跨间交混格架对EPR堆芯DNBR裕量的影响

采用FLICAⅢ-F子通道程序,分析了AFA 3GLE燃料组件加装跨间交混格架(MSMG)后对台山EPR堆芯热工参数和最小DNBR的影响。分析结果表明,在名义工况下加装MSMG后,轴向功率呈余弦分布和轴向功率偏差AO=+9%将分别提高EPR堆芯的DNBR裕量约为24%和28%,同时增加EPR堆芯压降约10.1%。

二柱掩护式支架水平力的研究

美国Cumberland矿17号工作面进行的现场试验发现,二柱掩护式支架在初撑阶段顶梁有向工作面方向的水平运动,从而证明了二柱掩护式支架能产生一个水平力作用于顶板,有利于对直接顶破坏的控制。本文介绍了该试验方法与结果,以及由此建立的研究液压支架水平力的力学模型。模型分析指出,二柱掩护式支架即使在增阻、恒阻阶段也都能给于顶板水平力作用。对此,在支架选型、使用和设计时应予足够的重视。最后,本文提出了增加和改善液压支架水平力的有效途径。

架棚巷道交岔点施工新方法

通过对架棚巷道交岔点传统施工方法缺点分析，提出了新的施工方法，新方法具有安全可靠、节省投入、经济效益好等许多优点。

输电线路不停电跨越架线施工技术方案研究

我国电力行业针对电力运输性能相对较差这一问题,对输电线路进行了全面的转化,对其相关的技术进行了有效的利用,尤其是输电线路架线施工不停电跨越技术,以此提升输电线路的稳定、安全等电力运输性能,满足了人们日常生活对电力的需求,以及符合了现代社会的发展形式。

既有线斜角度架梁施工技术研究

涡阳县位于安徽省西北部,淮北平原腹地,地处亳州市中心地带,有"老子故里天下道源"之称。属中部战略要地,S307省道、青阜铁路穿境而过,新建S307绕城段跨越青阜铁路立交桥,交叉角度为75°。邻近铁路两侧桥墩与线路平行设置,其余为正交。因此,架桥机架梁需要正交转斜交、斜交转正交进行架梁,在运营铁路上方进行这种施工无疑是一次挑战。文章探讨的是针对跨铁路正交变斜交架梁施工技术措施,采用架桥机改进、技术改进、确保铁路运营安全等措施,通过对新建S307绕城段跨越青阜铁路立交桥架梁正交转斜交的施工技术研究,对施工过程中的创新工艺进行了试验和研究。

Computations of Cross-Link Forces and Vibrations for the Test Bed of the Full Channel Gas

In order to control the cross? link forces and the vibration frequencies of the test bed of the full channel gas within the allowable ranges, the analyses of forces and deformation of the test bed was done, for the variously restrained elastic movable frame and the rigid one, the vibration frequencies were computed respectively by means of the methods of mechanics of materials, elasticity and vibration mechanics, the cross link forces and the vibration frequencies of the test bed were tested. The results of theoretical computation comparatively approach the experimental results. The computational methods could be used to availably estimate the design parameters relevant to the test bed of the full channel gas.

A Note on Tight Frames

Suppose that Φ(x)∈L 2(R) with compact support and V= span{Φ(x-k)|k∈Z}. In this note, we prove that if {Φ(x-k)k|k∈Z} is tight frame with bound 1 in V, then {Φ(x-k)|k∈Z} must be an orthonormal basis of V.

URANS与LES对带分裂式交混叶片定位格架5×5棒束通道流场数值模拟研究

利用非定常雷诺平均纳维斯托克斯模拟(URANS)和大涡模拟(LES)对带分裂式交混叶片定位格架5×5棒束通道流动特性进行了研究。数值计算中建模考虑了格架条带、交混叶片等几何结构对流场的影响,并将模拟结果与MATiS-H基准实验进行了对比。结果表明,URANS与LES均能较好地模拟格架下游3个流速分量时均值;对于格架下游流速分量脉动值,URANS中非定常SST k–ω模型几乎不能够模拟出流速脉动值,非定常RSM模型对于流速脉动值模拟比实验值偏低。与URANS相比,LES能相对较为准确地模拟流速脉动值,然而LES对格架附近流速脉动值模拟结果与MATiS-H基准实验相比仍然偏低。

Double layered self-expanding metal stents for malignant esophageal obstruction, especially across the gastroesophageal junction

AIM: To evaluate the clinical outcomes of double-layered self-expanding metal stents (SEMS) for treatment of malignant esophageal obstruction according to whether SEMS crosses the gastroesophageal junction (GEJ). METHODS: Forty eight patients who underwent the SEMS insertion for malignant esophageal obstruction were enrolled. Patients were classified as GEJ group (SEMS across GEJ, 18 patients) and non-GEJ group (SEMS above GEJ, 30 patients) according to SEMS position. Double layered (outer uncovered and inner covered stent) esophageal stents were placed. RESULTS: The SEMS insertion and the clinical improvement were achieved in all patients in both groups. Stent malfunction occurred in seven patients in the GEJ group and nine patients in the non-GEJ group. Tumor overgrowth occurred in five and eight patients, respectively, food impaction occurred in one patient in each group, and stent migration occurred in one and no patient, respectively. There were no significant differences between the two groups. Reflux esophagitis occurred more frequently in the GEJ group (eight vs five patients, P = 0.036) and was controlled by proton pump inhibitor. Aspiration pneumonia occurred in zero and five patients, respectively, and tracheoesophageal fistula occurred in zero and two patients, respectively. CONCLUSION: Double-layered SEMS are a feasible and effective treatment when placed across the GEJ for malignant esophageal obstruction. Double-layered SEMS provide acceptable complications, especially migration, although reflux esophagitis is more common in the GEJ group.

