边坡稳定性评价方法研究现状与发展趋势

随着岩土工程技术的进步与相关学科的发展,新的边坡稳定性分析方法不断涌现;另一方面,因对边坡工程地质条件缺乏足够的认识而评价方法选择不当导致工程事故时有发生。因此对边坡稳定性评价方法的原理、假设条件及适用范围进一步疏理很有必要。首先从评价方法的学科领域、基本原理、评价模型的假设条件等角度将其分为工程地质经验评价法、工程力学理论分析法、应用数学理论分析法、试验模拟法和现场监测与预测分析法等五大类。选择代表性的方法介绍每类评价方法的研究现状,指出存在的问题,分析与归纳各类评价方法的优缺点及其适用条件。最后对边坡稳定性研究及其评价方法的发展趋势进行展望。     

不同变截面桩竖向承载特性的数值分析

基于现场试验,采用Abaqus有限元软件对等截面桩及变截面桩单桩竖向承载力测试实验过程进行数值模拟。结果表明:弹性变形阶段,竖向荷载-沉降曲线呈线性变化趋势,等截面桩比变截面桩桩身沉降较小;塑性屈服阶段,等截面桩与变截面桩单桩承载力几乎一致。变截面位置对桩侧摩阻力沿深度的分布有一定影响,最大侧摩阻力位置根据变截面的位置而变化。变截面桩的平均侧摩阻力较等截面桩的平均侧摩阻力大,变截面桩侧摩阻力效果较等截面桩更有优势。在相同承载力条件下,变截面桩所耗费的材料较等截面少,对于竖向承载特性,变截面桩与等截面桩表现基本一致,因此使用变截面桩能节约工程成本。     

胍基阳离子捕收剂反浮选磷矿的性能与机理分析

为了研究磷矿反浮脱硅过程中,胍基阳离子磷矿捕收剂的作用机理,以N-椰油基-1,3-丙撑二胺、单氰胺、乙酸为原料制得一种阳离子表面活性剂,并用于傅里叶红外光谱仪表征,测试了该药剂与3种矿物作用前后的接触角、Zeta电位、红外光谱,进行了石英、白云石、胶磷矿的纯矿物浮选试验等。结果表明:该合成药剂属胍基阳离子表面活性剂,在广泛pH值范围内,对石英的捕收能力较强,对白云石次之,对胶磷矿较弱;在弱碱性下,对白云石捕收性能有所提高;相较白云石、胶磷矿,该药剂更易与石英产生吸附作用,使矿物表面呈现疏水性;接触角、Zeta电位、红外光谱测试结果说明与3种矿物的吸附主要是物理吸附。试验结果说明该胍基阳离子表面活性剂可以作为磷矿反浮脱硅捕收剂。     

冠脉造影图像血管增强及减影的优化方法

针对于传统X射线冠状动脉造影序列图像的血管的减影包含严重伪影以及减影结果不完整等问题,提出了冠脉造影图像血管增强以及减影优化的方法。基于冠脉造影序列图像的时空特性,将相同时相的图像匹配进行减影,得到初步减影结果。针对初步减影部分缺失,对有导管遮挡没有被识别的单根血管进行二次增强处理。增强方法为:运用区域生长确定被导管遮挡的血管部分,以此部分为基础按规定模板扩展,形成覆盖导管区域,区分血管和导管,改变两部分的灰度值,增大对比度。最后采用灰度线性变换、中值滤波等步骤,得到优化的冠脉血管减影。实验表明,本减影及优化方法可以从冠脉造影序列图中提取较为完整清晰的冠脉血管并且具有很好的可控性和鲁棒性。     

“两个一体化”战略下储能应用前景分析

储能对电能应用具有时序调节的作用,且储能技术在逐步完善,其应用场景也逐渐多元。在“风光水火储一体化”和“源网荷储一体化”（“两个一体化”）下,储能的灵活调节作用将得到更充分的发挥,储能有望迎来更广阔的发展空间。本文先对新能源领域相关政策以及“两个一体化”的建设规划概况进行梳理,然后分析了“两个一体化”下储能的灵活性以及经济性,研究了“两个一体化”下的储能规划,探究了“两个一体化”的商业化应用,提出了应因地制宜配置储能设施,储能收益多元,完善储能商业模式等建议,对今后储能的走向具有一定参考意义。     

