The establishment of Boron nitride@sodium alginate foam/polyethyleneglycol composite phase change materials with high thermal conductivity, shape stability, and reusability

Adopting organic phase change materials(PCMs) for the management of electronic devices is restricted by low thermal conductivity. In this paper, the composite PCMs are established by freeze-drying and vacuum impregnation. Herein, polyethylene glycol(PEG) is induced as heat storage materials, boron nitride(BN) is embedded as filler stacking in an orderly fashion on the foam walls to improve thermal conductivity and sodium alginate(SA) is formed as supporting material to keep the shape of the composite stable. X-ray diffractometry, scanning electron microscopy-energy dispersive spectrometer, thermal gravimetric analysis, thermal conductivity meter, differential scanning calorimeter, and Fourier transform infrared were used to characterize the samples and thermal cycles were employed to measure the shape stability. The results exhibit the BN@SA/PEG composite PCMs have good chemical compatibility, stable morphology, and thermal stability. Due to the high porosity of foam, PEG endows the composite PCMs with high latent heat(149.11 and 141.59 J·g^(-1)). Simultaneously, BN@SA/PEG shows an excellent heat performance with high thermal conductivity(0.99 W·m^(-1)·K^(-1)), reusability, and shape stability, contributing the composite PCMs to application in the energy storage field. This study provides a strategy to manufacture flexible, long-serving, and shape-stable PCMs via introducing BN@SA foam as a storage framework, and these PCMs have great potential in thermal management in the electronic field.

Growth of a-Plane GaN Films on r-Plane Sapphire by Combining Metal Organic Vapor Phase Epitaxy with the Hydride Vapor Phase Epitaxy

Hydride vapor phase epitaxy （HVPE） is utilized to grow nonpolar a-plane GaN layers on r-plane sapphire templates prepared by metal organic vapor phase epitaxy （MOVPE）. The surface morphology and microstructures of the samples are characterized by atomic force microscopy. The full width at half maximum （FWHM） of the HVPE sample shows a W-shape and that of the MOVPE sample shows an M-shape plane with the degree of 0 in the high-resolution x-ray diffraction （HRXRD） results. The surface morphology attributes to this significant anisotropic. HRXRD reveals that there is a significant reduction in the FWHM, both on-axis and off-axis for HVPE GaN are compared with the MOVPE template. The decrease of the FWHM of E2 （high） Raman scat tering spectra further indicates the improvement of crystal quality after HVPE. By comparing the results of secondary- ion-mass spectroscope and photoluminescence spectrum of the samples grown by HVPE and MOVPE, we propose that C-involved defects are originally responsible for the yellow luminescence.

Amperometric Biosensors Sensitive to Organic Peroxides Based on Immobilization of Redox Organic Dyes and Horseradish Peroxidase in Polyester Ionomer Film

Simple and effective organic biosensors sensitive to organic peroxides such as 2 butanone per oxide and tertbutyl hydroperoxide are constructed by immobilizing a series of redox organic dyes and horseradish peroxidase in Eastman AQ polymer film. The organic dyes are methylene blue, methylene green, meldola blue, new methylene blue N and N methyl phenazine methosulphate. The biosensors display high sensitivity and fast response to tertbutyl hydroperoxide and 2 butanone peroxide because of high efficiency of electron transfer between immobilized horseradish peroxidase and the electrode via the redox organic dyes. The comparison of the biosensors employing different organic dyes is made in formal potential, linear range and response time.

Traceless solid-phase synthesis of 3-substituted isoxazoles from polystyrene-supported vinyl selenide

A novel facile procedure for traceless solid-phase synthesis of 3-substituted isoxazoles in good yields and with excellent purities using polymer-supported vinyl selenide has been developed.

Solid-phase Synthesis of-Haloaldehydes from Polymer-supported 4-(Phenylseleno)morpholine

Polystyrene-supported 4-(phenylseleno)morpholine was synthesized and could be used as an efficient ?selenenylating agent for saturated aldehydes. ?Haloaldehydes were prepared by reaction of polystyrene-supported ?selenoaldehydes with bromine or sulfuryl chloride in good yield and high purity.

Solid-Phase Stereoselective Synthesis of(E)-1,2-Disubstituted Ethenes from Polymer-Sopportedα-Selenoaldehydes

Reaction of polymer-supported a-selenoaldehydes with Grignard reagents afforded polymer-bound B-hydroxyalkyl selenides, which treated with thionyl chloride and triethylamine leading to (E)-1, 2-disubstituted ethenes in good yield.

Solid-phase synthesis of (Z)-allyl iodides from 3-acetoxy-2-methylene-alkanoates with recyclable polymer-supported selenium bromide

Reaction of polystyrene-supported lithium selenide with 3-acetoxy-2-methylene-alkanoates afforded the corresponding allyl selenide resins and subsequent cleavage from the polymer by treating with methyl iodide to furnish （Z）-allyl iodides in good yields and high purities. The polymeric selenium reagent can be regenerated and reused. So it is a environmentally benign reagent.

