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Abstract As one of the detection targets of all gravitational wave detectors today, the stochastic gravitational wave background (SGWB) provides an important means of understanding the evolution of our universe. In this paper, we explore the feasibility of detecting the SGWB generated by the loops arising throughout the cosmological evolution of the cosmic string network, using both individual space detectors (LISA and TAIJI) and joint space detectors (LISA-TAIJI). For the joint detectors, we choose three different configurations of TAIJI, namely TAIJIm, TAIJIp, and TAIJIc, to form the LISA-TAIJI networks, and we investigate their ability to detect the SGWB. By comparing the power-law sensitivity (PLS) curves of individual space detectors and joint detectors with the energy density spectrum of SGWB, we find that LISA-TAIJIc has the best sensitivity for detecting the SGWB from cosmic string loops. It thus holds promise for further constraining the tension of cosmic strings $$G\mu =O(10^{-17})$$ G μ = O ( 10 - 17 ) .

Abstract Ge‐on‐insulators (GOIs) have been extensively explored as a potential platform for electronic‐photonic integrated circuits (EPICs), enabling various emerging applications. Although an efficient electrically‐injected light source is highly desirable, realizing such devices with optimal light emission efficiency remains challenging. Here, the first room‐temperature electrically‐injected Ge waveguide light emitters consisting of a lateral p–i–n homojunction on a GOI platform that can be monolithically integrated with EPICs are demonstrated. A high‐quality Ge active layer is transferred onto an insulator layer with the misfit dislocations in the Ge active layer eliminated to suppress unwanted nonradiative recombination. A 0.165% tensile strain is introduced to enhance the directness of the band structure and improve the light emission efficiency. The device comprises a waveguide structure with a significantly improved optical confinement as the optical resonator and a lateral p–i–n homojunction structure as the electrical injection structure. Under continuous‐wave electrical current injection at room temperature, enhanced electroluminescence is successfully observed at telecommunications wavelengths covering the C, L, and U bands, with improved efficiency. Theoretical analysis suggests that the quantum efficiency of Ge light emitters is dramatically affected by the defect density. These results pave the way for developing efficient, room‐temperature, electrically‐injected light emitters for next‐generation GOI‐based EPICs.

Populus euphratica Oliv., a dominant species of arid desert community, grows heteromorphic leaves at different crown positions. Whether heteromorphic leaves are a strategy of plant adaptation to drought stress is rarely reported. This study sequenced the transcriptome of three typical heteromorphic leaves (lanceolate, ovate and broad-ovate leaves) of P. euphratica, and measured their drought stress. We wanted to reveal the molecular mechanisms underlying the formation of heteromorphic leaves. Drought stress was increased significantly from lanceolate to ovate to broad-ovate leaves. Gene ontology (GO) and KEGG enrichment analysis showed that the MADs-box gene regulated the expression of peroxidase (POD) in the phenylpropane biosynthetic pathway. The up-regulated expression of the chalcone synthase (CHS) gene in broad-ovate leaves significantly activated the flavonoid biosynthetic pathway. In the process of leaf shape change, the different expressions of homeodomain leucine zipper (HD-ZIP) among the three heteromorphic leaves had potential interactions on the AUX and ABA pathways. The expression of Sucrose phosphate synthase (SPS) and sucrose synthase (SUS) increased from lanceolate to broad-ovate leaves, resulting in a consistent change in starch and sucrose content. We concluded that these resistance-related pathways are expressed in parallel with leaf formation genes, thereby inducing the formation of heteromorphic leaves. Our work provided a new insights for desert plants to adapt to drought stress.

For the coupling problems of lithium-ion batteries, a key issue at hand is that it is still unclear which mechanical failures can cause degradation and how, which is particularly salient at the electrode level. In this work, the correlation between electrode-level cracks and cycling capacity of silicon electrodes is investigated. Unexpectedly, for cracks in active layers, the capacity decreases with the increase of crack width, while the connection of other crack features to the capacity is weaker or even absent. Meanwhile, the modeling results, however, suggest that the increase in crack width cannot directly cause the capacity fading. To explain these results, the relationship between electrode debonding and active layer crack opening is also described quantitatively. By combining the debonding model and the porous electrode model, the connection between crack widths of active layers and capacity fading is clarified, and accurate predictions are obtained. These results indicate that the easily measurable width of active layer cracks is qualified to evaluate degradation, while the electrode debonding is in fact the direct cause of capacity fading. The findings in this work provide a more precise understanding of the degradation mechanism in lithium-ion battery electrodes.

