细粒式薄表层沥青混合料中粗集料的骨架特性

为研究薄表层沥青混合料的骨架特性,同时为保证公称最大粒径9. 5 mm(UTL-10)矿料级配的稳定性,在4. 75 mm与9. 5 mm筛孔中间增设7. 5 mm筛孔,通过捣实密度试验分析了不同粗集料配比的集料骨架间隙率(VCA)。同时,提出了利用粗集料-沥青胶浆试件的单轴贯入试验来研究不同组合的粗集料抗剪强度相关参数,确定了薄表层粗集料的级配设计控制指标,最终给出了薄表层粗集料的推荐配比范围。结果表明:集料内摩阻角φ能够很好地反映粗集料级配的骨架强度稳定性;采用VCA和内摩阻角φ双重指标可以有效控制薄表层沥青混合料的粗集料配比设计;公称最大粒径为13. 2 mm(UTL-13)矿料级配三档集料含量的推荐范围分别为12. 5%～22. 2%,37. 5%～44. 4%,33. 3%～50%;UTL-10三档集料含量的推荐范围分别为10%～16. 7%,40%～50%,33. 3%～50%。

薄表层沥青混合料路用性能研究

随着交通事业快速发展,对高等级公路的服务质量要求越来越高,沥青混凝土路面病害由传统的高温车辙、低温开裂、水损害等病害类型向耐久破坏形式转换。该文在确保薄表层沥青混合料使用耐久性能前提下,改善沥青路面的高温抗车辙、低温抗开裂、水损害等技术指标。通过级配类型和外加剂掺量的不同对AC- 10C,AC- 13C.UTL- 10.UTL- 13共4种细粒式薄表层沥青混合料性能展开研究,结果表明:相比AC型沥青混合料,UTL型沥青混合料具有较好的高温稳定性,但其抗低温开裂性能较AC型沥青混合料差;公称粒径较小的混合料,水稳定性更好;当外加剂掺量为0.4%时.UTL-13沥青混合料的水稳定性能最佳。

抗滑表层沥青混合料路用性能分析

选用AK16、SAC16、SMA16、SUP16型沥青混合料,比较系统地分析了其路用性能,特别是高温稳定性、水稳定性等力学性能以及表面的抗滑性及透水性。

自渗牛床中河沙与甘蔗渣两种表层垫料对西门塔尔母牛体表清洁度的影响

为了探讨自渗牛床不同表层垫料(河沙和甘蔗渣)对西门塔尔母牛体表清洁度的影响,试验选取体况良好、年龄及胎次接近的西门塔尔成年母牛30头,随机分成2组,15头/组,分别饲养在铺撒厚度为15 cm的河沙与甘蔗渣表层垫料的自渗牛床上,按照4分制对西门塔尔成年母牛的乳房、左侧上腿部、右侧上腿部、左侧下腿部、右侧下腿部、腹部、尾部7个体表部位进行连续10 d的清洁度评分。结果表明:牛群在两类垫料上的体表清洁度差异不显著(P>0.05),且均无最肮脏的4分;乳房清洁度评分最低,最清洁的1分所占比例为98%,2分所占比例为2%,3分所占比例为0。说明自渗牛床配合厚度为15 cm的甘蔗渣或河沙作为表层垫料均能维护牛群良好的体表清洁度。

广东地区高速公路养护工程表层沥青混合料抗滑性能评价

在调研广东地区高速公路养护工程表层沥青混合料抗滑性能检测数据的基础上,采用《公路路基路面现场测试规程》中的横向力系数指标,从初始抗滑性、抗滑耐久性、抗滑稳定性三个方面,评价微表处、AC16、Novachip的抗滑性能。结果表明:抗滑性能优劣排序为Novachip>AC16>微表处。

再生沥青混合料疲劳性能试验研究

为了评价掺有再生沥青路面(RAP)材料的沥青混合料的疲劳性能,以及不同RAP材料用量对沥青混合料疲劳性能的影响,进行了室内再生沥青混合料疲劳试验研究。疲劳试验中采用了沥青路面表面层沥青混合料,选用了间接拉伸(IDT)强度试验和半圆弯曲(SCB)疲劳试验方法,进行了RAP材料质量分数分别为0%、10%、20%和30%的疲劳试验。试验结果表明:沥青混合料中RAP材料质量分数小于20%时,对沥青混合料疲劳性能影响不大,而RAP材料质量分数为30%时,疲劳性能明显下降。初步建议了表层沥青混合料合适的RAP材料质量分数不宜超过20%。

