The thermal damaging process of diorite under microwave irradiation

Laboratory tests have been conducted to investigate the effects of thermal damage on diorite under microwave irradiation. The sample rocks were heated to high temperature range of 300 to 800 ℃ in a single-mode microwave furnace. The experimental results show that the rocks started to crack at 500 ℃ and completely disintegrated at 700 ℃. The intensities of quartz diffraction peaks were almost unchanged while the diffraction peak intensity of hornblende gradually decreased with temperature increasing. In addition, the chlorite diffraction peak disappeared at 500 ℃. The compressive strength of the sample decreased to 40% at 600 ℃ and it approached zero at 700 ℃. In this paper, the possible reasons for the thermal effects on the fracture of diorite were discussed, which can be related to water evaporation, thermal cracks and mismatch thermal expansion, and phase transition on quartz. The result indicates that diorite can be effectively destroyed under microwave irradiation

Tunable and absolute electromagnetic vacuum in two-dimensional photonic-band-gap Based on multiferroic materials

When multiferroic terbium manganite (TbMnO₃) crystal cylinders are periodically arranged in a square lattice, the resulting two-dimensional (2D) system exhibits photonic band gaps (PBGs). The absolute PBG originating from the Mie resonance is modulated from closed to open by applying an external static magnetic field, which is attributed to the electromagnon depression of the dielectric constant by the rearrangement of antiferromagnetic order. Tunable electromagnetic band structure may be realized by controlling the magnetic transition of manganese spins in TbMnO₃.The authors are grateful for financial support from the Outstanding Foundation of NJUST, the NJUST Research Funding (No. 2010ZDJH06), the National Natural Science Foundation of China (Grant Nos. 11004106, 50672034, 50832002, and 50901042), and the State Key Program for Basic Research of China (Grant Nos. 2009CB623303 and 2009CB929501)

Comparative study on the deterioration of granite under microwave irradiation and resistance-heating treatment

To investigate the deterioration of granite under microwave irradiation and heat transfer, granite specimens were heated up to 400-1000 °C and then kept for 15 min. Uniaxial compressive strength testing results demonstrate a similar variation in two groups in 400-900 °C, which is initial strengthening (less than 500 °C), subsequent weakening (500-600 °C) and final stabilizing (600-900 °C). Furthermore, the specimen irradiated by microwaves presented a second decline at 1000 °C. Compared to heat transfer, microwave irradiation can reduce the strengthening due to localized transition plasticity and further promotes the deterioration of rock structure in weakening stage. TG/DSC results indicate that the strengthening is related to the iron mineral transition. The formation of porous glass substance which is mainly composed of feldspar and biotite. Furthermore, temperature-controlled microwave irradiation induced the variation of feldspar crystallinities, which is consistent with the corresponding UCS data, especially the plagioclase. In practical application, microwaves can be used to irradiate the vulnerable positions (surface edge and cleavage) and kept the whole rock mass around 600 °C

The Overseeing Mother: Revisiting the Frontal-Pose Lady in the Wu Family Shrines in Second Century China

Located in present-day Jiaxiang in Shandong province, the Wu family shrines built during the second century in the Eastern Han dynasty (25–220) were among the best-known works in Chinese art history. Although for centuries scholars have exhaustively studied the pictorial programs, the frontal-pose female image situated on the second floor of the central pavilion carved at the rear wall of the shrines has remained a question. Beginning with the woman’s eyes, this article demonstrates that the image is more than a generic portrait (“hard motif ”), but rather represents “feminine overseeing from above” (“soft motif ”). This synthetic motif combines three different earlier motifs – the frontal-pose hostess enjoying entertainment, the elevated spectator, and the Queen Mother of the West. By creatively fusing the three motifs into one unity, the Jiaxiang artists lent to the frontal-pose lady a unique power: she not only dominated the center of the composition, but also, like a divine being, commanded a unified view of the surroundings on the lofty building, hence echoing the political reality of the empress mother’s “overseeing the court” in the second century during Eastern Han dynasty

