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An iridium-catalyzed asymmetric allylic benzylation of aryl vinyl carbinols under light irradiation is described. 2-Methylbenzophenone derivatives are employed and activated to hydroxy-o-quinodimethanes by an ultraviolet (UV) light. This approach enables asymmetric allylic benzylation with high enantioselectivity (up to 99 % ee) from readily available 2-methylbenzophenones without the utilization of strong bases, and pre-activation or pre-functionalization of the substrates. Moreover, deuterium experiments reveal the generation of nucleophilic benzyl species from 2-methylbenzophenone under UV irradiation.

Efficacious regulation of the geometric and electronic structures of carbon nanomaterials via the introduction of defects and their synergy is essential to achieving good electrochemical performance. However, the guidelines for designing hybrid materials with advantageous structures and the fundamental understanding of their electrocatalytic mechanisms remain unclear. Herein, superfine Pt and PtCu nanoparticles supported by novel S,N-co-doped multi-walled CNT (MWCNTs) were prepared through the innovative pyrolysis of a poly(3,4-ethylenedioxythiophene)/polyaniline copolymer as a source of S and N. The uniform wrapping of the copolymer around the MWCNTs provides a high density of evenly distributed defects on the surface after the pyrolysis treatment, facilitating the uniform distribution of ultrafine Pt and PtCu nanoparticles. Remarkably, the Pt1Cu2/SN-MWCNTs show an obviously larger electroactive surface area and higher mass activity, stability, and CO poisoning resistance in methanol oxidation compared to Pt/SN-MWCNTs, Pt/S-MWCNTs, Pt/N-MWCNTs, and commercial Pt/C. Density functional theory studies confirm that the co-doping of S and N considerably deforms the CNTs and polarizes the adjacent C atoms. Consequently, both the adsorption of Pt1Cu2 onto the SN-MWCNTs and the subsequent adsorption of methanol are enhanced; in addition, the catalytic activity of Pt1Cu2/SN-MWCNTs for methanol oxidation is thermodynamically and kinetically more favorable than that of its CNT and N-CNT counterparts. This work provides a novel method to fabricate high-performance fuel cell electrocatalysts with highly dispersed and stable Pt-based nanoparticles on a carbon substrate.

The application of Pt alloy catalysts for oxygen reduction reactions (ORRs) in proton-exchange membrane fuel cells is severely impeded by base metal leaching, since the produced metal ions can resu...

Direct methanol fuel cell (DMFC) with near-zero pollution emission, large energy density, and low operating temperature provides a beneficial and sustainable way for alleviating fossil energy crisis and ecological pollution issues. In this work, a systematic protocol was explored for the design of novel electrocatalyst based on PEDOT-PSS coated amino-functionalized SiO2 microspheres (SiO2–NH2@PEDOT-PSS) support, and then Pt nano-particles (NPs) were uniformly anchored for the anodic process of DMFCs. Characterization techniques, e.g. X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed that the dispersity and homogeneity of Pt NPs on the surface of SiO2–NH2@PEDOT-PSS were markedly improved due to PEDOT-PSS modification, and the distribution of Pt NPs was in a smaller mean-size ~2.8 nm. Subsequently, X-ray photoelectron spectroscopy (XPS) study exposed fast electron shift phenomenon from SiO2–NH2@PEDOT-PSS support to Pt NPs in the catalyst. The various electrochemical tests such as cyclic voltammetry (CV), chronoamperometry (CA) and impedance spectroscopy (EIS) revealed that the prepared Pt/SiO2–NH2@PEDOT-PSS catalyst presented higher electrocatalytic efficacy, excellent durability with improved CO-tolerance towards methanol oxidation reaction rather than commercial Pt/C catalyst. These distinctive physical and chemical features of designed catalyst raise the spirit to design an efficient electrocatalyst based on Pt/SiO2–NH2@PEDOT-PSS in DMFC applications.