表芯层长短秸秆刨花配比对定向结构麦秸板性能的影响

以长秸秆刨花作表层、短刨花作芯层,生产三层定向结构麦秸板(OSSB),探讨表芯层刨花的不同配比对板材性能的影响。结果表明,OSSB板材性能达到LY/T 2141-2013《定向结构麦秸板》中干燥状态下承载型板材的要求;改变表芯层刨花的配比,可以调控OSSB的性能指标。

Ocean surface currents retrieval based on the satellite remote sensing data

The ocean surface currents are reconstructed from the satellite remote sensing data containing altimeter-derived sea surface height and QuikSCAT satellite-derived wind data. Based on the method proposed by Lagerloef, a global weekly 0.5°×0.5°ocean surface current product was obtained over the period 2000 - 2008 by combining the geostrophic currents estimated from sea surface height with Ekman current estimated from the wind stress. Particularly, weight functions were introduced when calculating the Ekman currents to eliminate the discontinuity near 25°S and 25°N. These satellite-derived currents have been compared with TAO current meter and the SCUD product, respectively. The comparison showed that satellite-derived currents not only could capture the characteristics of ocean surface currents but also had high accuracy and reliability. The result showed that this innovatory method was effective.

A METHOD FOR PREDICTING BUCKLING LOADS OF COMPOSITE LAMINATED STRIPS WITH A SURFACE NOTCH

Surface notches lower the stiffness of laminated strips, so they lower the buckling loads of the laminated strips, too. In this paper a new method is proposed to predict the buckling loads of the laminated strips with a surface notch. The theoretical and experimental results show that the buckling loads decrease as the depth or width of the surface notches increase; when the stacking sequence of the laminated strips is [0°/0°/+ θ/-θ/0°/0°/+θ/-θ] s , the buckling load decrease as θ increases. It proves that the method is reliable and significant.

Effects of mushroom waste on improvement of reclaimed soil qualityin coal mining areas

Restoring soil quality is the main evaluation norm of the reclamation. In order to reveal the effects of mushroom waste on the quality improvement of reclaimed soil in coal mining areas, the physical, chemical and microbial characteristics of soil are studied. The results show clear improvement in the soil after using mushroom waste. Because of human cultivation and fertilization, cultivated soil after reclamation exhibits high comprehensive quality and the index of quality of surface soil reaches 0.64 and 0.73. The average index of surface soil quality is as high as 0.52 and 0.54. In comparison, the quality of reclaimed soil of forest land is low, with average index of 0.40. The effects of mushroom waste are mainly on the surface soil in the first 2 years after the application. After that period, with the decomposition of mushroom waste, soil quality index tends to be the same as the original soil. The quality of surface soil is higher than that of subsoil, especially after the application of mushroom waste, at which point the soil quality reaches a peak at about 15 cm. Cultivated soil after reclamation has great variance in quality, after the coefficient of 24.74%. Mushroom waste can reduce such variation, particularly with long-term use. The variance efficient falls to 3.59% after 3-year application.

Improvement of oxidation resistance in graphite for MgO-C refractory through surface modification

Graphite, used as a carbon source in a conventional magnesia-carbon(MgO-C) refractory, was modified with an acid reagent, resulting in a negative charge on the surface of graphite, to enhance the coating efficiency of aluminum(Al) phase, which was compared to the pristine graphite through its dispersibity and oxidation behavior. The graphite particles with and without surface modification were added, respecticely, in an Al(NO3)3 suspension used as a coating reagent, and then filtered at room temperature. The modified graphite shows better disperbility than the pristine graphite, indicating that the coating efficiency of Al precursor is enhanced in the modified graphite. With respect to oxidation behavior, the modified graphite without the coating layer is totally reacted with oxygen at heat treatment of 900 °C in air. However, the Al-coated graphite starts to react with oxygen at heat treatment of 900 °C and fully reacted with oxygen at heat treatment of 1000 °C, showing the gray and white colors, respectively. It is verified that the Al layer is individually and uniformly formed on the surface of graphite and the oxidation resistance of graphite is enhanced owing to the increased coating efficiency of Al precursor.

Effect of coating material and lubricant on forming force and surface defects in wire drawing process

A pilot wire drawing machine as well as wire end-pointing roller was developed. Using these machines, a wire drawing test for four different coating materials and two different lubricants was performed as the reduction ratio increased from 10% to 30%. Materials used for a substrate in this study are plain carbon steel （AIS11045） and ultra low carbon bainite steel. To compute the friction coefficient between the coating layer of wire and the surface of die lbr a specific lubricant, a series of finite element analyses were carried out. SEM observations were also conducted to investigate the surface defects of wire deformed. Results show that the behavior of drawing force varies with the lubricant-type at the initial stage of drawing. The powder-typed lubricant with a large particle causes the retardation of lull lubrication on the entire contact surface and the local delamination of coating layer on the wire surface. As the flow stress of a substrate increases, the delamination becomes severe.

