UV-Based Advanced Oxidation Processes for Antibiotic Resistance Control: Efficiency, Influencing Factors, and Energy Consumption

Antibiotic resistant bacteria(ARB)with antibiotic resistance genes(ARGs)can reduce or eliminate the effectiveness of antibiotics and thus threaten human health.The United Nations Environment Programme considers antibiotic resistance the first of six emerging issues of concern.Advanced oxidation processes(AOPs)that combine ultraviolet(UV)irradiation and chemical oxidation(primarily chlorine,hydrogen peroxide,and persulfate)have attracted increasing interest as advanced water and wastewater treatment technologies.These integrated technologies have been reported to significantly elevate the efficiencies of ARB inactivation and ARG degradation compared with direct UV irradiation or chemical oxidation alone due to the generation of multiple reactive species.In this study,the performance and underlying mechanisms of UV/chlorine,UV/hydrogen peroxide,and UV/persulfate processes for controlling ARB and ARGs were reviewed based on recent studies.Factors affecting the process-specific efficiency in controlling ARB and ARGs were discussed,including biotic factors,oxidant dose,UV fluence,pH,and water matrix properties.In addition,the cost-effectiveness of the UV-based AOPs was evaluated using the concept of electrical energy per order.The UV/chlorine process exhibited a higher efficiency with lower energy consumption than other UV-based AOPs in the wastewater matrix,indicating its potential for ARB inactivation and ARG degradation in wastewater treatment.Further studies are required to address the trade-off between toxic byproduct formation and the energy efficiency of the UV/chlorine process in real wastewater to facilitate its optimization and application in the control of ARB and ARGs.

Electrical Resistance Measurement of Glass Transition and Crystallization Characteristics of Zr-Al-Cu-Ni Metallic Glasses

In this paper, glass transition and thermal stability of the Zr-AI-Cu-Ni metallic glasses were investigated by using electrical resistance measurement (ERM), DSC and X-ray diffraction techniques. The experimental results show that the ERM is capable of detecting the glass transition of the amorphous alloys and can help to distinguish the crystallization products of the Zr-AI-Cu-Ni metallic glasses owing to the difference of the electrical resistivity between the precipitation phases.

Non-isothermal Crystallization Kinetics of Modified Poly(ethylene terephthalate) with Ultraviolet Protection

The non-isothermal crystallization kinetics of modified poly(ethylene terephthalate) (PET) with the function of ultraviolet (UV) protection was studied by means of differential scanning calorimetry. The kinetics of the modified polymer under non-isothermal crystallization was analyzed by Ozawa equation. The crystallization behavior of the modified polymer obeyed Ozawa theory. The additives in the polymer whose function was UV-resistant acted as crystal nucleus in the processing of crystallization, which resulted in the increase of Avrami index and the crystallization rate of the cooling system.

Effect of the CaF_2-fraction in the glass-ceramic with abrasion resistance on crystallization

Investigated the effect of an addition of CaF2 on the crystallization of a glass-ceramic with abrasion resistance. X-ray diffraction, differential thermal analysis and scanning electron microscopy were used to determine the effect. The results showed that a suitable addition of CaF2 promoted crystallization by forming an interme- diate crystalline phase. CaF2 can decrease the temperature and active energy of the base-glass for crystallization. When 4 mass-% of CaF2-fraction is added in the glass, the crystallization temperature and active energy is 936 ℃and 172.75 kJ/mol respectively. When CaF2 is increased to 6 mass-%, the temperature and active energy decrease to 890 ℃ and 88.81 kJ/mol. CaF2 is an efficient nucleating agent for the glass-ceramics with abrasion resistant, the optimal content of CaF2 is about 6 mass-%.

Ni–P coating on AZ31 magnesium alloy and its crystallization

Amorphous Ni-P coating was plated on AZ31 magnesium alloy via the electroless plating technique, and the plated alloy was subsequently annealed. X-ray dif- fraction （XRD）, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, and differential scanning calorimetry （DSC） were used to characterize the coating. The results show that the hardness of the coating is much higher than that of bare magnesium alloy, which further increases after crystallization. The electrochemical polarization and salt spray tests show that the coating exhibits a much higher corrosion resistance than that of the bare magnesium alloy. Moreover, the crystallized coating still exhibits a much stronger corrosion resistance than that of the bare magnesium alloy, although its corrosion resistance is lower than that of the as-plated one.

