Search

The layout design of nuclear power reactor coolant system requires a large amount of knowledge that satisfies many disciplines, which will waste designers a lot of time retrieving relevant knowledge in the design process. In order to obtain the knowledge efficiently and accurately, a knowledge retrieval method based on hypernetwork and deep structured semantic model (DSSM) was proposed. The knowledge hypernetwork model consisted of a designer sub-network, a design task subnetwork, and a design knowledge resource sub-network. Nodes in each sub-network and between different sub-networks were connected through special edges, which represented correlation degree information. Then an improved DSSM model was used to evaluate relevance at the semantic level between user query information and knowledge elements in hypernetwork. Correlation scores will be obtained based on relevance at the semantic level, and knowledge elements with lower scores will be removed during the process. Finally, the Bayesian method was used to calculate the knowledge recommendation probability to obtain the most relevant knowledge retrieval results. The knowledge retrieval results were sorted from high to low according to the calculated probability. A case study conducted in this work showed that the proposed approach was effective in capturing relevance at the semantic level and supporting efficient and accurate knowledge retrieval services.

Nuclear power is an indispensable part of modern energy systems. To operate the nuclear power plants safely and reliably, it is crucial to greatly develop the predictive maintenance of nuclear infrastructure with the support of various smart sensors and big data analytics. To this end, this paper proposes a novel collaborative edge computing-enabled solution for predictive maintenance in nuclear power plants, from which a key problem of efficiently allocating some edge computing tasks is formulated. Specifically, considering huge amounts of industrial data are continuously generated during plant operations, we first present a three-layer predictive maintenance computing framework for nuclear power plants. Subsequently, to timely process these data in some distributed and heterogeneous industrial computing nodes, a complicated scheduling optimization model with some interdependent computational tasks is established. To lower the size of model, we also introduce some reduction strategies. Finally, an actual predictive maintenance scenario in nuclear power plant is chosen and some algorithms are taken for comparisons.

Wheat straw produced annually in the Shaanxi Guanzhong region is a potential biomass feedstock for the production of transportation fuels and specialized chemicals through combustion, pyrolysis, or gasification. In this work, the pyrolytic characteristics, evolved gas products, and kinetics of Guanzhong wheat straw and its components were first investigated with a thermogravimetry-Fourier infrared spectroscopy (TG-FTIR) system. A comparative kinetic study was conducted using different model-free methods of Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), Kissinger, and the Coats-Redfern methods. The main pyrolysis products identified by FTIR include H2O, CH4, CO2, and CO as well as aromatics, acids, ketones, and aldehydes. Kinetic results showed that the pyrolytic apparent activation energy of the straw is approximately 200 kJ/mol obtained via FWO and KAS methods at the conversion range of 0.4 to 0.75, which was 30 kJ/mol higher than the value 171.1 kJ/mol obtained by the Kissinger method. The apparent activation energy of cellulose in its main pyrolysis region is 135.5 kJ/mol and is about three times larger than that of hemicellulose (49.5 kJ/mol). The apparent activation energy of lignin at the temperature range of 45 to 116 °C was 34.5 kJ/mol, while that value at the temperature range of 120 to 252 °C was 6.64 kJ/mol.

Fault-tolerant control strategy plays a significant role in improving the reliability of three-level T-type inverter where fault diagnosis method is the key and a research hotspot. Load power factor variation and modulation index regulation have great effect on conventional load current based diagnosis methods. Therefore, this article proposes a novel voltage vector based method for single-switch open-circuit fault diagnosis in three-level T-type inverter. Average output voltage vector calculated by voltages between dc-link neutral-point and bridge output terminals is taken as the eigenvector in the procedure and failed switch can be located by three diagnosis variables including angle of eigenvector, normalized modulus of eigenvector, and neutral-point potential. These variables will be some certain values under circuit fault, which are defined as eigenvalues. The vector trajectory prediction technology is utilized for threshold setting, by which the diagnosis is suitable for different power factors and different modulation indices. The strategy of redundant vector replacement is applied to realize fault-tolerant operation and verifying the proposed scheme. Simulations and experiments are carried out to illustrate the superiorities of the proposal.