Enhanced performances of polypropylene membranes by molecular layer deposition of polyimide

Molecular layer deposition （MLD） for the deposition of polyimide （PI） at low temperature of 110 ℃ has been firstly introduced into the field of membrane separation. With the optimized MLD deposition parameters, such low de- position temperature has successfully expanded the application of MLD for the surface modification of polymeric materials. Globular PI particulates grow on both the free surfaces as well as the pore walls of the polypropylene （PP） membranes as isolated islands during progressive precursor exposures. The PI-deposited PP membranes ex- hibit synergistically improved performances in various aspects. Evidently improved surface hydrophilicity and per- meation performance （30%） have been achieved v/a the MLD deposition of polyimide films. The overall separation efficiency maintained higher than 85% even after 250 cycles of MLD deposition. More importantly, the thermal sta- bility has been improved and the integrity of the porous structure for PI-deposited PP membranes has been well preserved even after harsh treatment, which ensures its potential application in industries.

Electrochemical Deposition of Ni-W Gradient Deposit and Its Structural Characterization

The Ni-W gradient deposit with nano-structure was prepared by an electrochemical deposition method.X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDXA) indicate that the crystallite size of the deposit decreases from 10.3nm to 1.5nm and the crystal grating aberrance increases with the increase of W content in the growing direction of the deposit. The structure of deposit changes from crystalline to amorphous stepwise with associated increase of crystal grating aberrance, and presents gradient distribution. These show that the deposit isgradient with nano-structure.

A non-labeled DNA biosensor based on light addressable potentiometric sensor modified with TiO_2 thin film

Titanium dioxide (TiO2) thin film was deposited on the surface of the light addressable potentiometric sensor (LAPS) to modify the sensor surface for the non-labeled detection of DNA molecules. To evaluate the effect of ultraviolet (UV) treatment on the silanization level of TiO2 thin film by 3-aminopropyltriethoxysilane (APTS),fluorescein isothiocyanate (FITC) was used to label the amine group on the end of APTS immobilized onto the TiO2 thin film. We found that,with UV irradiation,the silanization level of the irradiated area of the TiO2 film was improved compared with the non-irradiated area under well-controlled conditions. This result indicates that TiO2 can act as a coating material on the biosensor surface to improve the effect and efficiency of the covalent immobilization of biomolecules on the sensor surface. The artificially synthesized probe DNA molecules were covalently linked onto the surface of TiO2 film. The hybridization of probe DNA and target DNA was monitored by the recording of I-V curves that shift along the voltage axis during the process of reaction. A significant LAPS signal can be detected at 10 μmol/L of target DNA sample.

Lubricating a bright future:Lubrication contribution to energy saving and low carbon emission

Both the academic society and the industry are hunting for new energy forms for the future.However,the world should not forget the conventional technologies that contribute to the sustainable society by technical innovations.Among them,lubrication plays a significant role in energy saving and in low CO2emission by increasing the fuel efficiency and by prolonging the service life of machines.With the advance of novel synthetic approaches,and nanoscience and technologies,novel lubrication oils and additives and their formulations are being developed to reduce friction and wear,and novel surface treatment routes and surface coatings are invented and provide more efficient lubrication.These technologies create tremendous chances for machines to work more efficiently with low energy consumption.Here we review the recent progresses and challenges associated with some novel lubrication techniques that include novel surface treatment(such as texturing,high-performance nanocomposite coatings,adapting coating),tribology design(solid and liquid lubrication),energy-conserving engine oil and novel lubricants and formula(such as ionic liquids,low S,P content additives)which are to be adopted to enhance the fuel efficiency to achieve energy saving and low carbon emission.There is increased demand to replace fossil lubricants by degradable green lubricants.Specially designed coatings can reduce drag significantly during navigation of both airplanes and ships.All these aspects will be also reviewed in the paper.

WB crystals with oxidized surface as counter electrode in dye-sensitized solar cells

Tungsten boride(WB) crystals, whose surface tends to be oxidized when exposed to air, were demonstrated to have a comparable activity to platinum as counter electrode material in dye-sensitized solar cells. The synergistic effect of both catalytically active surface layer WOxand electronically conductive internal WB is considered to be responsible for the high activity of the WB crystals.