煤和聚丙烯腈炭化过程中负载铁原子在表面与体相间的质量迁移

采用XPS和Ar^+离子刻蚀技术,研究了炭化过程中铁原子在煤和聚丙烯腈表面和体相间的质量分布规律.结果发现.随炭化进行铁原子由表面向体相迁移和富集;炭化温度升高.迁移和富集增加.表面浓度逐渐降低.以致铁原子沿粒子径向呈浓度梯度分布.

重庆市涪陵区厚层软硬相间岩体失稳模式

重庆市涪陵区厚层软硬相间公路高边坡的详细调查发现,不同的岩层产状,不同开挖方向其斜坡变形破坏模式不同。本文根据野外实例总结了不同岩层产状与开挖方向对应的破坏模式,平缓层状斜坡破坏方式有滑塌式崩塌、倾倒式崩塌和坠落式崩塌;中倾角层状斜坡破坏方式有顺层滑移和崩塌;高陡倾角层状斜坡坡破坏方式有滑移式崩塌和坠落式崩塌。表明斜坡变形破坏地质力学模式与斜坡岩体结构之间存在着密切的成生联系。通过对不同倾角的斜坡岩体破坏方式研究,可以达到系统评价预测斜坡稳定性的目的;通过公路开挖对不同产状岩层可能造成灾害的预期,可以采用不同的预防措施,避免大型灾害的发生。

软硬相间岩体混凝土人工骨料初探

合适的料场对水电工程的成败至关重要。软硬岩相间岩体中含有较多饱和单轴抗压强度≤40 MPa的相对软岩,一般不适宜作为混凝土人工骨料。以某水电站右岸料场砂岩、板岩互层岩体为例,主要从强度的角度来探讨软硬相间岩体混凝土骨料的可行性和适宜性。料场中,砂岩、板岩比例约为55∶45,试验表明纯砂岩强度指标满足规范要求,而纯板岩抗压强度多低于40 MPa。按砂岩、板岩50∶50和70∶30的比例作为骨料分别配制混凝土进行试验,所得混凝土强度满足C20、C25混凝土的要求,则该料场中不低于上述强度比例的砂板混合岩体可作为混凝土骨料,软硬相间岩体混凝土骨料可行。

软硬相间岩层中地下厂房稳定性分析

对软硬相间岩层中地下厂房进行稳定性分析,既要考虑岩石的软弱性质,又要考虑岩石的脆性。本文分别采用弹塑脆性理论和弹塑性理论对某地下厂房进行稳定性分析,结果表明对于软硬相间岩层中地下厂房的稳定性分析,如果仅考虑其弹塑性性质,其结果是偏危险的。

巴基斯坦卡洛特水电站缓倾层状软硬相间边坡变形特性及防治建议

沉积岩层状岩体在地壳表层广泛存在,通常呈软、硬相间的互层结构,岩层各向异性显著。不同厚度的沉积岩层状岩体组合对边坡的稳定性影响很大。以巴基斯坦卡洛特水电站软硬相间岩体边坡为例,研究了该类岩体的结构、力学特性、地下水分布及其对工程边坡的影响,总结了该类岩体构成的自然及人工边坡的主要失稳破坏模式,分析了其产生的原因,并提出了相应的防治措施,以供类似工程参考。

Regulating crystal phase of TiO_(2) to enhance catalytic activity of Ni/TiO_(2) for solar-driven dry reforming of methane

Ni/TiO_(2) catalyst is widely employed for photo-driven DRM reaction while the influence of crystal structure of TiO_(2) remains unclear.In this work,the rutile/anatase ratio in supports was successfully controlled by varying the calcination temperature of anatase-TiO_(2).Structural characterizations revealed that a distinct TiO_(x) coating on the Ni nanoparticles(NPs)was evident for Ni/TiO_(2)-700 catalyst due to strong metal-support interaction.It is observed that the TiOx overlayer gradually disappeared as the ratio of rutile/anatase increased,thereby enhancing the exposure of Ni active sites.The exposed Ni sites enhanced visible light absorption and boosted the dissociation capability of CH4,which led to the much elevated catalytic activity for Ni/TiO_(2)-950 in which rutile dominated.Therefore,the catalytic activity of solar-driven DRM reaction was significantly influenced by the rutile/anatase ratio.Ni/TiO_(2)-950,characterized by a predominant rutile phase,exhibited the highest DRM reactivity,with remarkable H_(2) and CO production rates reaching as high as 87.4 and 220.2 mmol/(g·h),respectively.These rates were approximately 257 and 130 times higher,respectively,compared to those obtained on Ni/TiO_(2)-700 with anatase.This study suggests that the optimization of crystal structure of TiO_(2) support can effectively enhance the performance of photothermal DRM reaction.

