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In order to efficiently solve the problem of optimization of the micro-channel heat sink, an optimization strategy combining intelligent algorithms and CFD was proposed. The micro-channel heat sink with the trapezoidal cavity and solid/slotted oval pins was proposed to enhance heat transfer. The aspect ratio, distance from the center of the oval pin to the center of the cavity, and slot thickness were design variables. The thermal resistance and pumping power of the micro-channel heat sink were objective functions. Within the selected range of design variables, thirty groups of uniformly sampled sample points were obtained by the Latin hypercube experiment. The 3-D model was established by SOLIDWORKS software, and the numerical simulation was carried out by using FLUENT soft-ware. The genetic algorithm optimized back propagation neural network to construct the prediction model, and the simulated data of Latin hypercube sampling were trained to obtain the non-linear mapping relationship between design variables and objective functions. The optimal combination of structural parameters of the micro-channel heat sink was obtained by optimization of the genetic algorithm, which was verified by numerical simulation. The results show that the optimization scheme was suitable for getting the optimal value of the structural parameters of the micro-channel heat sink, which provided a reference for the optimal design of the micro-channel heat sink.

Photocatalytic technology can solve various environmental pollution problems, especially antibiotic pollution. A novel La-doped MIL-53(Al)/ZnO composite material was successfully synthesized by a combination of hydrothermal method and calcination, showing high photocatalytic degradation percent of sulfamethazine (SMT). The 2 mol% La MIL-53(Al)/ZnO photocatalyst shows the highest degradation efficiency toward SMT (92%) within 120 min, which is 4.1 times higher than pure ZnO (increased from 18% to 92%). In addition, the degradation analysis of SMT by high performance liquid chromatography proves that the products are CO2 and H2O. The improved photocatalytic activity is mostly caused by the following factors. (1) Doping La ions can decrease the band gap of ZnO, enhance light response, and effectively enhance the separation rate of photo-generated holes and electrons. (2) MIL-53(Al) can adsorb SMT and promote the separation of electron. This work shows that the synthesized La-doped MIL-53(Al)/ZnO photocatalyst is expected to be used as a green and effective method for treatment of environment water pollution.

Micro-channel heat sink is an effective way to solve the heat dissipation problem of electronic devices because of its compact structure and outstanding heat dissipation ability. In order to obtain the high efficiency and low resistance micro-channel heat sink, a new structure of open rectangular micro-channel heat sink with pin fins was proposed to enhance heat transfer. The orthogonal test method was used to design the experiment, and the 3-D software SOLIDWORKS was used to establish 25 groups of open rectangular micro-channel heat sink with pin fins structure model which has different structural parameters. The numerical calculation was carried out with ANSYS FLUENT simulation software and the experimental values with the structural parameters of the micro-channel heat sink as variables were obtained. According to the simulated experimental values, the objective functions of thermal resistance and pumping power were constructed, and the agent model between objective functions and the optimization variables were established. The Pareto optimal solutions of objective functions were calculated by non-dominated sorting genetic algorithm, which was analyzed by k-means clustering analysis and five clustering points were obtained, and five clusters points were compared and verified by simulation. it was found that there was effective tradeoff points between the highest and lowest points of the five clustering which can make both the pumping power and thermal resistance within the optimal range, so as to obtain the optimal micro-channel heat sink.

Zhonglin Wang,1 Jian Yu,2 Shangrui Rao,2 Zhe Lin,2 Zhongliang Pan,2 Xian Shen1 1Department of General Surgery, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, People’s Republic of China; 2Department of General Surgery, Wenzhou Central Hospital, Wenzhou, 325000, Zhejiang, People’s Republic of ChinaCorrespondence: Xian ShenDepartment of General Surgery, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, People’s Republic of ChinaTel/Fax +86-577-88002609Email 13968888872@163.comBackground: Increased surgical technology has led broad acceptance endoscopic thyroidectomy and its application in the treatment of thyroid diseases, including thyroid carcinoma. Although the incidence of complications and mortality of thyroid surgery has been significantly reduced, serious complications still occur from time to time. The purpose of this retrospective study is to identify the factors that influence the complications of endoscopic thyroidectomy.Methods: This study was carried out between January 2012 and December 2019, where a total of 630 patients undergoing endoscopic thyroidectomy via the total areola approach were retrospectively evaluated to identify the key influencing factors of complications.Results: The study established that the common complications included recurrent laryngeal nerve injury (3.33%), superior laryngeal nerve injury (2.54%), hypocalcemia (8.57%), and the incidence of complications was acceptable. Both univariate and multivariate analysis showed that thyroid carcinoma (P = 0.041), operation time lasting more than 150 minutes (P = 0.034) and operation before 2017 (P = 0.001) were risk factors of recurrent laryngeal nerve injury. We established that operation after 2017 (P < 0.005) was the only protective factor of superior laryngeal nerve injury. Thyroid carcinoma (P=0.04), operation mode (P=0.001), and surgery before 2017 (P< 0.001) are risk factors for parathyroid injury. Among the clinical groups, operation before 2017 was an independent risk factor for all complications.Conclusion: For thyroid specialists, after the early learning curve, with the continuous improvement of endoscopic operation technology, high-definition equipment and more sophisticated operation equipment can be used in clinical practice, which can prevent and reduce the occurrence of complications.Keywords: thyroidectomy, endoscopy, surgical complications, influencing factors