Improving the slow kinetics of hydrogen evolution/oxidation reaction(HER/HOR) on Pt in the alkaline electrolyte is key to the development of water splitting and hydroxide exchange membrane fuel cells, which feature a potential cost advantage over their acid-operating counterparts. However, it is still unconfirmed whether adsorbed surface hydroxyl species (OHad) plays a significant role in determining HER/HOR activity. Moreover, the active sites should be different in the alkaline due to the sluggish reaction rate. In the present work, electrochemical tests have shown that for modified bulk Pt surface and Pt3Ni nanoalloy, HER rate is co-determined by the oxophilic effect and electronic effect, while the rate of HOR is associated with the electronic effect. Density functional theory (DFT) calculations reveal the fundamentally different HER and HOR mechanism of Pt-based nanoparticles, and the surface charge may account for such difference. Finally, the adsorption and oxidation of carbon monoxide (CO) as a novel descriptor are provided to predicate the activity of HER and HOR.

As a cost-effective element, Mg has been applied as doped inactive atom to improve the electrochemical performance of sodium-ion cathode materials. Herein, we report Mg-substituted Na0.67Mn0.65Ni0.2Co0.15-xMgxO2 composites as high-performance cathode for sodium-ion batteries and investigate the underlying working mechanism using in situ investigation techniques to monitor the operando changes of electrodes. In situ X-ray diffraction investigation demonstrates P2-type structure is well preserved even charged to 4.3 V and the changes of lattice parameters and unit cell volume of Na0.67Mn0.65Ni0.2Mg0.15O2 are alleviated via Mg replacement. As a result, the capacity retention increases from 62% in Na0.67Mn0.65Ni0.2Co0.15O2 to 94% in Na0.67Mn0.65Ni0.2Mg0.15O2. Meanwhile, less CO2 evolution was detected in the coin cell with Na0.67Mn0.65Ni0.2Mg0.15O2 electrode than in that with Na0.67Mn0.65Ni0.2Co0.15O2 electrode in online differential electrochemical mass spectrometry test, suggesting a depressed side reaction between electrode and electrolyte after Mg completely replacing Co. In situ electrochemical impedance spectroscopy investigation further proves Mg is beneficial for the interfacial conductivity enhancement compared to Co, which provides evidence for enhanced high rate capabilities. These comprehensive results provide new viewpoints to explain the improved cycling and rate capabilities from the aspects of crystal structure evolution, coin cell gas evolution and electrolyte/electrode interface conductivity during charge/discharge process.

Reasonable design and synthesis of Fe/N/C-based catalysts is one of the most promising way for developing precious metal-free oxygen reduction reaction (ORR) catalysts in acidic mediums. Herein, we developed a highly active metal–organic framework-derived S-doped Fe/N/C catalyst [S-Fe/Z8/2-aminothiazole (2-AT)] prepared by thermal treatment. The S-Fe/Z8/2-AT catalyst with uniform S-doping possesses a three-dimensional macro–meso–micro hierarchically porous structure. Moreover, the chemical composition and structural features have been well-optimized and characterized for such S-Fe/Z8/2-AT catalysts; and their formation mechanism was also revealed. Significantly, applying the optimal S-Fe/Z8/2-AT catalysts into electrocatalytic test exhibits remarkable ORR catalytic activity with a half-wave potential of 0.82 V (vs reversible hydrogen electrode) and a mass activity of 18.3 A g–1 at 0.8 V in 0.1 M H2SO4 solution; the polymer electrolyte membrane fuel cell test also confirmed their excellent catalytic activi...