Comparison of conventional and inverted structures in fullerene-free organic solar cells

A n-type small molecule DC-IDT2E with 4,4,9,9-tetrakis（4-hexylphenyl）-indaceno[1,2-b：5,6-bt]dithiophene as a central building block, furan as rr-bridges, and 1,1 -dicyanomethylene-3-indanone as end acceptor groups, was synthesized and used as an electron acceptor in solution-processed organic solar cells （OSCs）. DC-IDT2F exhibited good thermal stability, broad and strong absorption in 500-850 rim, a narrow bandgap of 1.54 eV, LUMO of-3.88 eV, HOMO of-5.44 eV and an electron mobility of 6.5 × 10-4 cm2/（V.s）. DC-IDT2F-based OSCs with conventional and inverted structures exhibited power conversion efficiencies of 2.26 and 3.08% respec- tively. The effect of vertical phase separation and morphology of the active layer on the device performance in the two structures was studied.

Response time improvement of AlGaN photoconductive detectors by adjusting crystal-nuclei coalescence process in metal organic vapor phase epitaxy

AlGaN photoconductive ultraviolet detectors are fabricated to study their time response characteristics. Persistent photoconductivity, a deterring factor for the detector response time, is found to be strongly related to the grain boundary density in AlGaN epilayers. By improving the crystal-nuclei coalescence process in metal organic vapor phase epitaxy, the grain-boundary density can be reduced, resulting in an-order-of-magnitude decrease in response time.

Effects of InGaN barriers with low indium content on internal quantum efficiency of blue InGaN multiple quantum wells

Blue In0.2Ga0.8N multiple quantum wells （MQWs） with InxGa1-xN （x = 0.01 - 0.04） barriers are grown by metal organic vapour phase epitaxy. The internal quantum efficiencies （IQEs） of these MQWs are studied in a way of temperature-dependent photoluminescenee spectra. Furthermore, a 2-channel Arrhenius model is used to analyse the nonradiative recombination centres （NRCs）. It is found that by adopting the InGaN barrier beneath the lowest well, it is possible to reduce the strain hence the NRCs in InGaN MQWs. By optimizing the thickness and the indium content of the InGaN barriers, the IQEs of InGaN/InGaN MQWs can be increased by about 2.5 times compared with conventional InGaN/GaN MQWs. On the other hand, the incorporation of indium atoms into the intermediate barriers between adjacent wells does not improve IQE obviously. In addition, the indium content of the intermediate barriers should match with that of the lowest barrier to avoid relaxation.

Migration characterization of Ga and In adatoms on dielectric surface in selective MOVPE

Migration characterizations of Ga and In adatoms on the dielectric surface in selective metal organic vapor phase epitaxy （MOVPE） were investigated. In the typical MOVPE environment, the selectivity of growth is preserved for GaN, and the growth rate of GaN micro-pyramids is sensitive to the period of the patterned SiO2 mask. A surface migration induced model was adopted to figure out the effective migration length of Ga adatoms on the dielectric surface. Different from the growth of GaN, the selective area growth of InGaN on the patterned template would induce the deposition of InGaN polycrystalline particles on the patterned Si02 mask with a long period. It was demonstrated with a scanning electron microscope and energy dispersive spectroscopy that the In adatoms exhibit a shorter migration length on the dielectric surface.

A MOVPE method for improving InGaN growth quality by pre-introducing TMIn

We propose a metal organic vapor phase epitaxy(MOVPE) method of pre-introducing TMIn during the growth of uGa N to improve the subsequent growth of In Ga N and discuss the impact of this method in detail. Monitoring the MOVPE by the interference curve generated by the laser incident on the film surface, we found that this method avoided the problem of the excessive In Ga N growth rate. Further x-ray diffraction(XRD), photoluminescence(PL), and atomic force microscope(AFM) tests showed that the quality of In Ga N is improved. It is inferred that by introducing TMIn in advance, the indium atom can replace the gallium atom in the reactor walls, delivery pipes, and other corners. Hence the auto-incorporation of gallium can be reduced when In Ga N is grown, so as to improve the material quality.

A NEW POLYMER-BOUND 1,2-DIOL AS A PROTECTING AGENT FOR SYMMETRICAL DIALDEHYDE

A novel polymer-bound 1,2-diol, 3-polystyrylsulfonyl-1,2-propanediol (6) had been prepared by the reaction of sodium polystyrylsulfinate with allyl bromide, followed by oxidation and. hydrolysis or directly with 3-chloro-1,2-propanediol in the presence of a phase transfer catalyst, n-tetrabutylammonium iodide. The capacity of resin 6 for terephthaidehyde reached 1.43 mmol/g. The aldehydic groups attached to polymer 6 reacted with hydroxylamine hydrochloride or reduced by sodium borohydride giving p-formylbenzaldoxime (yield: 89%)and p-formyl-benzalcohol (yield: 734%), respectively. The high yields of these polymer-supported reactions showed that the polymer 6 possessed the effective isolation of its reactive sites.

