Performance improvement of lithium-ion battery by pulse current

Periodically changed current is called pulse current.It has been found that using the pulse current to charge/discharge lithium-ion batteries can improve the safety and cycle stability of the battery.In this short review,the mechanisms of pulse current improving the performance of lithium-ion batteries are summarized from four aspects:activation,warming up,fast charging and inhibition of lithium dendrites.Related content may help us use the pulse current to improve the performance of lithium-ion batteries and further optimize pulse current technology.     

Dependence of Performance of Organic Light-emitting Devices on Sheet Resistance of Indium-tin-oxide Anodes

IntroductionIndium-tin-oxide(ITO) has been widely used asthe anode material in organic light-emitting devices(OLEDs) because of its high transmittance in the visi-ble region and low electrical resistivity. In the pastyears, many investigations focused on …     

Improved Performance of W／HZSM-5 Catalysts for Dehydroaromatization of Methane

The dehydroaramatization of methane over W-supported ZSM-5 with varying degrees of Li^ ion-exchanged catalysts was studied with and without oxygen at 1073 K and atmospheric pressure.Catalyst activity and stability were found to be influenced by the catalyst acidity related to BrSnsted acid sites and by the presence of oxygen in the feed. The NH3-TPD and FTIR-pyridine results demonstrated that partially exchanged of H^ ions by Li^ into the W/HZSM-5 catalysts could be used to control the amount of strong acid sites on the catalyst surface. Without oxygen, the 3WHLi-Z (5:1) catalyst that has strong acid sites equal to nearly 74% of the original strong acid sites in the parent HZSM-5 exhibited the highest methane conversion and selectivity towards aromatics. However, the catalyst deactivated in a five hour period. In the presence of oxygen, the catalyst activity and stability could be improved further.The results of this study revealed that a suitable amount of strong Bronsted acid sites as well as oxygen addition in the feed increased the catalyst activity and stability. The 3WHLi-Z(5:1) catalyst exhibited improved performance in the dehydroaromatization of methane.     

Effect of Reduction Temperature on Hydrofining Performance of Supported Molybdenum Phosphide Catalyst

A series of supported molybdenum phosphide catalysts were prepared by impregnation method. XRD, TG-DTG, XPS and BET were used to study the phase, compositions and surface areas of the prepared catalysts. A model reactant containing thiophene, pyridine and cyclohexene was used for the measurements of catalytic activities. The effect of reduction temperature on catalytic activities was investigated. The analysis results by XRD and BET are very different when the reduction temperature is changed from 400 to 900 ℃. MoP/γ-Al2O3 catalysts and CoMoP/γ-Al2O3 catalysts prepared at the reduction temperature of 500 ℃ are the most active ones.     

Alkyl-Bridged Nitropyrazoles – Adjustment of Performance and Sensitivity Parameters

Starting from 3,5-dinitro-4-methylaminopyrazole ( 2 ), six different energetic salts and three new derivatives of methylene bridged nitropyrazoles were synthesized. The derivatives bear a methylamino ( 4 ), methylnitramino ( 5 ), and azido group ( 7 ). All compounds were intensively characterized using single crystal X-ray diffraction, multinuclear NMR spectroscopy, IR spectroscopy, mass spectrometry, elemental analysis and DTA/TGA measurements. The sensitivities were determined according to BAM standard methods and the energetic properties calculated using the EXPLO5 code. The energetic salts were compared with each other and with ANTA in terms of their energetic properties. On the basis of the methyl- and ethyl bridged derivatives, it was shown how the introduction of methylamino ( 4 ) and methylnitramino ( 5 ) groups in an alkyl-bridged nitropyrazole system modify its properties (performance & sensitivities). In addition, azido compound 7 was contrasted with its literature-known constitutional isomer and investigated for its suitability as a potential metal-free primary explosive.     

Synthesis and Separating Performance of SAPO-44 Zeolite Membrane

A defect-free SAPO-44 zeolite membrane firmly anchored the porous α-Al2O3 plate substrate was successfully synthesized. The separating results showed that the H2/N2 and H2/CO permselectivities were higher than those of the corresponding Knudsen diffusion and the substrate, attaining 5.78 and 7.15 respectively.     

