摘要：Non-pillar mining technology with automatically formed roadway is a new mining method without coal pillar reservation and roadway *** stability control of automatically formed roadway is the key to the successful application of the new *** order to realize the stability control of the roadway surrounding rock,the mechanical model of the roof and rib support structure is established,and the influence mechanism of the automatically formed roadway parameters on the compound force is *** this basis,the roof and rib support structure technology of confined lightweight concrete is proposed,and its mechanical tests under different eccentricity are carried *** results show that the bearing capacity of confined lightweight concrete specimens is basically the same as that of ordinary confined concrete *** bearing capacity of confined lightweight concrete specimens under different eccentricities is 1.95 times higher than those of U-shaped steel *** comparing the test results with the theoretical calculated results of the confined concrete,the calculation method of the bearing capacity for the confined lightweight concrete structure is *** design method of confined lightweight concrete support structure is established,and is successfully applied in the extra-large mine,Ningtiaota Coal Mine,china.

摘要：Lithography is a pivotal micro/nanomanufacturing technique,facilitating performance enhancements in an extensive array of devices,encompassing sensors,transistors,and photovoltaic *** key to creating highly precise,multiscale-distributed patterned structures is the precise control of the lithography ***,high-quality patterned ZnO nanostructures are constructed by systematically tuning the exposure and development times during *** optimizing these parameters,ZnO nanorod arrays with line/hole arrangements are successfully *** ZnO nanostructures with highly controllable morphology and structure possess discrete three-dimensional space structure,enlarged surface area,and improved light capture ability,which achieve highly efficient energy conversion in perovskite solar *** lithography process management for these patterned ZnO nanostructures provides important guidance for the design and construction of complex nanostructures and devices with excellent performance.

摘要：Short-range ordering(SRO)is one of the most important structural features of high entropy alloys(HEAs).However,the chemical and structural analyses of SROs are very difficult due to their small size,complexed compositions,and varied *** electron microscopy(TEM)as well as its aberration correction techniques are powerful for characterizing SROs in these compositionally complex *** this short communication,we summarized recent progresses regarding characterization of SROs using TEM in the field of *** using advanced TEM techniques,not only the existence of SROs was confirmed,but also the effect of SROs on the deformation mechanism was ***,the perspective related to application of TEM techniques in HEAs are also discussed.

摘要：针对大断面隧道初期支护拱架在承载时易发生平面外失稳的问题,本文通过开展单拱架全比尺试验和考虑纵向连接的拱框架结构的数值试验以及现场对比试验,对纵向连接与拱架组成的拱框架结构进行优化研究,使其横向上有足够承载能力、纵向上有较高稳定性。研究结果表明,单个拱架的破坏模式是局部面外失稳导致整体承载力丧失,考虑纵向连接的拱框架结构的平面内承载力和平面外稳定性都得到增强。通过调整纵向连接间距和拱架间距也可以调整初期支护拱框架结构和喷射混凝土的内力分担比,以充分发挥初期支护的承载能力,但纵向连接间距应小于1500 mm,拱架间距也应小于1200 mm。因而,在不改变初期支护现有结构形式的前提下,通过合理地布设纵向连接与拱架形成的具有空间承载效应的拱框架结构,不仅可以保证初期支护的承载能力,而且还提高施工效率和经济效益。研究成果可指导大断面隧道初期支护结构设计。

摘要：岩体强度与裂隙参数是反映工程岩体质量的基本参数,其准确获取是进行地下工程围岩分级与支护合理设计优化的前提。传统的岩体强度测试方法需要对现场围岩取芯并运至实验室测试,测试结果难以反映工程现场环境下的岩体力学性质,而对于岩体强度与裂隙参数的原位测试方法研究较少。本文基于能量守恒定律,建立了岩石切削能密度与随钻参数的关系式,构建了岩体等效强度随钻反演模型(ES-DP模型),系统开展了岩体数字钻进试验。结果表明,相对于传统测试方法,岩体等效强度随钻测试结果平均差异率为2.4%,验证了ES-DP模型对岩体等效强度测试的有效性。在此基础上,建立了岩体裂隙参数随钻识别模型,与实际测量结果相比,该模型测得的岩体裂隙位置与宽度平均精度分别为1.8和1.6 mm,测试精度较高。基于上述研究,本文提出了一种岩体强度-裂隙随钻识别方法,为实现地下工程围岩强度参数与结构特征的原位实时测试提供了新方法。

