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In order to guide the model test fillers and improve the test accuracy, the mudstone similar material was selected to make samples, and the effects of three factors affecting the filling process of model test on the mechanical properties of mudstone similar material was studied. The analysis results show that when the number of layers increases from 1 layer to 5 layers, the uniaxial compressive strength, elastic modulus and tensile strength of similar materials are reduced by 23.80%, 32.0% and 20.83% respectively. And the compaction times are increased from 1 to 5 times, the uniaxial compressive strength, elastic modulus and tensile strength of similar materials increased by 15.00%, 28.61% and 6.76%, respectively. Compared with the interface treatment method of rough treatment, the uniaxial compressive strength, elastic modulus and tensile strength respectively increased by 14.25%, 22.63% and 7.99%when gypsum was sprayed on this basis. The multiple linear regression equation between the mechanical properties of similar materials and the influencing factors of packing process is established. Combined with the test results and equations, the model test fillers can be guided, the mechanical properties of similar material can be prevented from decreasing, and the test accuracy can be improved.

Aims Left atrial appendage electrical isolation (LAAEI) has demonstrated a significant enhancement in the success rate of atrial fibrillation (AF) ablation. Nevertheless, concerns persist about the safety of LAAEI, particularly regarding alterations in left atrial appendage (LAA) flow velocity and the potential risks of thrombus. This study aimed to assess the efficacy and safety of LAAEI, investigating changes in LAA flow velocity in canines. Methods and results The study comprised a total of 10 canines. The LAAEI procedure used by a 23 mm cryoballoon of the second generation was conducted at least 180 s. Intracardiac ultrasonography (ICE) was employed to quantify the velocity flow of the LAA both prior to and following LAAEI. Following a 3-month period, subsequent evaluations were performed to assess the LAA velocity flow and the potential reconnection. Histopathological examination was conducted. Left atrial appendage electrical isolation was effectively accomplished in all canines, resulting in a 100% acute success rate (10/10). The flow velocity in the LAA showed a notable reduction during LAAEI as compared with the values before the ablation procedure (53.12 ± 5.89 vs. 42.01 ± 9.22 cm/s, P = 0.007). After the follow-up, reconnection was observed in four canines, leading to a success rate of LAAEI of 60% (6/10). The flow velocity in the LAA was consistently lower (53.12 ± 5.89 vs. 44.33 ± 10.49 cm/s, P = 0.006), and no blood clot development was observed. The histopathological study indicated that there was consistent and complete injury to the LAA, affecting all layers of its wall. The injured tissue was subsequently replaced by fibrous tissue. Conclusion The feasibility of using cryoballoon ablation for LAAEI was confirmed in canines, leading to a significant reduction of LAA flow velocity after ablation. Some restoration of LAA flow velocity after ablation may be linked to the passive movement of the LAA and potential reconnecting. However, this conclusion is limited to animal study; more clinical data are needed to further illustrate the safety and accessibility of LAAEI in humans. [ABSTRACT FROM AUTHOR]

In order to improve the quality of tobacco silk, the processing parameters of tobacco silk were optimized by using BP Neural Network (BPNN), taking the physical properties of tobacco silk, the physical properties of cigarettes and the chemical composition of cigarettes as quality control indicators. The BPNN optimization results were compared with the orthogonal test results, and the optimized parameters were verified. The results showed that the prediction results of the established BPNN model had high reliability and accuracy, and the optimal silk-making processing parameters combination predicted by BPNN was unique and accurate. There were differences in the parameter settings of steam flow and hot air temperature for the optimal combination of tobacco silk-making process parameters obtained by the orthogonal test method. After the parameters of the tobacco silk-making processing parameters were optimized, the whole cut rate and filling value of tobacco silk had been improved, the broken cut rate had been reduced, the standard deviation of single cigarette weight and cigarette suction resistance had decreased, and the CO, tar, and nicotine releases had been reduced, and the overall optimization effect was obvious. BPNN accurately predicted the optimal parameters of tobacco silkmaking, which avoided misjudgment, improved processing efficiency, and reduced time cost and resource waste. [ABSTRACT FROM AUTHOR]