Reversed－Phase High－Performance Liquid Chromatographic Determination of Drugs of Abuse

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High Performance Liquid Chromatographic Separation of Bryostatins 1–12

Abstract

A reversed-phase high performance liquid chromatographic (RP-8; acetonitrile-water gradient) separation procedure was developed for detecting bryostatins 1–12, using a photodiode array detector system. While bryostatins 6 and 9 were found to co-elute they were easily separated using a silica gel column with 9:1 n-hexane-n-propanol as eluent.     

Performance characteristics of a planar ‘clark-type’ oxygen sensor

A planar two-electrode oxygen sensor is fabricated using standard IC technology. It consists of an Ag cathode and an Ag/AgCl/Cl⁻ reference anode. The electrochemical characterization of the cathode and the long-term behaviour, i.e., stability, of the reference electrode are determined in order to optimize the fabrication procedure. The device is then completed with a hydrogel layer (poly 2-hydroxyethyl methacrylate, pHEMA) and a silicone rubber membrane. Voltammetric and chronoamperometric tests of the complete sensor are performed and its O₂ response determined.     

Application of High Performance Liquid Chromatography to Separation of Novel Chiral Tetrahedral Heterometal Clusters

A series of novel chiral tetrahedral heterometal clusters have firstly been separated on cellulose tris-(3,5-dimethylphenylcarbamate) stationary phase by high performance liquid chrom-atography, using hexane as the mobile phase with various alcohols as modifiers.     

Effects of Doped Elements on Electrochemical Performance of Ni（OH）2 Materials

High energy ball milling(HEBM)method was applied to synthesize Ni(OH)2 with different doped elements substitution for Ni2 .The morphology,structure and electrochemical behavior of prepared powders were studied.The results reveal that all the synthesized Ni(OH)2 particles were in sub-micron sizes and greatly agglomerated.Co-,Mg-,Fe-or Mn-doped Ni(OH)2 was of β-phase with 0.400-0.500 nm crystal interlayer distance,while Al-and Zn-doped products displayed α-phase with larger crystal interlayer spaces.The electrochemical mechanisms of synthesized Ni(OH)2 electrodes were discussed by EIS spectra.The specific capacity of Co-doped Ni(OH)2 is 245 mA·h·g-1,i.e.,60 mA·h·g-1 higher than that of Al-doped electrode,which has the highest discharging platform of a mid-voltage of 1.30 V.     

Investigation on the Performance of Supported Molybdenum Carbide for the Partial Oxidation of Methane

The performance of uspported and unsupported molybdenum carbide for the partial oxidation of methane (POM) to syngas was investgated.An evaluation of the catalysts indicates that bulk molybdenum carbied has a higher methane conversion during the initial stage but a lower selectivity to CO and H2/CO ratio in the products.The rapid deactivation of the catalyst is also a significant problem.However,the supported molybdenum carbide catalyst shows a much higher methane conversion,increased selectivity and significantly improved catalytic stability.The characterization by XRD and BET specific area measurements depict an improved dispersion of molybdenum carbide when using alumina as a carrier.The bulk or the supported molybdenum carbide exists in the β-Mo2C phase,while it is transformed into molybdenum dioxide postcatalysis which is an improtant cause of molybdenum carbide deactivation.     

Determination of Chromate Ion in Water Using High Performance Capillary Electrophoresis

ThereisarapidIyincreasingdemandforfastandreliableanalyticaImethodsforthedeterminationofchemicaIformsofelementSinenvironmentalsamples.IthaslongbeenknownthatCrfIII)isessentialformammals,however,CrfVI)isconsideredtobeatoxicagent[l].Theanalysisofchromateion(Vl)inenvironmentwaterisusuallyperformedbyusingspephotometryandatomicabsorption,p..tr...ny[2].TheformerneedsfairIylargeamountofsample,pretreatmenLandlonganalysistime.Thelaterequipmentismuchmoreexpensive.InpreviousreportS,chromateisnormaI1…     

Study on Dyeing Performance of Cationic Water-soluble Sulphur Black on Silk

A novel polyquaternaryammonium cationic sulphur black dye was synthesized and its dyeing behavior on silk was studied. The dye exhibited excellent dyeing fixation of up to 98.2 %,as well as excellent dyeing fastness on silk.     

