添加铈对锰基催化剂的织构-结构及其氧化还原性能的影响

考察了添加稀土Ce对Mn/γ-Al2O3催化剂的织构-结构、表面活性组分的分布及氧化还原性能的影响,以催化燃烧易挥发有机污染物(VOCs)苯为探针反应研究了Ce对Mn基催化剂催化性能的影响。采用传统的浸渍法制备了系列催化剂,利用粉末X射线衍射(XRD),N2吸脱附程序升温还原(TPR)等手段对催化剂进行了表征分析。结果表明,添加稀土使Mn基催化剂比表面积、孔体积减小,说明部分Ce进入孔道中,形成了更多的氧化还原活性位,并且进一步研究得知,适量Ce的添加可以促进催化剂活性位的自组装,达到理想的催化氧化性能。添加Ce后,催化剂的活性组分中高价Mn的含量明显增加,这些都有利于提高催化剂的氧化性能。活性实验结果表明,添加适量Ce优化了催化剂的织构-结构、表面活性组分及氧化还原性能,因此催化剂的活性和稳定性明显提高,其中以MnCe为1∶1时,活性最佳,280℃左右就能完全转化苯。

Dynamical changing patterns of histological structure and ultrastructure of liver graft undergoing warm ischemia injury from non-heart-beating donor in rats

AIM： To investigate the histological and ultra-structural characteristics of liver graft during different of warm ischemia time （WIT） in rats and to predict the maximum limitation of liver graft to warm ischemia. METHODS： The rats were randomized into 7 groups undergoing warm ischemia injury for 0, 10, 15, 20, 30, 45 and 60 min, respectively. All specimens having undergone warm ischemia injury were investigated dynamically by light and electron microscopy, and histochemistry staining. After orthotopic liver transplantation （OLT）, the recovery of morphology of liver grafts after 6, 24 and 48 h was observed. RESULTS： The donor liver from non-heart-beating donors （NHBD） underwent ischemia injury both in the warm ischemia period and in the reperfusion period. Morphological changes were positively related to warm ischemia injury in a time-dependent manner during the reperfusion period. The results demonstrated that different degrees of histocyte degeneration were observed when WIT was within 30 min, and became more severe with the prolongation of WIT, no obvious hepatocyte necrosis was noted in any specimen. In the group undergoing warm ischemia injury for 45 min, small focal necrosis occurred in the central area of hepatic Iobule first. In the group undergoing warm ischemia injury for 60 rain, patchy or diffused necrosis was observed and the area was gradually extended, while hepatic sinusoid endothelial cells were obviously swollen. Hepatic sinusoid was obstructed and microcirculation was in disorder.CONCLUSION： The rat liver graft undergoing warm ischemia injury is in the reversible stage when the WIT is within 30 min. The 45 min WIT may be a critical point of rat liver graft to endure warm ischemia injury. When the WIT is over 60 min, the damage is irreversible.

Impact of Zener-Hollomon parameter on substructure and texture evolution during thermomechanical treatment of iron-containing wrought aluminium alloys

The objective of the investigation is to evaluate the influence of the Zener-Hollomon parameter on substructure and texture evolution in iron-containing wrought aluminium alloys (type AA8011). Methods applied are X-ray texture analysis, electron backscatter diffraction (EBSD) and optical microscopy. The results show a serious impact of the Zener-Hollomon parameter on cube texture evolution during the thermomechanical treatment in iron-containing aluminium alloys. An increase in the Zener-Hollomon parameter reduces the survivability of cube texture during hot deformation and reinforces particle-stimulated nucleation (PSN) during the annealing process. However, thermomechanical treatment at low temperatures leads to active precipitation and as a result fine-dispersed participles tend to block all nuclei except for those producing large cube-oriented grains. It is concluded that in iron-containing wrought aluminium alloys, the general correlation between the Zener-Hollomon parameter and subgrain size is similar to that observed in 3xxx series alloys and can be described by the specific set of equations derived.