Structural Characteristics of Mesophase Spheres Prepared from Coal Tar Pitch Modified by Phenolic Resin

Mesocarbon microbeads （MCMB） were prepared from coal tar pitch modified by phenolic resin and from the same pitch modified by phenolic resin and hexamethylenetetramine at 440℃ for lh. By investigating the morphology of mesophase spheres and the structure of the MCMB carbonized at 1000℃ for lh using scanning electron microscope （SEM） and XRD, it was found that phenolic resin accelerated the formation and coalescence of mesophase spheres. Some of the obtained MCMB were hi- or tri-spheres with the distorted microtextural carbon layers. Hexamethylenetetramine in the pitch modified by phenolic resin accelerated the condensation of phenolic resin and consequently expedited the combination of mesophase spheres, which was proved by the formation of some tetra-spheres. Owing to the cross-linkage of the additives, MCMB with complex structure were obtained.

Spatial Spillover and the Factors Influencing Public Service Supply in Sichuan Province, China

This article examines the spatial characteristics of public service supply and the factors influencing such supply in cities of Sichuan Province, China using spatial-autocorrelation and spatial econometric models with statistical data in 2012. The results demonstrate that expenditures on different types of public services present different spatial autocorrelation patterns. Although the spatial differences in basic public service expenditures are relatively small, a clear fan-shaped spillover to the east can be seen in Chengdu City. Chengdu also shows high clustering of advanced public service expenditures, being a typical core-periphery pattern. Post-earthquake reconstruction expenditures are clustered in the "5.12 Wenchuan earthquake" region and spill over toward cities to the east. The efficiency of public services in the mountainous areas in western Sichuan is low and exhibits a pattern of low-low spatial autocorrelation. The efficiency of public service supply is affected by economic, social, political and geographical factors. Based on the results of this analysis, we recommend a supply strategy that incorporates different types of public services and a specialized public service supply strategy for mountainous areas. Overall public service efficiency should be enhanced by focusing on narrowing the gap in farmers' income among regions and accelerating urbanization. Decision-makers should consider moresupportive policies with regard to providing basic public services in mountainous areas to ensure an equalized supply of basic public services. To enhance the efficiency of advanced public service supply, additional growth pole should be encouraged and incentivized; however, investments are required to drive the development of the peripheral regions through regional economic integration. Both software and hardware types of infrastructure are required to supply services efficiently during post-disaster reconstruction.

Understanding visual-auditory correlation from heterogeneous features for cross-media retrieval

Cross-media retrieval is an interesting research topic,which seeks to remove the barriers among different modalities.To enable cross-media retrieval,it is needed to find the correlation measures between heterogeneous low-level features and to judge the semantic similarity.This paper presents a novel approach to learn cross-media correlation between visual features and auditory features for image-audio retrieval.A semi-supervised correlation preserving mapping(SSCPM)method is described to construct the isomorphic SSCPM subspace where canonical correlations between the original visual and auditory features are further preserved.Subspace optimization algorithm is proposed to improve the local image cluster and audio cluster quality in an interactive way.A unique relevance feedback strategy is developed to update the knowledge of cross-media correlation by learning from user behaviors,so retrieval performance is enhanced in a progressive manner.Experimental results show that the performance of our approach is effective.

Collective Hamiltonian for Multi-O（4） Model

The collective Bamiltonian up to the fourth order for multi-O（4） model is derived based on the self-consistent collective-coordinate （SCC） method, which is formulated in the framework of the time-dependent Hartree-Bogoliubov （TDHB） theory. The validity of the collective Hamiltonian is checked in the two special cases of the multi-O（4） model： the case where the number of the shells is equal to one （a single j-shell case）, and the case where the Hartree-Bogoliubov equilibrium point is spherical （the spherical case）. The collective Hamiltonian constitutes a good starting point to study nuclear shape coexistence.

