基于强混偏差样本的各向异性回归函数小波估计的相合性分析

针对强混条件下各向异性回归函数的估计问题,利用小波独特的局部时频分析特性构造了线性小波回归估计器,并在B_(p,q)~s(R~d)空间中讨论了L~p(1≤p<∞)误差意义下的相合性。研究结果表明,在样本容量充分大时,小波估计量■能够满足任何精度,当空间B_(p,q)~s(R~d)的各向异性指标相等时,结论与各向同性Besov空间中的结果保持一致。

不同粒度分布的高硫焦颗粒在强混燃烧器内的流动特性

利用一套新型强混燃烧器，对3种不同粒度分布的高硫焦颗粒的流动特性进行了较为详尽的考察．反应器主要由预混段和提升段组成，两部分结构尺寸分别为Ф240mm×3000mm和Ф70mm×9000mm．实验操作条件为：提升管表舰气速8～18m／s，颗粒循环速率60～200kg／（m^2·s）．通过对3种不同粒度分布的颗粒在强混燃烧器内颗粒固含率、颗粒速度轴径向分布的测定，发现随掺入细颗粒比例的增加，截面平均颗粒速度降低；在较粗的高硫焦颗粒中适当掺入细粉，可使床层内颗粒固含率增加，返混加剧，停留时间延长，有利于高硫焦的充分燃烧。

插电强混式车载电池储能系统碰撞安全性设计

针对插电强混式车载电池储能系统进行相关的碰撞安全研究,提出对车载电池储能系统在碰撞工况下的安全保护设计要求,并基于上汽所进行的插电式混合动力车型开发项目,实施具体的安全设计方案,通过试验验证设计方案的可行性,可以推广到其它相关项目应用。

高硫焦用强混反应器流动特性

根据炼油工业近年来流态化技术的发展及相关新技术的应用,设计了一套适合高硫焦燃烧特点的新型强混反应器冷态实验装置.强混反应器主要由混合段和提升段两部分构成,两部分的设备结构尺寸分别为φ240mm×3000mm和φ70mm×9000mm.选取了适合工业应用的实验操作条件:提升段操作表观线速度6～20 m/s,颗粒循环速率20～230 kg/(m2·s).系统考察了高硫焦模拟颗粒在混合段的流动特性.通过对强混反应器轴、径向颗粒浓度和速度分布的实验测定,将强混反应器的混合段沿轴向分为两个区,沿径向分为两个或三个区,并提出用径向分布指数来表征颗粒浓度和速度的径向不均匀性.

基于强混样本的带偏差密度模型的小波估计

为了解决强混样本下带偏差密度估计问题,基于小波方法构造了线性小波估计器,并在Bp,qs(R)空间中给出了该估计器在积分均方误差意义下的收敛阶。结果表明,当p≥2时,估计器达到最优收敛阶。另外,当样本由强混退回独立时,主要定理与独立情形下的结论相同。

基于烧结复合返矿分流的混合工艺应用

采用烧结原料先润湿、混匀、消化,然后再与返矿共同制粒的实验室实验和工业化应用,研究了烧结复合返矿分流的“强混+消化+制粒”工艺对混合制粒效果以及烧结经济技术指标的影响。结果表明,与传统混合工艺相比,烧结复合返矿分流的“强混+消化+制粒”工艺能够提高混合料混匀效果,实验室研究平均粒径提高0.56 mm,烧结指标也得到改善,烧结速度提高了2.99 mm/min,成品率提高了0.11%,转鼓强度提高0.01%,烧结机利用系数提高0.24 t/(m^(2)·h);工业实验结果显示,烧结矿平均粒径提高0.46 mm,利用系数提高0.07 t/(m^(2)·h),成品率提高了0.08%。

各向异性回归函数的小波点态估计

针对强混条件下各向异性回归函数的点态估计问题,利用小波方法构造了线性小波估计器,并在B_(p,q)^(S)(R^(d))空间讨论了估计器在l^(p)(1≤p<∞)点态误差意义下的收敛阶。研究结果表明,在强混条件下的结论比样本独立时的结果更接近实际应用,且当空间B_(p,q)^(S)(R^(d))的各向异性指标相等时,结论与各向同性Besov空间中的结果保持一致。

Study on High Strength Concrete Confined by Continuous Carbon Fiber Sheet

Eight high strength concrete (HSC) prisms strengthened with continuous carbon fiber sheet(CFS)were tested.As a result of the confinement provided by CFS,the concrete would fail at a greater strain than the unconfined and then a significant increase in ductility can be achieved.The lateral pressure exerted by CFS would increase the compressive strength of the concrete,resulting in higher load bearing capacity.This paper proposes the stress strain curve of this kind of hybrid specimen,which agrees well with the test results.Based on the stress strain relationship and the assumptions proposed in this paper,a computer program was developed to analyze HSC columns,confined by CFS,which were subjected to axial compression and biaxial bending.The results shown in this paper indicate that the ductility of HSC column is significantly improved and the strength is also increased by some degree.

