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.

Application of digital technology in nasal reconstruction

Nasal defects are facial defects caused by trauma,tumors,or congenital diseases that seriously damage a patient’s physical and mental health.Nasal defects,from skin defects to total nasal defects,require surgical repair and reconstruction to restore the appearance and function of the nose,which have always been challenges for rhinoplasty.The development of digital technology has increased the possibility of nasal reconstruction.Digital technology is involved in the preoperative,intraoperative,and postoperative stages of nasal construction and is of great significance in improving the effect of this surgery.This article reviews the application of major digital technologies,including three-dimensional(3D)imaging technology,computer-assisted surgical navigation,and 3D printing,in nasal reconstruction and discusses the shortcomings of the current application of digital technology.

Simulation analysis of combined UV/blue photodetector in CMOS process by technology computer-aided design

A composite ultraviolet （UV）/blue photode- tector structure has been proposed, which is composed of P-type silicon substrate, Pwelb Nwell and N-channel metal- oxide-semiconductor field-effect transistor （NMOSFET） realized in the PweH. In this photodetector, lateral ring- shaped Pwell-Nwell junction was used to separate the photogenerated carriers, and non-equilibrium excess hole was injected to the Pwell bulk for changing the bulk potential and shifting the NMOSFET＇s threshold voltage as well as the output drain current. By technology computer-aided design （TCAD） device, simulation and analysis of this proposed photodetector were carried out. Simulation results show that the combined photodetector has enhanced responsivity to UV/blue spectrum. More- over, it exhibits very high sensitivity to weak and especially ultral-weak optical light. A sensitivity of 7000 A/W was obtained when an incident optical power of 0.01 μW was illuminated to the photodetector, which is 35000 times higher than the responsivity of a conventional silicon-based UV photodiode （usually is about 0.2 A/W）. As a result, this proposed combined photodetector has great potential values for UV applications.

Sensitivity investigation of 100-MeV proton irradiation to SiGe HBT single event effect

The single event effect(SEE) sensitivity of silicon–germanium heterojunction bipolar transistor(Si Ge HBT) irradiated by 100-Me V proton is investigated. The simulation results indicate that the most sensitive position of the Si Ge HBT device is the emitter center, where the protons pass through the larger collector-substrate(CS) junction. Furthermore, in this work the experimental studies are also carried out by using 100-Me V proton. In order to consider the influence of temperature on SEE, both simulation and experiment are conducted at a temperature of 93 K. At a cryogenic temperature, the carrier mobility increases, which leads to higher transient current peaks, but the duration of the current decreases significantly.Notably, at the same proton flux, there is only one single event transient(SET) that occurs at 93 K. Thus, the radiation hard ability of the device increases at cryogenic temperatures. The simulation results are found to be qualitatively consistent with the experimental results of 100-Me V protons. To further evaluate the tolerance of the device, the influence of proton on Si Ge HBT after gamma-ray(^(60)Coγ) irradiation is investigated. As a result, as the cumulative dose increases, the introduction of traps results in a significant reduction in both the peak value and duration of the transient currents.

Analysis of displacement damage effects on the charge-coupled device induced by neutrons at Back-n in the China Spallation Neutron Source

Displacement damage effects on the charge-coupled device(CCD)induced by neutrons at the back-streaming white neutron source(Back-n)in the China Spallation Neutron Source(CSNS)are analyzed according to an online irradiation experiment.The hot pixels,random telegraph signal(RTS),mean dark signal,dark current and dark signal non-uniformity(DSNU)induced by Back-n are presented.The dark current is calculated according to the mean dark signal at various integration times.The single-particle displacement damage and transient response are also observed based on the online measurement data.The trends of hot pixels,mean dark signal,DSNU and RTS degradation are related to the integration time and irradiation fluence.The mean dark signal,dark current and DSNU2 are nearly linear with neutron irradiation fluence when nearly all the pixels do not reach saturation.In addition,the mechanisms of the displacement damage effects on the CCD are demonstrated by combining the experimental results and technology computer-aided design(TCAD)simulation.Radiation-induced traps in the space charge region of the CCD will act as generation/recombination centers of electron-hole pairs,leading to an increase in the dark signal.

Impact of proton-induced alteration of carrier lifetime on single-event transient in SiGe heterojunction bipolar transistor

This paper presents an investigation into the impact of proton-induced alteration of carrier lifetime on the singleevent transient(SET) caused by heavy ions in silicon–germanium heterojunction bipolar transistor(SiGe HBT).The ioninduced current transients and integrated charge collections under different proton fluences are obtained based on technology computer-aided design(TCAD) simulation.The results indicate that the impact of carrier lifetime alteration is determined by the dominating charge collection mechanism at the ion incident position and only the long-time diffusion process is affected.With a proton fluence of 5 × 1013 cm-2, almost no change is found in the transient feature, and the charge collection of events happened in the region enclosed by deep trench isolation(DTI), where prompt funneling collection is the dominating mechanism.Meanwhile, for the events happening outside DTI where diffusion dominates the collection process, the peak value and the duration of the ion-induced current transient both decrease with increasing proton fluence, leading to a great decrease in charge collection.

Modeling,simulations,and optimizations of gallium oxide on gallium-nitride Schottky barrier diodes

With technology computer-aided design(TCAD)simulation software,we design a new structure of gallium oxide on gallium-nitride Schottky barrier diode(SBD).The parameters of gallium oxide are defined as new material parameters in the material library,and the SBD turn-on and breakdown behavior are simulated.The simulation results reveal that this new structure has a larger turn-on current than Ga2O3 SBD and a larger breakdown voltage than Ga N SBD.Also,to solve the lattice mismatch problem in the real epitaxy,we add a Zn O layer as a transition layer.The simulations show that the device still has good properties after adding this layer.

Object-oriented CAD for Hydraulic Circuits of Pressing Machines

This paper describes the design and implementation of an intelligent computer-aided design (ICAD) system for hydraulic circuits of pressing machines. The CAD system is developed based on the object-oriented approach. The application domain of hydraulic presses has been studied thoroughly. The engineering data and the design knowledge are organized in an object-oriented database. A case study has been selected to illustrate the usefulness of the object-oriented CAD system in real applications.

Computer-assisted preoperative planning for proximal humeral fractures by minimally invasive plate osteosynthesis

Background Accurate and precise preoperative planning can provide information instrumental for performing less invasive articular fracture surgery. The purpose of this study was to determine that computer-assisted preoperative planning （CAPP） has the potential to improve efficiency and time in the operating room. Methods Sixty-four patients with proximal humeral fractures were treated using locking plates by minimally invasive plate osteosynthesis （MIPO） with CAPP. The time needed for virtual segmentation, reduction, and fixation of the fracture fragments were recorded. Intra and interobserver reliabilities were analyzed using the intraclass correlation coefficient. The clinical function was analyzed using Constant Score and radiology. Results The mean total time required for CAPP of two-part, three-part, and four-part proximal humeral fractures were （13.63±1.38） minutes, （23.14±2.18） minutes, and （39.61±3.01） minutes, respectively. The intra and interobserver reliabilities for all variables were high, ranging from 0.785 to 0.992. The mean operation time was （50.1±6.7） minutes. Fifty- two patients were followed up with an average time of 34.2 months. The mean Constant Score of the injury side was （82.5 ± 9.9）. Three of the fifty-two patients had four complications. Conclusion The application of CAPP was efficient and reliable, and provided excellent clinical and radiographic outcomes for the treatment of proximal humerus fractures by MIPO.