Flat heat pipe has many excellent characteristics such as high thermal conductivity, reversibility of heat flow direction and so on. In this paper, a flat heat pipe model with multiple microchannels is established, and the effects of different microchannel shapes and different materials on the heat transfer efficiency of flat heat pipe are studied. Then, based on the general rectangular and inverted trapezoidal microchannel shape, the enhancement is carried out. That is to fill a number of materials in the bottom of the microchannel to change the bottom shape of the microchannel. In the steady-state thermal simulation of flat heat pipe, the axial temperature of the flat heat pipe with enhanced microchannel shape is lower than that of the flat heat pipe with general microchannel, which shows that the enhanced microchannel shape is helpful to the heat dissipation of flat heat pipe. The fluid simulation results show that the enhanced rectangular microchannel shape can accelerate the flow velocity of working fluid. Therefore, the flat heat pipe with enhanced microchannel shape has better heat transfer performance. In order to obtain the local temperature of flat heat pipe quickly, the transient analytical solution is provided. In this paper, the temperature field calculated by using transient analytical solution is compared with that simulated by COMSOL. The results show that the maximum error between the results of discrete heat source model and continuous heat source model calculated by transient solution and COMSOL simulation results is less than 2%.

Based on transmission line modeling, a new technology of collaborative applying the ultralow-k dielectric and the high-k dielectric materials in coupled multilayer graphene nanoribbon (MLGNR) interconnects (i.e., case 4) to reduce propagation delay and to expand 3-dB bandwidth of the conventional pristine (undoped) MLGNR interconnects is proposed in this paper. By using the decoupling technique and ABCD parameter matrix approach, the transfer function of the equivalent circuit model for coupled MLGNR interconnects is derived to obtain step response, propagation delay, transfer gain and 3-dB bandwidth under in-phase and out-of-phase crosstalk modes at global level of 7.5 nm technology node, which is based on the defined four cases. The results show that the maximum reduction of propagation delay between the proposed new technology (case 4) and the conventional MLGNR interconnects (case 1) can reach 15.911 ns at out-of-phase crosstalk mode for an interconnect length of 4000 μm. The corresponding 3-dB bandwidth for them can be expanded over 2.978 times in the same length as the former. It is demonstrated that the proposed case 4 can obviously reduce the propagation delay and enhance the transfer gain and 3-dB bandwidth compared with the conventional case 1. Moreover, it is found that the coupled MLGNR interconnect under in-phase mode outperform that under out-of-phase mode in terms of propagation delay, transfer gain and 3-dB bandwidth at the same condition. In addition, it is manifested that the victim line of two-line coupled MLGNR interconnects have lesser propagation delay, higher transfer gain and larger 3-dB bandwidth, as compared to three-line coupled MLGNR interconnects at the same case. The proposed new technology in this paper would be beneficial to improve the performance of MLGNR interconnects and to provide the guidelines for the design of next generation on-chip MLGNR interconnect system.

Purpose. The purpose of this study was to find the clinical significance and methods of using CN in endoscopic treatment for PTC. Materials and Methods. A total of 108 cases were randomly enrolled and divided into two groups, with 50 cases in the CN injection group who were injected with CN and 58 cases in the control group with no CN injection. All cases were analyzed with the size of carcinoma, the number of lymph node, and parathyroid gland injury. Results. All operations were successfully completed. The lymph node dissection number was 274 for the control group and 322 (the rate of black stained was 87%) for the CN injection group. The average number of lymph nodes in the CN injection group was 6.44 ± 2.08, which was significantly higher than that in the control group (4.72 ± 1.89). The control group had a relatively higher incidence of incidental parathyroidectomy, compared to the CN injection group (27.6% in the control group vs. 12% in the CN injection group, P = 0.045 ). However, the incidence of hypoparathyroidism failed to show the significant difference between the two groups. Conclusion. Using CN in endoscopic PTC surgery could increase the detection rate of lymph nodes and reduce the injury of parathyroid glands to a certain extent.

