1-butyl-3-methylimidazolium chloride, as template. The crystallization of distinctly spherical MOF-5（IL） synthsized in ionic liquid by the electrochemical method is attributed to π-π stacking effect, ionic bond, and coordination bond. The analysis results show that the product MOF-5（IL） exhibits better crystallinity and higher thermal stability than MOF-5 generated using the solvothermal method. The cyclic voltammetry reveals that the electrosynthesis reaction is irreversible and controlled by the diffusion. The experiments on methylorange degradation show that the unique structure characteristics of MOF-5（IL） can enhance the photocatalytic ability of Bi OBr. Therefore, MOFs can replace noble metals to improve the photocatalytic properties of bismuth oxyhalide.

Electrodeposition of Al on AZ31 magnesium alloy in TMPAC-AlCl_3 ionic liquids

Aluminum was electrodeposited with constant current on AZ31 magnesium alloy pretreated under optimized conditions from trimethyl-phenyl-ammonium chloride and anhydrous aluminum chloride （TMPAC-AlCl3） quaternary ammonium room temperature ionic liquids with benzene as a co-solvent. The corrosion resistance of the as-deposited Al layers was evaluated in 3.5% NaCl solution by the electrochemical technologies. The Al depositions were characterized by scanning electron microscopy equipped with energy dispersion X-ray. The results show that the microstructures of the Al depositions have spherical equiaxed grains obtained at a high current density, and bulk grains at a low current density. The Al deposition obtained at 12.3 mA/cm2 has a smooth and compact surface. The electrochemical measurements indicate that the thicker Al deposition can more effectively protect the Mg substrate. The Al deposition with bulk grains hardly protects the AZ31 Mg substrate from corrosion owing to its porosity.

Modeling air gun signatures in marine seismic exploration considering multiple physical factors

Based on analyzing the limit of Ziolkowski＇s bubble oscillation formulation,a new model with various physical factors is established to simulate air gun signatures fo marine seismic exploration.The practical effects of physical factors,such as heat transfe across the bubble wall,air gun port throttling,vertical rise of the bubble,fluid viscosity,and the existence of the air gun body were all taken into account in the new model.Compared with Ziolkowski＇s model,the signatures simulated by the new model,with small peak amplitude and rapid decay of bubble oscillation,are more consistent with actual signatures The experiment analysis indicates：（1）gun port throttling controls the peak amplitude of ai gun pulse;（2）since the hydrostatic pressure decreases when the bubble rises,the bubble oscillation period changes;（3）heat transfer and fluid viscosity are the main factors tha explain the bubble oscillation damping.

Surface pretreatment of Mg alloys prior to Al electroplating in TMPAC-AlCl_3 ionic liquids

It is difficult to directly electroplate Al on Mg alloys. The effects of pretreatment parameters on the corrosion resistance of films obtained on AZ31 Mg alloy surface were studied by using potentiodynamic polarization curves, to produce a compact interfacial layer as zinc-immersion deposition. After the substrate was pretreated under optimized conditions, aluminum was electrodeposited on AZ31 from TMPAC-AlCl3 room temperature ionic liquids. The depositions were characterized by scanning electron microscope equipped with energy dispersion X-ray. The results show that the traditional pretreatment of Mg alloys was successfully used for the Al-electroplating process from TMPAC-AlCl3 ionic liquids. The entire procedure includes alkaline cleaning, chemical pickling, surface activation （400 mL/L HF acid, 10 min）, zinc-immersion （20 min） and anhydrous treatment. A relatively compact zinc-immersion film was prepared on the substrate surface. A silvery-colored satin aluminum deposition was obtained on AZ31 from TMPAC-AlCl3 using direct current plating.

Kinetics of cerium(Ⅳ) and fluoride extraction from sulfuric solutions using bifunctional ionic liquid extractant(Bif-ILE)[A336][P204]

The extraction kinetics of Ce（Ⅳ） and Ce（Ⅳ）-F^- mixture systems from sulfuric solutions to n-heptane solution containing Bif-ILE[A336][P204]（[trialkylmethylammonium][di-2-ethylhewanxylphosphinate]） with a constant interfacial area cell with laminar flow were studied,just to elucidate the extraction mechanism and the mass transfer models.The data were analyzed in terms of pseudo-first-order constants.The effects of stirring speed,specific interfacial area and temperature on the extraction rate in both systems were discussed,suggesting that the extractions were mixed bulk phases-interfacial control process.Supported by the experimental data,the corresponding rate equations for Ce（Ⅳ） extraction system and Ce（Ⅳ）-F^- mixture extraction system were obtained.The experimental results indicated the rate-controlling step.The kinetics model was deduced from the rate-controlling step and consistent with the rate equation.