A Family--The Tension and the Satisfaction

Family members solve not only their interests, but make provision for interests of other members of the family, too. The space for the control at a higher level is thus formed. Without notifying, individual members in the process of provision making proceed depending on general rules of the organisation of elements into higher structures, as they exist in all stable objects. This provision making has different forms, starting with the love and ending with an assisted coexistence. The understanding of the role of individual controlling structures allows to improve the functioning of the family. Similarly, as a regular discussion of its functioning in the family and perhaps, their controlled casting by some of partners, too. The submitted work describes roles and the control in the elementary family--in the childless coexistence of partners.

Analysis of 13Cr bloom solidification structure using CA-FE model

Solidification structure is critical in the control of the mechanical properties and quality during the continuous casting process. The thermo-physical properties of 13 Cr steel added some rare metals, such as Mo, V, Nb, are measured to better understand the solidification structure of 13 Cr bloom. A computational model using CA-FE(cellular automation-finite element) method coupled with heat transfer model is developed to describe the solidification structure in continuous casting process. It is found that the calculated solidification structure is in good agreement with the observed data. The influence of casting speed and superheat on the solidification structure of the bloom is studied in detail. In order to obtain more equiaxed crystal ratio and low degree of the segregation in the bloom, the optimized casting speed 0.6 m/min and superheat less than 25 °C are determined for the caster. Using the optimized manufacturing parameters, these samples are 60% with the equiaxed zone ratio of 8%–10% and below the degree of segregation 1.05.

High-strength Ti-BN composites with core-shell structured matrix and network-woven structured TiB nanowires

A novel architectural Ti composite composed of network-woven structured TiB nanowires in a core-shell structured Ti matrix was fabricated to improve the strength of Ti matrix composites(TMCs),where the shell consists of rich N solute atoms while the core is deficient of N solute atoms through spark plasma sintering of powder mixtures of Ti powder and BN nano-powder.The phase composition,morphology,element distribution,and mechanical properties of prepared samples were analyzed by X-ray diffraction(XRD),scanning electron microscope(SEM),electron probe microanalyzer(EPMA),and electronic universal material testing machine.The results indicate that the TMCs with designed architectures have been successfully achieved,and the as-prepared Ti-2BN(wt.%)composite exhibits an ultimate compressive strength of~1.8 GPa with a strain-to-fracture of~9%,while the Ti-1BN(wt.%)attains an ultimate compressive strength of~1.6 GPa and a strain-to-fracture of~20%.Moreover,the roles of the hybrid reinforcement structures in strengthening the Ti composites were discussed.

How Should We Construct Mind-Readers？

Structured models of kinds of mind-readers are explanatory tools in philosophy and psychology. Structure means that a structure like a theory with certain properties organizes the model of a kind of a reader. Structured models serve to explain mind-reading capabilities in opposition to pure behavior-reading capabilities by explicating properties of the structure that bring on specific capabilities of mind-reading. Typically, grades of fulfilling reading-capabilities are related to grades of rationality. But it is unclear： （1） when we are legitimated to title a reader a mind-reader or behavior-reader, and （2） how the kinds of readers are related with each other （if they can be related by a measure）. I argue that we know a reader if we can construct it and this gives legitimation. But it is unclear how to construct border-cases of readers, for example, minimal mind-readers. Should minimal mind-readers be constructed on the base of ＂reduced＂ mind-readers, or should they be constructed as ＂enriched＂ behavior-readers？ This is the specific question concerning the relations between readers the essay deals with by trying to reduce a maximal mind-reader by Craig-reduction. Because this kind of reduction-method fails, constructing specific kinds of mind-readers needs further research.

