Effect of biodegradable film (lyophilised alga Fucus spiralis and sorbic acid) on quality properties of refrigerated megrim (Lepidorhombus whiffiagonis)

The effect of replacing the on‐board currently employed polyethylene film by a novel type of environmentally friendly packaging was studied. For it, a polylactic acid (PLA) biodegradable film including lyophilised alga Fucus spiralis and sorbic acid was applied during megrim (Lepidorhombus whiffiagonis) refrigeration and its effect on fish quality loss was evaluated. Thus, sensory assessment showed that samples wrapped up with PLA film including 8% alga and 1% sorbic acid were still acceptable on day 11, while control fish specimens (kept under polyethylene film) were rejected at that time. Under such biodegradable film condition, a preservative effect was also implied according to chemical indices assessment related to microbial activity (trimethylamine–N) and lipid oxidation development (peroxide and fluorescent compounds formation); additionally, lower mean numbers for different microbiological groups (aerobes, Enterobacteriaceae and psychrotrophs) were detected. This result provides a promising replacement strategy to enhance refrigerated fish quality and reduce the waste material content.     

Hybrid nanocomposite thin films deposited by emulsion-based resonant infrared matrix-assisted pulsed laser evaporation for photovoltaic applications

Emulsion-based, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) was used to deposit CdSe nanoparticle films and hybrid nanocomposite films comprising colloidal CdSe nanoparticles embedded in a low band gap polymer, poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT). We show that, in contrast to traditional MAPLE deposition, the CdSe nanoparticle film deposited by emulsion based RIR-MAPLE is contiguous and uniform, and it maintains the optical properties of the nanoparticle solution. Moreover, we show that the RIR-MAPLE deposited PCPDTBT/CdSe hybrid nanocomposite film exhibits a relatively random and uniform distribution of CdSe nanoparticles without the significant phase segregation that is observed in hybrid nanocomposite films deposited by spin-casting. Finally, hybrid organic solar cells based on nanocomposite films deposited by the RIR-MAPLE technique were fabricated and characterized, showing 0.4% power conversion efficiency. This is the first demonstration of a polymer–nanoparticle hybrid organic solar cell fabricated by a MAPLE-related technique.     

Influences of Ga concentration on performances of CuInGaSe2 cells fabricated by sputtering-based method with ceramic quaternary target

Copper Indium Gallium Selenide (Cu(In,Ga)Se₂, CIGSe) absorbers with different Ga contents were prepared by sputtering CIGSe ceramic targets and post-annealing. CIGSe solar cell devices were fabricated with other functional layers. The device performances and absorber properties were investigated. Increasing Ga content led to an increase in V_OC and a decrease in J_SC. Ga was supposed to diffuse towards back contact during the annealing process. The best performance was obtained as the ratio of Ga/(In + Ga) reaches 0.32 with the efficiency of 13.8% and a V_OC of 537 mV.     

Enhancing the flash-sinterability of BaZr0.1Ce0.7Y0.2O3-δ proton-conducting electrolyte by nickel oxide doping for possible application in SOFCs

In the present work, effects of nickel oxide doping on flash-sinterability of BaZr_0.1Ce_0.7Y_0.2O_3-δ compound were investigated. A single-phase BZCY7 powder was synthesized by the solid-state reaction route. The effects of using 0.5, 1, 1.5, and 2 wt% of NiO additive on flash sintering of BZCY7 samples were examined. It was revealed that using 0.5 wt% of NiO additive can reduce the onset temperature of flash sintering in all the applied electric fields in the range of 100–500 V/cm and significantly enhances the sinterability of the BZCY7 compound. Microstructural investigations, using field emission scanning electron microscopy and energy-dispersive X-ray mapping, showed that NiO doping can lead to larger grain sizes, while no detectable segregation or second phase was observed. Utilizing electrochemical impedance spectroscopy, the total conductivity of samples at 600 and 700 °C was measured as 4.4 × 10^?3 and 7.0 × 10^?3 S/cm for the undoped BZCY7, and 8.6 × 10^?3 and 1.4 × 10^?2 S/cm for the 0.5 wt% NiO doped BZCY7 sample, respectively. The activation energies of conduction were determined as 0.37 and 0.41 eV for the doped and undoped samples, which represent the presence of predominant and facile protonic conduction.     

Inkjet-printed Ag@SDC core-shell nanoparticles as a high-performance cathode for low-temperature solid oxide fuel cells

This work demonstrates the superior thermostability of silver-based nanoparticle cathodes under continuous solid oxide fuel cell operation by coating the samarium-doped ceria (SDC) thin shell over silver nanoparticles. The Ag-core/SDC-shell (Ag@SDC) nanoparticles prepared by solvothermal synthesis (Ag core diameter = 48 nm; average SDC shell thickness = 2–5 nm) is inkjet-printed on electrolyte substrates as a thin film cathode. The Ag@SDC film survives the 48-h thermal annealing and its most porosities remain visibly un-agglomerated. The results of fuel cell current stability test show that the cell using the Ag@SDC nanoparticle cathode have only 3% of current degradation after 25 h, which is remarkably lower than that of the cell using the bare Ag nanoparticle cathode (96.1%). In addition, the electrochemical performance of the bare silver cathode in oxygen reduction reaction has significantly improved because of the enhanced surface oxygen adsorption/dissociation process provided by the SDC thin shell.     