The interconnect temperature of very large scale integration (VLSI) circuits keeps rising due to self-heating and substrate temperature, which can increase the delay and power dissipation of interconnect wires. The thermal vias are regarded as a promising method to improve the temperature performance of VLSI circuits. In this paper, the extra thermal vias were used to decrease the delay and power dissipation of interconnect wires of VLSI circuits. Two analytical models were presented for interconnect temperature, delay and power dissipation with adding extra dummy thermal vias. The influence of the number of thermal vias on the delay and power dissipation of interconnect wires was analyzed and the optimal via separation distance was investigated. The experimental results show that the adding extra dummy thermal vias can reduce the interconnect average temperature, maximum temperature, delay and power dissipation. Moreover, this method is also suitable for clock signal wires with a large root mean square current.

In this work, we successfully prepared regular hexagonal prism porous structure g-C3N4 (CN), and designed α-SnWO4 and UiO-66(NH2) on porous CN for constructing novel ternary α-SnWO4/UiO-66(NH2)/g-C3N4 (α-SW/UNCN) hybrid photocatalyst by solvothermal approach. The α-SW75/UNCN composite showed better photocatalytic performance, and the removal rate of Ibuprofen (IPF) reached 95.5% within 2 h and the H2 evolution efficiency reached 2105 μmol g−1 h−1 under simulated sunlight, which were 2.5 times and 21 times higher than those of α-SW (42.5% and 105 μmol g−1 h−1). The TOC removal efficiency of IPF can reach to 29%, showing higher mineralization ability compared with α-SW. In addition, the trapping experiment and ESR experiment proved that •O2- and •OH radicals played most important part in the photodegradation of IPF pollutants. The improved photocatalytic performance of α-SW/UNCN was owing to the construction of n-p-n type double Z-scheme heterojunction which enhanced carries separation. This work will provide a method for preparing novel and efficiency ternary composite catalyst for antibiotic contaminant degradation and H2 production.

Detail enhancement is the key to the display of infrared image. For the infrared image detail enhancement algorithms, it is very important to present a good visual effect for people effectively. A novel algorithm for detail enhancement of infrared images is proposed in this paper. The method is based on the relativity of Gaussian-adaptive bilateral Filter. The algorithm consists of three steps. The first step is to divide the input image into the base layer and the detail layer by the relativity of Gaussian-adaptive bilateral filter. In the second step, the detail layer is multiplied by the proposed weight coefficient, and the base layer is processed by histogram projection. The third step is to combine the detail layer and the base layer processed in the second step and output it to the 8-bit domain display. Compare with other methods, the new algorithm reduces the running time greatly. The experimental results showed that the proposed algorithm improves the contrast of infrared images effectively.

This paper proposes a noniterative analytical thermal model for 3-D integrated circuits (3-D-ICs) based on the solution of the governing energy equations using Green’s function, separation of variables, and superposition methods. The model is applicable to both transient and steady-state heat conduction problems. Any finite number of dies equally sized in plane can be taken into consideration in current analysis. In addition, the analytical solution presented here is very general, so that it takes into account the different interface boundary conditions between the dies. Importantly, the thermal properties (i.e., $k$ , $\rho $ , $c$ ) and thickness of different dies can be different, and the spatial and time-varying volumetric heat generation can be applied in each of the different dies. The results compared with the finite-element simulations show that the temperature fields predicted by the proposed model can offer an accurate and efficient solution to compute the temperature fields in the representative 3-D-ICs, with a maximum deviation between the two being around 2.0% in the transient heat conduction. In the steady-state case, the maximum deviation can reach even less than 1.0%.

Electrocardiography(ECG) signal suffers from noise interference during the recording and transmission, which would result in morphological structure distortion and affects proper diagnosis of diseases related to the cardiac system. For the purpose of filtering the noise to obtain the clean signal, in this paper, the recently developed complete ensemble empirical mode decomposition with adaptive noise algorithm(CEEMDAN) with morphological structure of ECG signal is proposed for ECG enhancement. The experimental results indicate that the proposed CEEMDAN based method could be capable of removing both high frequency interference and low frequency baseline wander, which provides competitive performances compared to other signal de-nosing approaches explored in this paper.