Vacuum deposited film growth,morphology and interfacial electronic structures of 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene(C8-BTBT)

Interfaces play critical roles in electronic devices and provide great diversity of film morphology and device performance.We retrospect the substrate mediated vacuum film growth of benchmark high mobility material 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene(C8-BTBT)and the interface electronic structures.The film growth of C8-BTBT molecules is diversified depending on the substrate-molecule and molecule-molecule interactions.On atomic smooth substrates C8-BTBT film grows in layer-by-layer mode while on coarse substrate it grows in islands mode.The initial molecular layer at dielectric,semiconductor and conductive substrates displays slight different lattice structure.The initial molecule orientation depends on the substrate and will gradually change to standing up configuration as in bulk phase.C8-BTBT behaves as electron donor when contacting with dielectric and stable conductive materials.This usually induces a dipole layer pointing to C8-BTBT and an upward bend bending in C8-BTBT side toward the interface.Although it is air stable,C8-BTBT is chemically reactive with some transition metals and compounds.The orientation change from lying down to standing up in the film usually leads to decrease of ionization potential.The article provides insights to the interface physical and chemical processes and suggestions for optimal design and fabrication of C8-BTBT based devices.

Rheological Properties and Structural Changes in Different Sections of Boiled Abalone Meat

Changes in tissue structures, rheological properties of cross- and vertical section boiled abalone meat were studied in relation to boiling time. The adductor muscle of abalone Haliotis discus which was removed from the shell, was boiled for 1, 2, and 3 h, respectively. Then it was cut up and separated into cross- and vertical section meat. When observed by a light microscope and a scanning electron microscope, structural changes in the myofibrils were greatest in the cross section meat compared with the vertical section meat. When boiling time was increased from 1 h to 3 h, the instantaneous modulus E 0 and rupture strength of both section meat decreased gradually with increased boiling time, and no significant differences were observed between these two section meat for the same boiling time. When boiled for 1 h, the relaxation time of cross section meat was much longer than that of vertical section meat. There were no significant changes in the relaxation time of vertical section for different boiling time, but the relaxation time of cross section meat was reduced gradually with increasing boiling time. These results confirmed that the difference in rheological properties between the cross- and vertical section meat was mainly due to the denaturation level of myofibrils when heated for 1 h, as well as due to the changes in the amount of denatured proteins, and the manner in which the inner denatured protein components weve exchanged after boiling time was increased from 1 h to 3 h.

Practice of Project Management Methodology for Commercial Aero engines Based on Integrative Project Architectures

To collect and share information of projects or products and make it consistent and correct so that the quality and costs of projects can be effectively controlled,an integrative project architecture integrating different types of breakdown structures is necessary.In this paper,the international research status on work breakdown structure(WBS)was analyzed,and an integrative project architecture for commercial aero-engines was designed,where product breakdown structure(PBS),WBS,organization breakdown structure(OBS)and cost breakdown structure(CBS)were integrated and built.And the architecture was applied in information systems.A transfer from technological views of complex products through their lifecycles to management views has been realized with this standardized architecture,thus development tasks and costs can be controlled.

Effects of extrusion temperature on microstructure evolution and mechanical properties of heterogeneous Mg−Gd alloy laminates via accumulated extrusion bonding

The influence of extrusion temperature on microstructure and mechanical properties of heterogeneous Mg−1Gd/Mg−13Gd laminate prepared by accumulated extrusion bonding was investigated.The results reveal that the Mg−1Gd/Mg−13Gd laminate forms a significant difference in grain size between the successive layers when extruded at 330℃,and this difference gradually disappears as the extrusion temperature increases from 380 to 430℃.Besides,the growth rate of recrystallized grains in fine-grained layers is faster than that in coarse-grained layers.Moreover,the diffusion ability of Gd element increases with elevating extrusion temperatures,promoting the increase and coarsening of precipitates in fine-grained layers.Tensile tests indicate that the sample extruded at 380℃ has a superior combination of strength and ductility.This is mainly attributed to the synergy of the heterogeneous texture between coarse and fine-grained layers,hetero-deformation induced strengthening and hardening.The fine-grained layers facilitate the activation of prismaticáañslips,while coarse-grained layers make it easier to active basaláañand pyramidalác+añslips,especially for the sample extruded at 380℃.The activation of pyramidalác+añslips contributes to coordinating further plastic deformation.

