A combination of digital design and three-dimensional printing to assist treatment of thoracolumbar compression fractures using percutaneous kyphoplasty

Objective:To evaluate the clinical efficacy of the preoperative digita1 design combined with three dimensional(3D)printing models to assist percutaneous kyphoplasty(PKP)treatment for thoracolumbar compression frac tures.Methods:From January 2018 to August 2020,we obtained data of 99 patients diagnosed thoracolumbar compression fractures.These patients were divided into control group(n=50)underwent traditional PKP surgery,and observation group(n=49)underwent preoperative digital design combined with 3D printing model assisted PKP treatment.The clinical efficacy was evaluated with five parameters,including operation time,number of intraoperative radiographs,visual analogue scale(VAS)score,Cobb Angle change,and high compression rate of injured vertebrae.Results:There were statistically significant differences of operation time and number of intraoperative radio graphs between the two groups(P<0.05).For VAS score,Cobb Angle change and vertebral height compression rate,all of these three parameters were significantly improved when the patients accepted surgery teatment in two groups(P<0.05).However,there were no significant differences between control group and observation group for these three parameters either before or after surgery(P>0.05).Conclusions:Through the design of preoperative surgical guide plate and the application of 3D printing model to guide the operation,the precise design of preoperative surgical puncture site and puncture Angle of the injured vertebra was realized,the number of intraoperative radiographs was reduced,the operation time was shortened and the operation efficiency was improved.

The Design of a Three-Dimensional Physical Modeling System for Real-Time Groundwater Flows

In the past decades,physical modeling has been widely used in hydrogeology for teaching,studying and exhibition purposes.Most of these models are used to illustrate hydrogeological profiles,but few can depict three-dimensional groundwater flows,making it impossible to validate groundwater flows simulated by numerical methods with physical modeling.

Structural Design and Optimization of Comb-type Electric Bicycle Three-dimensional Parking Garage

With the reduction of urban land, the three-dimensional garage is increasingly built with its advantages of saving land. But the current three-dimensional garage is built for the car. It is hardly stereo parking garage for electric bicycles. This paper designed a hollow tower electric bicycle stereo parking garage with fork comb structure, based on the analysis of the characteristics of electric bicycles and the characteristics of existing three-dimensional garages. A fixed comb is mounted on the garage frame. The movable comb is mounted on the middle lift mechanism of the garage. The access of the vehicle is achieved by the exchange of the comb. The key comb structure was modeled using SolidWorks software and the stress distribution of the structure was analyzed. It was optimized by MATLAB software. The result shows that this structure can improve access efficiency. The quality of the comb structure can be minimized under the constraints of strength requirements.

Design of an Acoustic Levitator for Three-Dimensional Manipulation of Numerous Particles

We present a design of an acoustic levitator consisting of three pairs of opposite transducer arrays.Three orthogonal standing waves create a large number of acoustic traps at which the particles are levitated in mid-air.By changing the phase difference of transducer arrays,three-dimensional manipulation of particles is successfully realized.Moreover,the relationship between the translation of particles and the phase difference is experimentally investigated,and the result is in agreement with the theoretical calculation.This design can expand the application of acoustic levitation in many fields,such as biomedicine,ultrasonic motor and new materials processing.

Three-dimensional global interconnect based on a design window

Based on a stochastic wire length distributed model, the interconnect distribution of a three-dimensional integrated circuit （3D IC） is predicted exactly. Using the results of this model, a global interconnect design window for a giga-scale system-on-chip （SOC） is established by evaluating the constraints of 1） wiring resource, 2） wiring bandwidth, and 3） wiring noise. In comparison to a two-dimensional integrated circuit （2D IC） in a 130-nm and 45-nm technology node, the design window expands for a 3D IC to improve the design reliability and system performance, further supporting 3D IC application in future integrated circuit design.

Set up the Mechanical Curriculum System Based on Three-Dimensional Design

The changes of design methods and manufacturing techniques have brought new requirements for engineers in enterprises, and therefore brought a challenge to the traditional teaching system of mechanical major courses. A new teaching system based on three-dimensional design to cultivate modern engineers with solid specialty bases and high creativity in a wide range of fields is presented.

Integration system research and development for three-dimensional laser scanning information visualization in goaf

An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.

Three-dimensional(3D) Printing Technology Assisted by Minimally Invasive Surgery for Pubic Rami Fractures

The feasibility of three-dimensional (3D) printing technology cgmbined with minimally invasive surgery in the treatment of pubic rami fractures was explored.From August 2015 to October 2017,a series of 30 patients who underwent surgical stabilization of their anterior pelvic ring (all utilizing the 3D printing technology)by one surgeon at a single hospital were studied.The minimally invasive incisions were made through anterior inferior cilia spine and pubic nodule.Data collected included the operative duration,the blood loss,the damage of the important tissue,the biographic union and therecovery of the function after the operation.Measurements on inlet and outlet pelvic cardiograph were made immediately post-operation and at all follow-up clinic visits.The scores of reduction and function were measured during follow-up.Results showed that the wounds of 30 patients were healed in the first stage,and there was no injury of important structures such as blood vessels and nerves.According to the Matta criteria,excellent effectiveness was obtained in 22 cases and good in 8 cases.According to the functional evaluation criteria of Majeed,excellent effectiveness was obtained in 21 cases and good in 9 cases.It was suggested that the 3D printing technology assisted by minimally invasive surgery can better evaluate the pelvic fracture before operation,which was helpful in plate modeling, and can shorten surgery duration and reduce intraoperative blood loss and complications. The positioning accuracy was improved,and better surgical result was finally achieved.

