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The selective catalytic oxidation (SCO) is an effective method for removing slipped high-concentration ammonia from NH3-fueled engine exhaust gas. Herein a novel bifunctional catalyst was synthesized by mechanically mixing sulfated Ce/ZrO2 (Ce/ZrO2-S) with a small fraction of Pt/Al2O3 (Pt 0.1 wt.%) for SCO of NH3. As expected, the introduction of a small amount of Pt/Al2O3 significantly improved NH3 conversion ability of Ce/ZrO2-S catalysts toward low-temperature direction. When the mass ratio of Pt/Al2O3 to Ce/ZrO2-S was 7.5% (the corresponding mixed catalyst was denoted as P@CZS-7.5), T90 temperature was 312 °C. More importantly, P@CZS-7.5 catalyst exhibited a much better N2 selectivity (> 96%) in a wide temperature range (320 ~ 450 °C). H2-TPR results revealed that the addition of a trace amount of Pt/Al2O3 significantly led to a distinct shift of reduction temperature peak toward low-temperature direction, thereby greatly improved the low-temperature redox performance of mixed catalysts. Furthermore, NH3-TPD and BET results showed that P@CZS-7.5 catalyst exhibited a similar NH3 adsorption capacity to Ce/ZrO2-S catalyst, while the former had a relatively higher specific surface area than the latter. It was considered as a crucial factor for P@CZS-7.5 catalyst maintaining superior N2 selectivity in high-concentration NH3 (5000 ppm) removal processes. In situ DRIFTS results indicated that P@CZS-7.5 catalyst followed the internal selective catalytic reduction (i-SCR) mechanism in NH3-SCO reactions. [ABSTRACT FROM AUTHOR]

In view of the problem of poor coupling adaptability and easy rib spalling of coal wall in large mining height comprehensive mining, based on the effective inhibition effect of face guard mechanism on coal wall spalling, the structural characteristics and bearing capacity of different structural forms of the face guard mechanism are compared and analyzed. According to the surrounding rock adaptability of the face guard mechanism, established a numerical analysis model for rigid-flexible coupling of the face guard mechanism under different spalling forms. In order to accurately simulate the stress state of the protective mechanism, a variable stiffness spring damping system is used to replace the hydraulic cylinder. The load-bearing performance and response characteristics of the face guard mechanism under rib spalling coupling conditions were analyzed by applying uniform normal load and impact load to the face guard. The findings indicated that, the integral-type face guard mechanism has a better effect on suppressing rib spalling. When the face guard mechanism bears the static load of the coal wall, the entire response process of the face guard jack can be divided into three stages: initial support, increasing resistance bearing, constant resistance bearing; both the impact load position and the coupling state of the rib spalling will affect the characteristics of force transmission at the face guard mechanism's hinge point, the hinge point between the extensible canopy and the primary face guard is most sensitive to biased load. The research results can provide reference for optimizing the face guard mechanism of large mining height hydraulic support and improving the reliability of coal wall support. [ABSTRACT FROM AUTHOR]

The combined rock breaking method with the saw blade and conical pick is proposed to improve the rock breaking efficiency. The numerical simulation of combined rock breaking with the saw blade and conical pick is established to investigate the rock damage mechanism. And verified and modified the numerical simulation model with the rock breaking comprehensive test bench, the quantitative analysis error is less than 0.05, indicated quantitative analysis system is accuracy. The result indicated that the cutting parameters of the saw blade and conical pick affect the rock damage. And the cutting parameters of conical pick and structural parameters of rock plate have been studied to influence rock breaking volume. The research result could help optimize the cutting parameters of the saw blade and conical pick to improve the rock breaking efficiency. [ABSTRACT FROM AUTHOR]