Construction and structural Research of Organizational Ethical Climate Scales

Organizational ethical climate is an effective way to solve organizational ethical problems and dilemmas. Therefore study on our organizational ethical climate has the great significance to solve ethical problems and dilemmas faced by the organization and staff. Through semi-structured interview, structural interview and questionnaire survey and other methods this study gets to understand internal structural elements of organizational ethical climate under Chinese cultural background, and constructs organizational ethical climate questionnaire, which has good reliability and validity; carries out surveys in large scale by using the revised questionnaire, and recycles 709 valid questionnaires. The results of exploratory factor analysis and confirmatory factor analysis show that Chinese organizational ethical climate＇ s internal structure includes five factors： egoism, altruism, independence orientated, organizational system orientated, and law and code orientated.

Structure Types and Discourse Function of N＋N Nominal Sentence in Mandarin Chinese

N＋N nominal sentence is an important structure type of nominal sentences in Mandarin Chinese. Attributive-center, combination, apposition and subject-predicate are its main structure types. In main literary genres, the distribution of N＋N nominal sentence shows a certain trend of dominant hierarchy： poem﹥drama﹥novel﹥prose. No matter what kind of literary genres, attributive-center structure is the type with maximum quantity, while appositive structure is the type with minimum quantity. Statistical result indicates that most of N＋N nominal sentence is nominal and its use is limited by genres. Function of N＋N nominal sentence is textual. When it comes to discourse, it can be used as theme, rheme and dual identity of theme and rheme based on the theory of Theme-Rheme （T-R） structure pattern. It does not only construct the information structure to deliver textual information, but also its a vital means of discourse cohesion and coherence.

Accounting Regulation Research and Structuration Theory

This paper considers accounting regulation research from a structuration and cultural perspective. Therefore, accounting regulation research spans over three spheres of enquiry： （1） an accounting focus of standard-setting; （2） a cultural analysis in an empirical context; and （3） the use of a research methodology drawn from Anthony Giddens＇ structuration theory. In such approach, accounting regulation research analyzes the accounting regulation actors drawing upon the cultures in their standard-setting actions and interactions, referring to Giddens＇ three structural properties of meaning, power, and morality. The integration of these three spheres of enquiry is not entirely original. A few prior studies have similar combinations： Although they stress the uses and consequences of accounting systems in producing and reproducing organizational culture and negotiating meaning at the organizational level, this paper chooses the research approach of contextual analysis of accounting systems at more macro-societal and cultural levels. This different research interest and design provides this paper with its distinguishable characteristic from the prior similar studies.

Microfluidic generation of Buddha beads-like microcarriers for cell culture

The fabrication of functional microcarriers capable of achieving in vivo-like three-dimensional cell culture is important for many tissue engineering applications. Here,inspired by the structure of Buddha beads, which are generally composed of moveable beads strung on a rope, we present novel cell microcarriers with controllable macropores and heterogeneous microstructures by using a capillary array microfluidic technology. Microfibers with a string of moveable and releasable microcarriers could be achieved by an immediate gelation reaction of sodium alginate spinning and subsequent polymerization of cell-dispersed gelatin methacrylate emulsification. The sizes of the microcarriers and their inner macropores could be well tailored by adjusting the flow rates of the microfluidic phases; this was of great importance in guaranteeing a sufficient supply of nutrients during cell culture. In addition, by infusing multiple cell-dispersed pregel solutions into the capillaries, the microcarriers with spatially heterogeneous cell encapsulations for mimicking physiological structures and functions could also be achieved.