Three-Dimensional Ocean Sensor Networks:A Survey

The past decade has seen a growing interest in ocean sensor networks because of their wide applications in marine research,oceanography,ocean monitoring,offshore exploration,and defense or homeland security.Ocean sensor networks are generally formed with various ocean sensors,autonomous underwater vehicles,surface stations,and research vessels.To make ocean sensor network applications viable,efficient communication among all devices and components is crucial.Due to the unique characteristics of underwater acoustic channels and the complex deployment environment in three dimensional(3D) ocean spaces,new efficient and reliable communication and networking protocols are needed in design of ocean sensor networks.In this paper,we aim to provide an overview of the most recent advances in network design principles for 3D ocean sensor networks,with focuses on deployment,localization,topology design,and position-based routing in 3D ocean spaces.

The Enlightenment of British Flower Border Design to Chinese Flower Border Design

In recent years, flower borders have been widely used in urban parks and road landscape in China, and have gradually become a hot spot in garden design. However, China's flower border design is still in the primary stage, and the practical application effect is not good. This study sorted out the evolution, development reasons, and design features of flower borders in British gardens, drew lessons from British flower border design in terms of planting form, plant configuration, facade design, color matching, and space artistic conception, and proposed inspiration for the design of Chinese flower borders, so as to enrich flower border design in China.

Prediction of three-dimensional elastic behavior of filament-wound composites based on the bridging model

This work provides a method to predict the three-dimensional equivalent elastic properties of the filament-wound composites based on the multi-scale homogenization principle.In the meso-scale,a representative volume element(RVE)is defined and the bridging model is adopted to establish a theoretical predictive model for its three-dimensional equivalent elastic constants.The results obtained through this method for the previous experimental model are compared with the ones gained respectively by experiments and classical laminate theory to verify the reliability of this model.In addition,the effects of some winding parameters,such as winding angle,on the equivalent elastic behavior of the filament-wound composites are analyzed.The rules gained can provide a theoretical reference for the optimum design of filament-wound composites.

Analysis of Flower Border Design and Maintenance in the Later Period

Since the 21st century,China's economy has enjoyed rapid development and people's living standards have been improved.At the same time,the pursuit of beauty of people is getting increasingly higher and landscaping of and design of gardens has been widely pursued by people.This paper has discussed and analyzed the design of flower border and maintenance of flower border in the later period,hoping to provide some help and support for the relevant technical workers.

Three-Dimensional Velocity Distribution Measurement Using Ultrasonic Velocity Profiler with Developed Transducer

This study describes an ultrasonic velocity profiler that uses a new ultrasonic array transducer with unique 5-element configuration, with all five elements acting as transmitters and four elements as receivers. The receivers are designed to reduce the amount of uncertainty. As the fluid moves through this setup, four Doppler frequencies are obtained. The multi-dimensional velocity information along the measurement line can be reconstructed. The transducer has a compact geometry suitable for a wide range of applications, including narrow flow areas. The transducer’s basic frequency and sound pressure are selected and evaluated to be compatible with the application. First, to confirm the measurement ability, the measurement of the developed system in two-dimensional flow is validated by comparing it to the theoretical data. The uncertainty of measurement was within 15%. Second, the three-dimensional measurement in turbulent and swirling flow is proved experimentally to check the applicability of the proposed technique.

SAR regional all-azimuth observation orbit design for target 3D reconstruction

Three-dimensional(3D) synthetic aperture radar(SAR)extends the conventional 2D images into 3D features by several acquisitions in different aspects. Compared with 3D techniques via multiple observations in elevation, e.g. SAR interferometry(InSAR) and SAR tomography(TomoSAR), holographic SAR can retrieve 3D structure by observations in azimuth. This paper focuses on designing a novel type of orbit to achieve SAR regional all-azimuth observation(AAO) for embedded targets detection and holographic 3D reconstruction. The ground tracks of the AAO orbit separate the earth surface into grids. Target in these grids can be accessed with an azimuth angle span of360°, which is similar to the flight path of airborne circular SAR(CSAR). Inspired from the successive coverage orbits of optical sensors, several optimizations are made in the proposed method to ensure favorable grazing angles, the performance of 3D reconstruction, and long-term supervision for SAR sensors. Simulation experiments show the regional AAO can be completed within five hours. In addition, a second AAO of the same area can be duplicated in two days. Finally, an airborne SAR data process result is presented to illustrate the significance of AAO in 3D reconstruction.

