复杂地质条件下地下厂房吊车梁岩壁成型控制爆破

针对雅安小关子水电站地下厂房吊车梁岩壁的特点 ,提出了对岩壁保护层的双层光面爆破方案及主要的爆破参数。爆破效果表明 ,所确定的控制爆破方案及设计参数是正确的 ,为类似的控制爆破工程提供了有益的经验     

减振沟对爆破振动加速度峰值减振效应的试验研究

通过对减振沟开挖前后两个阶段爆破振动加速度峰值的监测,采用回归分析的方法,得到两种情况下的萨道夫斯基经验公式。通过对比分析的方法,得到减振沟对振动加速度峰值的减振规律。结果表明,合理的开挖减振沟可有效地降低爆破振动加速度峰值。     

Sputtered Ir–Ru based catalysts for oxygen evolution reaction: Study of iridium effect on stability

Magnetron sputtered low-loading iridium-ruthenium thin films are investigated as catalysts for the Oxygen Evolution Reaction at the anode of the Proton Exchange Membrane Water Electrolyzer. Electrochemical performance of 50 nm thin catalysts (Ir pure, Ir–Ru 1:1, Ir–Ru 1:3, Ru pure) is tested in a Rotating Disk Electrode. Corresponding Tafel slopes are measured before and after the CV-based procedure to compare the activity and stability of prepared compounds. Calculated activities prior to the procedure confirm higher activity of ruthenium-containing catalysts (Ru pure > Ir–Ru 1:3 > Ir–Ru 1:1 > Ir pure). However, after the procedure a higher activity and less degradation of Ir–Ru 1:3 is observed, compared to Ir–Ru 1:1, i.e. the sample with a higher amount of unstable ruthenium performs better. This contradicts the expected behavior of the catalyst. The comprehensive chemical and structural analysis unravels that the stability of Ir–Ru 1:3 sample is connected to RuO₂ chemical state and hcp structure. Obtained results are confirmed by measuring current densities in a single cell.     

Electronic regulation and core-shell hybrids engineering of palm-leaf-like NiFe/Co(PO3)2 bifunctional electrocatalyst for efficient overall water splitting

Constructing efficient and stable bifunctional electrocatalysts for overall water splitting remains a challenge because of the sluggish reaction kinetics. Herein, the core-shell hybrids composed of Co(PO₃)₂ nanorod core and NiFe alloy shell in situ grown on nickel foam (NiFe/Co(PO₃)₂@NF) are synthesized. Owing to the hierarchical palm-leaf-like structures and strong adhesion between NiFe alloys, Co(PO₃)₂ and substrates, the catalyst provides a large surface area and rapid charge transfer, which facilitates active sites exposure and conductivity enhancement. The interfacial effect in the NiFe/Co(PO₃)₂ core-shell structure modulates the electronic structure of the active sites around the boundary, thereby boosting the intrinsic activity. Benefiting from the stable structure, the durability of the catalyst is not impaired by the inevitable surface reconfiguration. The NiFe/Co(PO₃)₂@NF electrode presents a low cell voltage of 1.63 V to achieve 10 mA cm^?2 and manifests durability for up to 36 h at different current densities.     

An active balancer with rapid bidirectional charge shuttling and adaptive equalization current control for lithium-ion battery strings

This article proposes an active balancer, which features bidirectional charge shuttling and adaptive equalization current control, to fast counterbalance the state of charge (SOC) of cells in a lithium-ion battery (LIB) string. The power circuit consists of certain bidirectional buck-boost converters to transfer energy among the different cells back and forth. Owing to the characterization of the open-circuit voltage (OCV) vs SOC in LIB being relatively smooth near the SOC middle range, the SOC-inspected balance strategy can achieve more precise and efficient equilibrium than the voltage-based control. Accordingly, a compensated OCV-based SOC estimation is put forward to take into account the discrepancy of SOC estimation. Besides, the varied-duty-cycle (VDC) and curve-fitting modulation (CFM) methods are devised herein to tackle the problems of slow equalization rate and low balance efficacy, which arise from the diminution in balancing current as the SOC difference between the cells decreases in the later duration of equalization especially. The proposed strategies have taken the battery nonlinear characteristic and circuit parameter nonideality into account and can adaptively modulate the duty cycle with the SOC difference to keep balancing current constant throughout the balancing cycle. Simulated and experimental results are given to demonstrate the feasibility and effectiveness of the same prototype constructed. Compared with the fixed duty cycle and the VDC methods, the proposed CFM has the best balancing efficiency of 81.4%, and the balance time is shortened by 27.1% and 18.6%, respectively.     