Growth and physical characterization of high resistivityFe:β-Ga2O3 crystals

High quality 0.02 mol%,0.05 mol%,and 0.08 mol%Fe:β-Ga2O3 single crystals were grown by the floating zone method.The crystal structure,optical,electrical,and thermal properties were measured and discussed.Fe:β-Ga2O3 single crystals showed transmittance of higher than 80%in the near infrared region.With the increase of the Fe doping concentration,the optical bandgaps reduced and room temperature resistivity increased.The resistivity of 0.08 mol%Fe:β-Ga2O3 crystal reached to 3.63×1011Ω·cm.The high resistivity Fe:β-Ga2O3 single crystals could be applied as the substrate for the high-power field effect transistors(FETs).

Ultraviolet and mid-infrared continuum generation by cross-phase modulation between red-shifted solitons and blue-shifted dispersive waves in a photonic crystal fiber

Using a photonic crystal fiber with a zero dispersion wavelength of the fundamelItal mode at 780 nm designed and fabricated in our lab, the ultraviolet and mid-infrared continua are generated by cross-phase modulation between red-shift solitons and blue-shift dispersive waves. The dependences of continuum on the pump power and wavelength are investigated. With the pump working at 820 nm, when the pump power increases froul 300 to 500 mW, the bandwidths of ultraviolet and mid-infrared continua change from 80 to 140 nm and 100 to 200 nm, respectively. The wavelength of ultraviolet continuum is below 246 nm, and the wavelength of mid-infrared continuum exceeds 2500 nm. Moreover, the influences of pump power on wavelength and conversion efficiency of different parts of continua are also demonstrated.

Preparation and Characterization of Lignosulfonate Intercalated Layered Double Hydroxides and Their Application in Improving Ultraviolet Aging Resistance for Bitumen

In order to develop economically anti-ultraviolet(UV) aging additives to bitumen and extend the comprehensive utilization of lignin materials, lignosulfonate(LS) was selected to intercalate into layered double hydroxides(LDHs), then the LS intercalated LDHs(LS-LDHs) were applied to improve UV aging resistance of bitumen. With the characterization of X-ray diffraction(XRD), Fourier transform infrared(FTIR) spectroscopy, chemical analysis and scanning electron microscopy(SEM), LS was successfully intercalated into the galleries of LDHs. The ultraviolet and visible(UV-vis) absorbance curves showed LS-LDHs had excellent UV absorptive ability from 200 to 400 nm. Thermogravimetry and differential scanning calorimetry(TG-DSC) indicated LS-LDHs could have a good thermal stability during the processing of bitumen. Compared with the LDHs, the LS-LDHs exhibited better performance in UV aging resistance of bitumen.

High-power ultraviolet 278-nm laser from fourth-harmonic generation of an Nd：YAG amplifier in CsB3O5 crystal

We report on the experimental investigation and theoretical analysis of a nanosecond pulse high power ultraviolet（UV） 278 nm laser by fourth-harmonic generation（FHG） of a 1112-nm Nd：YAG amplifier in LiB3O5（LBO） and CsB3O5（CBO） crystals. The UV laser delivers a maximum average power of 10.3 W at 278 nm with peak power of 36.8 k W under input pump power of 41 W at 556 nm. This is, to the best of our knowledge, the highest output power at the specific UV wavelength of 278 nm. We also performed the theoretical investigation on the FHG with a model in the Gaussian approximation of both spatial and temporal profiles, especially accounting for the two-photon absorption effect in CBO crystal for the first time. The average output power, pulse width, and beam spatial distribution of the UV laser were simulated. The theoretical calculations are in close agreement with the experimental results.

Atomic crystals resistive switching memory

Facing the growing data storage and computing demands, a high accessing speed memory with low power and non- volatile character is urgently needed. Resistive access random memory with 4F2 cell size, switching in sub-nanosecond, cycling endurances of over 1012 cycles, and information retention exceeding 10 years, is considered as promising next- generation non-volatile memory. However, the energy per bit is still too high to compete against static random access memory and dynamic random access memory. The sneak leakage path and metal film sheet resistance issues hinder the further scaling down. The variation of resistance between different devices and even various cycles in the same device, hold resistive access random memory back from commercialization. The emerging of atomic crystals, possessing fine interface without dangling bonds in low dimension, can provide atomic level solutions for the obsessional issues. Moreover, the unique properties of atomic crystals also enable new type resistive switching memories, which provide a brand-new direction for the resistive access random memory.

Ultraviolet Continuum Generation in the Fundamental Mode of Photonic Crystal Fibers

The ultraviolet continuum generation in the fundamental mode of photonic crystal fibers designed and fabricated in our lab are experimentally demonstrated.When the pump works in the normal dispersion regions of 780 nm and 830 nm,and the average powers increase from 100 to 500 m W,anti-Stokes signals can be efficiently generated based on the phase-matched degenerate four-wave mixing.The cross-phase modulation between the pump and the generated anti-Stokes signals can effectively extend the continuum into the ultraviolet wavelength range.This can provide an efficient light source for ultraviolet photonics and spectroscopy.

