Product design must not only consider basic functionality, but also pay attention to consumers' perceptual demands. This thesis takes product form as the research object and bicycle form design as ...the breakthrough point to study the product form design method based on Kansei Engineering. This paper first establishes a library of bicycle perceptual imagery space and morphological features based on the theory of Kansei Engineering in product design. Also establish a quantitative relationship model between the two through quantitative theory, and give guiding suggestions on the evaluation of perceptual imagery of product form design. Then an adaptation function is established based on the prediction model of Kansei Engineering, and an iterative algorithm of product form based on Kansei Engineering is proposed. It provides a theoretical basis for the subsequent design of bike-sharing.
A new method for the Suzuki-Miyaura cross-coupling of phenols and arylboronic acids through insitu phenol activation mediated by PyBroP is presented. The reaction proceeds efficiently by using ...cost-effective, markedly stable NiCl2(dppp) (dppp=1,3-bis(diphenylphosphino)propane) as the catalyst in only 5mol% loading, as well as in the absence of extra ligands. The method exhibits broad applicability and high efficiency towards a wide range of both phenols and boronic acids, including activated, nonactivated, deactivated, and heteroaromatic coupling partners. In addition, various functional groups, such as ether, amino, cyano, ester, and ketone groups, are compatible with this transformation. Notably, arylboronic acids containing an unprotected NH2 group and 2-heterocyclic boronic acids, which are generally problematic for coupling under conventional conditions, are also viable substrates, although moderate yields were obtained for sterically hindered substrates. Consequently, the insitu cross-coupling methodology coupled with the use of an inexpensive and stable nickel catalyst provides a rapid and efficient pathway for the assembly of biaryls and heterobiaryls with structural diversity from readily available phenol compounds.
In this paper, eight seismic activity parameters, which are independent of each other with clear physical meanings, are selected and the special-temporal scanning method is adopted so as to establish ...an autocratic identification model for abnormal seismicity on the purpose of prediction. On this basis, seismic data (M L ≥2.0) collected from 1987 to 2009 in North China (30°~44°N, 106°~126°E) is selected to test the model. The results show that abnormal seismicity identification method can lower the false alarm rate and improve the capability of identifying the abnormal seismicity.
A straightforward approach for the synthesis of alkyl 1
H
-tetrazol-5-yl thioethers from aldehydes and 1
H
-tetrazole-5-thiol through a one-pot procedure is presented. The aldehydes were first ...condensed with
N
-tosylhydrazine to generate the
N
-tosylhydrazones, which were then reductively coupled
in situ
with 1
H
-tetrazole-5-thiols under metal-free conditions to afford the thioethers in high to excellent yields.
A method for the straightforward synthesis of alkyl 1
H
-tetrazol-5-yl thioethers from aldehydes and 1
H
-tetrazole-5-thiols through a one-pot procedure is presented.
Objective To find the regulatory effect of miR-125a-5p on the growth and invasion of acute myeloid leukemia (AML) cell lines. Methods The expression of miR-125a-5p and TRIM71 in bone marrow specimens ...of AML patients, AML cell lines (U937 and HL60) and PBMC were examined by RT-qPCR. The U937 and HL60 cells were divided into control group (control), miR-125a-5p mimic group (miR-125a-5p mimic), miRNA negative control group (miR-NC), TRIM71 over-expression plasmid group (pcDNA3.1-TRIM71) and control plasmid group(pcDNA3.1-NC). U937 and HL60 cells were transfected with miR-125a-5p mimic, pcDNA3.1-TRIM71 and negative control using Lipofectamine 2000. Cell proliferation was measured by MTT assay; Cell invasion was measured by Matrigel invasion assay; And cell apoptosis was detected by flow cytometry. The expression of TRIM71, Bax, Bcl-2, NF-κB p65 was detected by RT-qPCR or Western blot. The targeted regulation relationship between miR-125a-5p and TRIM71 was verified by luciferase reporter gene assay. Results Compar
A central task in the field of quantum computing is to find applications where quantum computer could provide exponential speedup over any classical computer. Machine learning represents an important ...field with broad applications where quantum computer may offer significant speedup. Several quantum algorithms for discriminative machine learning have been found based on efficient solving of linear algebraic problems, with potential exponential speedup in runtime under the assumption of effective input from a quantum random access memory. In machine learning, generative models represent another large class which is widely used for both supervised and unsupervised learning. Here, we propose an efficient quantum algorithm for machine learning based on a quantum generative model. We prove that our proposed model is exponentially more powerful to represent probability distributions compared with classical generative models and has exponential speedup in training and inference at least for some instances under a reasonable assumption in computational complexity theory. Our result opens a new direction for quantum machine learning and offers a remarkable example in which a quantum algorithm shows exponential improvement over any classical algorithm in an important application field.
