Anisotropic creep behavior of soft-hard interbedded rock masses based on 3D printing and digital imaging correlation technology

Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent properties of natural layered rock masses.In this paper,soft-hard interbedded rock masses with different dip angles were prepared based on 3D printing(3DP)sand core technology.Uniaxial compression creep tests were conducted to investigate its anisotropic creep behavior based on digital imaging correlation(DIC)technology.The results show that the anisotropic creep behavior of the 3DP soft-hard interbedded rock mass is mainly affected by the dip angles of the weak interlayer when the stress is at low levels.As the stress level increases,the effect of creep stress on its creep anisotropy increases significantly,and the dip angle is no longer the main factor.The minimum value of the long-term strength and creep failure strength always appears in the weak interlayer within 30°–60°,which explains why the failure of the layered rock mass is controlled by the weak interlayer and generally emerges at 45°.The tests results are verified by comparing with theoretical and other published studies.The feasibility of the 3DP soft-hard interbedded rock mass provides broad prospects and application values for 3DP technology in future experimental research.

Effect of TiO_(2)Addition on Properties of Al_(2)O_(3)Ceramics Prepared by Digital Light Printing(DL.P)

Ceramic slurry of 78 mass%solid loading was prepared using photosensitive acrylic resin and dispersant SP-710 as the liquid phase,Al_(2)O_(3) powder(d50=2.38μm)and TiO_(2) powder additive as the solid phase.Alumina ceramics were prepared by DLP,sintering for 4 h at 1450,1500,1550 or 1600℃,respectively.The effects of the TiO_(2) addition(0,1%,2%,3%and 5%,by mass)on the properties of the ceramics were studied.The results show that the addition of TiO_(2) can improve the sintering of Al_(2)O_(3) ceramics,significantly improve the densification,and reduce the sintering temperature.With the optimum TiO_(2) addition of 3%and the optimum sintering temperature of 1600℃,the obtained Al_(2)O_(3) ceramics have shrinkage of 15.7%,15.8%and 23.8%at the x axis,the y axis,and the z axis,respectively,the porosity of 2.4%,the bulk density of 3.74 g·cm-3 and the three-point bending strength of 251.1 MPa.Compared with the undoped alumina ceramics,the doped alumina ceramic has increased bulk density by 0.56 g·cm-3,decreased apparent porosity from 20.2%to 2.4%,and the three-point bending strength increases by 2.5 times.Therefore,the density and the strength of DLP prepared ceramics can be improved effectively by adding an appropriate amount of TiO_(2),and the performance of the DLP prepared ceramics is close to that of the pressed samples.Thus,it is hopeful to apply DLP in refractories field.

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.

Introduction of Digital Printing

Digital Printing is an academic journal of specializing in printing and packaging industries, found China Academy of Printing Technology. Digital Printing has been selected Core Journals of China for 2014 and 2017 edition. It mainly reports monograph of the related theory and technology, research paper of theory and application and scientific results in printing and packaging fields including basic research such as material science and engineering.

Introduction of Digital Printing

Digital Printing is an academic journal of specializing in printing and packaging industries, found China Academy of Printing Technology. Digital Printing has been selected Core Journals of China for 2014 and 2017 edition. It mainly reports monograph of the related theory and technology, research paper of theory and application and scientific results in printing and packaging fields including basic research such as material science and engineering.

Introduction of Digital Printing

Digital Printing is an academic journal of specializing in printing and packaging industries,found China Academy of Printing Technology.Digital Printing has been selected Core Journals of China for 2014 and 2017 edition.It mainly reports monograph of the related theory and technology,research paper of theory and application and scientific results in printing and packaging fields including basic research such as material science and engineering,electromechanical engineering and automation,computer science and technology,information engineering and technology,color science and technology,image communication engineering and technology,data science etc.and including other application research in the printing packing engineering such as digital media technology,printing technology,packaging technology,printing/packaging mechanical engineering,printing/packaging intelligent manufacturing,printing/packaging standards and standardization,printing packaging education and so on.It serves as a platform for promoting international and domestic academic exchanges in printing and packaging.