Energy management and coordination control of microgrid in elevated station of urban rail transit

The rapid development of urban rail transit brings convenience to the public,but its huge energy consumption problem cannot be ignored.A microgrid composed of photovoltaic power generation unit,regenerative braking energy feedback unit and battery energy storage unit is proposed,which provides green power for the station.In order to suppress the fluctuation of photovoltaic power generation and the intermittence of regenerative braking feedback energy,the energy management mode of microgrid is designed according to the illumination situation,braking energy feedback situation,battery state of charge and so on.In addition,a coordination control method based on virtual synchronous generator(VSG)is proposed to realize smooth switching among modes.Finally,the proposed energy management and coordination control method for elevated station microgrid is verified by Matlab/Simulink.The results show that the elevated station microgrid can operate safely and reliably under various energy management modes and realize smooth switching among modes.

Research on Cultural Schemas for Social Interactions

Social interactions strategies refer to saying the proper words and sentences on proper occasions. They could be affected by different cultural backgrounds （schemas）. Culture is usually treated as the basis of our social interactions which influences the way we deal with problems, and even our thought and behavior. Therefore, although many communication problems occur on the interpersonal level, most difficulties and misunderstandings can be traced to cultural differences. With a deeper comprehension, the cultural differences are the schema differences which are a kind of framework of a specific culture that exists in people＇s brain and influences people＇s judgments and behavior of daily life. Furthermore, this schema conflict would also confuse people＇s judgment and make them to choose the wrong way to respond. Thus, the schema conflict interferes our social interactions.

Design of an unbuffered switch for network on-chip

In the complex multicore chip system,network on-chip(NoC)is viewed as a kind of system interconnection that can substitute the traditional interconnect networks,which will improve the system performance and communication efficiency.With regard to the complex and large scale NoC,simple and efficient routing nodes are the critical factors to achieve low-cost and low-congestion communication performance.This paper proposes an unbuffered switch architecture and makes detailed analysis of the mechanism of buffer in the switch architecture.According to the simulation results,the S-mesh using the unbuffered switch architecture is better in terms of the optimal performance in message latency than some typical NoC architectures,such as 2D-mesh,Fat-tree,Butterfly,Octagon and so on.The synthesis results of design compiler indicate that the unbuffered switch has obvious advantages of achieving cost and operating speed for the chips.

CH_4 oxidation to oxygenates with N_2O over iron-containing Y zeolites:Effect of preparation

Developing effective iron-incorporated zeolites and determining their active centers for the direct oxidation of CH_4 to oxygenates have remained challenging topics so far.In this paper,we successfully prepare the highly-dispersed iron supported Y zeolites by a facile solid-state ion-exchange method with ferrocene,which was conducted under water-free conditions followed by a series of calcination.Moreover,extra-framework dinuclear Fe^(2+)complexes are identified as so-called activeα-iron sites on zeolites.ICP-OES,N_2 adsorption–desorption test,X-ray diffraction,solid-state^(27)Al NMR,N_2O titration,TEM,EPR and^(57)Fe M?ssbauer spectra were carried out to characterize properties of sample structure,acid sites,as well as the supported iron species.Characterization results indicate that high-temperature treatments have no effect on the typical structure feature of zeolites.Compared with catalysts synthesized by conventional impregnation,the samples prepared by the facile approach possess abundant dinuclear Fe^(2+)complexes but no Fe_2O_3 bulks and show weak acidity.These lead to a higher oxygenate selectivity in CH_4 oxidation to oxygenates.Remarkably,the oxygenate(HCHO and CH_3OH)selectivity of 6.5% at 375°C can be eventually obtained.

Limits of Level 3 Fair Value Measurement： Based on Conceptual Framework

The IASB stated that in the review of the conceptual framework, if measurement uncertainty is very high, a measurement basis different from fair value may provide more appropriate information. Level 3 fair value measurements are inappropriate for areas （called ＂Level 4＂ by the author） in which models are not formulated and that have material uncertainty in measurement. The purpose of this paper is to elucidate ＂measurement uncertainty＂, which impacts ＂faithful representation＂ in fair value measurement, from the perspective of ＂verifiability＂. To do so, it will employ a conceptual examination of the limits of Level 3 fair value measurement based on IFRS 13 （Fair Value Measurement）. While taking into consideration recent discussions on reviewing conceptual framework, the author will reorganize the conceptual categories of verifiability （i.e., clarification of the ＂reasonable verifiability＂ categories） to underpin the fact that material uncertainties in measurement have obstructed constructing faithful representation. In addition, the author will discuss the problem that the dichotomy of direct and indirect found in IASB is not accurate enough to fully understand the concept of verifiability. In this context, the author will also suggest that the concept of verifiability, reorganized through ＂reasonable verifiability＂, can satisfy the requirements for constructing faithful representation.