This paper proposes a hybrid vertex-centered fi- nite volume/finite element method for solution of the two di- mensional （2D） incompressible Navier-Stokes equations on unstructured grids. An ...incremental pressure fractional step method is adopted to handle the velocity-pressure coupling. The velocity and the pressure are collocated at the node of the vertex-centered control volume which is formed by join- ing the centroid of cells sharing the common vertex. For the temporal integration of the momentum equations, an im- plicit second-order scheme is utilized to enhance the com- putational stability and eliminate the time step limit due to the diffusion term. The momentum equations are discretized by the vertex-centered finite volume method （FVM） and the pressure Poisson equation is solved by the Galerkin finite el- ement method （FEM）. The momentum interpolation is used to damp out the spurious pressure wiggles. The test case with analytical solutions demonstrates second-order accuracy of the current hybrid scheme in time and space for both veloc- ity and pressure. The classic test cases, the lid-driven cavity flow, the skew cavity flow and the backward-facing step flow, show that numerical results are in good agreement with the published benchmark solutions.
Demonstrating quantum advantage requires experimental implementation of a computational task that is hard to achieve using state-of-the-art classical systems. One approach is to perform sampling from ...a probability distribution associated with a class of highly entangled many-body wavefunctions. It has been suggested that this approach can be certified with the Linear Cross-Entropy Benchmark (XEB). We critically examine this notion. First, in a "benign" setting where an honest implementation of noisy quantum circuits is assumed, we characterize the conditions under which the XEB approximates the fidelity. Second, in an "adversarial" setting where all possible classical algorithms are considered for comparison, we show that achieving relatively high XEB values does not imply faithful simulation of quantum dynamics. We present an efficient classical algorithm that, with 1 GPU within 2s, yields high XEB values, namely 2-12% of those obtained in experiments. By identifying and exploiting several vulnerabilities of the XEB, we achieve high XEB values without full simulation of quantum circuits. Remarkably, our algorithm features better scaling with the system size than noisy quantum devices for commonly studied random circuit ensembles. To quantitatively explain the success of our algorithm and the limitations of the XEB, we use a theoretical framework in which the average XEB and fidelity are mapped to statistical models. We illustrate the relation between the XEB and the fidelity for quantum circuits in various architectures, with different gate choices, and in the presence of noise. Our results show that XEB's utility as a proxy for fidelity hinges on several conditions, which must be checked in the benign setting but cannot be assumed in the adversarial setting. Thus, the XEB alone has limited utility as a benchmark for quantum advantage. We discuss ways to overcome these limitations.
A novel multi-functional grid-connected inverter (MFGCI), composed of a three-port three-phase DC/AC converter and a front-end DC/DC converter, is investigated and evaluated in this paper. A low ...voltage DC source can exchange most energy with the AC grid only through the DC/AC converter and only partial power needs to be processed by the DC/DC converter. Therefore, power conversion stages can be reduced and overall conversion efficiency is improved. To make sure most active power can be transferred directly from the DC source to the AC grid within single-stage conversion, a modified SVPWM strategy is adopted and evaluated experimentally. Impact factors on the single-stage power transferring when the MFGCI compensates reactive and harmonic currents for power quality enhancement is analyzed in detail as well. Compared with traditional solutions, the presented MFGCI can realize active power delivery with high efficiency in addition to enhancing power quality. Experimental results with a 5kVA inverter prototype are provided to verify the feasibility and effectiveness of the three-port three-phase DC/AC converter-based MFGCI.
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