The paper reports an experimental investigation of a newly proposed solar collector that integrates a closed-end pulsating heat pipe (PHP) and a compound parabolic concentrator (CPC). The PHP is used as an absorber due to its simple structure and high heat transfer capacity. The CPC has a concentration ratio of 3.4 and can be readily manufactured by three-dimensional printing. The CPC can significantly increase the incident solar irradiation intensity to the PHP absorber and also reduce the heat loss due to the decrease in the area of the hot surface. A prototype of the solar collector has been built, consisting of a PHP absorber bent by 4 mm diameter copper tube, CPC arrayed by 10 × 2 CPC units with the collection area of 300 × 427.6 mm 2 , a hot water tank and a glass cover. HFE7100 was utilized as the working fluid at a filling ratio of 40%. The operating characteristics and thermal efficiency of the solar collector were experimentally studied. The steady and periodic temperature fluctuations of the evaporation and condensation sections of the PHP absorber indicate that the absorber works well with a thermal resistance of about 0.26 °C/W. It is also found that, as the main factor to the the thermal performance of the collector, thermal resistance of the PHP absorber decreases with increasing evaporation temperature. The collector apparently shows start-up, operational and shutdown stages at the starting and ending temperatures of 75 °C. When the direct normal irradiance is 800 W/m 2 , the instantaneous thermal efficiency of the solar collector can reach up to 50%.

A novel electrocatalyst of PdPtNi ternary alloy nanoparticles supported on multi-walled carbon nanotubes (MWCNTs) for formic acid oxidation (FAO) reaction is synthesized by a simple hydrogen co-reduction process. The as-synthesized catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy and X-ray photoelectron spectroscopy (XPS). It is found that highly dispersed PdPtNi alloy nanoparticles of ca. 2.56 nm are homogeneously deposited on the MWCNT surface, and the alloying with Pt and Ni alters the electronic structure of Pd atoms with the downshift of Pd d-band center. Studies of cyclic voltammetry and chronoamperometry indicate that the electrocatalytic activity and durability of the PdPtNi/MWCNT for FAO are significantly enhanced as compared with the PdPt/MWCNT and commercial Pd/C catalysts. This study implies that the prepared PdPtNi/MWCNT composite is a promising anode electrocatalyst of direct formic acid fuel cells.

Doped nanocarbon materials (e.g., carbon nanotubes, graphene) are considered as effective electrocatalyst supports for fuel cells, and their electrochemical properties are closely related to the synthetic methods and the types of doping elements. In the current paper, we report a novel approach to synthesize sulfur-doped multi-walled carbon nanotubes (S-MWCNTs) as a highly efficient support material for Pt nanoparticle catalysts. The S-MWCNTs are obtained by annealing poly(3,4-ethylenedioxythiophene) (PEDOT) functionalized multi-walled carbon nanotubes at 800 °C. The prepared nanohybrids were physically characterized by Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). It has been found that the doping of sulfur into MWCNTs could significantly improve the dispersion of supported Pt nanoparticles of 2.37 nm in size and increase the electrochemically active surface area (ECSA, 161.4 m2 g−1). The doped sulfur atoms not only provide uniformly dispersed anchoring sites for the deposition of Pt nanoparticles on the surface of MWCNTs but also enhance the electron transfer interaction between Pt nanoparticles and the S-MWCNT support. The electrochemical properties of the catalysts were evaluated by using cyclic voltammetry (CV) and chronoamperometry (CA) techniques. The results demonstrate that the as-prepared Pt/S-MWCNTs exhibit much higher electrocatalytic activity, long-term durability and CO-tolerance ability for the methanol oxidation reaction (MOR) compared to the undoped MWCNT supported Pt and commercial Pt/C catalysts.

Experimental work was carried out to clarify the thermal performance of a pulsating heat pipe (PHP) with the tube body was pretreated by a muffle furnace at 500℃for 5 hours. It is found that the annealing of the pipe body improves the wettability of the working fluid on the tube wall, thus enhance heat transfer between the tube wall and working fluid due to the increase in the liquid film area. Experimental results show that after annealing, the PHP starts to accelerate. Comparing to the original PHP, the starting time of the surface annealed PHP can be shortened by 78s at 30W while the minimum starting power is reduced from 30W to 16Wand the starting temperature can be reduced by about 10°C.