Construction Project Delivery System Selection Framework： Professional Service Firms＇ Perspective

There is a variety of PDSs （project delivery systems） in today＇s construction industry. This leads to confusion when it comes to selecting the most suitable PDS for a specific project. The wrong selection decision might lead eventually to reduced profit margins or perhaps financial losses to PSFs （professional service firms）. This research proposes a conceptual framework that helps PSFs in the selection of one or more suitable PDSs for their construction operations. The framework uses SWOT （strengths, weaknesses, opportunities and threats） analysis as a tool for assessing each PDS considered in this research. The PDSs included in the framework are design-bid-build, design-build, construction management agency, public-private partnerships and integrated project delivery. The main aim of this research framework is to enhance decision-making efficiency in PDS selection for PSF operations.

Integrating Interaction Framework for Agent Negotiation

Agent negotiation has become increasingly important since the advent of electronic commerce.There are two kinds of interactions in the process of agent negotiation.One is the interaction between different agents,and the other is the interaction between the agent and the human user.In this paper,firstly,we introduce Q language,a scenario description language for designing interactions between agents and human users.Then we propose an integrating interaction framework for agent negotiation,in which both kinds of interactions are described by Q scenario.Our framework can make the interaction process open and easy to be understood by the users.Users can understand how the negotiation process goes and what is happening in the system including some erroneous or inappropriate actions caused by the negotiation agent.This gives the users a chance to terminate or change the behavior of negotiation agent in time to avoid unfavorable negotiation outcome.In addition,users can customize the agent's behaviors through visible interactions with it.

Al_(x)/HKUST-1 prepared by synthetic exchange as catalyst for reduction of NO by CO at low temperature

Al_(x)/HKUST-1(x=1/24,1/12,1/6,1/3),one of the bimetallic copper-based organic framework materials,was successfully prepared by the synthetic exchange method and characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),specific surface area(BET),thermogravimetric analysis(TG),infrared spectra(IR),X-ray photoelectron spectroscopy(XPS),and H_(2)-temperature programmed reduction(H_(2)-TPR).The findings indicated that Al_(x)/HKUST-1 maintained the octahedral morphology of its precursor(HKUST-1).The thermal stability and catalytic reduction ability of HKUST-1 skeleton were improved by doping aluminum(Al^(3+)).Al_(1/12)/HKUST-1 showed the best performance among all samples,with a nitric oxide(NO)conversion rate of 100%at 210℃(50℃lower than that of HKUST-1).The valence kind of Al,Cu,and O in Al_(1/12)/HKUST-1 did not change after the catalytic reaction,but the contents of Al,Cu,and O in different forms changed significantly.The catalytic process of the Al_(x)/HKUST-1 followed a Langmuir-Hinshelwood mechanism.

DEGRADATION AND PROCESSING OF PLA AND ITS APPLICATION IN FIXATION OF BONE FRACTURE

PLA is presently considered as the most attractive compound for temporarytherapeutic application in the biomedical field. In this paper we give an overview of thepresent knowledge on the degradation behavior,processing technology of PLA and itsapplication in the fixation of bone fracture.

Preparation of Chitosan/Poly(L-Lactide) Porous Composite Scaffolds

This research investigates the formation of chitosan/poly （L-lactide） （CS/PLLA） porous composite scaffold using a novel emulsion freeze-drying technique. First, an oil in-water （O/W） emulsification system was used in the presence of surfactant Tween-80, in which CS solution was used as the water phase and PLLA solution was used as the oil phase. The emulsion was observed by inverted microscope （× 200）. The emulsion droplet was spherical and uniform in size. FT-IR analysis revealed that there were hydrogen bonding interactions between CS and PLLA components. The microstructure and physical properties of the scaffolds were also analyzed. The SEM results showed that composite scaffolds formed well interconnected pore structure and homogenous distribution of CS and PLLA. When the content of PLLA reached 50%, the porosity of CS/PLLA composite scaffolds were between 83 %-91% and density in the range of 0.047 to 0.11 g/era3. The porosity showed a slight decrease and the density increased with the increase of PLLA dose. The compressive strength increased from 0.32 to 0.43 MPa, while the compressive modulus increased from 1.99 to 3.91 MPa as the PLLA contents increased from 10% to 50%.

AN ALGORITHM FOR DICTIONARY GENERATION IN SPARSE REPRESENTATION

The K-COD (K-Complete Orthogonal Decomposition) algorithm for generating adaptive dictionary for signals sparse representation in the framework of K-means clustering is proposed in this paper,in which rank one approximation for components assembling signals based on COD and K-means clustering based on chaotic random search are well utilized. The results of synthetic test and empirical experiment for the real data show that the proposed algorithm outperforms recently reported alternatives: K-Singular Value Decomposition (K-SVD) algorithm and Method of Optimal Directions (MOD) algorithm.