Preface to the Special Issue on Semiconductor Optoelectronic Integrated Circuits

The past 20 years have witnessed the rapid growth of photonic integration circuits(PIC)technology,which has been warmly embraced by both academia and the industry.Powered by the advanced development in material growth,processing,and design capability,the PIC technology now covers multiple material platforms,including III–V(InP,GaAs),silicon,silica,lithium niobate on insulator(LNOI)polymer,etc.The integration level has evolved from a single functional device to thousands of components on-chip.The increase in the performance and the complexity of the PICs have become an energetic booster for communication and information technology.     

木片筛余物高得率半化学法清洁制浆技术研究

以太阳纸业备料车间木片筛选碎料（筛余物）为原料，对其烧碱法半化学制浆的实验室工艺和生产试验进行了研究。结果表明，筛余物采用半化学法制浆可获得较高得率和环压强度的纸浆，且用碱量对纸浆性能有显著影响。相对8%NaOH （相对于绝干原料）化学预处理，采用14%NaOH化学预处理结合两段浆浓22%的高浓磨浆工艺，所制半化学浆抄造浆张的裂断长和环压指数分别达2.89 km和9.76 N·m/g，是前者的1.9倍和1.2倍，而且优于现用国内OCC废纸浆抄造浆张；生产试验得到的浆张性能指标与实验室相吻合，其中紧度和环压强度分别达到GB/T 13023—2008瓦楞芯（原）纸AA级和A级优等品要求。     

Relations between asphaltene content,viscosity reduction rate of heavy oil and ultrasonic parameters

Ultrasonic treatment could decrease the viscosity of heavy oil and previous study on had focused on one heavy oil sample and involved less on the influence of asphaltene content. This study examined the effect of asphaltene content on viscosity reduction rate by ultrasonication. A comparison on samples with various asphaltene content and vibration parameter was made. The results showed that the optimal vibration frequency might decrease as the asphaltene content increased, whereas the optimal vibration intensity and the optimal treatment time were suggested to be enlarged. A semi-quantitative correlation was matched, which helped for numerical simulation about ultrasonic treatment.     

多分量数据全波形反演在气藏检测中的关键问题——以苏里格气田为例

苏里格气田是中国典型的致密砂岩气藏，构造简单、平缓，横向非均质性强，有效储层与围岩声学特征差别小，地震响应不明显，常规地震监测方法预测难度大，但气田含气砂岩泊松比低，是地震气藏检测的有效参数。利用弹性全波形反演精度高和能处理复杂非均质介质的优势，反演地层拉梅常数、剪切模量和密度，并计算泊松比，从而进行气藏预测。重点阐述了苏里格气田多分量数据全波形反演初始模型建模、先验模型建模和地震数据预处理3个关键问题的处理方法。二维三分量数据反演和"甜点"预测结果表明：①对于具有强非均质性的苏里格气田，利用全波形反演获得精度较高的地层弹性参数能显著提高气藏预测的准确度；②苏里格地区构造简单、平缓，利用常规叠加速度并结合构造解释可以建立比较好的初始模型，从而有效地解决了周波跳跃和局部极小的难题；③先验知识的约束和地震数据的预处理是全波形反演成功应用于苏里格气田气藏检测的关键。     

TBP-TEVA萃取色层分离-α能谱法测定辐照镎靶溶解液中痕量236Pu的可行性

²³⁶Pu的含量控制是钚热源的一项重要参数，通过α能谱准确测量镎靶溶解液中痕量²³⁶Pu，建立镎靶辐照靶件溶解液中钚的分离方法。根据杂质组成特点采用TBP-TEVA萃取色层双柱分离，用氨基磺酸亚铁以及亚硝酸钠对钚进行调价，对靶件溶解液中的Al、Fe、U、Th和Np等进行分离，去污系数均大于10⁴，钚的回收率为90.7%。研究大量²³⁸Pu对α能谱测定²³⁶Pu的干扰，结果表明，大量²³⁸Pu会造成仪器本底升高，²³⁸Pu能谱峰分辨率降低；在7 500 Bq ²³⁸Pu干扰下，测量4.3 h 时，²³⁶Pu的最小可检测活度为1.20×10^-2 Bq（当量质量为6.11×10^-16 g）。计算结果表明，镎靶溶解液样品中钚的同位素比值n(²³⁶Pu)/n(²³⁸Pu) ≥4.63×10^-8时，取合适的样品量使得电沉积源中²³⁸Pu 活度在 450~7 500 Bq范围内，均可测量其中的痕量²³⁶Pu，同时可准确测定同位素比值n(²³⁶Pu)/n(²³⁸Pu)。     

A novel coverless information hiding method based on the average pixel value of the sub-images

Multimedia Tools and Applications - In traditional information hiding methods, the secret information is embedded into the carriers, which will inevitably leave traces of modification on the...     