Although p21 activated kinase 5 (PAK5) is related to the progression of multiple cancers, its biological function in breast cancer remains unclear. Apoptosis-inducing factor (AIF) is a vital apoptosis factor in mitochondria, which can be released from mitochondria and enter the nucleus, causing caspase-independent apoptosis. In this study, we reveal that PAK5 inhibits apoptosis by preventing the nuclear translocation of AIF. PAK5 inhibits the release of AIF from mitochondria in breast cancer cells by decreasing the mitochondria membrane permeability and increasing the membrane potential. Furthermore, PAK5 phosphorylates AIF at Thr281 site to inhibit the formation of AIF/importin α3 complex, leading to decrease AIF nuclear translocation. Functionally, we demonstrate that PAK5-mediated AIF phosphorylation promotes the proliferation of breast cancer cells and accelerates the growth of breast cancer in vivo. Significantly, PAK5 and AIF expression in breast cancer are positively correlated with poor patient prognosis. PAK5 expression is negatively correlated with AIF nuclear translocation. These results suggest that PAK5-AIF signaling pathway may play an essential role in mammary tumorigenesis, providing a new therapeutic target for the treatment of breast cancer.

Water flooding technology is widely used to improve oil recovery efficiency in oilfields. The capillary barrier effect induced by the complex pore structures in the reservoir rocks is a crucial reason for the trapping of a great deal of residual oil in oil reservoirs after water flooding. However, the formation condition along with the effect on the recovery rate of the capillary barrier under different wettability conditions should be investigated further. To bridge the gap between the microscopic mechanism of the capillary barrier effect and the macroscopic mechanism of oil displacement efficiency, a simple conceptual capillary model is constructed to obtain the formation conditions of the capillary barrier using the analysis method, and its influence on macroscopic oil displacement efficiency in the porous media model with an opening angle of 45° is systematically investigated in this study using direct numerical simulations (DNS) coupled with the volume of fluid method. The results showed that the capillary barrier effect plays a significant role in the formation of the residual oil in the reservoir rock and the contact angle and the opening angle are the primary factors for the formation of the capillary barrier. The capillary force is the driving force when the oil–water interface advances in the throat channel under water-wet conditions, while the capillary force hinders the movement of oil–water movement when the liquid flows out of the throat channel and when θ + β > 90o. Furthermore, the highest oil displacement efficiency is achieved at the intermediate capillary number and in the case that the minimum conditions of occurrence of the capillary barrier phenomenon are satisfied. This is of great significance for controlling the optimized contact angle to further enhance the oil recovery rate of current oil reservoirs using waterflooding technology.

Assessment of the state of a pulse power supply requires effective and accurate methods to measure and reconstruct the tracking error. This paper proposes a tracking error measurement method for a digital pulse power supply. A de-noising algorithm based on Empirical Mode Decomposition (EMD) is used to analyse the energy of each Intrinsic Mode Function (IMF) component, identify the turning point of energy, and reconstruct the signal to obtain the accurate tracking error. The effectiveness of this EMD method is demonstrated by simulation and actual measurement. Simulation was used to compare the performance of time domain filtering, wavelet threshold de-noising, and the EMD de-noising algorithm. In practical use, the feedback of current on the prototype of the power supply is sampled and analysed as experimental data.

With the rapid expansion of Industrial Internet of Things, cloud computing and artificial intelligence, many intelligent information services have been developed in smart factories. One of the most important applications is helping factory managers predict the quality of assembled products. Traditional prediction methods of assembly quality mainly focus on building classification or regression models with high accuracy. However, less attention is paid to high-dimensional and imbalanced data, which is a special but common scenario at real-life assembly quality prediction. In this paper, we first use random forest to reduce dimension and analyze critical-to-quality characteristics. Then, a SMOTE-Adaboost method with jointly optimized hyperparameters is proposed for imbalanced data classification in assembly quality prediction. In addition, edge computing is introduced to improve the efficiency and flexibility of quality prediction. Finally, the practicality and effectiveness of the proposed method are verified by a case study of wheel bearing assembly line, and the experimental results show that the proposed method is superior to other classification methods in assembly quality prediction.