Small onion-like BN leads to ultrafine-twinned cubic BN

Nanotwinned cubic boron nitride(nt-cBN) with remarkable hardness, toughness, and stability has attracted widespread attention due to its distinct scientific and industrial importance. The key for nt-cBN synthesis is to adopt an onion-like BN(oBN) nano-precursor and induce phase transition under high pressure. Here, we found that the size change of oBN used greatly affected the mechanical performance of products. With the precursor size decreasing from^320 to 90 nm, the Vickers hardness of nanostructured products improved from 61 to 108 GPa, due to the fact that large oBN nanoparticles possessed more flattened, orderly and graphite-like shell layers, in sharp contrast to the highly wrinkled and imperfect layers in small-diameter nanoparticles, thus resulting in the apparent reduction of ultrafinetwin substructure in the synthetic products. This study reveals that only small oBN precursor could produce complete ultrafine nt-cBN with outstanding performance. A practical route was proposed to further improve the performance of this important material.

Evolution of microstructure and texture of cold-drawn polycrystalline Ag with low stacking fault energy

The evolution of microstructure and texture for drawn polycrystalline Ag was investigated by transmission electron microscopy and electron backscattering diffraction.The results show that there are deformation twins and some un-tangled discrete dislocations at low strains.When the strain is increased to 0.58,a lot of high density dislocation walls and microbands come into being.At the same time,some twins lose the twinning relationship of 60°<111>.At a strain of 0.94,both dislocation boundaries and twin boundaries will rotate to the axis direction of wires and the shear bands start to appear.When the strain is higher than 1.96,most of the boundaries are parallel to the drawn direction.Texture analysis indicates that with the strain increasing,the volume fraction of complex texture component decreases,but<111>and<100>texture components increase.However,the variation in the volume fraction of each texture component as strains is not evident when the strains are higher than 0.58.For polycrystalline Ag with low stacking fault energy,complex texture components are easily formed.

Microstructure and texture evolution in fully pearlitic steel during wire drawing

The evolution of morphology of pearlite and crystallographic texture of ferrite matrix in fully pearlitic steels during wire drawing were quantitatively investigated. The study revealed that a fiber structure of the pearlite morphology and a 〈110〉 fi- ber texture of the ferrite matrix begin to take shape and develop gradually with increasing strain. The growth rates of the fiber structure and the 〈110〉 texture are different in different regions within the wires with increasing drawing strain. There is a close relationship between the pearlite morphology and the crystalline texture during wire drawing. The pearlite interlamellar spacing （ILS） and thickness of cementite lamellae （To） decrease gradually both in longitudinal and transverse sections. The definition of pearlite colony should be reconsidered for describing microstructure of the wire drawing deformed pearlitic steels.

Long noncoding RNAs as Organizers of Nuclear Architecture

In the eukaryotic cell nucleus, chromatin and its associated macromolecules must be organized into a higher-ordered conformation to function normally. However, mechanisms underlying the organization and dynamics of the nucleus remain unclear. Long noncoding RNAs(lnc RNAs), i.e., transcripts longer than 200 nucleotides with little or no protein-coding capacity, are increasingly recognized as important regulators in diverse biological processes. Recent studies have shown that some lnc RNAs are involved in various aspects of genome organization, including the facilitation of chromosomal interactions and establishment of nuclear bodies, suggesting that lnc RNAs act as general organizers of the nuclear architecture. Here, we discuss recent advances in this emerging and intriguing field.

Wetting property of smooth and textured hydrophobic surfaces under condensation condition

Static and dynamic wetting behaviors of sessile droplet on smooth,microstructured and micro/nanostructured surface under condensation condition are systematically studied.In contrast to the conventional droplet wetting on such natural materials by dropping,we demonstrate here that when dropwise condensation occurs,the sessile droplet will transit from the Cassie-Baxter wetting state to the Wenzel wetting state or partial Cassie-Baxter wetting state on the microstructured surface or the micro/nanostructured surface,which leads to a strong adhesion between the droplet and the substrate.In contrast,the apparent contact angle and the sliding angle on the smooth surface changes a little before and after the condensation because of small roughness.Theoretical analysis shows that the roughness factor controls the adhesion force of the droplet during condensation,and a theoretical model is constructed which will be helpful for us to understand the relationship between the adhesion force and the geometry of the surface.