Monolayer (ML) transition metal dichalcogenides (TMDs) are of great research interest due to their potential use in ultrathin electronic and optoelectronic applications. They show promise in new concept devices in spintronics and valleytronics. Here we present a growth study by molecular-beam epitaxy of ML and sub-ML MoSe 2 , an important member of TMDs, revealing its unique growth characteristics as well as the formation processes of domain boundary (DB) defects. A dramatic effect of growth temperature and post-growth annealing on DB formation is uncovered.

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In the light of growing global competition, organizations around the world today are constantly under pressure to produce high-quality products at an economical price. The integration of design and manufacturing activities into one common engineering effort has been recognized as a key strategy for survival and growth. Design for manufacturability (DFM) requires product designers to simultaneously consider the manufacturing issues of a product along with the geometrical and design aspects. In this paper, part manufacturability was analyzed in detail. An evaluation system of DFM was proposed. Product design can be guided according to feedback information by evaluating the part manufacturability.

CD34+ cells from human umbilical cord blood (CB) were isolated and investigated for megakaryocytic (MK) colony formation in response to recombinant human (rh) stimulatory and suppressive cytokines and compared with their counterparts in normal BM and G-CSF-mobilized peripheral blood (mPBL). First, we observed that IL-11 by itself at any dosage had no stimulator activity on MK colony formation derived from CD34+ cells in CB, mPBL, and BM. IL-3, steel factor (SLF), or thrombopoietin (Tpo) alone stimulated numbers of colony-forming unit-megakaryocyte (CFU-MK) in a dose-dependent fashion. Maximum growth of MK progenitor cells was noted in the presence of a combination of cytokines: IL-11, IL-3, SLF, and Tpo. The frequency of CFU-MK in CB and mPBL was significantly greater than that in BM, and the size of colonies in CB and mPBL was significantly greater than that in BM, and the size of colonies was larger as well. In addition, an increased number of big mixed colonies containing MK were observed in CB and mPBL. In the presence of IL-11, IL-3, SLF, and Tpo, CFU-MK derived from CB, mPBL, and BM was suppressed by tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta1 (TGF-beta1). CFU-MK derived from normal BM was inhibited by some chemokines evaluated, whereas CFU-MK derived from CB was suppressed only by platelet factor-4 (PF-4), IFN-inducible protein-10 (IP-10), Exodus-1, Exodus-2, and Exodus-3, but to a lesser degree. In CB, unlike granulocyte-macrophage (CFU-GM), erythroid (BFU-E), high-proliferative potential (HPP-CFC), or multipotential (CFU-GEMM) progenitors, at least a subpopulation of MK progenitors are in S-phase. Therefore, CB MK progenitors respond to the suppressive effects of some members of the chemokine family. Similar results were noted for burst-forming unit-MK (BFU-MK). Our results indicate that CB and mPBL are rich sources of MK progenitors and that MK progenitors in CB are responsive to the suppressive effects of TNF-alpha and TGF-beta1 and some members of the chemokine family.

This paper is to explain the application of DELMIA in 3D digital virtual assembly. It takes ARJ21 aircraft central wing assembly simulation process as an example. It introduces the related modules of DELMIA software and discusses the application of DELMIA in aircraft assembly simulation through the central wing assembly process simulation and human task simulation in the ARJ21 aircraft central wing assembly simulation.

The vibration of the exhaust system has led to cars vibration and high noise. Without doubt, they affect the performance and especially make the people particularly uncomfortable who ride in the car. The paper will resolve the trouble by the application software of the SOLIDWORKS. It establishes the exhaust system model then makes its finite element analysis of frequency to research the relationship between lugs hanging positions and amplitudes. Obtain a conclusion is to change the hanging position can reduce the maximum amplitude of the exhaust system. The article will show how to finish the all working process from building a model to getting the optimization scheme of reducing the exhaust system vibration and the best hanging position. Thus it provides a simple feasible method as the paragon of designing other parts.

Combined with available local resources and traditional manufacturing techniques of Yimeng mountain area, several transformation methods, which are ecological economical and practical for the existing rural housing, are put forward. After optimization, the rural residence will be more energy-efficient, more environmental and more comfortable. The aim of the paper is to make the eco-renovation feasible and economical for farmers and popularize the reform measures in more rural areas like Yimeng.

Part manufacturability under Concurrent Engineering (CE) environment was analyzed in detail. An evaluation system of Design For Manufacturing (DFM) was proposed according to CE ideas. The evaluation methods for part manufacturability feature-based are intended to present in this paper. Product design can be guided according to feedback information by evaluating the part manufacturability. Finally an example of rabbet-feature manufacturability of a turbine blade was given to show the method available and practicable.