New Resistance Anomaly in Superconducting Bi_(2)Sr_(2)CaCu_(2)O_(8) Single Crystals

We have measured the resistance of some Bi_(2)Sr_(2)CaCu_(2)O_(8) superconducting single crystals along ab plane and the c axis.For some of the single crystals,a resistivity anomaly near the superconducting transition temperature is observed in the ab plane.This giant resistance peak is independent of the small driving current(I≤40 mA),and the peak is suppressed and vanished gradually with the increasing applied magnetic field(>100 G).We proposed that the resistance peak is a quasi-reentrant behavior due to the superconducting phase inhomogeneous distribution.

Magnetic Properties and Low-Field Magnetoresistance of Pr_(0.7)Pb_(0.3)MnO_(3) Single Crystals

The magnetic properties and magnetoresistance of Pr_(0.7)Pb_(0.3)MnO_(3) single crystals have been studied.At low temperature,the temperature dependence of magnetization can be represented as M(T)=M(0)(1-BT^(3/2)).A large B value was observed.The spontaneous magnetic moment is slightly larger than the spin-only value for Mn3+and Mn4+ions.Above the Curie temperature,the susceptibility obeys the Curie-Weiss Law and the resistivity R can fit well with R0 exp(T0/T)^(1/4).It is found that the effective paramagnetic moment obtained from the Curie constant is larger than the theoretical value.The large effective paramagnetic moment may originate from the magnetic clusters.A large low-field magnetoresistance of ΔR/R(0)=-50% is observed at 230 K in 1T.

Effects of pre-deformation on microstructure and properties of Al–Cu–Mg–Ag heat-resistant alloy

The effects of the pre-deformation on the microstructure, mechanical properties and corrosion resistance of Al–Cu–Mg–Ag alloys were investigated by means of hardness tests, tensile tests, intergranullar corrosion(IGC) tests and transmission electron microscopy(TEM), respectively. The results show that with the increase of deformation amount, the aging hardening rate increases while the strength of the alloy decreases and then increases. The sample with a pre-deformation of 6% possesses the highest tensile strength due to the refinedly and homogeneously distributed precipitations. The pre-deformation aging accelerates the heterogeneous nucleation of ? and θ′ phases at dislocations, and also refines the precipitations both in the grains and along the grain boundaries. The precipitation of ? phase is restrained while that of θ′ phase is accelerated in pre-deformed Al–Cu–Mg–Ag alloy compared with the sample without pre-deformation. In addition, the width of the precipitate free zone decreases with increasing the pre-deformation amount, leading to a narrower IGC passageway. This results in an enhanced IGC resistance of Al–Cu–Mg–Ag alloy treated by pre-deformation aging.

Optical and Irradiation-Resistant Properties of ITO Films on F46 and PI Substrates

This study investigated indium tin oxide(ITO) films that were deposited on fluororesin-46(F46) and polyimide(PI) transparent flexible substrates by a DC magnetron sputtering system. The optical properties of ITO films on F46 and PI including transmittance and reflectance in visible, near-infrared, and infrared spectral regions were obtained, and the surface morphology, and optical and electrical properties of ITO/F46 and ITO/PI after vacuum ultraviolet irradiation were investigated. The results showed that the mean transmittances of ITO/F46 and ITO/PI decreased and the sheet resistance increased after the irradiation, and these effects were mainly attributed to the greater surface roughness and crystal defects caused by the irradiation.

利用孢子紫外诱变选育秀珍菇新菌株

为缓解高温胁迫对南方地区秀珍菇夏季设施栽培的影响,开展秀珍菇耐高温新品种选育工作,以台秀5766为亲本,采用孢子紫外线诱变、多孢自交、高温筛选、系统选育等组合育种方法选育获得秀珍菇耐高温新菌株。经拮抗试验、分子遗传鉴定和出菇筛选获得耐高温菌株P71。经rDNA ITS测序,其序列长度为693 bp,在GeneBank中经BLAST比对确定其为侧耳属秀珍菇(Pleurotus pulmonarius)。该菌株菌丝在35℃条件下培养,显微镜观察未发现菌丝收缩、变形、受损情况,且菌丝洁白、生长势较强,15 d内能缓慢生长。在35~38℃高温条件下出菇,P71菌株前2潮菇产量和单菇质量均显著优于亲本台秀5766。由此可见,新菌株P71与亲本台秀5766相比,菌丝生长阶段和出菇阶段均具有耐高温的特点,值得进一步在南方地区进行秀珍菇夏季设施栽培的试验、示范和推广应用,从而突破秀珍菇耐高温品种短缺造成的产业发展瓶颈。