Cluster test of complex circuits is very difficult. The paper uses boundary scan test technology, different test algorithm, and test method for performing output operations on the boundary scanning units at each end of the interconnect network, and does a lot of test and analysis, effectively solves the problems of cluster test of complex circuits, and gives high fault resolution.

The multilayer graphene nanoribbons (MLGNR) by inserting the high-k dielectric material between adjacent graphene nanoribbons (GNR) layers to reduce propagation delay and to expand bandwidth of the conventional pristine (undoped) MLGNR interconnects is presented in this paper. An equivalent distributed circuit model of the proposed MLGNR interconnect with high-k dielectric materials is established to derive the analytical expressions of propagation delay, step response, transfer gain and 3-dB bandwidth for 7.5 nm technology node at global level. The numerical simulation results show that the maximum reduction of propagation delay between the proposed MLGNR by inserting SrTiO3 dielectric material and the pristine MLGNR can reach 12.746 ns for an interconnect length of 4000 μm. The corresponding 3-dB bandwidth for them can be expanded over 4 times for the interconnect length. It is demonstrated that the proposed MLGNR by inserting the high-k dielectric material can greatly reduce propagation delay and enhance transfer gain and 3-dB bandwidth compared with the conventional pristine MLGNR interconnects. Moreover, it is found that the results obtained by the proposed model have close agreement with Synopsys HSPICE simulation and the maximum relative error for them is less than 5%, and the average efficiency of CPU runtime is improved 95% by using the proposed model, as compared to HSPICE simulation. The proposed design method has many potential applications in improving performance of MLGNR interconnect and providing guidelines for the next generation on-chip interconnect system.

Background With the development of surgical technics, endoscopic thyroid surgery has been gradually accepted and utilized in thyroid disease treatment, including thyroid carcinoma. This study aimed to evaluate the learning curve for endoscopic hemithyroidectomy (EHT) with ipsilateral central neck dissection (CND) and investigate how many cases must be performed before a surgeon becomes competent and proficient in this approach. Methods Ninety-nine consecutive patients who underwent EHT with ipsilateral CND for papillary thyroid microcarcinoma by a single surgeon between June 2015 and October 2017 were analyzed. Multidimensional cumulative summation (CUSUM) analysis was performed to evaluate the learning curve. Results The CUSUM graph showed the learning curve ascended in the first 31 cases and declined in the following cases. The number of lymph nodes removed in phase 2 (the following 68 cases) was significantly more than that in phase 1 (the first 31 cases) (5.06 ± 1.44 vs. 4.19 ± 1.51, P = 0.001). The operation time in phase 2 was shorter than that in phase 1 (123.38 ± 12.71 min vs. 132.90 ± 13.95 min, P = 0.008) and the rate of accidental removal of parathyroid gland decreased from 35.5% in phase 1 to 16.2% in phase 2 (P = 0.040). There was a declining trend but no significant difference in the rate of postoperative complications (9.7% in phase 2 vs. 4.4% in phase 1, P = 0.309). Conclusion EHT with ipsilateral CND performed by surgeons was mastered after 31 cases, and the safety and feasibility of this endoscopic approach can also be demonstrated.

To explore the possible way of detecting the poisonous gas SO2, we have investigated the interactions between SO2 molecule and modified (8,0) single-walled carbon nanotubes by using the density functional theory (DFT) method. The adsorption energies, interaction distances, changes of geometric and electronic structures were all analyzed to investigate the sensitivity of variety of models of CNTs with Ni doping, vacancies, and a combination of them toward SO2 molecule. From our investigations, we found that SO2 molecule was more likely to be absorbed on vacancy-defected CNTs with relatively higher adsorption energy and shorter binding distance compared with the perfect CNTs. In addition, after doping Ni atom on the vacancies, the modified CNTs which were not very much sensitivity to SO2 molecule could become much sensitivity to it. In other words, the number of sensitive adsorption sites increased. The partial density of states (PDOS) and the electron concentration of the adsorption systems suggested the strong electrons interaction between SO2 molecule and defected or Ni-doped defected CNTs. Therefore the vacancies and Ni-doped vacancies CNTs had the potential capacities to make the sensors for SO2 molecule detecting.

The phonon dispersions and phonon density of states of LaSe are obtained, based on density functional perturbation theory and the norm-conserving pseudo-potential method. An anomaly in calculated phonon dispersion curves is presented and interpreted as a Kohn anomaly. The heat capacity of LaSe is calculated then. For the three-phonon process scattering, the lowest non-harmonic cubic terms of the interatomic potential are considered to obtain single-phonon relaxation rate by applying the Fermi's golden rule. For the boundary scattering, the average phonon relaxation time was obtained. Considering two kinds of phonon scattering mechanisms, we obtain the lattice thermal conductivity of LaSe.