The Relationship Between Hysteresis and Liquid Flow Distribution in Trickle Beds

Experiments were conducted on a trickle bed with 0.283m ID to elucidate the relationship between hysteretic phenomena and liquid distribution. The hysteresis of pressure drop and the variance of radial liquid distribution were observed simultaneously. Residence time distribution (RTD), holdup and mean residence time (RT) of liquid phase were also found to demonstrate hysteresis of the same nature. RTD, liquid holdup and mean RT calculated with a simple model from the distribution of liquid flow rate show characteristics consistant with the experimental data, suggesting that the hyteretic phenomena originate from the multiplicity and nonuniformity of liquid flow distribution.

Incoherently Coupled Grey-Grey Spatial Soliton Pairs in Biased Two-Photon Photovoltaic Photorefractive Crystals

The incoherently coupled grey-grey screening-photovoltaic spatial soliton pairs are predicted in biased two-photon photovoltaic photorefractive crystals under steady-state conditions. These grey-grey screening-photovoltaic soliton pairs can be established provided that the incident beams have the same polarization, wavelength, and are mutually incoherent. The grey-grey screening-photovoltaic soliton pairs can be considered as the united form of grey- grey screening soliton pairs and open or closed-circuit grey-grey photovoltaic soliton pairs.

New Two-Mode Coherent-Intermediate-Entangled State and Its Squeezing Operator

The coherent-intermediate-entangled state ｜α, x）λ,v is proposed in the two-mode Fock Space, which exhibits both the properties of the coherent and entangled states. The ｜α, x）λ,v makes up a new quantum mechanical representation, and the completeness relation of ｜α, x）λ,v is proved by virtue of the technique of integral within an ordered product of operators. The corresponding squeezing operators are derived. Furthermore, Generalized P-representation is constructed in the coherent-intermediate-entangled state ｜α, x）λ,v and the Schmidt decomposition of ｜α, x）λ,v is investigated.

Microstructural and mechanical properties assessment of transient liquid phase bonding of CoCuFeMnNi high entropy alloy

The transient liquid phase(TLP)bonding of CoCuFeMnNi high entropy alloy(HEA)was studied.The TLP bonding was performed using AWS BNi-2 interlayer at 1050℃ with the TLP bonding time of 20,60,180 and 240 min.The effect of bonding time on the joint microstructure was characterized by SEM and EDS.Microstructural results confirmed that complete isothermal solidification occurred approximately at 240 min of bonding time.For samples bonded at 20,60 and 180 min,athermal solidification zone was formed in the bonding area which included Cr-rich boride and Mn3Si intermetallic compound.For all samples,theγsolid solution was formed in the isothermal solidification zone of the bonding zone.To evaluate the effect of TLP bonding time on mechanical properties of joints,the shear strength and micro-hardness of joints were measured.The results indicated a decrement of micro-hardness in the bonding zone and an increment of micro-hardness in the adjacent zone of joints.The minimum and maximum values of shear strength were 100 and 180 MPa for joints with the bonding time of 20 and 240 min,respectively.

Laser Light Scattering Study on Aggregation of Cellulose Diacetate in Acetone

We have investigated the properties of cellulose diacetate in solution by using laser light scattering. The cellulose diacetate molecules can form micelles and micellar clusters in acetone besides the individual chains. As the concentration increases, the average hydrodynamic radius （Rh） linearly increases, whereas the ratio of gyration radius to hydrodynamic radins 〈Rg〉/〈Rh〉 linearly decreases. It indicates that the micelles associate and form micellar clusters due to the intermolecular interactions.

Calculation of Gas-Liquid Critical Curves for Binary Systems Containing Methane

The critical curves for binary systems of methane combined with nitrogen, carbon monoxide, carbon dioxide, ethane, propane, butane and water at temperatures from 125 K to 650 K and pressures from 3.5 MPa to 250 MPa were calculated by using Heilig-Franck equation of state. This equation of state contains a repulsion term and an attraction term for intermolecular interaction. With pairwise combination rules for these potentials, three adjustable parameters are needed. The results showed that the critical curves of the former six binary systems belonged to type I, and CH4＋H2O system belonged to type III. The calculated data were compared with the experimental data,which yielded good results for the pressure-temperature, pressure-composition and temperature-composition behaviors of the seven systems. Moreover, the values of the adjustable parameters were obtained from the calculation of the critical curves. They can also be used for other relevant calculation.