Sorption and phase distribution of ethanol and butanol blended gasoline vapours in the vadose zone after release

The sorption and phase distribution of 20% ethanol and butanol blended gasoline （E20 and B20） vapours have been examined in soils with varying soil organic matter （SOM） and water contents via laboratory microcosm experiments. The presence of 20% alcohol reduced the sorption of gasoline compounds by soil as well as the mass distribution of the compounds to soil solids. This effect was greater for ethanol than butanol. Compared with the sorption coefficient （Kd） of unblended gasoline compounds, the Kd of E20 gasoline compounds decreased by 54% for pentane, 54% for methylcyclopentane （MCP） and 63% for benzene, while the Kd of B20 gasoline compounds decreased by 39% for pentane, 38% for MCP and 49% for benzene, The retardation factor （R） of E20 gasoline compounds decreased by 53% for pentane, 53% for MCP and 48% for benzene, while the R of B20 gasoline compounds decreased by 39% for pentane, 37% for MCP and 38% for benzene. For all SOM and water contents tested, the Kd and R of all gasoline compounds were in the order of unblended gasoline 〉 B20 〉 E20, indicating that the use of high ethanol volume in gasoline to combat climate change could put the groundwater at greater risk of contamination,

Clinical and Experimental Study of Effect on Acute Phase Protein of Multiple Organ Dysfunction Syndrome Treated with Dachengqi Decoction

Objective: To investigate the level of acute phase proteins (APP)-synthesized in hepatocytes in pathogenic process of multiple organ dysfunction syndrome (MODS) and the effect of Dachengqi Decoction (DCQD) on it. Methods: The levels of C-reactive protein (CRP),α1-acid glycoprotein (AAG), α1-antitrypsin total (α1AT), α2-macroglobulin (α2-MG), ceruloplasmine (CP), hepatoglobin (HP) and transferrin (TF) synthesis were determined in 32 cases of MODS patients and rat models of MODS induced by acute infective peritonitis and mesenterial artery ischemia-reperfusion.Results: The serum APP level in MODS patients was increased and higher than that in the control group (P < 0. 01 ). After 3 days of DCQD treatment it reduced significantly (P <0. 05). Serum APP level in MODS model was also increased significantly, and after 3 days of DCQD treatment, it reduced significantly (P < 0. 05). The APP secreting level of rat hepatocytes cultured in vitro raised after stimulated and activated by lipopolysacchride, which was reduced after cultured with rabbits serum containing different concentration of effective ingredients of DCQD. The APP inhibiting effect of DCQD was dose dependent. Conclusion: Purgation therapy with DCQD could reduce the stimulation of pathogenic factors on hepatocytes, protect tissues and organs from damage caused by excessive inflammatory reaction.Original article on CJIM(Chin) 1998; 18(8): 453

MOVPE Growth of In_xGa_(1-x)N(x～0.4) and Fabrication of Homo-junction Solar Cells

The metal organic vapor phase epitaxy （MOVPE） growth of indium gallium nitride （InGaN） has been discussed in detail towards the fabrication of solar cell. The InGaN film with In contents up to 0.4 are successfully grown by controlling the fundamental growth parameters such as the precursor gas flow rates, temperature etc. The formation of metallic In originates from the higher value （0.74） of trimethylindium/ （trimethylindium ＋ triethylgallium） （TMI/（TMI ＋ TEG）） molar ratio with low （4100） V/lll weight molar ratio while the lower value （0.2） of TMI/（TMI ＋ TEG） causes the phase separation. It is also necessary to control the growth rate and epitaxial film thickness to suppress the phase separation in the material. The crystalline quality of grown films is studied and it is found to be markedly deteriorated with increasing In content. The lattice parameters as well as the thermal expansion coefficient mismatch between GaN template and InGaN epi-layer are primarily considered as the reasons to deteriorate the film quality for higher In content. By using Ino.16Ga0.84N films, an n＋-p homo-junction structure is fabricated on 0.65 μm GaN template. For such a device, the response to the light illumination （AM 1.5） is observed with an open circuit voltage of 1.4 V and the short circuit current density of 0.25 mA/cm2. To improve the performance as well as increase solar photon capturing, the device is further fabricated on thick GaN template with higher In content. The In0.25Ga0.75N n＋-p junction solar cell is found better performance with an open circuit voltage of 1.5 V and the short circuit current density of 0.5 mA/cm2. This is the InGaN p-n homo-junction solar cell with the highest In content ever reported by MOVPE.

Stereoselective Synthesis of (E)-and (Z)-1,2-Disubstituted Ethene from Polymer-Supported Vinylic Selenide

This letter describes a method for the stereoselective synthesis of polymer supported vinylic selenides and their applications to synthesis of ( E ) and ( Z ) 1,2 disubstituted ethenes on solid phase by the coupling reaction with Grignard reagents under the catalysis of NiCl 2(PPh 3) 2.