Shearer is an essential equipment in mechanized coal mining process. Roof cutting often turns up for shearer during working process, leading to extra vibration on shearer and reducing its service life. Coal and rock interface recognition is a fundamental technical way for shearer to avoid continuous roof cutting. In this paper, an effective method for coal and rock interface is proposed and it is mainly based on the cutting loads on shearer drum in three different kinds of working states. The constitutions of cutting force on shearer drum are analyzed under conditions of different proportions of rock thickness in the cutting range and then model for calculation of cutting force in the coal–rock mixed seam are proposed which is a function of rock proportion in the cutting range. To verify the model, hard roof with different material strengths and different interfaces are established with the numerical method and rock proportions in the cutting range are derived based on the mentioned method. In terms of the situations where rock material properties are close to coal and the results are obtained with lower accuracy, enlarging the difference of rock proportions in the second and third states is proposed and the relations between the recognition accuracy and the differences of rock proportions in different states are explored as well. The results show that the estimation method works well with qualititative analysis of coal and roof interface even if coal and rock material properties are various and not able to be known in advance. In addition, the adjustment height of shearer drum is the important factors highly related with the estimation accuracy and it would be helpful for accuracy improvement in conditions where the material properties of coal and roof are closer to each other or larger roof cutting thickness happens in coal mining. The method provides the possibility for qualititative analysis of coal and roof interface with easy accessibility and wide adaptability. [ABSTRACT FROM AUTHOR]

Top coal caving in fully mechanized caving mining will cause an irregular impact on the caving mechanism of hydraulic support. The vibration response of the caving mechanism varies under different forms of impact. This response difference is a prerequisite for new coal rock identification technology in intelligent mining. Therefore, this work studies the difference in vibration response of the caving mechanism under different forms of impact. An innovative mechanical–hydraulic coupling system model of the caving mechanism impact by coal rock is established. The metal plate impact test proved the significant difference in vibration response of the caving mechanism under coal rock impact of different materials. Afterward, a more improved mechanical–hydraulic co-simulation model analyzed the difference in the vibration response of the caving mechanism under different rock materials, volumes, velocities and impact positions. The results show that the vibration response is more intense under rock impact than under coal impact. A lower position, a faster velocity and a larger volume correspond to a more noticeable response difference in the caving mechanism. The vibration and fault sensitive areas of the caving mechanism are determined. This study has a reference significance for improving the caving mechanism's structural design and failure prevention. The conclusions provide guidance for a new intelligent coal rock identification technology based on vibration signals. [ABSTRACT FROM AUTHOR]

Circular saw blades are widely used in stone processing. The circular saw blade cutting hard rock numerical simulation model based on ANSYS/LS-DYNA was established to investigate the complex dynamic problem in rock cutting. The failure mechanism of the rock and the influence of cutting parameters on the cutting force and rock fragments were studied by numerical simulation. The results demonstrated that the failure modes of the rock were mainly tensile failure with some shear failure and compressive failure. The cutting force and the number of fragments increased with the feed speed. With the increasing circular saw blade rotational speed, the cutting force and the number of fragments decreased and tended to stabilize. With the distance between the circular saw blades increasing, the cutting force and rock fragments number increase and then maintain basic stability, and when the distance between double circular saw blades reaches 25 mm, it will form a completed rock plate and the interaction of circular saw blades will decrease. The numerical simulation can accurately simulate rock breakage and force when a circular saw blade cuts rock. [ABSTRACT FROM AUTHOR]

Background and objective: Cervical spondylosis (CS) is often accompanied by persistent cervical pain, and psychological complications including depression and anxiety, which aggravate pain. Past studies have revealed brain alterations in chronic pain patients. However, the cortical mechanism for NSAID (non-steroidal anti-inflammatory drug) responders relative to non-responders is still lacking. Therefore, we aimed to investigate the brain functional differences between responders to NSAID relative to non-responders using amplitude of low-frequency fluctuation (ALFF) and dynamic functional connectivity variance (DFCV). To our knowledge, our study is the first to investigate the DFCV in CS patients. Materials and methods: We first explored the differences in psychological inventories in CS patients who respond to NSAID vs non-responders. The voxel-wise ALFF was calculated and compared between CS patients and healthy controls. The ALFF within the resultant clusters were extracted and compared between responders and non-responders. DFCV among the resulting clusters was compared in responders vs non-responders. Results: We found that (1) compared to responders, non-responders exhibited higher levels of anxiety and depression; (2) relative to healthy controls, CS patients exhibited altered ALFF within the middle cingulate cortice (MCC), cerebellum, and middle frontal gyrus (MFG); (3) moreover, compared with responders, non-responders exhibited lower ALFF within MCC; furthermore, non-responders also exhibited increased DFCV between MCC and cerebellum, and between MCC and MFG. Conclusion: Our data indicate that psychological comorbidities (e.g., anxiety) influence response to NSAID in CS patients. Relative to NSAID responders, non-responders had altered MCC function, which may be associated with anxiety in CS patients. [ABSTRACT FROM AUTHOR]