The First International Digital Printing and Image Technology Exhibition & The Sixth International Exhibition of Quick Printing Equipment & Technology

Time: Sept.4-6, 2008Venue: Shenzhen Convention & Exhibition CenterSponsor: Printing and Printing Equipment Industries Association of China (PEIAC)Organizers: The Exhibition Department of

Shanghai International Digital Printing Industry Fair presents interview with EFI Reggiani

The 9th Shanghai International Digital Printing Industry Fair(TPF2018)will be held from the 19th to the 21st of April,2018,in Shanghai New International Expo Centre.TPF 2018 is organized by UBM China and SUNEXPO.As one of the most influential digital textile printing

Preparation of PDOT:PSS Transparent Conductive Film Using Ink-Jet Printing

Flexible devices produced using organic materials have attracted the attention of many researchers. Important components of these flexible devices include transparent electrodes, which transmit visible light and possess conductivity. The present study improved the characteristics of a transparent conductive film that was made of poly(3, 4 ethylenedioxythiophene):poly(styrenesul-fonate) (PEDOT:PSS), an organic conductive material, and that had been prepared using ink-jet printing. To improve the resistance value and visible light transmittance of the film, the film substrate was first cleaned with ultraviolet/ozone treatment, and then the film was annealed after it was deposited on the substrate and dipped into a polar solvent. Consequently, the resistance value of the thin film decreased. However, the surface state of the film changed according to the treatment method and affected its visible light transmittance. Thus, the surface state of the film substrate, the annealing temperature after film deposition, and the dipping treatment with a polar solvent influenced the characteristics of a thin film.

Microfluidic bubble-generator enables digital light processing 3D printing of porous structures

Three-dimensional(3D)printing is an emerging technique that has shown promising success in engineering human tissues in recent years.Further development of vatphotopolymerization printing modalities has significantly enhanced the complexity level for 3D printing of various functional structures and components.Similarly,the development of microfluidic chip systems is an emerging research sector with promising medical applications.This work demonstrates the coupling of a digital light processing(DLP)printing procedure with a microfluidic chip system to produce size-tunable,3D-printable porosities with narrow pore size distributions within a gelatin methacryloyl(GelMA)hydrogel matrix.It is found that the generation of size-tunable gas bubbles trapped within an aqueous GelMA hydrogel-precursor can be controlled with high precision.Furthermore,the porosities are printed in two-dimensional(2D)as well as in 3D using the DLP printer.In addition,the cytocompatibility of the printed porous scaffolds is investigated using fibroblasts,where high cell viabilities as well as cell proliferation,spreading,and migration are confirmed.It is anticipated that the strategy is widely applicable in a range of application areas such as tissue engineering and regenerative medicine,among others.

Characteristics Improvement of PEDOT:PSS Transparent Conductive Film Prepared by Ink-Jet Printing

Recently, a high-performance and low-priced transparent conductive film has been expected to be developed because flexible devices produced using organic materials have been actively studied. An indium tin oxide (ITO) thin film, which has been generally used as a material for a transparent conductive film, has problems, such as fragility to bending stress and depletion of the resource. The present study used poly(3, 4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS), an organic electroconductive material, and examined the improvement in the resistance value and visible light transmittance of a transparent conductive film produced using the ink-jet method. In previous studies, we reported that, to improve the resistance value and visible light transmittance of a thin film, it was effective to clean the film substrate with ultraviolet/ozone (UV/O3) treatment, anneal the film after it was deposited on the substance, and dip the annealed film into a polar solvent. Focusing on the thin film processing between printing operations, the present study improved resistance value and visible light transmittance by examining both the application methods of a polar solvent and the annealing time between printing operations. As a result, the resistance value and visible light transmittance of a PEDOT:PSS thin film were 390.4 Ω and 86.6%, respectively. This film was obtained by applying a polar solvent and performing annealing for 30 min between printing operations. The printing was performed three times.

Application of nonlinear color matching model to four-color ink-jet printing

Through discussing the color matching technology and its application in printing industry the conventional approaches commonly used in color matching, and the difficulties in color matching, a nonlinear color matching model based on two step learning is established by finding a linear model by learning pure color data first and then a nonlinear modification model by learning mixed color data. Nonlinear multiple regression is used to fit the parameters of the modification model. Nonlinear modification function is discovered by BACON system by learning mixture data. Experiment results indicate that nonlinear color conversion by two step learning can further improve the accuracy when it is used for straightforward conversion from RGB to CMYK. An improved separation model based on GCR concept is proposed to solve the problem of gray balance and it can be used for three to four color conversion as well. The method proposed has better learning ability and faster printing speed than other historical approaches when it is applied to four color ink jet printing.

The Effect of Silica Particle Size on the Performance of Color Ink-jet Printing Paper

In this paper,the effects of four sorts of silica with the particle size range of 4～10μm on coated paper properties and printing performance were studied.The results showed that the smaller particle size silica can provide the coated paper with higher density and contrast, better definition and good printing performance.

Digital Manufacturing： What Are We Able to Print？

在合理锻练，在现在的纸， ICT (信息和通讯技术) 的发展和添加剂生产的早期的工艺的发展怎么有潜力改变我们的协会，被外推。在下列，它在物理物质上正在分析人的进化并且这怎么塑造了我们的社会。在 human-machine-environment 关系中标记一个先验的变化的历史上的主要里程碑或关键阶段被识别了并且因而导致了我们问我们自己：什么是，我们多远，并且什么下我们能够打印？在一次尝试到识别当前的现状，加亮那些添加剂技术能提供的可能性。

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.

