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Chen D.,China Academy of Machinery Science and Technology | Chu Z.,China Academy of Machinery Science and Technology | Zheng H.,China Academy of Machinery Science and Technology | Zheng H.,Machinery Technology Development Co. | Wang X.,China Academy of Machinery Science and Technology
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys | Year: 2012

Basing on die casting mold optimal selection, structure design and die offer of the authority knowledge and expert experience, we estabished die-casting die material knowledge base, design knowledge base and offer knowledge base. Human-machine interface was designed which mainly included material selection module, design module, offer module and knowledge module. Casting die material selection and auxiliary design expert system was eventually developed through the man-machine interface and knowledge base connection.

Liao Z.,Tsinghua University | Fogel G.R.,Spine Pain Begone | Pu T.,Machinery Technology Development Co. | Gu H.,Shenzhen Second Hospital | Liu W.,Tsinghua University
Medical Science Monitor | Year: 2015

Background: The ideal surgical approach for cervical disk disease remains controversial, especially for multilevel cervical disease. The purpose of this study was to investigate the biomechanics of the cervical spine after 3-level hybrid surgery compared with 3-level anterior cervical discectomy and fusion (ACDF). Material/Methods: Eighteen human cadaveric spines (C2-T1) were evaluated under displacement-input protocol. After intact testing, a simulated hybrid construct or fusion construct was created between C3 to C6 and tested in the following 3 conditions: 3-level disc plate disc (3DPD), 3-level plate disc plate (3PDP), and 3-level plate (3P). Results: Compared to intact, almost 65~80% of motion was successfully restricted at C3-C6 fusion levels (p<0.05). 3DPD construct resulted in slight increase at the 3 instrumented levels (p>0.05). 3PDP construct resulted in significant decrease of ROM at C3-C6 levels less than 3P (p<0.05). Both 3DPD and 3PDP caused significant reduction of ROM at the arthrodesis level and produced motion increase at the arthroplasty level. For adjacent levels, 3P resulted in markedly increased contribution of both upper and lower adjacent levels (p<0.05). Significant motion increases lower than 3P were only noted at partly adjacent levels in some conditions for 3DPD and 3PDP (p<0.05). Conclusions: ACDF eliminated motion within the construct and greatly increased adjacent motion. Artificial cervical disc replacement normalized motion of its segment and adjacent segments. While hybrid conditions failed to restore normal motion within the construct, they significantly normalized motion in adjacent segments compared with the 3-level ACDF condition. The artificial disc in 3-level constructs has biomechanical advantages compared to fusion in normalizing motion. © Med Sci Monit, 2015.

Liao Z.,Tsinghua University | Pu T.,Machinery Technology Development Co. | Wei N.,Tsinghua University | Yan B.,Shenzhen Second Peoples Hospital | Liu W.,Tsinghua University
Qinghua Daxue Xuebao/Journal of Tsinghua University | Year: 2015

This study analyzed the cervical spine kinematics after 4-level hybrid constructs compared the results with the kinematics after 4-level anterior cervical discectomy and fusion. Twelve human cadaveric spines were evaluated using three-dimensional optoelectronics measurements for an intact spine, a 4-level hybrid construct (C3-C4 disc replacement, C4-C6 plate, C6-C7 disc replacement) and a 4-level fusion (C3-C7 plate). The motion characteristics of the normal cervical spine and the coupled motion are also discussed. Although the 4-level hybrid construct restored only part of the native kinematics of the cervical spine, this construct generated better biomechanical conditions than the 4-level fusion at adjacent levels by limiting contributions of these segments to the global range of motion. ©, 2015, Press of Tsinghua University. All right reserved.

Liao Z.,Tsinghua University | Pu T.,Machinery Technology Development Co. | Gu H.,Shenzhen Second Hospital | Liu W.,Tsinghua University
Bio-medical materials and engineering | Year: 2015

To compare the biomechanical characters of three-level anterior cervical fusion and hybrid constructs by measuring coupled motion changes of the cervical spine, Eighteen adult human cadaveric cervical spines were biomechanically investigated under eccentric displacement control in lateral bending and axial rotation by measuring vertebral motion (X, Y, Z -axis).The 3DPD condition displayed similar coupled motion compared to the intact condition both in lateral bending and in axial rotation, while the 3PDP condition was similar only in lateral bending. However, the coupled motion of the cervical spine under 3P conditions markedly changed in both lateral bending and axial rotation. Considering the coupled motion characteristics, the 3DPD hybrid construct is biomechanically advantageous in three types of reconstructions (3DPD, 3PDP, 3P).

Peng Y.,Beijing University of Technology | Peng Y.,Harbin Institute of Technology | Yang A.,Beijing University of Technology | Li L.,Machinery Technology Development Co. | Wu L.,Beijing University of Technology
Harbin Gongye Daxue Xuebao/Journal of Harbin Institute of Technology | Year: 2013

Domestic wastewater was treated by using three parallel sequencing batch reactors (SBR) at the pH of 7.9-8.0 to optimize aeration duration of partial nitrification. The partial nitrification was achieved and maintained by controlling the aeration time of t/2, t/4, t/8 respectively (t was aeration time) before appearance of "ammonia valley". Nitrite accumulation ratios were improved by 50%, 65%, 90% respectively in the three reactors which were operated in 145 days. FISH quantitative analysis showed that the percentage of ammonia oxidizing bacteria (AOB) in the reactors increased differently. AOB and nitrite oxidizing bacteria (NOB) was 3.89% and 0.27% of the total bacteria respectively in No.3 reactor, which showed that AOB is the dominant bacteria in nitrifying bacteria. It is concluded that synergistic effect between the optimal control of aeration duration and the inhibition of FA would be the key factors to rapid start-up and maintain the stable nitrification.

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