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991.
Metamodeling or surrogate modeling is becoming increasingly popular for product design optimization in manufacture industries.
In this paper, an extended Gaussian Kriging method is proposed to improve the prediction performance of widely used ordinary
Kriging in engineering design. Unlike the forgoing approaches, the proposed method places a variance-varying Gaussian prior
on the unknown regression coefficients in the mean model of Kriging and makes prediction at untried design points based on
the principle of Bayesian maximum a posterior. The achieved regression mean model is adaptive, therefore capable of capturing
more effectively the overall trend of computer responses and leading to a more accurate metamodel. Particularly, the regression
coefficients in the mean model are estimated by a fast numerical algorithm, making extended Gaussian Kriging implemented roughly
as efficient as ordinary Kriging. Experiment results on several examples are presented, showing remarkable improvement in
prediction using extended Gaussian Kriging over ordinary Kriging and several other metamodeling methods. 相似文献
992.
This paper demonstrates a promising and low-cost method for fabricating PZT nano-dot array by using sol–gel template method combined with laser interference lithography. ZrO2 template with the pitch of 1?μm is firstly fabricated by sol–gel method and laser interference with a 325?nm He-Cd laser. Afterwards, PZT nano dot array with diameter of 500?nm and thickness of 20?nm is prepared on the ZrO2 template. Atomic force microscope results show that the PZT nano dot array is uniform and highly ordered. Ferroelectric properties of PZT nano dot array are in situ measured through online-operation of TF analyzer and AFM. A ferroelectric hysteresis loop is obtained for the PZT nano dot. 相似文献
993.
A web services-based approach to develop a networked information integration service platform for gear enterprise 总被引:1,自引:0,他引:1
Jianjun Yang Jubo Li Xiaozhong Deng Kai Xu Hua Zhang 《Journal of Intelligent Manufacturing》2012,23(5):1721-1732
In order to deal with the problems of information integration and data sharing across distributed heterogeneous application systems in gear enterprises, it is imperative to build up a high quality information integration platform. Web Services, an emerging form of service-oriented architecture (SOA) for distributed computing, have the potential to serve as a key enabling technology to integrate heterogeneous systems under the distributed environment. This paper presents a novel information integration service platform which offers better support for the networked manufacturing of gear enterprise by taking full advantage of technologies of SOA and Web services. In this paper, the information integrated operation mode of gear enterprise networked manufacturing is deeply analyzed and the functional architecture of the networked information integration service platform is proposed. Furthermore, the application integrated framework of gear enterprise is constructed and the software architecture of the service platform is implemented in the .NET environment. Finally, an actual application example of hypoid gear networked manufacturing is provided to demonstrate the practicability of the proposed platform. 相似文献
994.
本文对大孔吸附树脂分离纯化女贞子中齐墩果酸的方法进行优化研究.以齐墩果酸的吸附率和解吸附率为考察指标,筛选出D101、D201、LSD001、XDA-7、C008、LSA-10、LSA-40、LSA-21等8种树脂中最适合齐墩果酸分离的树脂,并确定其分离纯化女贞子中齐墩果酸的最佳工艺条件.结果最优树脂为LSA-21型,最佳工艺条件为女贞子溶液浓度为4.0mg/mL,吸附流速为3mL/min,上样量2BV,洗脱剂为无水乙醇,解吸流速为3mL/min,洗脱剂用量为1.5BV.洗脱液经浓缩重结晶得结晶,经与齐墩果酸对照品进行TLC检查及熔点测定,确定其为齐墩果酸. 相似文献
995.
采用密度泛函理论中的广义梯度近似对(CdTe)n和(HgTe)n(n=2~8)团簇的几何结构进行优化,计算了其能量,研究了其电子性质。结合能、最高占据轨道和最低未占据轨道的能隙计算结果表明,n=3、6是团簇的幻数;比较2种团簇的基态结构,发现2种团簇的最低能量结构不同,这可能是导致块体材料CdTe是宽带隙半导体材料,而HgTe是半金属材料的原因。 相似文献
996.
针对圆形和单粒组颗粒模拟试验的缺陷,基于PFC2D的clump命令,开发了非圆形颗粒组,采用单向法、各向同法和沉积法生成不同初始组构特征的试验样品,模拟了砂土直接剪切试验过程.探讨了初始组构各向异性对砂土抗剪强度与剪胀性的影响规律,研究了剪切过程中力链的演化形式,分析了颗粒旋转以及剪切带内外颗粒长轴定向的变化特征.数值试验结果表明:颗粒初始组构的差异对抗剪强度的影响较大,对材料的剪胀性以及内摩擦角的影响较小;剪切过程应力主轴发生了偏转,颗粒接触角向主应力方向靠拢;颗粒旋转主要发生在8倍于平均颗粒半径的条带内,颗粒长轴定向也发生了偏转,偏转方向与主应力偏转方向相同,但滞后于主应力的偏转速度;初始组构的不同影响剪切带内颗粒的旋转速度. 相似文献
997.
分析了挖泥船排泥管内流体流动状态,推导了试验台的相似准数,研究了各相似准数在模型中的作用,分析了它们在模型与原型的相似关系中的主次地位,得出了模型与原型主要是阻力相似的结论,并以此为依据构造了模型实验台. 相似文献
998.
The Pfaff-Birkhoff variational principle is discretized,and based on the discrete variational principle the discrete Birkhoffian equations are obtained.Taking the discrete equations as an algorithm,the corresponding discrete flow is proved to be symplectic.That means the algorithm preserves the symplectic structure of Birkhoffian systems.Finally,simulation results of the given example indicate that structure-preserving algorithms have great advantage in stability and energy conserving. 相似文献
999.
To investigate airflow pattern and its impact on particle deposition, finite-volume based computational fluid dynamics (CFD)
simulations were conducted in the diseased triple-bifurcation airways. Computations were carried out for twenty Reynolds numbers
ranging from 100 to 2 000 in the step of 100. Particles in the size range of 1–10 μm were conducted. Two particle deposition
mechanisms (gravitational sedimentation and inertial impaction) were considered. The results indicate that there are strong
relationship between airflow structures and particle deposition patterns. Deposition efficiency is different for different
particles in the whole range of the respiratory rates. Particles in different sizes can deposit at different sites. Smaller
particles can be uniformly deposited at the inside wall of the considered model. Larger particles can be mainly deposited
in the proximal bifurcations. Deposition fraction varies a lot for different inlet Reynolds numbers. For lower Reynolds numbers,
deposition fraction is relatively small and varies a little with varying the diameters. For higher Reynolds numbers, there
is a most efficient diameter for each Reynolds number to target the aerosols at the specific site. 相似文献
1000.
The influences of BaCu(B2O5) (BCB) addition on sintering, microstructure and microwave dielectric properties of Li2MgTi3O8 ceramics were investigated using X-ray diffractometry, scanning electron microscopy and microwave dielectric measurements.
The experimental results show that a small amount of BaCu(B2O5) addition can effectively reduce the sintering temperature to 900 °C, and induce only a limited degradation of the microwave
dielectric properties. Typically, the best microwave dielectric properties of ɛ
r=24.5, Q×f =24 622 GHz, τ
f=4.2×10−6 °C−1 are obtained for 1.0% BCB-doped Li2MgTi3O8 ceramics sintered at 900 °C for 3 h. The BCB-doped Li2MgTi3O8 ceramics can be compatible with Ag electrode, which may be a strong candidate for low temperature co-fired ceramics applications. 相似文献