Supplemental Digital Content is available in the text, Background: Neuroprotective effects of dexmedetomidine are reported in preclinical and clinical studies but evidence regarding the postoperative neurocognitive function is still unclear. This study performed a meta-analysis on outcomes of studies which examined neurocognitive performance and inflammatory factors to investigate the effects of dexmedetomidine on postoperative cognitive dysfunction (POCD) and inflammation in patients after general anaesthesia. Methods: Literatures were searched in several electronic databases and studies were selected by following precise inclusion criteria. We searched PubMed, EMBASE, the Cochrane Library, China Academic Journals full-text database (CNKI), and Google Scholar to find randomized controlled trials (RCTs) of the influence of dexmedetomidine on POCD and inflammation in patients who had undergone general anaesthesia. Two researchers independently screened the literature, extracted data, and evaluated quality of methodology against inclusion and exclusion criteria. Meta-analyses of pooled ORs of POCD incidences and mean differences in neurocognitive assessment scores and inflammation levels were carried out and subgroup analyses were performed. Stata 12.0 was used to conduct our meta-analysis. Results: Twenty-six RCTs were included. Compared with controls, perioperative dexmedetomidine treatment significantly reduced the incidence of POCD (pooled ORs = 0.59, 95% confidence interval (CI) 0.45–2.95) and improved Mini-Mental State Examination (MMSE) score (standardized mean difference (SMD) = 1.74, 95% CI 0.43–3.05) on the first postoperative day. Furthermore, perioperative dexmedetomidine treatment significantly decreased IL-6 (SMD = −1.31, 95% CI −1.87–0.75, P

Deep eutectic solvents (DESs) are being increasingly used in electrochemically controllable synthesis of functional nanomaterials because of their unique merits (e.g., high conductivity, wide electrochemical windows and environmental friendship). Herein, we report a novel strategy in DESs for the fabrication of multi-walled carbon nanotubes (MWCNTs)-supported Pd-based alloy nanostructures. Using a NaBH4 solvothermal reduction process in DESs, highly active PdSn alloy nanocatalysts supported on MWCNTs towards the formic acid oxidation (FAO) reaction were synthesized for the first time. The as-synthesized materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy, X-ray photoelectron spectroscopy (XPS) and electrochemical tests. The results demonstrate that the PdSn nanocluster structure with a rough surface provides a high density of catalytically active sites and thereby increases the electrochemically active surface area. There is a strong charge transfer interaction between Pd and Sn in the PdSn/MWCNT catalyst due to its high degree of alloying. The electrochemical studies indicate that the PdSn/MWCNT shows remarkably improved electrocatalytic performance towards FAO compared to Pd/MWCNT and commercial Pd/C catalysts. This study suggests an effective synthesis strategy for Pd-based electrocatalysts with high performance for DFAFCs applications.

Background: The aim of this study was to explore the association between CD24 Ala/Val polymorphism and susceptibility of multiple sclerosis (MS). Methods: A comprehensive literature search for relevant studies was performed on google scholar, PubMed, Web of science, Embase, the Chinese National Knowledge Infrastructure and the Chinese Biology Medicine. This meta-analysis was conducted using the STATA 11.0 software and the pooled odds ratio with 95% confidence interval was calculated. Results: Seven case-control studies were included in this meta-analysis. The results showed significant association between CD24 Ala/Val polymorphism and susceptibility to MS. Stratified analysis by areas also showed significant association in Asians. However, no association was found in Europeans. Conclusion: This study suggested that the CD24 Val allele was associated with an increased risk of MS and larger-scale studies of populations are needed to explore the role of CD24 Ala/Val polymorphism during the pathogenesis of MS.

Crisis communication theories suggest that crisis communications must appeal to publics’ perceptions and expectations. But in crisis there could be gaps between communicators and audiences about communicated objects. There were two kinds of gaps could happen: crisis situations and expected strategies. The gaps between the organization and publics in crisis communication dynamic are still unexplored. This research designed virtual crisis situations and communication strategies, surveyed the subject’s responses, analysed how gaps influence the communication effect, found the acceptability of explanations was crucial of crisis communication effect. This research constructed a model, theoretical and practical implications also discussed.