Preparation and Performance of Polysulfone‐Cellulose Acetate Blend Ultrafiltration Membrane

In the development of high performance polymeric membranes, it is essential to design the molecular and morphological characteristics for specific applications. Polysulfone and cellulose acetate of blend membranes with various concentration of polymer pore former, PEG600 were prepared by phase inversion technique and used for ultrafiltration. Polymer blend composition, additive concentration, and casting conditions were optimized. The blend membranes were characterized in terms of compaction, pure water flux, water content, hydraulic resistance and separation of dextran studies. Surface morphology of the embranes was analyzed using scanning electron microscopy at different magnifications. Further, the characterized membranes were attempted for treatment of distillery effluents after secondary treatment and the results are discussed in detail.     

Performance Evaluation of Hybrid Gas–Liquid Pulse Discharge Plasma-Induced Degradation of Polyvinyl Alcohol-Containing Wastewater

A multi-needle-to-plate pulsed discharge plasma reactor was designed to investigate its potential for polyvinyl alcohol-containing wastewater (PVA) treatment. The effects of some operational parameters such as PVA initial concentration, pulse peak discharge voltage, air flow rate, solution pH value, and iron additives on PVA degradation were examined. The results indicated that PVA could be effectively degraded from aqueous solutions. PVA degradation efficiency was 76.0 % within 60 min’s discharge plasma treatment with 1.5 mmol L^?1 Fe²⁺ addition. Decreasing PVA initial concentration and increasing pulse peak discharge voltage were both beneficial for PVA degradation. There existed appropriate air flow rate for obtaining great PVA degradation efficiency in the present study. A little acid environment was conducive to PVA degradation. The presence of Fe²⁺ and Cu²⁺ could both benefit PVA degradation, and the increment of Fe²⁺ and Cu²⁺ concentrations to a certain extent could enhance its degradation efficiency, as well as energy yield. PVA possible degradation mechanisms were discussed, and the degradation processes were mainly triggered by the reactions of PVA with \(^{ \cdot } {\text{OH}}\) radicals.     

The Performance of Rhodium Complex—diphosphine Systems in the Hydroformylation of 1—Dodecene

The catalytic performances of four HRh(CO)(PPh3)3-diphosphine (BISBI,BDPX,BDNA and BINAP) systems in 1-dodecene hydroformylation were investigated and compared with HRh(CO)(PPh3)3-PPh3 system.The catalyst system HRb(CO)(PPh3)3-BISBI exhibited very hig regioselectivity for the formation of linear aldehyde.     

Effect of Temperature and Discharge Rate on Electrochemical Performance of Fiber Nickel–Cadmium Cell

Russian Journal of Electrochemistry - The effect of temperature and discharge rate on the discharge capacity of nickel–cadmium (Ni?Cd) cell is investigated quantitatively. Ni–Cd...     

Acceptor-acceptor-type Organoboron Conjugated Polymers: Effect of Backbone Configuration on Thermoelectric Performance

The development of n-type polymer thermoelectrics lags far behind that of p-type ones in view of material diversity and performance.New structural insights into the thermoelectric performance are needed for efficient n-type polymer thermoelectric materials. Herein, we developed three acceptor-acceptor type organoboron polymers and investigated the effect of backbone configuration on thermoelectric performance. The three polymers are designed based on double B←N bridged bipyridine(BNBP) unit with...     

Quantification of Levosulpiride in Human Plasma by High‐Performance Liquid Chromatography

Abstract

An analytical procedure was developed and validated for the quantification of levosulpiride in human plasma. After subjecting a plasma sample to a two‐step extraction procedure, an aliquot of the aqueous phase was injected onto an high‐performance liquid chromatography system equipped with a fluorescence detector. The detector response was linear for levosulpiride concentrations in the range of 2.5 to 500 ng/ml. The intra‐ and inter‐day precision was below 15.4 and 10.1%, and the accuracy was in a range from 89.7 to 109.4%. The method is applicable for use in the pharmacokinetic characterization of levosulpiride after a 75‐mg oral dose in humans.