2025-04-23 2017, Volume 23 Issue 5

  • Select all
  • Wen Hou , Xiaohong Zhang , Chuan-Fa Liu

    For the proteins that cannot be expressed exactly by cell expression technology (e.g., proteins with multiple posttranslational modifications or toxic proteins), chemical synthesis is an important substitute. Given the limited peptide length offered by solid-phase peptide synthesis invented by Professor Merrifield, peptide ligation plays a key role in long peptide or protein synthesis by ligating two small peptides to a long one. Moreover, high-molecular-weight proteins must be synthesized using two or more peptide ligation steps, and sequential peptide ligation is such an efficient way. In this paper, we reviewed the development of chemical protein synthesis, including solid-phase peptide synthesis, chemical ligation, and sequential chemical ligation.

  • Shitao Liu , Li Wang , Zhijue Quan

    InGaN has been predicted to be an efficient photovoltaic material. However, the high-density polarization charges and large potential barrier at the i-InGaN/n-GaN interface create an electric field that severely decreases the collection efficiency of p-InGaN/i-InGaN/n-GaN heterostructure solar cells. We demonstrate that, according to numerical simulations, utilizing a p-InGaN/i-InGaN/n-ZnO heterostructure can greatly reduce the piezoelectric field in the absorption layer and reduce the potential barrier between the n-type layer and the absorption layer interface, thus improving the performances of the solar cell. Moreover, we studied the influence of the band alignment on the ZnO/InGaN interface on the performance of the solar cell. We found that the band alignment of the ZnO/InGaN interface can keep the solar cells at a very high efficiency over a wide scope.

  • Denghua Zhong , Zhiqiang Chu , Bingyu Ren , Mengqi Zhao , Tao Guan , Wenshuai Song

    The construction of arch dams exhibits high uncertainty. Sensitivity analysis of construction parameters is important for the design and optimization of dam construction duration. However, current research cannot fully consider the combined influences of multiple parameters on the total construction. To effectively analyze the duration of arch dam construction, this study proposes a global comprehensive sensitivity analysis method in view of the whole process of arch dam construction based on an orthogonal experiment. This method could comprehensively consider the influence of the construction parameters that may lead to the uncertainty of construction duration. In addition, this method is able to identify the key parameters that may have a significant effect on duration uncertainty and sums up the general rules of combined parameters’ interaction effect, which provides a scientific basis for reasonable optimization of the duration of dam construction.

  • Puyang Zhang , Zhi Zhang , Junjie Ma , Hongyan Ding , Ruiqi Hu

    The composite bucket foundation (CBF) is a new kind of foundation which has been applied in the offshore wind industry. A reasonable connection pattern between the tower and the CBF top cover is crucial for load transmissions from the superstructure. Therefore, it is essential to choose an optimum structure type for the transition section. The line type and the arc transition section models were established by ABAQUS, and the internal forces of cross section were extracted along the height direction. Specifically, the force transfer mechanism for different types of the transition sections was investigated comparatively with monotonic as well as composite loadings. The results show that the curved transition structure exhibits the better mechanical characteristics under the monotonic and composite loadings, and the reason can be illustrated that its specific arc-shape structure can effectively convert the tremendous bending moment from the turbine tower into the limited tensile and compressive stresses downwards, without the occurrence of force concentration.

  • Hongyan Ding , Yan Zhu , Puyang Zhang , Conghuan Le

    A hydraulics model is built in Moses to find the optimal internal skirt spacing for the maximum floating stability of the skirted foundation. The results show that the increase in the internal skirts’ number can help improve the floating stability of the skirted foundation. However, with the increase in the internal skirts’ number, the improvement of floating stability becomes more and more weak. In this study, an optimal number of four are found for the internal skirt spacing. Moreover, to testify the feasibility of internal skirt spacing, a practical project is modeled, which indicates that the optimal internal skirt spacing can satisfy the requirements of towing.