Herein, we report a novel electrocatalyst consisting of Pt nanoparticles supported on a polyindole (PIn)-functionalized multi-walled carbon nanotube (MWCNT) composite (Pt/PIn-MWCNT) for use in the methanol oxidation reaction (MOR). The PIn-MWCNT support is synthesized via in situ chemical polymerization of indole on the MWCNT surface. The transmission electron microscopy (TEM) images indicated that the Pt nanoparticles were approximately 3.0 nm in size and were uniformly deposited on the surface of PIn-MWCNTs with no aggregation into larger clusters. X-ray photoelectron spectroscopy (XPS) measurements confirm the strong electron interaction between the Pt nanoparticles and the PIn-MWCNT support as well as the formation of the Pt–N bond. The electrochemical tests demonstrate that the Pt/PIn-MWCNT composite exhibits much higher electrocatalytic activity, durability and CO tolerance than the Pt/MWCNT and commercial Pt/C catalysts toward MOR. The results indicate that the as-prepared Pt/PIn-MWCNTs are promising for use as an anode electrocatalyst in direct methanol fuel cells (DMFCs).

The hydrothermal synthesis of a novel Pd electrocatalyst using copper phthalocyanine-3,4′,4″,4′″-tetrasulfonic acid tetrasodium salt (TSCuPc) functionalized multi-walled carbon nanotubes (MWCNTs) composite as catalyst support for Pd nanoparticles is reported. The prepared nanocomposites were characterized by UV–vis absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical tests. It is found that Pd nanoparticles are uniformly deposited on the surface of TSCuPc-MWCNTs, and their dispersion and electrochemical active surface area (ECSA) are significantly improved. Studies of cyclic voltammetry and chronoamperometry demonstrate that the Pd/TSCuPc-MWCNTs exhibits much higher electrocatalytic activity and stability than the Pd/AO-MWCNTs catalyst for formic acid oxidation. This study implies that the as-prepared Pd/TSCuPc-MWCNTs will be a promising candidate as an anode electrocatalyst in direct formic acid fuel cell (DFAFC).

Two waste heat recovery systems of barbershops were presented to increase its heat utilization efficiency. One was the waste heat recovery system with water-to-water heat exchanger (WHR-HE). The other is the waste heat recovery system with both water-to-water heat exchanger and heat pump (WHR-HE-HP). The two waste heat recovery systems were analyzed by both economics and thermodynamics principles. Compared to conventional heat utilization systems of barbershops, the WHR-HE decreases annual energy consumption by 54.2%, and the WHR-HE-HP decreases annual energy consumption by 87.5%. The gain investment recovery periods of WHR-HE and WHR-HE-HP are below half one year. Compared to the WHR-HE, the WHR-HE-HP is with larger energy-saving potential, lower running cost, larger first cost and larger gain investment recovery period. The critical value of energy-saving financial subsidy is 0.778 ¥/W for the WHR-HE-HP. The WHR-HE-HP is very suited to the large and medium-sized barbershops, especially in the cold climate zone.

We herein report a facile and effective ultrasonication method to non-covalently functionalize graphene with copper phthalocyanine-3,4′,4″,4‴-tetrasulfonic acid tetrasodium salt (TSCuPc) as a promising catalyst support for Pt nanoparticles. With the assistance of TSCuPc, Pt nanoparticles are homogeneously deposited on the surface of graphene, and their dispersivity and electrochemical active surface area (ECSA) are obviously enhanced. Studies of cyclic voltammetry and chronoamperometry demonstrate that the as-prepared Pt/TSCuPc–graphene catalyst exhibits much higher electrocatalytic activity and stability than the Pt/graphene and commercial Pt/C catalysts for methanol oxidation. It is concluded that the strategy of TSCuPc-functionalized graphene with Pt catalysts will be potential in design and synthesis of the highly efficient electrocatalysts for DMFCs applications.