The adsorption of SO 2 molecules on the surfaces of Ni-doped single-walled zigzag ( n ,0)CNTs ( n = 4,5,6, Ni-SWCNTs) has been investigated using density functional theory. The adsorption energies and changes in geometric and electronic structures after the adsorption were analyzed to characterize the sensitivity of Ni-SWCNTs toward SO 2 molecules. Our calculated results showed that Ni-SWCNTs had much higher adsorption energy, larger net charge transfer values and shorter binding distances than pure SWCNTs owning to chemisorption of the SO 2 molecule. The obtained density of states and frontier orbitals demonstrated that the orbital hybridization was obvious between the SO 2 molecule and Ni-SWCNTs, while there was no evidence for hybridization between SO 2 molecule and pure SWCNTs because of weak physisorption according to the total electron density maps. After doping of Ni atom, the primary symmetry of SWCNTs decreased, which enhanced the chemical activity of SWCNTs toward SO 2 molecules consequently. Furthermore, the adsorption capability of Ni-SWCNTs was improved gradually with the increase of tube diameter in the small range. The above results have profound meaning for the design and fabrication of SO 2 sensing devices.

The GaAs material is a major semiconductor material, and it has high electron transfer rate and direct transition energy band structure. The devices and integrated circuits fabricated on the GaAs substrates have a lot of advantages such as high speed information processing. Small perturbations in the manufacturing of GaAs materials can lead to defects. The defects in the GaAs materials can degrade the performance of materials. A new method is presented in this paper for detecting the micro-defects in GaAs materials by using time resolved emissions. In this method, the micro-defects in GaAs materials are detected by making use of the photon emission features of micro-defects. The strength of the emitted photons from the micro-defects is increased by applying the electric current or the periodic pulse signals to GaAs materials. The single-photon detector is used to detect the photon emissions of the micro-defects. The time resolved photon emissions and single-photon detection are used to record and compare the amounts of the emitted photons that come from the given regions of the normal GaAs materials and the defective GaAs materials. A lot of experimental results show that the micro-defects in the GaAs materials can be detected by using the method proposed in this paper.

The MOS circuits must be tested thoroughly for insuring the reliability. A new testing approach for MOS circuits is presented in this paper, which makes use of single-photon detectors and high magnetic fields. If there are faults in the circuit under test, the photon emission from the circuit components is detected by a single-photon detector, the faults are located by the amount of the emitted photons. The following two techniques are proposed in this paper. First, the high magnetic field is applied to the circuit under test, i.e., the circuit is put in high magnetic field environment. To some extent this technique can solve the problem that some faults have poor strengths of emitted photons under general environment. Second, the special circuit input vectors are designed by using binary decision diagrams. The input vectors can make the positions of circuit components to produce signal transitions or switching behaviors, therefore the photon emission strengths of circuit components are enhanced. A lot of experimental results show that the faults in MOS circuits can be tested accurately by the approach proposed in this paper.

The defects of semiconductor wafer may be generated from the manufacturing processes. A novel defect inspection method of semiconductor wafer is presented in this paper. The method is based on magneto-optic imaging, which involves inducing eddy current into the wafer under test, and detecting the magnetic flux associated with eddy current distribution in the wafer by exploiting the Faraday rotation effect. The magneto-optic image being generated may contain some noises that degrade the overall image quality, therefore, in this paper, in order to remove the unwanted noise present in the magneto-optic image, the image enhancement approach using multi-scale wavelet is presented, and the image segmentation approach based on the integration of watershed algorithm and clustering strategy is given. The experimental results show that many types of defects in wafer such as hole and scratch etc. can be detected by the method proposed in this paper.

The superconducting magnets have many advantages compared with conventional electromagnets. A novel design approach is presented in this paper for the high temperature superconducting magnets by the cultural evolution algorithm. First of all, the optimization model of high temperature superconducting magnet is constructed. Secondly, the feasible solutions of the optimization model are encoded as individuals; the better individuals are produced by the cultural evolution algorithm. The cultural evolution algorithm consists of three major components: a population space, a belief space, and a communication protocol. The chaotic maps and particle swarm optimization are used in the evolutionary procedure of the individuals in the population space and belief space. The experimental results show that the superconducting magnets with the better volume of solenoid coils can be obtained by the approach proposed in this paper.