Rationale: P21-activated kinase 6 (PAK6) is a member of the class II PAKs family, which is a conserved family of serine/threonine kinases. Although the effects of PAK6 on many malignancies, especially in prostate cancer, have been studied for a long time, the role of PAK6 in mitochondria remains unknown. Methods: The expression of PAK6, SIRT4 and ANT2 in prostate cancer and adjacent non-tumor tissues was detected by immunohistochemistry. Immunofuorescence and immunoelectron microscopy were used to determine the subcellular localization of PAK6. Immunoprecipitation, immunofuorescence and ubiquitination assays were performed to determine how PAK6 regulates SIRT4, how SIRT4 regulates ANT2, and how PAK6 regulates ANT2. Flow cytometry detection and xenograft models were used to evaluate the impact of ANT2 mutant expression on the prostate cancer cell cycle and apoptosis regulation. Results: The present study revealed that the PAK6-SIRT4-ANT2 complex is involved in mitochondrial apoptosis in prostate cancer cells. It was found that PAK6 is mainly located in the mitochondrial inner membrane, in which PAK6 promotes SIRT4 ubiquitin-mediated proteolysis. Furthermore, SIRT4 deprives the ANT2 acetylation at K105 to promote its ubiquitination degradation. Hence, PAK6 adjusts the acetylation level of ANT2 through the PAK6-SIRT4-ANT2 pathway, in order to regulate the stability of ANT2. Meanwhile, PAK6 directly phosphorylates ANT2 atT107 to inhibit the apoptosis of prostate cancer cells. Therefore, the phosphorylation and deacetylation modifications of ANT2 are mutually regulated, leading to tumor growth in vivo. Consistently, these clinical prostate cancer tissue evaluations reveal that PAK6 is positively correlated with ANT2 expression, but negatively correlated with SIRT4. Conclusion: These present findings suggest the pivotal role of the PAK6-SIRT4-ANT2 complex in the apoptosis of prostate cancer. This complex could be a potential biomarker for the treatment and prognosis of prostate cancer.

Water flooding technology is an important measure to enhance oil recovery in oilfields. Understanding the pore-scale flow mechanism in the water flooding process is of great significance for the optimization of water flooding development schemes. Viscous action and capillarity are crucial factors in the determination of the oil recovery rate of water flooding. In this paper, a direct numerical simulation (DNS) method based on a Navier–Stokes equation and a volume of fluid (VOF) method is employed to investigate the dynamic behavior of the oil–water flow in the pore structure of a low-permeability sandstone reservoir in depth, and the influencing mechanism of viscous action and capillarity on the oil–water flow is explored. The results show that the inhomogeneity variation of viscous action resulted from the viscosity difference of oil and water, and the complex pore-scale oil–water two-phase flow dynamic behaviors exhibited by capillarity play a decisive role in determining the spatial sweep region and the final oil recovery rate. The larger the viscosity ratio is, the stronger the dynamic inhomogeneity will be as the displacement process proceeds, and the greater the difference in distribution of the volumetric flow rate in different channels, which will lead to the formation of a growing viscous fingering phenomenon, thus lowering the oil recovery rate. Under the same viscosity ratio, the absolute viscosity of the oil and water will also have an essential impact on the oil recovery rate by adjusting the relative importance between viscous action and capillarity. Capillarity is the direct cause of the rapid change of the flow velocity, the flow path diversion, and the formation of residual oil in the pore space. Furthermore, influenced by the wettability of the channel and the pore structure’s characteristics, the pore-scale behaviors of capillary force—including the capillary barrier induced by the abrupt change of pore channel positions, the inhibiting effect of capillary imbibition on the flow of parallel channels, and the blockage effect induced by the newly formed oil–water interface—play a vital role in determining the pore-scale oil–water flow dynamics, and influence the final oil recovery rate of the water flooding.