We herein report a novel Pt-based electrocatalyst for direct methanol fuel cells (DMFCs) using multi-walled carbon nanotubes (MWCNTs) supported manganese oxide and poly(3,4-ethylenedioxythiophene) (PEDOT) nanocomposite (MnO x –PEDOT–MWCNTs) as catalyst support for Pt nanoparticles. The prepared nanocomposites are characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical tests. The results demonstrate that Pt nanoparticles are uniformly deposited on the surface of MnO x –PEDOT–MWCNTs, and their dispersion and electrochemical active surface area (ECSA) are obviously improved. The methanol electrooxidation activity and stability of the Pt/MnO x –PEDOT–MWCNTs are significantly enhanced as compared with the Pt/PEDOT–MWCNTs and Pt/MWCNTs catalysts. This study implies that the as-prepared Pt/MnO x –PEDOT–MWCNTs will be a promising candidate as an anode electrocatalyst in DMFCs.

The thermal performance Rov of Flat-Plate Closed-Loop Pulsating Heat Pipe(FCLPHP) are effected by several elements such as the heat load Q, the tilt angle θ and the filling ratio F, they are interacted each other. In order to predict the effect of Q and θ on the thermal performance at locations Q and θ other than the experimental data conditions, and to study the relationship among the Rov, Q and θ in the range of the experimental data, we need a fitted regression model to estimate the function relationship that describes the data. The postulated depends on the range of the regression variables encountered in the data. In this paper, a simple model was developed. Since the coefficients in the model have been estimated from the experimental data, studies were carried out on an experimental set-up. FC72 was employed as working fluid. Method of least squares was used for building the model. By using the model, effects of the heat load and the tilt angle on the thermal performance of FCLPHP were discussed. It was found that the tilt angle had minimum value in a certain heat load in the experimental range (θ=30° -70°), and it increases with the increase of heat load. A sensitivity analysis was done with the model.

To improve the energy efficiency of refrigeration systems, carbon nanopowders, such as fullerene (C60) and carbon nanotubes (CNTs), are used widely because of their remarkable lubrication and heat transfer capacities. In this work, the dispersion stabilities of mineral oil with added C60, CNTs, and compound C60/CNTs nanopowders were investigated, respectively, by means of sedimentation observation and UV–visible scanning spectrophotometry. The results show that the two methods correspond well. C60 is more stable than CNTs with increasing time; the absorbency of fullerene nanorefrigeration oil displays increasing order with increased concentration, whereby 2 g/L is the inflection point; but a similar pattern appears in CNTs–oil only when the concentration is below 0.5 g/L, after which the concentration of the suspension cannot be measured by the absorbency because their values are alike. The agglomeration of CNTs in mineral refrigeration oil can be restored and it may not create any problems when employed in operational refrigeration systems. The different preparation procedures of compound C60/CNTs–oil exert a large influence on dispersion stability; by grinding fullerene first, one obtains the best dispersion stability of the complex nanorefrigeration oil, in comparison with other methods.

Adding dispersants like surfactants and polymers to modify nanoparticles surface is an effective way to enhance the dispersion stability of nanoparticles in refrigeration oil. In this paper, many groups of nano-CoFe2O4refrigeration oil were prepared. In order to obtain the most effective kind of dispersant and the optimum additive amount, sedimentation observation method was employed for evaluation of the dispersion stability of CoFe2O4nanoparticles in 3GS mineral lubricant. The spectral behavior of the surface modified nano-CoFe2O4was studied by Fourier transform infrared (FT-IR) spectrometer. It was revealed that the optimized mass ratio between nano-CoFe2O4and dispersant ratio is 2 to 5; a relatively appropriate dispersant for nano-CoFe2O4would be Tween40, Tween60, Span80, Span80; Tween60 was the best. It was also illustrated in the infrared spectrum that nano-CoFe2O4particles surface modified by Tween60 was connected by organic groups in Tween60. Thus, the particles changed from hydrophilic to lipophilic and performed good dispersity and high stability when dispersed in mineral refrigeration oil.

Thermodynamics of Pb(II) complex equilibrium in Pb(II)-NH3-NH4Cl-H2O system were studied using the double equilibrium method. Varying the concentration of ammonia and ammonium chloride, respectively, in range of 0~5mol/L, the equilibrium concentration of all the species in the system are calculated, and thermodynamic diagram are plotted. The dissolution laws of Pb(II) in the system are revealed and the high dissolution fields of Pb(II) are found. The solubility of lead increase with the ammonium chloride concentration increasing, and the highest solubility reaches 0.29mol/L, whereas the concentration of lead always remains 0 in pure ammonia solution. Add ammonium chloride to the solution and maintain its concentration constant, the concentration of lead decreases with ammonia concentration increasing.