Preparation and properties of modified graphene oxide incorporated waterborne polyurethane acrylate

In this study, a new modifier (KPG) was prepared by modifying graphene oxide with γ‐glycidoxypropyl trimethoxysilane (KH560) and polydimethylsiloxane (PDMS). KPG was in turn added to aqueous urethane acrylate for the fabrication of waterborne polyurethane polyacrylate emulsion modified with KH560‐PDMS composite (KPG/WPUA). Textural characterizations of the KPG/WPUA coating were achieved via Fourier transform infrared, SEM, TGA and AFM techniques, which revealed that the KPG/WPUA film possessed a smooth surface. The synthesized KPG/WPUA films were tested for mechanical properties, hydrophobicity and acid/water corrosion performance which suggested their highly hydrophobic surface. KPG/WPUA with 0.1% KPG showed a contact angle of 118.35°, 30.35° higher than that of pristine WPUA. The KPG/WPUA film exhibited higher thermal stability, i.e. a 5% weight loss temperature of 305 °C, which was 30 °C higher than that of pristine WPUA film. The Young's modulus and elongation at break of the KPG/WPUA film were 34.1 MPa and 74.88% respectively, which were higher than that of WPUA film. Furthermore, KPG/WPUA films exhibited greater resistance (without obvious blistering and the white spotting phenomenon) to H₂O₂, HCl and water corrosion than pristine WPUA. The superior performance of KPG/WPUA films was attributed to the network chain structure formed upon the introduction of KPG into WPUA. The outstanding performance of KPG/WPUA films in terms of mechanical properties, thermal stability and high resistance to acidic and water corrosion makes them interesting alternative contenders for target applications. © 2019 Society of Chemical Industry     

超高回采巷道顶部柔膜袋快速充填技术

针对阳泉煤业集团南庄煤矿8836运输巷局部超高,威胁安全生产的问题,实测了3个充填区域,设计了顶部柔膜袋快速充填方案,并进行了现场试验。结果表明:高水充填材料具备速凝早强特性,2 h强度1.25 MPa,28 d强度3.98 MPa,材料消耗约305 kg/m^3;效果考察表明,在工作面超前区,充填体下方单体柱受力均匀、明显,充填体接顶充分,工作面后方充填体垮落效果良好,未形成悬顶。     

A large-grain-size thick-film polycrystalline diamond detector for x-ray detection

A diamond film with a size of 6 × 6 × 0.5 mm³ is fabricated by electron-assisted chemical vapor deposition. Raman spectrum analysis, x-ray diffraction and scanning electron microscope images confirm the high purity and large grain size, which is larger than 300 μm. Its resistivity is higher than ${10}^{12}\,{\rm{\Omega }}\cdot {\rm{cm}}.$ Interlaced-finger electrodes are imprinted onto the diamond film to develop an x-ray detector. Ohmic contact is confirmed by checking the linearity of its current–voltage curve. The dark current is lower than 0.1 nA under an electric field of 30 kV cm⁻¹. The time response is 220 ps. The sensitivity is about 125 mA W⁻¹ under a biasing voltage of 100 V. A good linear radiation dose rate is also confirmed. This diamond detector is used to measure x-ray on a Z-pinch, which has a double-layer 'nested tungsten wire array'. The pronounced peaks in the measured waveform clearly characterize the x-ray bursts, which proves the performance of this diamond detector.     

Inhibition of stress corrosion cracking in 304 stainless steel through titanium ion implantation

The effects of titanium ion implantation on the stress corrosion cracking (SCC) behaviour of 304 austenitic stainless steel were studied. Slow strain rate tests (SSRTs) were conducted on 304 steel in air and in 5?wt-% NaCl solution. The microscopic effects of ion implantation were evaluated by Stopping and Range of Ions in Matter Procedures (SRIM). Fracture morphologies and microstructures were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The fracture surfaces illustrate that ion implantation significantly inhibits the corrosion pits that initiate SCC. A dense passive film, which inhibits SCC, was formed during the ion implantation process. SCC initiation was restrained due to the dense dislocation nets that were generated by titanium ion implantation.

Highlights

• Ion implantation inhibits SCC susceptibility.

• The lack of Cr at the grain boundary leads to the expansion of SCC along the grain boundary.

• Implantation-induced damage leads to high-density dislocations.

• The surface was amorphised due to high-density dislocations.

     

极端电场环境激励下的VO2相变性能研究与应用

为揭示VXOY薄膜场致相变规律,推广钒氧化物应用于卫星控制系统,指导氧化钒规模制备,将磁控溅射法和真空退火工艺相结合,在Al2O3陶瓷基片上制备出VXOY薄膜,降低了实验对仪器精度的要求,提高了实验的成功率。对基片进行磁控溅射镀膜,在管式炉中进一步氧化处理生成表面均匀的V2O5,然后进行高温退火处理,对不同退火条件下的生成的薄膜进行了XRD表征。测得了电场激励下VXOY薄膜的相变现象,验证了电场激励下焦耳热并非薄膜相变的主导因素;总结了不同组分下VXOY薄膜的相变规律,研究了不同V6O13含量对VO2薄膜临界相变电压的影响规律,可指导VXOY薄膜应用于微纳卫星等极端环境下的设备控制系统。