Application of Digital Technology in Road and Bridge Design

With the development and progress of science and technology,road and bridge design has experienced rapid development,from the initial manual drawing design to the popularity of Computer-Aided Design(CAD),and then to today’s digital software design era.Early designers relied on hand-drawn paper design forms which was time-consuming and error-prone.Digital support for road and bridge design not only saves the design time but the design quality has also achieved a qualitative leap.This paper engages in the application of digital technology in road and bridge design,to provide technical reference for China’s road and bridge engineering design units,to promote the popularity of Civil3D and other advanced design software in the field of engineering design and development,ultimately contributing to the sustainable development of China’s road and bridge engineering.

基于遗传算法的区域性Flower星座设计

分析和确定了Flower星座的优化参数,从参数编码、适应度评价和算法流程设计三个方面进行讨论,给出了Flower星座的遗传算法优化模型.利用自行开发的卫星星座仿真软件SatSim(satellite simulation)和STK(satellite tool kit)工具包,设计了适合中国区域通信的三个Flower星座并进行了性能分析.仿真结果表明,4和5颗星的星座在最小仰角10°的条件下对中国的平均覆盖率分别为97.26%和99.24%;6颗星的星座在最小仰角15°的条件下对中国的平均覆盖率为99.88%,基本实现对中国的连续覆盖,可以满足卫星移动通信的需求.

The Extraction Process Optimization of Phenolic Compounds from Okra Flower and Its Antioxidant Activities

[Objective] The aim of the study was to investigate extraction optimization and antioxidant activity of polyphenol in okra flower in order to enhance extraction efficiency and developing value of okra flower. [Method] Optimization of supersonic assisted extraction of phenolic compound in okra flower was investigated using uniform design methodology, and its antioxidant activity was analyzed including reducing power and the capacity of scavenging superoxide anion radicals（O-2·）. [Result]The optimal process parameters of supersonic assisted extraction were as follows：ratio of sample to solvent of 1：35, ethanol concentration of 55%, supersonic time of22 min, and in the extraction condition the experimental yield of phenolic compound was 4.28%. Moreover, phenolic compound in okra flower exhibited stronger antioxidant activities, reducing power of 0.2 mg/ml extraction fluid reached 0.672 and the rate of scavenging O-2· was 13.13%. [Conclusion] The optimization of extraction technology of phenolic compound in okra flower is simple and reliable, the result contributes to the development of phenolic compound in okra flower.

基于格式塔理论的花园植物形态分类体系构建与应用

花园是以植物造景为主要形式的园林形态。在设计花园时,植物的形态是首先要考虑的因素,然而目前针对这一领域的研究尚显不足。该文在综合国内外花园植物形态研究的基础上,基于格式塔理论的闭合原则,对常见花园植物形态进行简化、分类和提炼,依据几何形态归纳为一级形态5类,即:圆形、锥形、方形、丘状和其他形状,并结合具体形态进一步细分二级形态共14种,构建了花园植物形态分类体系,并总结出每种形态的代表植物和应用特征。在此基础上从草本、木本、草本+木本三大类花园核心植物组合类型出发,深入分析典型花园实践案例。同时总结不同类型的植物形态搭配规律,将花园植物形态分类体系运用于设计。旨在为花园植物设计的理论和实践提供新思路、新依据,推动形式美学与模块化设计在花园设计领域的应用。

唐代簪花在当代服饰设计中的应用

文章旨在探讨唐代簪花元素在现当代服饰设计中的应用。通过文献综述与设计实践案例分析相结合的研究方法,深入分析了唐代簪花的文化习俗、簪花的分类及其在现当代服饰设计中的应用。研究认为,簪花不仅是一种发饰搭配,更是唐代社会文化与审美观念的物质载体。将这一传统手工艺与现当代服饰设计相融合,能够为设计师提供创新的设计灵感,拓展现当代服饰的风格与文化深度,满足消费者对于传统文化与现代时尚结合的服饰需求。

Quasi-three-dimensional high-lift wing design approach considering three-dimensional effects of slipstream for distributed electric propulsion aircraft

The efficient utilization of propeller slipstream energy is important for improving the ultra-short takeoff and landing capability of Distributed Electric Propulsion(DEP)aircraft.This paper presents a quasi-three-dimensional(2.5D)high-lift wing design approach considering the three-dimensional(3D)effects of slipstream for DEP aircraft,aiming at maximizing the comprehensive lift enhancement benefit of the airframe-propulsion coupling unit.A high-precision and efficient momentum source method is adopted to simulate the slipstream effects,and the distributed propellers are replaced by a rectangular actuator disk to reduce the difficulty of grid generation and improve the grid quality.A detailed comparison of the 2.5D and 3D configurations based on the X-57 ModⅣis performed in terms of flow characteristics and computational cost to demonstrate the rationality of the above design approach.The optimization results of the high-lift wing of the X-57 ModⅣshow that the aerodynamic performance of the landing configuration is significantly improved,for instance,the lift coefficient increases by 0.094 at the angle of attack of 7°,and 0.097 at the angle of attack of 14°.This novel approach achieves efficient and effective design of high-lift wings under the influence of distributed slipstream,which has the potential to improve the design level of DEP aircraft.