Precursor of tungsten was obtained by spray drying process with high purity APT crystal liquor as material. The precursor was analysized by electron microscopy and X-ray. A suitable spray drying process was found through the morphology and powder structure. The influence of atomization disk rotational speed, the concentration ratio of ammonia to WO3 in APT liquor and APT liquor’s concentration on particle size, structure and morphology of the ball precursor were studied. Uniformity superfine WO3 was obtained from precursor by calcined.

Pulsating heat pipes are high efficiency heat transfer components having a great potential application in the field of electronic cooling and space applications. In this investigation, an experiment was conducted to study the influence of working fluid thermophysical properties on the thermal performance of flat-plate closed loop pulsating heat pipes (FCLPHP). The analysis of the forces acting on the liquid-vapor mixture shows that the surface tension, viscosity and latent heat of vaporization have important impact on the thermal performance of FCLPHP. The overall thermal resistance decreases with the decrease in surface tension, viscosity and latent heat of vaporization, leading to the heat transfer improvement of FCLPHP. An experimental correlation was developed to describe the relationship among the relative overall thermal resistance and the relative thermophysical properties. With the correlation, a sensitivity analysis was made. The results show that latent heat of vaporization is the prior factor to the all others to impact the thermal performance of FCLPHP.

Reaches in nanofluids heat transfer have conducted for decades, and lead to the development of the currently used heat transfer enhancement techniques. This paper is mainly concerned about the character of nanoparticles as an additive to the refrigeration system, and the preparation of nanofluids. Review the literatures about the nanoparticles used in the refrigeration system and refrigeration oil, and enhance of heat transfer of nanorefrigerant or nanorefrigeration oil. The suspended metallic or nonmetallic nanoparticles change the transport properties and heat transfer characteristics of the host fluid. The aim of this paper is outlook for foreground of the nanoparticles used in the refrigeration system, and to provide a guide line or perspective for future research.

The saturated vapor pressures of R22 uniformly mixed with refrigeration oil and nano- refrigeration-oil were measured experimentally at a temperature range from 263 to 333K and mass fractions from 1 to 5%. The experimental results showed that the saturated vapor pressure of R22/KT56 mixture was lower than that of pure R22; the pressure deviation between them increased with a raising mass fraction of refrigeration oil and temperature. After adding nano-NiFe2O4 and nano-fullerene into KT56, the pressure deviation increased at the same mass fraction and temperature. A saturated vapor pressure correlation for R22 and refrigeration oil/nano-refrigeration-oil mixture was proposed, and the calculated values agreed with the experimental data within the deviation of ± 0.77%.

Performance and degradation of direct methanol fuel cell (DMFC) membrane electrode assembly (MEA) are analyzed after repeated freeze/thaw cycles. Three different MEAs stored at −20 °C for 8 h with the anode side full of methanol solution are selected to test the effects of low temperatures on performance. After the cell heated to 60 °C within 30 min, they are inspected to determine the degradation mechanism. The resistance R obtained by the polarization curve is essential for identifying the main component affecting cell performance. The electrochemical impedance spectroscopy (EIS) technique is used to characterize the DMFC after freeze/thaw cycles. Thus, deterioration is assessed by measuring the high-frequency resistance (HFR) and the charge-transfer resistance (CTR). The electrochemical surface area (ECA) is employed to investigate not only the actual chemical degradation but also membrane status since sudden loss of ECA on the cathode side can result from a broken membrane. Moreover, a strategy is designed to simulate actual conditions that may prevent the membrane from being broken. A DMFC stack without any heating or heat-insulation devices shall avoid to be stored at subzero temperatures since the membrane will be useless due to frozen of methanol solution.