With the increasing population density and relatively limited space and resources, cities are becoming more intelligent to provide adequate provision of services for the inhabitants. The utilization of the Internet-of-Things and Edge-of-Things technologies presents a significant foundation for the development of smart cities where intelligent transportation system is one of the most important applications. Due to the obvious advantages of reducing energy consumption and carbon emissions, electric vehicles are playing an increasingly important role in the intelligent transportation system. However, there is no shared framework for the interaction between electric vehicles and intelligent transportation system in smart cities. To handle this issue, this work proposes a practical framework to collect trajectory data of electric vehicles via edge devices and use a novel modified dynamic time warping method to analyze drivers’ preference. The analysis based on real data shows that a certain percentage of electric vehicle drivers have driving preference. That is, they tend to go through specific routes or locations during commuting. Furthermore, a few simulation experiments are conducted to compare the system performance between the time-of-use and load-of-use pricing strategies of the charging stations. The results demonstrate that the load-of-use pricing strategy can effectively divert the traffic flow and balance the load differences between different charging stations.

Recently, the permanent magnet linear synchronous motor (PMLSM) servo control technology has become a research hotspot. However, the control performance under the traditional PID control is not ideal, which usually has the problems of slow response speed, large overshoot and poor anti-interference performance. In addition, adding nonlinear links with certain characteristics purposefully can greatly improve the performance of the system and achieve the expected effect that the traditional linear controllers cannot achieve. Based on this, this paper introduces the nonlinear PID control strategy into the field of servo control, and proposes a nonlinear control strategy of the three-loop of the servo system to improve the above problems. Firstly, the proposed structure is explained and the rule of nonlinear parameters selection is discussed. Secondly, the conditions for the structural stability of the proposed nonlinear control strategy are analyzed. Finally, experiments on the servo system platform are carried out and the results verify the fast dynamic response, precise positioning and good anti-disturbance performance.

Active power filter (APF) has become an effective approach to suppress harmonic and compensating the reactive power of a power grid. In this paper, the topological structure of the single-phase APF is T-type three-level which can suppress harmonic. For the traditional dual-loop PI control of APF, the voltage loop has poor disturbance rejection performance and long response time under nonlinear load and load mutation. To eliminate the impact on the reduction of power quality of the power grid, this paper uses a PI control of the current loop and a linear active disturbance rejection control (LADRC) of voltage loop. The first-order LADRC controller, which uses a linear extended state observer (ESO) and a linear state error feedback (SEF), does not depend on an explicit mathematical model of the controlled object. In this paper, a 2kVA experimental prototype with a processor of TMS320F28335 is designed to testify the performance and effectiveness of the presented method. The results of simulation and experiments show that the LADRC has better disturbance rejection performance and faster dynamic response than PI control under nonlinear load and load mutation.

P21-activated kinase 5 (PAK5) plays an important role in tumors. However, the functional role of PAK5 in mammary tumorigenesis in vivo remains unclear. Here, we show that PAK5 deficiency represses MMTV-PyVT-driven breast tumorigenesis. DEAD-box RNA helicase 5 (DDX5) is a substrate of PAK5, which is phosphorylated on threonine 69. PAK5-mediated DDX5 phosphorylation promotes breast cancer cell proliferation and metastasis. The increased expression levels of PAK5 and phospho-DDX5 threonine 69 are associated with metastasis and poor clinical outcomes of patients. PAK5 facilitates the phosphorylation-dependent sumoylation of DDX5 to stabilize DDX5. Both the phosphorylation and sumoylation of DDX5 enhance the formation of a DDX5/Drosha/DGCR8 complex, thus promoting microRNA-10b processing. Finally, we verify decreased expression of DDX5 phosphorylation and sumoylation and mature miR-10b in PAK5