Real-Time Characterization of Fibrinogen Interaction with Modified Titanium Dioxide Film by Quartz Crystal Microbalance with Dissipation

The adsorption of fibrinogen can be used as a quick indicator of surface haemocompatibility because of its prominent role in coagulation and platelet adhesion. In this work the molecular interaction between fibrinogen and a modified titanium oxide surface/platelet has been studied by quartz crystal microbalanee with dissipation （QCM-D） in situ. In order to further characterize the conformation of adsorbed fibrinogen, αC and γ-chain antibody were used to check the orientation and denaturation of fibrinogen on solid surface. QCM-D investiga- tions revealed the fibrinogen have the trend to adsorb on hydropllilic surface in a side-on orientation by positively charged αC domains, which would reduce the exposure of platelet bonding site on γ chain and enable less platelet adhesion and be activated. These obser- vations suggest that certain conformations of adsorbed fibrinogen are less platelet adhesive than others, which opens a possibility for creating a non-platelet adhesive substrates.

Influence of Intermolecular Hydrogen Bonding to Spin Crossover Property of Iron （111） Complexes with a N3O2 Pentadentate Ligand and a Monodentate Ligand

Three iron （III） complexes with the formula of [Feat（X）L2]BPh4 were studied, in which a pentadentate Schiff-base ligand （H2L2 = bis （3-methoxysalicylideneiminopropyl） methylamine） and a counter anion BPh4 were fixed, and three monodentate ligands, 3-Mepy （3-methylpyridine）, 4-NH2py （4-aminopyridine）, and 2-Meim （2-methylimidazole） were used as the axial ligand X. The temperature dependence of magnetic susceptibility measurements demonstrated that [Fem（3-Mepy）L2]BPh4 showed a gradual spin equilibrium between HS （high-spin） （S = 5/2） and LS （low-spin） （S = 1/2） states, [Fem（4-NH2py）L2]BPh4 showed a steep SCO （spin crossover） and [FeIH（2-Melm）L2]BPh4 was in the HS state even at 100 K. The single crystal X-ray analyses demonstrated that [FelH（4-NH2py）L2]BPh4 has an one-dimensional chain structure constructed by intermolecular hydrogen bonding between 4-amino group of 4-NH2py and methoxy oxygen of adjacent molecular-cation. The crystal structure of [FenI（3-Mepy）L2]BPh4 has no such intermolecular interaction and its SCO site behaves independently, and the crystal structure of [FeIII（2-Meim）L2]BPh4 has a NH...n interaction between imidazole group of 2-Meim of cation and a phenyl group of anion BPh4. The result demonstrates that the intermolecular hydrogen bonding affects SCO profile significantly.

An Osmotic Pressure Equation of Uncharged Micelle and Oil/Water Microemulsion Systems

1 INTRODUCTIONMicroemulsion and micelle systems are wide-spread in the industry and agriculture applications,e.g.the petroleum exploitation,food industry chemical engineering and biological engineering,but so far,their properties are still not very well understood.Both micelle and microemulsion systems are dispersed systems and consist of the aggregationsof the surfactant.The difference between them is that there is dispered liquid phase in the coreof the aggregation in the case of the microemulsion,but in the micelle there is not any

Tokyo Playground： The Interplay Between Infrastructure and Collective Space

Tokyo Playground aims to investigate the leftover space produced when the infrastructure overlaps with the urban tissue and to highlight how these are metabolized, then transformed into meaningful public spaces. The ＂hybridization＂ of Tokyo is examined using three references as a starting point. First is the spatial typology of sakariba that transformed what were transitional zones into pleasure districts during the Edo period, creating what was arguably the most definitive type of collective space for citizens of Edo. The second reference is Roland Barthes＇ description of the infrastructuraI experience. Thirdly, the book Made in Tokyo illustrated the strong mutual dependence among infrastructure, architecture, and the city as a unique characteristic of Tokyo. Transit space can be reused on the human scale with different programs related to time for pleasurable activities. Tokyo Playground aims to capture the idea of emotional space within infrastructure. It aims to highlight some possible design strategies and tools that help to domesticate the infrastructure through the injection of pleasure and playful programs with an understanding of how humans experience, occupy, and interpret such spaces. Leftovers within the infrastructure are opportunities for social and ecological reuse and these precious voids contribute to creating the contemporary soul of the city as it becomes the source of vibrant energy for transcultural urban regeneration.