Two novel light-emitting materials bis-[2′-2″-(9H-fluoren-2-yl)-vinyl-8-hydroxyquinoline] zinc(II) (3) and bis-[2′-4″-(4,5-diphenyl-1H-imidazol-2-yl)styryl-8-hydroxyquinoline] zinc(II) (4) containting 8-hydroxyquinoline and fluorene or imidazole moieties have been synthesized. The optical properties of these complexes were influenced by the styryl substituents, and exhibited orange-emission. They have higher fluorescence quantum yields than Alq3, and good stabilities with thermal decomposition temperatures 395 °C and 435 °C. The single-layer OLED fabricated by 3 emitted lemon-yellow, and exhibited good device performance with a maximum luminance of 489 cd m−2, and luminance efficiency of up to 0.41 cd A−1. The single-layer OLED fabricated by 4 emitted yellow-green, and exhibited good device performance with a maximum luminance of 323 cd m−2, and luminance efficiency of up to 0.54 cd A−1.

Lead and indium were recovered by electrolysis and nonequilibrium solvent extraction process from lead bullion. The effects of current density, electrolytic period and circle amount of electrolyte on the electrochemical dissolution of lead and indium were investigated. The effects of extraction phase ratio and mixing time on solvent extraction of indium and striping phase ratio and stripping stage on the loaded organic phase stripping were also investigated. The experimental results indicate that under optimum conditions, the purity of lead deposited on cathode is 98.5% and the deposit rate of lead is 99.9%, the dissolution rate of indium is 94.28%, the extraction rate of indium is 98.69%, the stripping rate of indium is almost 100%, and the impurity elements, such as Zn, Fe and Sn can be removed.

The leaching kinetics of low grade zinc oxide ore in NH3-NH4Cl-H2O system was studied. The effects of ore particle size, reaction temperature and the sum concentration of ammonium ion and ammonia on the leaching efficiency of zinc were examined. The leaching kinetics of low-grade zinc oxide ore in NH3-NY4Cl-H2O system follows the kinetic law of shrinking-core model. The results show that diffusion through the inert particle pores is the leaching kinetics rate controlling step. The calculated apparent activation energy of the process is about 7.057 kJ/mol. The leaching efficiency of zinc is 92.1% under the conditions of ore particle size of 69 μm, holding at 80 °C for 60 min, sum ammonia concentration of 7.5 mol/L, the molar ratio of ammonium to ammonia being 2:1, and the ratio (g/mL) of solid to liquid being 1:10.

A novel nanostructured catalyst of platinum nanoparticles supported on 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin tetra(p-toluenesulfonate) (TMPyP) functionalized graphene (TMPyP-graphene) is synthesized by the hydrothermal polyol process. The as-synthesized nanocomposites are characterized by Fourier transform infrared (FTIR) spectroscopy, UV-vis absorption spectroscopy, Raman spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical tests. It has been found that Pt nanoparticles of ca. 3.4 nm are uniformly dispersed on the surface of TMPyP-graphene, and hold a high electrochemical active surface area (ECSA) of 126.2 m(2) g(-1). The results demonstrate that the Pt/TMPyP-graphene catalyst exhibits a much higher electrocatalytic activity and stability than the Pt/graphene and commercial Pt/C catalysts for methanol oxidation, which is of significant importance in improving the efficiency of Pt-based electrocatalysts for DMFCs applications.

As Environment-friendly refrigerants HFCs utilized, nano-materials give the opportunity to optimize the performance of refrigeration systems by their special properties. A prerequisite for applying nanoparticles to refrigerating system is dispersing and making them stabilized in refrigeration lubricant. In this paper, the dispersion stability of fullerene C60 in different mineral based refrigeration oils (KT56 LUNARIA, 3GS SUNISO, 4GS SUNISO) were investigated by sedimentation observation method and Fourier transform infrared (FTIR) spectra method. The results indicate: C60 are successfully modified by tween60 and span40; the dispersity in KT56 and 4GS lubricants is better than 3GS; the best stability appears in KT56 lubricant. Comprehensive considering of the dispersion stability, fullerene C60 modified with tween60 and span40 are optimum in KT56 refrigeration oil.