Background Ten years after the introduction of the Chinese Ministry of Health (MoH) version of Surgical Safety Checklist (SSC) we wished to assess the ongoing influence of the World Health Organisation (WHO) SSC by observing all three checklist components during elective surgical procedures in China, as well as survey operating room staff and surgeons more widely about the WHO SSC. Methods A questionnaire was designed to gain authentic views on the WHO SSC. We also conducted a prospective cross-sectional study at five level 3 hospitals. Local data collectors were trained to document specific item performance. Adverse events which delayed the operation were recorded as well as the individuals leading or participating in the three SSC components. Results A total of 846 operating room staff and surgeons from 138 hospitals representing every mainland province responded to the survey. There was widespread acceptance of the checklist and its value in improving patient safety. 860 operations were observed for SSC compliance. Overall compliance was 79.8%. Compliance in surgeon-dependent items of the ‘time-out’ component reduced when it was nurse-led (p Conclusion The WHO SSC remains a powerful tool for surgical patient safety in China. Cultural changes in nursing assertiveness and surgeon-led teamwork and checklist ownership are the key elements for improving compliance. Standardised audits are required to monitor and ensure checklist compliance.

Objective To investigate the safety and efficacy of piezosurgery in anterior cervical discectomy and fusion (ACDF) for treating patients with cervical spondylotic myelopathy (CSM) coincident retrovertebral body osteophytes adjacent to the endplate or a free nucleus pulposus migrated to the vertebral body, posteriorly; known as complex cervical spondylotic myelopathy (cCSM) here.Methods Forty-seven patients with cCSM underwent ACDF surgery from 2014 to 2017. Among these patients, 26 underwent ACDF using piezosurgery (group A) and 21 underwent ACDF by traditional tools such as air drill, bone curet and gun-shaped bone forceps (group B). Average operative duration, intraoperative blood loss, surgical complications, preoperative and postoperative Japanese Orthopaedic Association (JOA) scores and improvement rate were measured.Results Average operative duration and intraoperative blood loss were significantly lower in the piezosurgery group than those in the traditional group (P < 0.01). The incidences of surgical complications were 3.8% and 23.8% in the piezosurgery and traditional groups (P < 0.05), respectively. Whereas JOA scores and improvement rate were insignificantly different at each data collection period (P > 0.05); preoperative, postoperative 3 days and postoperative 1 year follow-up were included.Conclusion For treating cCSM, both the piezosurgery and traditional tools led to significant neurological improvement. However, the piezosurgery was superior to the traditional tools in terms of operative duration, blood loss, and complication rate. Hence, the piezosurgery was a safe and effective adjunct for ACDF treating cCSM.

With the development of communication and control technology, intelligent transportation systems (ITS) have received increasing attention from both industry and academia. However, plenty of studies providing different formulations for ITS depend on Master Control Center and require a high level of hardware configuration. The systematized technologies for distributed architectures are still not explored in detail. In this paper, we proposed a novel distributed cyber–physical system for connected and automated vehicles, and related methodologies are illustrated. Every vehicle in this system is modeled as a double-integrator and supposed to travel along a desired trajectory for maintaining a rigid formation geometry. The desired trajectory is generated by reference leading vehicles using information from multiple sources, while ordinary following vehicles use velocity and position information from their nearest neighbors and sensor information from on-board sensors to correct their own performance. Information graphs are used to illustrate the interaction topology between connected and automated vehicles. Edge computing technology is used to analyze and process information, such that the risk of privacy leaks can be greatly reduced. The performance scaling laws for the network with a one-dimensional information graph are generalized to networks with D -dimensional information graphs, and the results of the experiments show that the performance of the connected and automated vehicles matches very well with analytic predictions. Some design guidelines and open questions are provided for the future study.

Synthetic aperture radar (SAR) monopulse angle measurement is an adequate method of target angle measurement in low signal-to-clutter and noise ratio. However, there is a contradiction between the instantaneous angle measurement and the SAR coherent accumulation. In this study, the authors use the total variation method to solve the above problem, and propose the monotone iterative method to enhance the efficiency of the total variation method, which is verified in the simulation.