Saturation Magnetization and Law of Approach to Saturation for Selfformed Ionic Ferrofluids Based on MnFe2O4 Nanoparticles

The magnetization curves of MnFe2O4 nanoparticles and self-formed ferrofluids based on these particles have been measured at room temperature. The median size of the particles is 13.67 nm. The specific saturation magnetization is less than the theoretical value for the ferrofluids. In the high field range from 5 kOe to 10 kOe, the higher the particle volume fraction is, the steeper the slope of the magnetization curves is when it approaches saturation. The behavior of the saturation magnetization and the law of approach to saturation are due to the presence of self-assembled aggregates of ring-like micelle structures which form in the absence of the magnetic field and field-induced aggregates, respectively. The field-induced aggregates have a dissipative structure, so that at high field, the law of approach to saturation magnetization is different from the one described using Langevin paramagnetism theory. The large particles in the ferrofluids result in apparent hysteresis.

Electrodeposition of iridium from composite ionic liquid

In order to study the electrodeposition process of iridium in composite ionic liquid, the effects of N, N-dimethylacetamide（DMAC） on the viscosity, conductivity and electrochemical stability of composite ionic liquid BMIC-BMIBF4, as well as the electrochemical behavior of Ir Cl3 in this system were studied. Iridium（Ir） coatings were deposited at different constant potentials and characterized by SEM and XRD. The results show that the addition of DMAC can evidently decrease the viscosity of the composite system, increase conductivity and improve electrochemical stability of the composite system. Cyclic voltammograms of a Au electrode illustrate that the process controlled by diffusion rate is irreversible with the average charge transfer coefficient of 0.170 and average diffusion coefficient of 1.096×10-6 cm^2/s. In addition, SEM image shows that Ir film deposited at the reduction peak potential is dense and even, while XRD pattern shows that Ir deposit is polycrystalline structure.

Numerical study on dehumidifying process in falling film dehumidifier

A counter flow model of simultaneous heat and mass transfer of a vapor absorption process in a falling film dehumidifier is developed. The governing equations with appropriate boundaries and interfacial conditions describing the dehumidifying process are set up. Calcium chloride is applied as the desiccant. The dehumidifying process between falling liquid desiccant film and process air is analyzed and calculated by the control volume approach. Velocity field, temperature distribution and outlet parameters for both the process air and desiccant solution are obtained. The effects of inlet conditions and vertical wall height on the dehumidification process are also predicted. The results show that the humidity ratio, temperature and mass fraction of salt decrease rapidly at the inlet region but slowly at the outlet region along the vertical wall height. The dehumidification processes can be enhanced by increasing the vertical wall height, desiccant solution flow rates or inlet salt concentration in the desiccant solution, respectively. Similarly, the dehumidification process can be improved by decreasing the inlet humidity ratio or flow rates of the process air. The obtained results can improve the performance of the dehumidifier and provide the theoretical basis for the optimization design, and the ooeration and modulation of the solar liquid desiccant air-conditioning systems.

Electrochemical Properties of PP13TFSI-LiTFSI-P（VdF-HFP） Ionic Liquid Gel Polymer Electrolytes

N-Methyl-N-propylpiperidiniumbis（trifluoromethanesulfonyl）imide （PP13TFSI）, bis（triflu- oromethanesulfonyl）imide lithium salt （LiTFSI）, and poly（vinylidene difluoride-co- hexafluoropropylene） （P（VdF-HFP）） were mixed and made into ionic liquid gel polymer electrolytes （ILGPEs） by solution casting. The morphology of ILGPEs was observed by scanning electron microscopy. It was found that the ILGPE had a loosened structure with liquid phase uniformly distributed. The ionic conductivity, lithium ion transference num- bet and electrochemical window were measured by electrochemical impedance spectroscopy, chronoamperometric and linear sweep voltammetry. The ionic conductivity and lithium ion transference number of this ILGPE reached 0.79 mS/cm and 0.71 at room temperature, and the electrochemical window was 0 to 5.1 V vs. Li＋/Li. Battery tests indicated that the ILGPE is stable when being operated in Li/LiFePO4 batteries. The discharge capacity maintained at about 135, 117, and 100 mAh/g at 30, 75, and 150 mA/g rates, respectively. The capacity retentions were almost 100% after 100 cycles without little capacity fading.