The volume detection of medical mice feed is crucial to understand the food intake requirements of mice at different growth stages and to grasp their growth, development, and health status. Aiming at the problem of volume calculation in the way of feed bulk in mice, a method for detecting the bulk volume of feed in mice based on binocular stereo vision was proposed. Firstly, the three-dimensional point coordinates of the feed's surface were calculated using the binocular stereo vision three-dimensional reconstruction technology. The coordinates of these dense points formed a point cloud, and then the projection method was used to calculate the volume of the point cloud; and finally, the volume of the mice feed was obtained. We use the stereo matching data set provided by the Middlebury evaluation platform to conduct experimental verification. The results show that our method effectively improves the matching degree of stereo matching and makes the three-dimensional point coordinates of the obtained feed's surface more accurate. The point cloud is then denoised and Delaunay triangulated, and the volume of the tetrahedron obtained after the triangulation is calculated and summed to obtain the total volume. We used different sizes of wood instead of feed for multiple volume calculations, and the average error between the calculated volume and the real volume was 7.12%. The experimental results show that the volume of the remaining feed of mice can be calculated by binocular stereo vision. [ABSTRACT FROM AUTHOR]

Introduction: Longer follow-up was necessary to determine the exact value of mastoscopic axillary lymph node dissection (MALND). Methods: From January 1, 2003, to December 31, 2005, 1027 patients with breast cancer were randomly assigned to two groups: MALND and CALND (conventional axillary lymph node dissection); 996 eligible patients were enrolled. Results: The final cohort of 996 patients was followed for an average of 198 months. Events other than death differed significantly between the two cohorts (p = 0.0311; 46.3% in MALND and 53.2% in CALND, respectively). The sum of events other than death and deaths from other causes was much higher in the CALND (59.6%) than MALND (53.4%) group (p = 0.0494). The 17-year disease-free survival DFS rates were 36.7% for the MALND and 33.6% for the CALND group, respectively. There was a significant difference between the groups (p = 0.0306). Overall survival (OS) rates were 53.2% after MALND and 46.0% after CALND (p = 0.0119). MALND patients had much less axillary pain (p = 0.0000), numbness or paresthesia (p = 0.0000), arm mobility (p = 0.0000) and arm swelling on the operated side (p = 0.0000). Aesthetic appearance of the axilla was much better in the MALND than CALND group (p = 0.0000) at an average follow-up of 17 years. Conclusions: The use of MALND in breast cancer surgery not only decreases the relapse and arm complications but also improves long-term survival of patients. Therefore, MALND should be one of the preferred approaches for breast cancer surgery when ALND is needed. Trial Registration Information: The comparison of long-term outcomes of mastoscopic and conventional axillary lymph node dissection in breast cancer: a multicenter randomized control trial. ChiCTR-TRC-11001477, CHiCTR. First registration 08/14/2011. [ABSTRACT FROM AUTHOR]

Impact contact behaviors with different velocities, direction and contact states occurred in the process of coal drawing between coal gangue particles and the hydraulic support greatly increase the difficulty of coal gangue recognition in top coal caving. In order to finally realize coal gangue recognition in top coal caving, this paper studied the impact behavior of a single particle coal gangue and the metal plate at any position and the problem of the identification of coal gangue particles. First, the any position impacting test bench and test system is constructed, in which multipoint acceleration information acquisition space is built. Second, 2400 groups of random impact tests between coal gangue particle and the metal plate are conducted. Third, while each impact test was going on, acceleration signals in the seven different positions of the metal plate were collected. Forth, after all the impact tests are completed, signals are processed by segmentation and re-sorted by randomization. Then, the method of signals serial splicing is proposed to process the different position standardized signals obtained in each group of impact test, and coal gangue recognition is proposed based on processed signal data and SVM algorithm. After that, the effect of parameters on coal gangue recognition accuracy of SVM algorithm is studied, and the corresponding parameter settings of SVM are accordingly determined. Finally, coal gangue recognition was conducted by using SVM based on different data samples, the influence law of the training set data set expansion method and the test set data matching relationship, the number of tandem sensors and matching relationship, and the number of training set samples on coal gangue recognition accuracy were studied. The study will serve as the research basis for the application of SVM and signals serial splicing method in coal gangue recognition. [ABSTRACT FROM AUTHOR]

