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11.
Li Yao-Chen 《Engineering Fracture Mechanics》1984,19(5):959-972
A new regular polygon singular element is presented here. Its displacement is divided into two parts—linear and singular, the latter including the stress intensity factors vanishes on the boundary of the singular element, so the continuity of the displacement is satisfied. Furthermore, each element in the singular stiffness matrix can be expressed in some more simple analytic formulas. The procedure of analysing and reasoning of this technique is given in this paper, with which the intensity factors of the three kinds of loading system—uniform tension, three-point bending and shearing—are calculated. The results of the calculation show that this method is successful. 相似文献
12.
During chemical–mechanical planarization (CMP), a rotating wafer is pressed against a rotating pad, while a slurry is dragged
into the pad–wafer interface. Here, taking into account the dependence of local material removal rate (MRR) on the slurry’s
chemical activity, the effects of pad groove geometry and various other process parameters on the spatial average and non-uniformity
of MRR are examined. Technically, the slurry flow is calculated by following an existing approach that integrates two-dimensional
fluid-film lubrication theory and contact-mechanics models. A slurry impurity transport equation is then used to calculate
the impurity concentration that determines the slurry’s chemical activity and hence the local MRR. The numerical results obtained
here indicate that the presence of pad grooves generally decreases the average slurry impurity concentration, and increases
the average contact stress on the pad–wafer interface. However, as a grooved pad has less contact area for effective interaction
with the wafer surface, the average MRR may or may not be increased, depending upon the specific setting of process parameters.
Meanwhile, it appears that the retaining ring generally used to keep the wafer in place also plays an important part in reducing
the MRR non-uniformity. 相似文献
13.
14.
Yao-Chen Tsai Chung-Yi Huang Kuan-Yuan Lin Jiing-Yih Lai Wen-Der Ueng 《The International Journal of Advanced Manufacturing Technology》2009,42(1-2):152-167
The computer-aided design model reconstruction process is generally very complex, as it requires substantial efforts in planning and editing data points, curves, and surfaces. A novel method is developed in this study for automatic surface reconstruction from a huge number of triangular meshes. The proposed method is mainly composed of the following five steps: mesh simplification, quadrilateral mesh generation, curve net construction, connectivity data preparation, and multiple surfaces fitting with G1 continuity across the boundaries. The first three steps build the boundary curves of the surfaces. The fourth step prepares the data needed for surface fitting, which includes segmented points, continuity conditions on the boundaries, and topological relationship of the data. In the final step, all regions of points are fitted into appropriate surfaces, with the accuracy and smoothness of the surfaces controlled and G1 continuity between the surfaces. A detailed discussion for each of the above algorithms is provided. Successful examples are also presented to demonstrate the feasibility of the proposed method. 相似文献
15.
The undertaking of construction projects in metropolitan areas is a risky, competitive, and dynamic proposition requiring a reliable risk assessment model for adequate planning. This study employs a fuzzy multiple criteria decision making (FMCDM) approach to systematically assess risk for a metropolitan construction project. Consistent fuzzy preference relations (CFPR) are used to measure and investigate the relative impact on project performance of twenty identified risk factors included in four risk dimensions. The fuzzy multiple attributes direct rating (FMADR) approach is employed to analyze the occurrence probability of multiple risk factors. Furthermore, the level of risk for the overall project caused by individual risk factor is evaluated with the synthesized analysis of the relative impacts and probability of occurrence. The implementation of FMCDM makes the proposed risk assessment approach more reliable and practical than the traditional statistical approach. The proposed approach can be employed to effectively evaluate the overall project risk, and can be benefited to efficiently identify significant risks of a metropolitan construction project. 相似文献
16.
Ting-Wan Kao Yao-Chen Chuang Hsin-Lun Lee Chia-Chun Kuo Yao-An Shen 《International journal of molecular sciences》2022,23(23)
Rare subpopulations of cancer stem cells (CSCs) have the ability to self-renew and are the primary driving force behind cancer metastatic dissemination and the preeminent hurdle to cancer treatment. As opposed to differentiated, non-malignant tumor offspring, CSCs have sophisticated metabolic patterns that, depending on the kind of cancer, rely mostly on the oxidation of major fuel substrates such as glucose, glutamine, and fatty acids for survival. Glutaminolysis is a series of metabolic reactions that convert glutamine to glutamate and, eventually, α-ketoglutarate, an intermediate in the tricarboxylic acid (TCA) cycle that provides biosynthetic building blocks. These building blocks are mostly utilized in the synthesis of macromolecules and antioxidants for redox homeostasis. A recent study revealed the cellular and molecular interconnections between glutamine and cancer stemness in the cell. Researchers have increasingly focused on glutamine catabolism in their attempt to discover an effective therapy for cancer stem cells. Targeting catalytic enzymes in glutaminolysis, such as glutaminase (GLS), is achievable with small molecule inhibitors, some of which are in early-phase clinical trials and have promising safety profiles. This review summarizes the current findings in glutaminolysis of CSCs and focuses on novel cancer therapies that target glutaminolysis in CSCs. 相似文献