EFFECTS OF SPECIFIED BLANK SIZE ON BODY WRINKLING DURING HYDRODYNAMIC DEEP DRAWING OF TAPERED RECTANGULAR BOX

1.~nonHydridapawhcdeepdrawing(HDD)belongstothefieldofsheetmetalfoeingandcanbeaPPliedinthefieldofautomotive,aerospace,drilitaryindustryetc.Ithasbeenrecognizedwidelyintheworld["'j.Fig.Ishowsitsprinciple:TheliqUidthatisfilledinthe~ngdiecavitywillbepressedwhenthepunchgoesdownsothattheeffectoffrictionkeepingandoverflowlubricatingcanbeformed,astherestilt,thefoeinglicitofsheetmetalwillbeimprovedareailvandthegualitVofthefinishedpartswillbeup~ed.BecauseofmanyadvantagesofHDDprocees,ithasbeenwidelys…     

EFFECT OF ALLOY ELEMENTS ON QUASIEQUILIBRIUM MICROSTRUCTURE IN Fe-Mn-Ni-Cr STEELS

The microstructures of Fe-Mn-Ni-Cr steels with medium carbon and the effect of alloy ele-ments on them have been investigated by means of X-ray diffraction quantitative phase ana-lyses,metallography and hardness tests.The volume fraction of martensite in steels quenchedat 1100℃ can be expressed as:f_M~(1100)=162.643-15.482Mn-7.36Ni-4.286(Cr+Mo+V)Based on this expression,the quasi-equilibrium microstructure diagram has been obtained.Itis shown that the effect of Mn on the austenite stability is greater than that of Ni.The equiva-lent [Ni]=2.104Mn+Ni and equivalent [Cr]=Cr+Mo+V.The driving force for martensite transformation at M_s point has been calculated to hedrastically decreased by element Mn.     

Advances in the research of nitrogen containing stainless steels

The current status of nitrogen containing stainless steels at home and aboard has been introduced. The function and existing forms of nitrogen in the stainless steels, influence of nitrogen on mechanical properties and anti-corrosion properties as well as the application of nitrogen containing cast stainless steels were discussed in this paper. It is clear that nitrogen will be a potential and important alloying element in stainless steels. And Argon Oxygen Decarbonization (AOD) refining can provide an advanced manufacture process for nitrogen containing stainless steels with ultra-low- carbon and high cleanliness.     

4-methoxy-2,6-bis(3,5-dimethylpyrazoyl)-1,3,5-triazine modified carbon paste electrode for trace Cu(Ⅱ) determination by differential pulse volt-ammetry

A differential pulse voltammetric method was developed for the sensitive and selective determination of Cu(Ⅱ) at 4-methoxy-2,6-bis(3,5-dimethylpyrazoyl)-l,3,5-triazine modified carbon paste electrode in 0.05 mol/L KHC8H4O4 solution (pH = 4.02). The oxidation peak of Cu(Ⅱ) was observed at 0.065 V(vs Ag/AgCl) by scanning the potential in positive direc-tion. The analysis procedure consisted of an open circuit accumulation step in stirred sample solution. It was followed by medium exchange to a clean solution and subsequently an anodic potential scan was affected to obtain the voltammetric peak. The current was proportional to the concentration of the Cu(Ⅱ) ion in a range of 1× 10-7-1×10-4 mol/L for 6 min accumulation; the most of metal ions did not interfere with the determination. The developed method was applied to Cu(Ⅱ) determination in coal-ash sample, the results agreed with that of atomic adsorption spectroscopy(AAS).     

Water modeling of molten steel flow in a multi-strand tundish with gas blowing

Fluid flow characteristics in a four-strand tundish with gas blowing were studied by water modeling experiments.It is found that gas blowing can greatly improve the flow characteristics in the tundish with a turbulence inhibitor.It dramatically increases the peak concentration time,and greatly decreases the dead volume,and reduces the minimum residence time.The gas blowing location,gas flow rate,and porous plug area greatly influence the flow characteristics in the tundish;the gas blowing location near t...