To solve the complex computation, unstable network and slow learning speed problems of a generative adversarial network for image super-resolution (SRGAN), we proposed a single image super-resolution reconstruction model called the Res_WGAN based on ResNeXt. The generator is constructed by the ResNeXt network, which reduced the computational complexity of the model generator to 1/8 that of the SRGAN. The discriminator was constructed by the Wasserstein GAN(WGAN), which solved the SRGAN's instability. By removing the normalization operation in the residual network, the learning rate is improved. The experimental results from the Res_WGAN demonstrated that the proposed model achieved better performance in the subjective and objective evaluations using four public data sets compared with other state-of-the-art models. [ABSTRACT FROM AUTHOR]

The manufacturing of additives with projection micro litho stereo exposure (PµLSE) has provided an opportunity for the fabrication of metastructures with complex microstructures at micro-nano resolutions. However, the performance evaluation of as-fabricated metastructures is challenging. The benefit of synchrotron radiation-based 3D imaging techniques and advanced image processing methods makes it is feasible to study fabrication defects and damage processes of micro-nanoscale body-centered cubic (BCC) lattices manufactured with PµLSE. First, synchrotron radiation technology is used to capture the structural features inside the micro-lattice samples. Subsequently, several types of statistical defects-based image finite element models are adopted to analyze the failure process of the structure under compression loading. Finally, comparisons between in situ experiments and numerical simulation results are performed for verification. The method of the combined non-destructive testing of synchrotron radiation and image finite element technology provides a robust technique for evaluating the performances of additive-manufactured micro-lattice with complex microstructures. [ABSTRACT FROM AUTHOR]

In this paper, the effect of ultrasonic impact treatment (UIT) on the residual stress of 316L welded butt-joint was investigated. Firstly, the temperature field distribution in the welded joint was simulated based on the double-ellipsoidal heat source model, and the residual stresses were calculated by a sequential coupling thermo-mechanical finite element method. Subsequently, based on the theory of transient contact mechanics, the effects of UIT on releasing of the welding residual stress was analyzed. The microstructure of the weld metal before and after the UIT treatment was compared to study the influence of UIT. The results show that the maximum residual stresses in the weld metal and heat affected zones are released due to the dislocation multiplication during the UIT, and this effect on the weld metal is more remarkable than that on the heat affected zones. The results of numerical simulation of UIT are consistent with the corresponding experimental results. After UIT, the transverse and longitudinal tensile stresses near the fusion line are changed to compressive stresses. [ABSTRACT FROM AUTHOR]

The collision between the coal–gangue and the metal plate of the hydraulic support is a typical mechanical contact behavior in the surface coal mining, which will cause vibration in the tail beam and even in the whole hydraulic support. This paper presents a contact analysis of coal–gangue impact on the metal plate to discover how vibration signals are generated and propagated in the collision process. We build a dynamic model for rock impact on the metal plate based on the elastoplastic contact theory, the Drucker–Prager criterion and the Tavares and King particle impact damage model. We establish a finite element model of the impact system between the coal–gangue and the metal plate, conduct contact simulation using the software LS-DYNA and study the stress transfer process on the metal plate contact surface. We compare the parameters of coal and gangue impact on the metal plate and discuss how they are different by calculating the stress and displacement created in the metal plate, kinetic energy of the coal–gangue particles and the total energy of the metal plate. In addition, we study the effect of impact velocity on the vibration response of the metal plate. Results show that the stress wave diffuses outward from the center of the metal plate. The collision frequency, contact position of the rock sphere and re-collision time are random. As the impact velocity increases, the contact responses all increase. This study provides guidance for the analysis of vibration response of coal–gangue impact on tail beam. [ABSTRACT FROM AUTHOR]

Service-oriented manufacturing is a trend in the manufacturing industry in the 21st century. Numerous theories related to this trend have been proposed. In particular, three typical theories, namely, industry 4.0, industrial Internet, and cloud manufacturing (CMfg), are discussed in this paper, including their differences. Existing problems in CMfg are analyzed. From the perspective of the service supplier, and by considering former research, three application modes of CMfg are proposed. A 3D printing application mode of CMfg is presented based on the characteristics of 3D printing and discussed in detail. The key technologies of 3D printing in CMfg are explained according to the differences between traditional manufacturing and CMfg. [ABSTRACT FROM AUTHOR]