Calculation on uniaxial compressive strength of high strength concrete after wrapped by FRP

A theoretical calculation method of the axial compressive strength of a high strength concrete with fibre reinforced plastics (FRP) constraint is proposed. It is shown by test verification that the FRP strength devotion factor used for this method is in accordance with actual conditions. FRP is not up to the ultimate strength when the concrete reaches the ultimate strength, whose strength devotion factor is in the range of 0.28 to 0.59, which is related to an elastic modulus. The method can be used to estimate axial compressive strength of the concrete strengthened with FRP. The theoretical strength is 10% to 30% higher than the measured one. The deviation comes mainly from a non-ideal bonding condition of FRP-concrete interfaces and discrete property of the testing data of compressive strength.

RESEARCH ON T SHAPED HIGH STRENGTH CONCRETE MEMBERS SUBJECTED TO AXIAL COMPRESSION AND BIAXIAL BENDING

Based on experiments, a computer program is developed. The calculated results agree well with the experimental results. The flexural behavior of T shaped high strength concrete members subjected to axial compression and biaxial bending is studied. The main factors affecting the flexural behavior of T shaped high strength concrete members are loading angle, axial compression ratio and reinforcement ratio.

再造烟丝生产线配比系统改进

针对薄片线料液下料系统液料在重力作用下流入强混机构,造成配比精度过大,混合物料黏稠度易超过工艺指标要求的问题,通过对辊压法薄片液料下料电气控制系统和程序的设计应用,提高薄片再造烟丝液料与粉料配比的控制精度,使其误差在工艺指标范围内微小的波动,提高物料的利用率,有效消除薄片再造烟丝质量缺陷的问题。

Mechanical performance of the mixed post-installed connection in low-strength concrete

Due to inadequate bearing capacity of the chemically-planted steel bar in low-strength concrete, a new mixed post-installed connection is proposed using small diameter anchoring steel bars and grouting materials together to anchor the main steel bar. To investigate the feasibility of the proposed post-installed connections, a series of pull-out tests with different anchors were conducted for comparison,including fully adhesive anchors, partially adhesive anchors,grouting material anchoring connection and the new mixed post-installed connection. The experimental results of the single steel bar pull-out test show that the mixed post-installed connection can effectively enhance the bearing capacity of post-installed steel bars in low-strength concrete. The bearing capacity is increased by nearly two times with no cone-type concrete failure compared with the fully adhesive anchor. The results show that adopting the new mixed post-installed connection can ensure that joint performance meets the requirements if the space dimension is available.

Strength of circular concrete columns under concentric compression

An experimental study, in which six columns were loaded concentrically toinvestigate the behavior of reinforced normal strength and high strength circular columns underconcentric compression, is described. The concrete strengths of the columns were 30 MPa and 60 MPa.The primary variables considered were the concrete strength and the amount of transversereinforcement. Test results indicate that smaller hoop spacing provides higher column capacity andgreater strength enhancement in a confined concrete core of columns. For the same lateralconfinement, high strength concrete columns develop lower strength enhancement than normal strengthconcrete columns. Both the strength enhancement ratio (f'_(cc) /f'_(co)) and the column capacityratio (P_(test)/P_o) were observed to show linear increase variations with rho_s f_(yt)/f'_c incircular columns.

Laboratory evaluation of epoxy resin modified asphalt mixtures

The pavement performance of epoxy resin modified asphalt mixtures was investigated by the Marshall test, the indirect tensile test, the rutting test, the three-pointed bending test and the composite beam fatigue test. In comparison with the performance of epoxy resin modified asphalt mixtures, the performance of stone matrix asphalt mixtures （SMA10） was also investigated. The rutting test and composite beam fatigue test results show that the epoxy resin modified asphalt mixtures can improve permanent deformation and fatigue characteristics. They also show lower temperature susceptibility and greater resistance to moisture damage compared to the SMA10. Findings from the research indicate that the epoxy resin modified asphalt mixture provides an optional material for the pavement of long-span steel bridges in China due to profound performance and economic advantages.

Evaluation of fracture properties of epoxy asphalt mixtures by SCB test

The fracture properties of epoxy asphalt mixtures （EAM） are evaluated based on J-integral and ultimate strength. Totally 60 semi-circular bending （SCB）specimens cored from superpave gyratory compactor （SGC）with three groups of notch depths are tested at the temperature of - 10 and 20 ℃. The experimental results reveal good repeatability in EAM characterization. The tensile strength ratio of SCB to the indirect tensile test （IDT） is at a range of 1.4 to 1.7, and the ultimate strength of EAM is exponentially dependent on the notch depths. At the test temperatures, the critical J-integral value of EAM is much higher than that of hot mix asphalt（ HMA） with thermoplastic asphalt binder. The response mode of EAM changes from ductile mode to brittle mode and the fracture energy increases 30% when temperature decreases from 20 to - 10℃, while its critical J-integral value decreases only 15%. It is concluded that EAM has better fracture resistance than thermo-plastic HMA; more fracture energy is needed to initiate cracks in EAM at low temperature, and the cracks propagate more rapidly than at room temperature.