3D-PRINTING在口腔修复领域应用的初步探讨

3D打印是当今数字化制造的产物,具有精准,方便,快速的特点。在发达国家,3D打印已应用于高精端领域,并取得了卓越的成效。而在我国,该技术的发展与应用尚处于初级阶段,3D打印技术由于其自身的独特优势,符合临床应用的要求,适合植入式医疗器械的制作,尤其是口腔修复学。本文对3D-PRINTING在口腔修复领域的应用作一简要综述。

Color control of the multi-color printing device

Conventional color-printing systems often use inks of three hues, such as CMY, CMYK and CMYKLcLm, but in order to obtain more realistic color reproductions, the ink set of more than three hues has been adopted by some color-printing systems. It is difficult, however, to model the composed color with the multiple inks when the number of the output ink hues exceeds three due to the none-unique mapping between the color spaces of the CIE Lab and the multi-color printing device. In this paper, we propose a fine color-printing method for multi-color printing device with the ink set of more than three hues. The proposed approach has good color expression ability and provides fine control of the printed color. By dividing the output color space into several subspaces, our method allows one-to-one mapping between the standard color space and the multi-color output color space. It has been proved effective when applied to the digital inkjet printer—Mutoh8000.

Teaching Reform of Building Construction Course under the Background of New Digital Technology

With the advent of the information age,all walks of life have paid more and more attention to the development and application of digital technology.At the same time,the construction industry,which is a traditionally important industry,is not an exception.A series of high-tech digital technologies have been widely used in architectural design and construction,such as BIM technology,3D printing technology,and VR technology.In view of the teaching link of architectural talent training,it is necessary to keep up with the development trend of the digital age,integrate these three kinds of technology into architectural teaching,and impart knowledge to students from planar 2D textbooks to 3D visual digital models,and further transform it from 3D digital to physical perceive or virtual simulation level,and reform teaching methods in all dimensions and in all dimensions to improve teaching effect.In this paper,the feasibility and necessity of integration of the above three architectural digital techniques into the teaching process of"building construction"from the aspects of teaching content,teaching method and teaching evaluation were discussed,and a new teaching model under the background of digital technology was proposed,which has certain teaching reference significance.

Effect of layer thickness on the flexural property and microstructure of 3D-printed rhomboid polymer-reinforced cemented tailing composites

For mines with poor ore bodies and surrounding rocks,the general mining method does not allow the ore to be extracted from underground safely and efficiently.For these mines,the downward layered filling mining technique is undoubtedly the most suitable mining method.The downward filling mining technique may eliminate the troubles relating to poor ore deposit conditions,such as production safety,ore loss rate,and depletion rate.However,in this technique,the safety of the artificial roof of the next stratum is of paramount importance.Cementitious tailings backfilling(CTB)that is not sufficiently cemented and causes collapses could threaten ore production.This paper explores a diamond-shaped composite structure to mimic the stability of a glued false roof in an actual infill mine based on the recently emerged three-dimensional(3D)printing technology.Experimental means such as three-point bending and digital image correlation(DIC)techniques were used to explore the flexural characteristics of 3D construction specimens and CTB combinations with different cement/tailings weight ratios at diverse layer heights.The results show that the 3D structure with a 14-mm ply height and CTB has strong flexural characteristics,with a maximum deflection value of 30.1 mm,while the 3D-printed rhomboid polymer(3D-PRP)structure with a 26-mm ply height is slightly worse in terms of flexural strength characteristics,but it has a higher maximum flexural strength of 2.83 MPa.A combination of 3D structure and CTB has more unique mechanical properties than CTB itself.This research work offers practical knowledge on the artificial roof performance of the downward layered filling mining technique and builds a scientific knowledge base regarding the successful application of CTB material in mines.

Development and prospects of digital orthopedics in Hubei province

Based on the development and application of new technology,as a new interdisciplinary subject,digital orthopedics becomes an important development direction of modern medicine in the past years.Using digital orthopedics technology,such as 3D digital printing technology,mixed reality technology,provides new impetus of orthopedic surgery and indicates its great potential of precision medicine and personalized therapy for orthopedic disorders.In 2017,Hubei Branch of China Digital Orthopaedic Society of SociétéInternationale de Chirurgie Orthopédique et de Traumatologie(SICOT)was founded.It is an important milestone and academic event for the development of digital orthopedics in Hubei.After that,Hubei's digital orthopedics professionals have made great progress in clinical,scientific research,conference and social activities.The development of 5G technologies in China will provide more opportunities and challenges for global digital orthopedics in the near future.