Nano-porous Composites Based on Liquid： Synthesis, Characterization, Esterification Heteropolyacid Functionalized Ionic and Catalytic Performance in

Fhnctionalized ionic liquid samples （bmim-PW12） were synthesized by 1-butyl-3-methyl- imidazolium bromide （bmimBr） and 12-phosphotungstic heteropolyacid （PW12）. The samples were annealed at 100-450 ℃ and were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, thermal gravity-DTG, brunauer emmett teller, and NHa-temperature programmed desorption. The results showed that the bmim-PW12 samples were crystal and maintained intact Keggin structure. The organic parts of those samples were partly decomposed at a temperature more than 350 ℃. The sample annealed at 400 ℃ exhibited nano-porous structure, strong acidity, and excellent catalytic activity on the esterification of n-butanol with acetic acid. The higher ester yield was obtained when the mass ratio of catalyst over the reactants amount was 5% for bmim-PW12 catalyst annealed at 400 ℃.

Structural Analogy for Dynamic Analysis of Liquid Sloshing

The analogy between the wave equation of liquid and the Navier equations of structural elasticity is examined in detail. By introducing appropriate parameters, the structural counterpart of the liquid sloshing model can be easily built. Therefore, the dynamic analysis of liquid sloshing can be reduced to that of structural elasticity, and the existing FEM structural analysis computer programs can be applied to liquid sloshing analysis without any modification. The present method also reveals the internal relationship between liquid sloshing and structural vibration. The effectiveness and reliability of the method is illustrated by the numerical example.

Precursor solution prepared by evaporation deamination complex method for solvent separation of Mo and W by H_2O_2-complexation

An novel method on preparation of precursor solution for solvent separation of molybdenum （Mo） and tungsten （W） by hydrogen peroxide （H2O2）-complexation from the ammonium tungstate solution containing high Mo was studied. The precursor solution was obtained via evaporation deamination and H202-complex transformation processes. Then it was extracted with a mixture extractant of tri-alkyl phosphine oxide （TRPO） and tributyl phosphate （TBP） to separate Mo and W. The results indicated that the evaporation deamination complex method reduced the acid consumption by more than 90% in comparison with the traditional directly acid regulation complex method. The transformation rates of W and Mo were higher than 95% and the decomposition rate of H202 was less than 15% at a 1.8-1.9 times H202 dosage, 45-50 ℃, initial pH of 1.80-1.90, and transformation volume ratio of 100% for 60 min in the H2O2-complexation transformation process. The minimum extraction rate of W was 2%, the maximum extraction rate of Mo was 82.6% and the highest separation coefficient was 76.7 in a single-stage extraction.

Electrodeposition of As-Sb alloy from high arsenic-containing solutions

As-Sb alloy was electrodeposited from high arsenic-containing solutions. The influences of current density, Sb（3＋） concentration, reaction temperature and HCl concentration on the electrolyte composition, cell voltage and current efficiency were investigated. The surface morphology, composition and structure of the deposits were analyzed by scanning electron microscopy（SEM）, inductively coupled plasma mass spectrometry（ICP-MS） and X-ray diffraction（XRD）, respectively. The results show that the prepared As-Sb alloy shows an amorphous structure under all conditions. Under the optimized condition, i.e., 10 g/L As（3＋）, 2 g/L Sb（3＋）, 4 mol/L HCl, current density of 4 mA/cm2 and temperature of 20 °C, desired As-Sb alloy with a composition of 70.26% As and 29.74% Sb（mass fraction） is obtained. What is more, the current efficiency is as high as 94.74% and high arsenic removal rate is achieved under this condition.