摘要：Metal chalcogenide compounds can be used as high-performance cathodes for aqueous Zn ***,the low accessible surfaces and violent volumetric expansion limit their properties and *** address these,phase-engineering strategies coupled with a hollow structure were applied to regulate the adsorption/desorption of OH−on the electrode surface and enhance the electrochemical *** this study,using a Se@C nanorod template,a series of carbon nanotube(CNT)-supported nickel selenides,including cubic NiSe_(2),NiSe_(2)/Ni_(0.85)Se composites,and hexagonal Ni_(0.85)Se,were synthesized through an in situ selenylation process for the first *** to the large specific surface,high porosity,and hollow carbon skeleton,the optimized NiSe_(2)/Ni_(0.85)Se/CNT has a high specific capacity of 616 Cg^(−1),excellent rate capability,and stable cycling *** addition,its inside Faradic mechanism was investigated using a series of ex situ characterizations and density functional theory ***,the fabricated Ni//Zn battery presents a high energy density of 311.4 W h kg^(−1) at 3485 W kg^(−1) and long cycling *** study offers an ingenious strategy for designing nickel selenide electrodes and deeper perception for its Faradic mechanism in alkaline Zn battery.

摘要：A series of quaternary ammonium ionic liquids(ILs)were synthesized and employed as catalysts for the production of poly(isosorbide carbonate)(PIC)from diphenyl carbonate and isosorbide via a melt polycondensation *** relationship between the anions of the ILs and the catalytic activities was investigated,and the readily‐prepared IL tetraethylammonium imidazolate(TEAI)was found to exhibit the highest catalytic *** optimizing the reaction conditions,a PIC with a weight‐average molecular weight(Mw)of25600g/mol was obtained,in conjunction with an isosorbide conversion of92%.As a means of modifying the molecular flexibility and thermal properties of the PIC,poly(aliphatic diol‐co‐isosorbide carbonate)s(PAIC)s were successfully synthesized,again using TEAI,and polymers with Mw values ranging from29000to112000g/mol were obtained.13C NMR analyses determined that the PAIC specimens had random microstructures,while differential scanning calorimetry demonstrated that each of the PAICs were amorphous and had glass transition temperatures ranging from50to115°*** analyses found Td‐5%values ranging from316to332°C for these *** on these data,it is evident that the incorporation of linear or cyclohexane‐based diol repeating units changed the thermal properties of the PIC.

摘要：Compared to the traditional lumped-parameter model, computational fluid dynamics （CFD） attracted more attentions due to facilitating more accurate reactor design and optimization methods when analyzing the heat transfer in the industrial packed bed. Here, a model was developed based on the CFD theory, in which the heterogeneous fluid flow was resolved by considering the oscillatory behavior of voidage and the effective fluid viscosity. The energy transports in packed bed were calculated by the convection and diffusion incorporated with gaseous dispersion in fluid and the contacting thermal conductivity of packed particles in solids. The heat transfer coefficient between fluid and wall was evaluated by considering the turbulence due to the packed particles adjacent to the wall. Thus, the heat transfer in padded bed can be predicted without using any adjustable semi-empirical effective thermal conductivity coefficient. The experimental results from the literature were employed to validate this model.

摘要：Pt/Au/WO_3 bimetallic catalysts were prepared by impregnation of Pt onto preformed Au/WO_3,obtained by a hexadecyl trmethyl ammonium bromide（CTAB）-assisted one-pot synthesis *** resulting Pt/Au/WO_3 catalysts exhibited remarkable synergistic effects for selective hydrogenolysis of glycerol to 1,3-propanediol. The characterization results showed that doping of Au promoted the reduction of both Pt and W at low temperatures and uniform dispersion of Pt on the WO_3 support. Furthermore, more low-valence Pt species were produced on the WO_3 surface after introduction of Au. These changes in electronic properties resulted in enhancement of both glycerol conversion and selectivity for 1,3-propanediol.

摘要：The double drum coal shearer is widely applied for the underground coal exploration in the mining *** vibration and noise control are significant factors for the stability design of the double drum coal *** this paper,the vibration properties of a double drum coal shearer are firstly *** horizontal,transverse and torsional vibrations of the motor body and the angle displacements of the rockers are taken into *** walking units and the hydraulic units are modeled by the stiffness-damping *** nonlinear equation of motion of the double drum coal shearer is established by applying the Lagrange’s *** nonlinear vibration response of the system is calculated by using the Runge Kutta numerical *** effects of the shearing loads,the equivalent damping and stiffness of the walking units,the inclination angels of the rockers and the equivalent damping and stiffness of the hydraulic units on the vibration properties of the system are discussed.