The all-for-one tourism guides the development of the tourism industry in China and promotes coordinated development of the economy and society. Existing studies emphasize the significance of all-for-one tourism but pay limited attention to the impact and mechanism of all-for-one tourism on the high-quality development of tourism. By employing the all-for-one tourism demonstration zones as a quasi-natural experiment, this research uses the time-varying difference-in-differences (DID) model to empirically investigate the relationship between all-for-one tourism demonstration zones and the high-quality development of tourism. In particular, under the guidance of the new development philosophy, this research constructs a measurement and evaluation indicator system for the high-quality development of tourism from five dimensions, including innovative, coordinated, green, open, and shared development. The results show that the all-for-one tourism demonstration zones positively impact the high-quality development of tourism, and the result is robust to a series of robustness checks, including the placebo test and the propensity score matching (PSM) procedures. Network infrastructure construction and tourism talent agglomeration are mechanisms channelling through all-for-one tourism demonstration zones and high-quality tourism development. Heterogeneity analysis reveals positive impacts of all-for-one tourism demonstration zones on central and western regions and provinces with a low proportion of tertiary sector. [ABSTRACT FROM AUTHOR]

To improve the accuracy of tobacco impurity detection and removal, a cascade detection method for tobacco impurity images based on computer vision and machine learning was designed. This method used color features and gradient energy computer vision methods to locate tobacco impurities. Combining HOG and LBP features with a cascade Adaboost classifier, a multi-window detection algorithm was designed to detect tobacco impurities in real time. The experimental results showed that the accuracy of the static impurity detection method based on color features was higher than that of the gradient energy method. After combining HOG features and multi-level cascade Adaboost classifier algorithm, the detection results were very stable, and the accuracy of tobacco impurity detection reached 97. 33%. In the actual operation process, there was no need to manually adjust the algorithm parameters, ensuring the accuracy and effectiveness of the algorithm while reducing the time cost. [ABSTRACT FROM AUTHOR]

A photonic lantern is a coherent beam combination device that can increase the fiber laser brightness by adaptively controlling the input light properties, such as phase, intensity, and polarization. However, the control effect is closely related to the initial optical field, which affects the convergence speed to obtain the optimum solutions. In this work, we propose a novel control strategy using the prior structural information of the photonic lantern. Taking a 6 × 1 photonic lantern as an example, we calculate the transmission matrix of the photonic lantern. The initial optical field conditions, fed as the control inputs, for various mode outputs can be obtained. Compared with the random and equal amplitude control methods, the preset method from the transmission matrix presents a significant improvement of the desired mode content. Our optimization method is generally useful for adaptive control systems to improve their performance, taking advantage of their own structural information. [ABSTRACT FROM AUTHOR]

The melt-electrospinning performance of poly (butyleneadipate-co-terephthalate) (PBAT) was investigated, and the relationship between the melt differential electrospinning process parameters and properties of the resultant PBAT fibers were studied. The results indicated that the fiber diameter decreased and its diameter distribution decreased at first and then tended to increase with an increase in spinning temperature. With an increase in spinning voltage, the fiber diameter decreased and the distribution was uniform. Meanwhile, the mechanical properties of the fiber membranes were improve gradually. The optimal fiber fineness and uniformity were obtained at a spinning distance of 9 cm, a spinning temperature of 260 °C, and a spinning voltage of 45 kV. The obtained fibers exhibited a diameter of 4.31 μm, a standard diameter distribution deviation of 0.76. The fiber membranes obtained tensile strength of 9.9 MPa and elongation at break of 111.2 %. [ABSTRACT FROM AUTHOR]

In this paper, we analyze the modulating retro‐reflector (MRR) channel under different correlated conditions and derived its closed‐form expressions for the probability density function, which is helpful to the design of practical MRR free space optical (FSO) systems. A series of closed‐form expressions for BER performance of several perspective modulation schemes is investigated for MRR FSO communication system over moderate to strong fading channels by use of Gamma‐Gamma (G‐G) distribution. Simulation results show that the effect of correlation between links play a significant role in FSO communication, while varies markedly under different modulation schemes, which provide guidelines for the design and optimization of satellite‐ground laser communication system. [ABSTRACT FROM AUTHOR]