Strength regularity and failure criterion of plain HSHPC under biaxial compression after exposure to high temperatures

Biaxial compression tests are performed on 100 mm × 100 mm × 100 mm cubic specimens of plain high-strength highperformance concrete （HSHPC） at seven kinds of stress ratios, σ2：σ3 =0 ： - 1, -0.20 ： - 1, -0.30 ： - 1, -0.40 ： - 1, -0.50 ： -1, -0. 75 ： - 1, and - 1.00 ： - 1 after exposure to normal and high temperatures of 20, 200, 300, 400, 500 and 600 ℃, using a large static-dynamic true triaxial machine. Frictionreducing pads are three layers of plastic membranes with glycerine in-between for the compressive loading plane. Failure modes of the specimens are described. The two principally static compressive strengths are measured. The influences of the temperatures and stress ratios on the biaxial strengths of HSHPC after exposure to high temperatures are also analyzed. The experimental results show that the uniaxial compressive strength of plain HSHPC after exposure to high temperatures does not decrease completely with the increase in temperature; the ratios of the biaxial to its uniaxial compressive strengths depend on the stress ratios and brittleness-stiffness of HSHPC after exposure to different high temperatures. The formula of the Kupfer-Gerstle failure criterion modified with the temperature and stress ratio parameters for plain HSHPC is proposed.

STUDY ON OPTIMIZATION OF HIGH PERFORMANCE CONCRETE ADMIXTURES

Influences of admixtures on the workability and strength of high performance concrete （HPC） are in- vestigated. The types of investigated admixtures include naphthalene series high range water reducing agent, polycarboxlic series high range water reduce agent and sodium sulfate hardening accelerating agent. Two kinds of curing condition, namely steam curing condition and standard curing condition, are adopted. The result shows that HPC, added with polycarboxlic series of high performance water reducer, has high workability and strength, while sodium sulfate accelerating agent causes poor workability and low strength. Thus for vapor-cured HPC and its formulations, naphthalene series high range water reducing agent with less sodium sulfate should be given pri- ority. Therefore, the differences of curing conditions should be considered when selecting HPC admixtures.

Fatigue behavior of basalt-aramid and basalt-carbon hybrid fiber reinforced polymer sheets

In order to study the fatigue failure mode and fatigue life laws of basalt-aramid and basalt-carbon hybrid fiber reinforced polymer （ FRP ） sheets, fatigue experiments are carried out, considering two hybrid ratios of 1 ： 1 and 2：1 under different stress levels from 0.6 to 0.95. The results show that fractures occur first in carbon fibers or aramid fibers for the specimens with hybrid ratio of 1： 1, namely B1A1 and B1C1, while a fracture occurs first in basalt fibers for the specimens with a hybrid ratio of 2： 1, namely B2A1 and B2C1. The fatigue lives of the hybrid FRP sheets increase with the improvement of the content of carbon fibers or aramid fibers, and the influence of the carbon fibers content improvement to fatigue life is more significant. The fatigue performance of B2A1 is relatively worse, while the fatigue performance of B1C1 and B2C1 is relatively better. Finally, a new fatigue stiffness degradation model with dual variables and double inflection points is presented, which is applicable to both hybrid and normal FRP sheets.

早强型混凝土自保温砌块配合比设计

自保温砌块的材质是混凝土,但是与混凝土又有所不同:(1)由于砌块存在隔热孔洞的原因,混凝土的强度与砌块的强度存在很大差别;(2)砌块的养护也与一般混凝土制品不同,砌块不能带模养护,所以在脱模后必须使砌块有一定的抵抗变形和自承重的能力。(3)混凝土布料时是在成型机上,不同的成型机振动强度、时间不同。即使是同一种配合比生产出来的成品砌块强度也会有所差异。(4)成型出来以后,直接参与销售外观上也必须有一定的要求,表面的光泽度、平整度、色泽都需要考虑。因此在设计配合比时,必须考虑此类问题。本文是通过对原材料的选用、粗细骨料的颗粒级配、混凝土强度水灰比、用水量等因素设计混凝土砌块配合。

Bending performance of TRC-strengthened RC beams with secondary load under chloride erosion

Textile reinforced concrete(TRC)has good bearing capacity,crack resistance and corrosion resistance and it is suitable for repairing and reinforcing concrete structures in harsh marine environments.The four-point bending method was used to analyze the influence of the salt concentration,the damage degree and the coupled effect of the environment and load on the bending performance of TRC-strengthened beams with a secondary load.The results showed that as the salt concentration increased,the crack width and mid-span deflection of the beam quickly increased,and its bearing capacity decreased.As the damage degree increased,the early-stage crack development and mid-span deflection of the beam were less affected and the ultimate bearing capacity significantly decreased.In addition,the coupled effect of the environment and load on the beams with a secondary load was significant.As the sustained load increased,the ultimate bearing capacity of the strengthened beam decreased,and cracks developed faster in the later stage.In addition,the mid-span deflection of the beam decreased at the same load level because of the influence of the initial deflection due to the sustained load corrosion.