Rationale: P21-activated kinase 6 (PAK6) is a member of the class II PAKs family, which is a conserved family of serine/threonine kinases. Although the effects of PAK6 on many malignancies, especially in prostate cancer, have been studied for a long time, the role of PAK6 in mitochondria remains unknown. Methods: The expression of PAK6, SIRT4 and ANT2 in prostate cancer and adjacent non-tumor tissues was detected by immunohistochemistry. Immunofuorescence and immunoelectron microscopy were used to determine the subcellular localization of PAK6. Immunoprecipitation, immunofuorescence and ubiquitination assays were performed to determine how PAK6 regulates SIRT4, how SIRT4 regulates ANT2, and how PAK6 regulates ANT2. Flow cytometry detection and xenograft models were used to evaluate the impact of ANT2 mutant expression on the prostate cancer cell cycle and apoptosis regulation. Results: The present study revealed that the PAK6-SIRT4-ANT2 complex is involved in mitochondrial apoptosis in prostate cancer cells. It was found that PAK6 is mainly located in the mitochondrial inner membrane, in which PAK6 promotes SIRT4 ubiquitin-mediated proteolysis. Furthermore, SIRT4 deprives the ANT2 acetylation at K105 to promote its ubiquitination degradation. Hence, PAK6 adjusts the acetylation level of ANT2 through the PAK6-SIRT4-ANT2 pathway, in order to regulate the stability of ANT2. Meanwhile, PAK6 directly phosphorylates ANT2 atT107 to inhibit the apoptosis of prostate cancer cells. Therefore, the phosphorylation and deacetylation modifications of ANT2 are mutually regulated, leading to tumor growth in vivo. Consistently, these clinical prostate cancer tissue evaluations reveal that PAK6 is positively correlated with ANT2 expression, but negatively correlated with SIRT4. Conclusion: These present findings suggest the pivotal role of the PAK6-SIRT4-ANT2 complex in the apoptosis of prostate cancer. This complex could be a potential biomarker for the treatment and prognosis of prostate cancer.

Brazing materials can be made into different shapes to meet the requirements of different scenarios and the welding rod is a very common form. The rough-processed welding rods must be properly finished by the drawing bench to remove the oxide film on the surface and made into a uniform diameter. However, the continuous welding rod often breaks resulting low production efficiency. To reduce the frequency of workers’ reconnection operation of broken welding rods, we proposed a digital twin-based approach to improve the design of the structure of the drawing bench. First, we established a full life cycle digital twin model for the welding rod from the formulation stage to the finishing stage. The product ontology of the welding rod was built and the key process parameters were collected. Second, based on the product ontology, the key structural parameter of the drawing bench that affects the internal stress of the welding rod was determined by means of analytic hierarchy process. Third, we modified the key structural parameter in the digital twin model and simulated the finishing process. A near-optimal parameter was found. Last, we improved the structure of the actual drawing bench accordingly and carried out some experiments. The results matched well with the simulation prediction and the frequency of welding rod breaking is significantly reduced, which proved the effectiveness of our proposed improved design approach.