镓硼共掺对6英寸VGF法锗单晶电阻率均匀性的影响

由于杂质分凝效应,镓掺杂垂直梯度凝固(VGF)法锗单晶的电阻率分布不均匀,理论上利用镓和硼分凝系数的差异,镓硼共掺工艺可以提升锗单晶电阻率均匀性。采用镓硼共掺工艺制备了6英寸(1英寸≈2.54 cm)VGF法锗单晶,对比分析了掺杂工艺对锗单晶电阻率均匀性的影响。当镓和硼杂质浓度分别为5.13×10^(18)cm^(-3)和0.67×10^(18)cm^(-3)时,在等径0~40 mm范围内轴向电阻率不均匀性为4.92%,等径0 mm和40 mm处径向电阻率不均匀性分别为1.63%和0.45%,与镓杂质浓度为5.13×10^(18)cm^(-3)的镓掺杂工艺相比,锗单晶头部的电阻率均匀性明显提升。当硼杂质浓度提高到1.89×10^(18)cm^(-3)时,镓硼共掺锗单晶头部电阻率均匀性变差。结果表明,适量硼掺杂的镓硼共掺工艺可以提升锗单晶头部电阻率均匀性。

废液晶玻璃再生制备低膨胀硼硅玻璃及其理化性能研究

基于废液晶玻璃的高值化再生利用,以废液晶玻璃作为主要原料,石英砂、硼酸、纯碱为辅助原料,制备了低膨胀硼硅玻璃。通过浮力法、压痕法、石英膨胀法和重量试验法,探究了废液晶玻璃和辅助原料(Na_(2)O和B_(2)O_(3))掺量对玻璃理化性能的影响。结果表明:随着废液晶玻璃掺量增加,玻璃密度、线热膨胀系数和耐酸质量损失增大,维氏硬度和耐碱质量损失减小;随着辅助原料中Na_(2)O含量增大,玻璃密度、线热膨胀系数、耐酸质量损失和耐碱质量损失增大,维氏硬度减小;随着辅助原料中B_(2)O_(3)含量增大,玻璃密度和维氏硬度减小,线热膨胀系数和耐酸耐碱质量损失增大;当废液晶玻璃、辅助原料中Na_(2)O和B_(2)O_(3)质量分数分别为60.00%、1.00%和14.72%时,玻璃维氏硬度最大、密度和线热膨胀系数最小,分别为7.1430 GPa、2.3097 g·cm^(-3)和3.5317×10^(-6)℃^(-1);当废液晶玻璃、辅助原料中Na2O和B2O3质量分数为60.00%、3.00%、9.72%时,玻璃耐酸质量损失最小,为0.6140 mg·cm^(-2);当废液晶玻璃、辅助原料中Na2O和B2O3质量分数为70.00%、2.00%、11.67%时,玻璃耐碱质量损失最小,为1.2140 mg·cm^(-2)。

延安清凉山石窟砂岩表层防风化保护材料研究

针对陕西延安清凉山石窟砂岩由于水/盐运移活动频繁导致的病害,本研究选用商用硅酸酯(KSE-300)和现代合成两性离子聚氨酯(ZPU)、POSS杂化两性离子聚氨酯(POSS-D+ZPU)、CaCO_(3)寡聚体交联两性离子聚合物[CaCO_(3-)c-P(MPC-ran-MPS)]、POSS增强柔性硅氧烷(POSS-AHAPTMS)对砂岩进行实验室表面渗透保护试验,并对比评估保护性能。结果表明,分散体尺寸小、成膜性相对较差,且能够与砂岩基体化学键合的CaCO_(3-)c-P(MPC-ran-MPS)和KSE-300保护材料更易向砂岩内部渗透、且不易改变砂岩原有孔隙结构;与砂岩极性匹配较高的CaCO_(3-)c-P(MPC-ran-MPS)、ZPU和POSS-D+ZPU保护材料对砂岩的表面色度影响较小;CaCO_(3-)c-P(MPC-ran-MPS)保护材料因兼具加固与水/盐运输功能而使砂岩表现出最佳的抗盐结晶循环性能,而疏水性ZPU和KSE-300因阻碍了砂岩内部水/盐运移路径而使砂岩在盐结晶循环中表现出断裂和层状剥落的风险。综上,CaCO_(3-)c-P(MPC-ran-MPS)保护材料更适用于砂岩表层预防性抗盐结晶破坏。