Microstructure and Tensile Strength of the Bonded Interfaces and Parent Materials in W/ODS Steel Joints Fabricated by Direct SSDB

In the present work, Tungsten (W)/oxide dispersion strengthened (ODS) steel joints were fabricated by the direct solid state diffusion bonding (SSDB) technology with a multistage cooling process, and the microstructure and tensile strength of the bonded interfaces and parent materials were experimentally investigated. The results show that W and ODS steel can be successfully bonded at the temperature ranging from 900 °C to 1050 °C, without severe macroscopic deformation or obvious microscopic defects. Reaction layers generated at the bonded interfaces are evolutive with the bonding temperature, result in different fracture locations of the bonded joints. In the joint bonded at 950 °C, a higher interfacial strength of ~ 234.2 MPa is achieved, due to the formation of nano-scale intermetallic compound FeW. Microstructure of W remains stable after all the SSDB processes, while the lath structure of ODS steel is completely broken and transformed into the equiaxed grains, which should be responsible for the deterioration of strength. When the bonding temperature is higher than 950 °C, the pinning effect of precipitates M₂₃C₆ and nano-oxide particles on the movement of dislocations is observed.

     

基于连续介质损伤力学的7075铝合金高温成形极限理论预测与数值仿真

开展7075铝合金高温单向拉伸试验和成形极限试验，获得了不同温度和应变率的应力-应变曲线和成形极限曲线。结果表明，在较高的温度和应变率时7075铝合金的强度减小、成形性提高。为描述7075铝合金高温损伤演化过程，提出一种改进的连续介质损伤模型，并建立了耦合损伤的多轴统一黏塑性本构模型。基于试验结果，运用NSGAII遗传算法标定了模型中的参数，标定后的本构模型可以很好地预测7075铝合金的高温热力行为和极限应变。通过有限元软件Abaqus的用户材料子程序VUMAT，该本构模型被编入到Abaqus软件中进行数值仿真计算。结果表明，仿真获得的成形极限曲线和应变场分布与试验和理论结果吻合度好，进一步证明了所建立的耦合损伤的多轴本构模型的正确性及其在高温成形极限有限元仿真中的适用性。     

Strength and strain-hardening enhancement by generating hard delta-ferrite in twinning-induced plasticity steel

ABSTRACT

A dual-phase (12?vol.% delta-ferrite?+?78?vol.% austenite) high manganese twinning-induced plasticity (TWIP) steel was produced by hot rolled and annealing treatment. In comparison with the fully austenitic TWIP steel, both the yield and ultimate tensile strength of the dual-phase TWIP steel reinforced by hard delta-ferrite are significantly increased. It was found that the delta-ferrite in dual-phase steel exhibits a high hardness owing to the formed DO₃ structured intermetallic phase within ferrite. The presence of delta-ferrite dramatically improves the strain-hardening ability of TWIP steel. This is principally attributed to the effects of strain partitioning between hard delta-ferrite and softer austenite on the kinetics of deformation twinning and/or additional geometrical necessary dislocation (GND) during the deformation process.     

Bimetallic CuCo2S4 Nanozymes with Enhanced Peroxidase Activity at Neutral pH for Combating Burn Infections

Peroxidase-mimicking nanozymes that can generate toxic hydroxyl radicals (^.OH) hold great promise as antibacterial alternatives. However, most of them display optimal performance under strongly acidic conditions (pH 3–4), and are thus not feasible for many medical uses, including burn infections with a wound pH close to neutral. Herein, we report a copper-based nanozyme (CuCo₂S₄) that exhibits intrinsic peroxidase-like activity and can convert H₂O₂ into ^.OH at neutral pH. In particular, bimetallic CuCo₂S₄ nanoparticles (NPs) exhibited enhanced peroxidase-like activity and antibacterial capacity, superior to that of the corresponding monometallic CuS and CoS NPs. The CuCo₂S₄ nanozymes possessed excellent ability to kill various bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Furthermore, this CuCo₂S₄ nanozymes could effectively disrupt MRSA biofilms in vitro and accelerate MRSA-infected burn healing in vivo. This work provides a new peroxidase mimic to combat bacteria in neutral pH milieu and this CuCo₂S₄ nanozyme could be a promising antibacterial agent for the treatment of burn infections.