To investigate the feasibility and effectiveness of modified replanting posterior ligament complex (PLC) applying piezoelectric osteotomy in the treatment of primary benign tumors in thoracic spinal canal.The clinical data of 38 patients with primary benign tumors in thoracic spinal canal between March 2014 and March 2016 were retrospectively analyzed. There were 16 males and 22 females, aged from 21 to 72 years (mean, 47.1 years). The disease duration ranged from 6 to 57 months (mean, 32.6 months). Pathological examination showed 24 cases of schwannoma, 6 cases of meningioma, 4 cases of ependymoma, 2 cases of lipoma, and 2 cases of dermoid cyst. The lesions located in 18 cases of single segment, 15 cases of double segments, and 5 cases of three segments. The length of the tumors ranged from 0.7 to 6.5 cm. There were boundaries between the tumors and the spinal cord, cauda equina, and nerve roots. The preoperative Japanese Orthopaedic Association (JOA) score was 12.2±2.3 and the thoracic Cobb angle was (11.7±2.7)°. Modified PLC replantation and microsurgical resection were performed with piezoelectric osteotomy. Continuity of uniside supraspinal and interspinous ligaments were preserved during the operation. The PLC was exposed laterally. After removing the tumors under the microscope, the pedicled PLC was replantedThe operation time was 56-142 minutes (mean, 77.1 minutes). The intraoperative blood loss was 110-370 mL (mean, 217.2 mL). The tumors were removed completely and the incisions healed well. Three cases complicated with cerebrospinal fluid leakage, and there was no complications such as spinal cord injury and infection. All the 38 patients were followed up 24-28 months (mean, 27.2 months). There was no internal fixation loosening, malposition, or other related complications. At last follow-up, X-ray films showed no sign of kyphosis and instability. CT showed no displacement of vertebral lamina and reduction of secondary spinal canal volume, and vertebral lamina healed well. MRI showed no recurrence of tumors. At last follow-up, the thoracic Cobb angle was (12.3±4.1)°, showing no significant difference when compared with preoperative value (Modified replanting PLC applying piezoelectric osteotomy and micro-reconstruction with titanium plate for the primary benign tumors in thoracic spinal canal can reconstruct the anatomy of the spinal canal, enable patients to recover daily activities quickly. It is an effective and safe treatment.探讨应用超声骨刀行改良棘突椎板韧带复合体（posterior ligament complex，PLC）回植术治疗原发性胸椎管内良性肿瘤的可行性及疗效。.回顾分析 2014 年 3 月—2016 年 3 月收治并获完整随访的 38 例原发性胸椎管内良性肿瘤患者临床资料。其中男 16 例，女 22 例；年龄 21～72 岁，平均 47.1 岁。病程 6～57 个月，平均 32.6 个月。病理检查示神经鞘瘤 24 例、脊膜瘤 6 例、室管膜瘤 4 例、脂肪瘤 2 例、皮样囊肿 2 例。病变位于单节段 18 例，双节段 15 例，3 节段 5 例；肿物长度 0.7～6.5 cm，肿瘤与脊髓、马尾及神经根存在界限。术前日本骨科协会（JOA）评分为（12.2±2.3）分，胸椎 Cobb 角为（11.7±2.7）°。采用超声骨刀行改良 PLC 回植、显微镜下肿瘤切除术。术中保留一侧棘上、棘间韧带连续性，将 PLC 向侧方掀起显露，显微镜下摘除肿瘤后将带蒂 PLC 原位回植，双侧微型重建钛板固定。术后行 X 线片、CT 及 MRI 检查，观察脊柱稳定性、椎管成形及肿瘤切除情况，采用 JOA 评分进行临床效果评定。.手术时间为 56～142 min，平均 77.1 min；术中出血量为 110～370 mL，平均 217.2 mL。所有患者肿瘤完整切除，切口愈合良好。3 例出现脑脊液漏，无脊髓损伤、感染等相关并发症发生。38 例患者均获随访，随访时间 24～28 个月，平均 27.2 个月。随访期间无内固定物松动移位及其他相关并发症发生。末次随访时 X 线片复查未见脊柱侧后凸畸形及失稳征象；CT 复查椎板无移位及继发椎管容积减小，椎板均骨性愈合；MRI 示肿瘤无复发。末次随访时，胸椎 Cobb 角为（12.3±4.1）°，与术前比较差异无统计学意义（应用超声骨刀行改良 PLC 回植、微型重建钛板内固定术治疗原发性胸椎管内良性肿瘤，可恢复椎管正常解剖，操作安全，患者可早期活动，疗效较好。.

In order to reduce the position overshoot of the permanent magnet synchronous linear motor (PMSLM) vector control system and improve the system response, on the basis of given mathematical model and mechanical motion equations of PMSLM in the d-q rotating coordinate system, controlled auto regressive integrated moving average (CARIMA) model have been introduced. A new generalized predictive controller of PMSLM system have been designed based on this model and Sun Jun’s proposed generalized predictive control algorithm that takes full advantage of predictive information. Simulation results show that this controller has the advantages of small overshoot and excellent tracking performance.