切顶卸压技术在双鸭山矿区沿空留巷中的应用

为了使双鸭山矿区煤炭资源最大程度地被采掘,减少资源浪费,提高矿井效益,延长矿井服务年限及促进矿井安全生产,以双鸭山矿区3个缓倾斜中厚煤层综采工作面为工程背景,对切顶卸压无煤柱开采技术进行深入探索,经过实际的检验证明,在双鸭山矿区缓倾斜中厚煤层中,采用切顶卸压技术进行沿空留巷,技术可行,经济合理,工艺简单,成巷率高。     

离子型稀土矿山淋洗及尾水富集试验研究

对浸矿后离子型稀土原地浸矿场采用清水进行淋洗，在184天的清水淋洗过程中，尾水氨氮值从最开始的507mg/L，降低至140mg/L，淋洗尾水pH4.52~3.10。淋洗尾水采用两级反渗透膜分离，既回收有价资源稀土，又能使出水氨氮达标。结果表明，产水氨氮浓度稳定低于15mg/L，对稀土的截留率高于98.25%，浓水中稀土离子平均浓度313.4mg/L，可进一步回收稀土资源。     

Effects of high hydrostatic pressure on the structure and retrogradation inhibition of oat starch

As a non-thermal processing technology, high hydrostatic pressure (HHP) can be used for starch modification without affecting the quality and flavour constituents. The effect of HHP on starch is closely related to the treatment pressure of HHP. In this paper, we investigated the impacts of HHP treatment pressure (0, 100, 200, 300, 400, 500, 600 MPa) on the microstructure and retrogradation characteristics of oat starch, established the retrogradation kinetic model and elaborated the mechanism of HHP treatment inhibiting the retrogradation of oat starch. Results show that HHP treatment caused the microstructure of oat starch experienced crystallisation perfection (100–300 MPa), crystallisation destruction (400 MPa), crystallisation disintegration and gelatinisation (500–600 MPa). Results of oat starch retrogradation showed that, after treated at 500 MPa for 15 min, the recrystallisation rate of oat starch was reduced, the formation of nuclei at the early stage of oat starch retrogradation suppressed and its nucleation mode was changed from instantaneous to spontaneous, otherwise, the mobility of water in oat starch gel system reduced. Therefore, 500 MPa treated for 15 min can inhibits the retrogradation of oat starch. This study provides theoretical guidance for the application of HHP technology in starch modification and food processing.     

从蚕的生命到艺术：中国古代生命观的哲学表达

中国考古出土的蚕业实物及蚕的艺术形象比较丰富,蚕的艺术形象如蚕纹、陶蚕蛹、牙雕蚕、玉石蚕、铜蚕、金蚕等,可统称为"蚕的模拟形态"。对蚕的模拟形态的功用,已有的诸多解释都有待完善。研究表明,蚕的模拟形态或艺术形象表达的功用或为饰品,或为装饰图案,或有待进一步考究。但无论哪种功用,用"蚕"这一形象都蕴含了特有的用意。通过对中国古代生命观的考察,文章认为蚕的艺术形象折射出相应的中国古代哲学生命观,即中国古人追求的死而复生、生生不息、羽化成仙、长乐无极等观念。     

Improving water retention of chicken breast meats by CaCl2 combined with pulsed electric fields

Frozen poultry meat is the most widely consumed animal-based food. However, water loss often leads to quality loss of poultry meat. Therefore, the present study sought to investigate the combined effect of calcium chloride (CaCl₂) and pulsed electric fields (PEF) treatment on chicken breast meats and the mechanisms underlying protein degradation. The results showed that the synergistic effect was superior to the single treatment. Compared with the untreated group, the combination of CaCl₂ and PEF increased water holding capacity of chicken breast meats by 16.61% and decreased cooking loss by 28.93%. Low-field nuclear magnetic resonance (LF-NMR) results indicated that the synergistic treatment promoted water molecules' binding capacity in myofibrils of poultry meat, which exhibited higher immobilised water. Additionally, the combination of CaCl₂ and PEF led to increased degradation of proteins of high-molecular weight and surface hydrophobicity of myofibrillar protein. Furthermore, the extension of the protein molecule and microenvironmental changes promoted interaction between protein and water. In conclusion, the synergistic treatment of CaCl₂ and PEF enhanced water retention and improved physicochemical properties of the myofibrillar protein in chicken breast meats.