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Android Malware Detection Based on a Hybrid Deep Learning Model

In recent years, the number of malware on the Android platform has been increasing, and with the widespread use of code obfuscation technology, the accuracy of antivirus software and traditional detection algorithms is low. Current state-of-the-art research shows that researchers started applying deep learning methods for malware detection. We proposed an Android malware detection algorithm based on a hybrid deep learning model which combines deep belief network (DBN) and gate recurrent unit (GRU). First of all, analyze the Android malware; in addition to extracting static features, dynamic behavioral features with strong antiobfuscation ability are also extracted. Then, build a hybrid deep learning model for Android malware detection. Because the static features are relatively independent, the DBN is used to process the static features. Because the dynamic features have temporal correlation, the GRU is used to process the dynamic feature sequence. Finally, the training results of DBN and GRU are input into the BP neural network, and the final classification results are output. Experimental results show that, compared with the traditional machine learning algorithms, the Android malware detection model based on hybrid deep learning algorithms has a higher detection accuracy, and it also has a better detection effect on obfuscated malware

Decentralized fault-tolerant control of modular robot manipulators with actuator saturation: neural adaptive integral terminal sliding mode-based control approach

Abstract A novel neural adaptive integral terminal sliding mode control for decentralized fault-tolerant control strategy, including the integral terminal sliding mode surface, the nonlinear disturbance observer, the radial basis neural network and robust controller, is presented in this paper to achieve fault-tolerant control of modular robot manipulators. First, the integral terminal sliding mode is designed for the fault-tolerant controller. Then, to boost the performance of the controlled system, the radial basis neural network and disturbance observer are introduced to approximate the nonlinear terms and disturbances. The reconstructed approximate uncertainty term is applied as compensation. Next, the super-twisting technique is employed to compensate for estimation errors to ensure stability. In addition, for the actuator saturation problem, the radial basis function neural network-based compensation control is proposed. Finally, the stability of the closed-loop robotic system is demonstrated based on Lyapunov theory. Computer simulations verified the efficiency and advantages of the presented approach

Exploring the Effects of Sampling Locations for Calibrating the Huff Model Using Mobile Phone Location Data

The introduction of the Huff model is of critical significance in many fields, including urban transport, optimal location planning, economics and business analysis. Moreover, parameters calibration is a crucial procedure before using the model. Previous studies have paid much attention to calibrating the spatial interaction model for human mobility research. However, are whole sampling locations always the better solution for model calibration? We use active tracking data of over 16 million cell phones in Shenzhen, a metropolitan city in China, to evaluate the calibration accuracy of Huff model. Specifically, we choose five business areas in this city as destinations and then randomly select a fixed number of cell phone towers to calibrate the parameters in this spatial interaction model. We vary the selected number of cell phone towers by multipliers of 30 until we reach the total number of towers with flows to the five destinations. We apply the least square methods for model calibration. The distribution of the final sum of squared error between the observed flows and the estimated flows indicates that whole sampling locations are not always better for the outcomes of this spatial interaction model. Instead, fewer sampling locations with higher volume of trips could improve the calibration results. Finally, we discuss implications of this finding and suggest an approach to address the high-accuracy model calibration solution

Pollution and corporate valuation: evidence from China

Environmental pollution brings severe challenges in the context of a high growing economy of China. Pollution events bring serious ecological cost to the environment, direct costs from sanction, and reputational damage to the listed firms. We study the market reaction to 145 pollution events in China during Jan 2008 and Feb 2015. We find that the 2-day cumulative abnormal returns (CARs) of pollution events are significantly negative, which shows the disciplining effect of the stock market on the listed firms. In addition, pollution events with sanctions have lower CARs than otherwise, which are heterogeneous among different sanction types such as shutting down, fines and rectification. Finally, water pollution has lower CARs than other pollution types. We find that direct economic loss is an important reason for the negative market reactions to pollution events