Permanent magnet synchronous linear motor (PMLSM) has excellent performance and wide application, but its special structure makes it sensitive to external disturbance. This paper aims at the disturbance problem of X-Y motion platform driven by PMLSM under actual operating conditions. In the cross-coupling control strategy, the input command is compensated by the coupling control quantity between axes, and the linear active disturbance rejection controller (LADRC) is applied to the position loop in the three-loop control strategy to suppress the external disturbance and reduce the influences caused when the coupling control quantity is compensated to the uniaxial servo system. Finally, it is verified by Simulink. The simulation results show that the LADRC-based disturbance compensation method has better dynamic performance than the traditional cross-coupling control, and the contour control accuracy is higher.

There are some problems accompanied by detecting rotor parameters of the traditional method on the permanent magnet linear synchronous motor (PMLSM), such as inaccurate detection and poor anti-interference ability. Based on this, this paper proposes a speed closed-loop control strategy based on PID neural network (PIDNN) without speed sensor. The algorithm obtains the error between real current and the given current of the q-axis by calculating the observation angle and the actual angle. The algorithm obtains the error between the given current and the feedback value of the q-axis, and uses the gradient descent algorithm to update the parameters and to obtain the fitted electrical angle. When the current error converges to zero, the output is the velocity of the mover. The simulation and experimental results show that the algorithm can track the speed very well, which reduces the cost and improves the reliability of the system.

OBJECTIVE: To compare the long-term effectiveness of wheather posterior ligamentous complex (PLC) preserved between posterior fenestration decompression interbody fusion and posterior total laminectomy interbody fusion. METHODS: The clinical data of 89 patients who suffered from single segmental degenerative diseases of lower lumbar spine and followed up more than 10 years after receiving lumbar spinal fusion between January 2000 and January 2005 were retrospectively analysed. The patients were divided into two groups according to the different surgical methods, the 33 patients in group A were treated with posterior lumbar fenestration decompression, interbody fusion, and internal fixation, while 56 patients in group B were treated with posterior total laminectomy resection decompression, interbody fusion, and internal fixation. There was no significant difference in gender, age, body mass index, type of lesion, disease duration, lesion segment, and preoperative Japanese Orthopedic Association (JOA) score, visual analogue scale (VAS) score, and Cobb angle of lumbar lordosis between the two groups (P>0.05). The effectiveness was evaluated by JOA score, and the improvement of pain was evaluated by VAS score. The incidence of adjacent segment degeneration (ASD) at last follow-up was recorded. RESULTS: Both groups were followed up 10-17 years (mean, 12.6 years). There were 3 cases (9.1%) in group A and 5 cases (8.9%) in group B complicated with cerebrospinal fluid leakage, showing no significant difference (χ(2)=0.001, P=0.979). There was no complication such as infection, nerve root injury, internal plant loosening or transposition in both groups. Intervertebral fusion was satisfactory in both groups. The fusion time in groups A and B was (3.4±1.2) months and (3.7±1.6) months respectively, and there was no significant difference between the two groups (t=0.420, P=0.676). At last follow-up, the JOA score and VAS score of the two groups were significantly improved when compared with preoperative ones (P

With environmental pollution and the shortage of resources becoming increasingly serious, the disassembly of certain component in mechanical products for reuse and recycling has received more attention. However, how to model a complex mechanical product accurately and simply, and minimize the number of components involved in the disassembly process remain unsolved problems. The identification of subassembly can reduce energy consumption, but the process is recursive and may change the number of components to be disassembled. In this paper, a method aiming at reducing the energy consumption based on the constraints relation graph (CRG) and the improved ant colony optimization algorithm (IACO) is proposed to find the optimal disassembly sequence. Using the CRG, the subassembly is identified and the number of components that need to be disassembled is minimized. Subsequently, the optimal disassembly sequence can be planned using IACO where a new pheromone factor is proposed to improve the convergence performance of the ant colony algorithm. Furthermore, a case study is presented to illustrate the effectiveness of the proposed method.