  • Xiaobin Zhu , Xiaoling Wang , Minghui Liu , Zhen Wang , Xiaoxin Zhang

    Channel engineering stability with underground goafs is a complex three-dimensional problem, especially when considering channel leakage, and is influenced by a number of processes, such as seepage, fluid structure interaction (FSI), modeling, and selection of geological mechanical parameters. In this study, stability finite element analysis by one-way FSI was performed by establishing an integrated 3D engineering geological model. The extended Fourier amplitude sensitivity test was used to quantitatively assess the first-order and total sensitivities of the engineering model to critical geological mechanical parameters. Results illustrate that the channel engineering deformation is under a reasonable range and the elastic modulus is the highest total sensitivity parameter for the channel tilt and curvature at 0.7395 and 0.7525, respectively. Moreover, the most observable coupling effects for the curvature and horizontal strain are cohesion (0.1933) and density (0.7410), respectively.

  • Zhimin Zhang , Hegao Wu , Yang Wang , Qiling Zhang , Teng Li

    Inner-reinforced girders, also known as ribs, are widely used in hydropower bifurcations. However, while they strengthen structures, they also cause energy loss. This work aims to develop an appropriate geometry form for ribs that can diminish head loss in hydropower bifurcations. The term rib/breadth ratio (RBR) is defined to describe the geometrical form of ribs. An investigation is conducted to study the flow and performance characteristics of bifurcations with ribs using computational fluid dynamics. The dependence of the head loss coefficient on the RBR is given in six working conditions. Results show that the ribs change the local flow patterns and slightly increase the water head loss in some cases. In other cases, however, the ribs make the flow smooth. An appropriate RBR is the key to improve the flow patterns in hydropower bifurcations. The head loss varies with the RBR and reaches the minimum when the RBR is 0.3.

  • Feiyu Li , Zhenfeng Shi , Chenguang Wu , Yixing Yuan , Yan Zhu

    Based on information entropy theory, the definition of relative entropy, and the relative entropy minimum principle, this study establishes a multi-objective optimization model for a key valve opening of an urban water distribution network (WDN). Each node pressure is taken as the main research object to reduce pipeline leakage. Moreover, genetic algorithm is applied in the proposed model to solve the key valve opening of the actual WDN in a city in southern China. Using the proposed model, the relevant decision variables of a WDN can be optimized to provide a new manner of network dispatching.

  • Shan Jiang , Yunpeng Yang , Zhiyong Yang , Zhen Zhang , Sheng Liu

    To implant radioactive seeds through a needle precisely and safely, a novel multi-DOF surgical robotic system is presented in this paper for percutaneous prostate intervention through the patient’s perineum under real-time ultrasound image guidance. The proposed robot, which is designed with 9-DOF, consists of a 3-DOF automatic location platform for position adjustment, 2-DOF for automatic ultrasonic probe adjustment mounted with electromagnetic trackers, and 4-DOF for manually adjusting the guided template. Meanwhile, a new registration method based on the quaternion algorithm and least square method is developed, and the needle insertion is performed under the real-time guidance of a navigation system. Furthermore, the robot system has undergone some preliminary experiments with a laser tracker to evaluate the repeatability and accuracy of the robot system. The location error of the puncture needle tip can be controlled under 0.7 mm in air for the whole robotic system. The acquired results endorse the precision of the robot system for prostate seed implantation brachytherapy.

  • Jianqiao Sun , Wen Zheng , Furui Xiong , Zhichang Qin , Qian Ding

    In this paper, we investigate a multi-objective optimal design of a tuned vibration absorber for a two degrees-of-freedom linear system, in which we take white Gaussian noise as the excitation. We use the simple cell mapping method to obtain solutions to the multi-objective optimization problem. We optimize tuned vibration absorbers in two different configurations. As our objective, we take various features of the response of the power spectrum density function. Our results show that the primary mass vibration with the optimally designed absorber has a lower peak power spectrum value. In addition, the two natural frequencies of the optimized system are further apart than in the non-optimized system, which implies that the absorber has a wider effective region in the frequency domain.

  • Yonghong Hou , Hang Li , Chuankun Liu , Liang Zhang

    With the appearance of RGB-D camera, the field of three-dimensional (3D) reconstruction receives more and more attention. In this paper, we present an optimization approach to produce high-quality textured 3D models based on the real-time 3D reconstruction system. The resulting models of real-time texture reconstruction often suffer from blurring, ghosting, and other artifacts. Our approach addresses this texture quality problem using blur detection and an optimized weight function. Experimental results demonstrate that our approach can improve the quality of textured 3D models by reducing the blur and ghosts on the model surface.