This study presents a computationally efficient maximum likelihood (ML) algorithm for estimating the carrier frequency offset (CFO) of generalized frequency division multiplexing systems. The proposed algorithm uses repetitive subsymbols and virtual carriers to estimate the fractional and integer CFOs, respectively. Through the use of repetitive subsymbols, this study first calculates the ML estimate of the fractional CFO in the time domain and then, accordingly, compensates for it from the received signal. The integer CFO can then be estimated through a virtual-carrier-mapping process in the frequency domain. In addition to improving performance in terms of estimation accuracy and computational complexity, the proposed non-data-aided algorithm is spectrally efficient relative to traditional algorithms.

With the rapid advancement of technology, IoT has become inseparable from human lives. IoT is extensively used in transport, healthcare, and manufacturing, among other sectors. However, this technology lacks sufficient security defense capabilities, thus becoming a highway for malicious actors. IoT networks use infrastructure-based (INF) and device-to-device (D2D) communications to propagate data. The INF communication utilizes technologies such as WLAN, LTE, GPRS, and GSM to relay information from source to destination. The D2D paradigm, on the other hand, is a close-proximity communication in which sensors exchange data in a multi-hop manner. Since malware can utilize both D2D and INF links to spread out, IoT networks are exceptionally vulnerable to attacks. Therefore, we propose Susceptible-Exposed-Infected-Recovered-Dead (SEIRD) model to examine the dynamics of IoT malware spread via INF and D2D communications. We analyze the impacts of mobility on infection propagation and illustrate that our model adequately captures IoT malware spread behaviors through mathematical analysis and simulations. We also compute the malware transmission threshold, which can be used as a guideline to mitigate and suppress an attack.

Abstract Having infected by Helicobacter pylori, the infection often leads to gastritis, gastric ulcer, or even gastric cancer. The disease is typically treated with antibiotics as they used to effectively inhibit or kill H. pylori, thus reducing the incidence of gastric adenoma and cancer to significant extent. H. pylori, however, has developed drug resistance to many clinically used antibiotics over the years, highlighting the crisis of antibiotic failure during the H. pylori treatment. We report here that the fucoidan from Sargassum hemiphyllum can significantly reduce the infection of H. pylori without developing to drug resistance. Fucoidan appears to be a strong anti-inflammation agent as manifested by the RAW264.7 cell model examination. Fucoidan can prohibit H. pylori adhesion to host cells, thereby reducing the infection rate by 60%, especially in post treatment in the AGS cell model assay. Mechanistically, fucoidan intervenes the adhesion of BabA and AlpA of H. pylori significantly lowering the total count of H. pylori and the level of IL-6 and TNF-α in vivo. These results all converge on the same fact that fucoidan is an effective agent in a position to protect the stomach from the H. pylori infection by reducing both the total count and induced inflammation.

Smart dust, which refers to miniaturized, multifunctional sensor motes, would open up data acquisition opportunities for Internet of Things (IoT) and Environmental protection applications. However, critical obstacles remain challenging in the integration of high-density sensors, further miniaturization of device platforms, and reduction of cost. Here, we demonstrate the concept of smart digital dust to address these problems, the results of which combine the benefit of (i) maturity of complementary metal-oxide semiconductor (CMOS) processing approaches and (ii) unique form factors of emerging flexible electronics. As a prototype for smart digital dust, we present a millimeter-scale multifunctional optoelectronic sensor platform consisting of high-performance optoelectronic sensor cores and commercially available integrated-circuit components. The smart material-assisted optoelectronic sensing mechanism enables real-time, high-sensitivity hydrogen, temperature, and relative humidity (RH) sensing based on a single chip with ultralow power consumption. Such a microsystem presented here introduces a viable solution to the multifunctional sensing need of IoT and could serve as a building block for the rapidly evolving future framework of smart dust.

Many facial landmark methods based on convolutional neural networks (CNN) have been proposed to achieve favorable detection results. However, the instability landmarks that occur in video frames due to CNNs are extremely sensitive to input image noise. To solve this problem of landmark shaking, this study proposes a simple and effective facial landmark detection method comprising a lightweight U-Net model and a dynamic optical flow (DOF). The DOF uses the fast optical flow to obtain the optical flow vector of the landmark and uses dynamic routing to improve landmark stabilization. A lightweight U-Net model is designed to predict facial landmarks with a smaller model size and less computational complexity. The predicted facial landmarks are further fed to the DOF approach to deal with the unstable shaking. Finally, a comparison of several common methods and the proposed detection method is made on several benchmark datasets. Experimental evaluations and analyses show that not only can the lightweight U-Net model achieve favorable landmark prediction but also the DOF stabilizing method can improve the robustness of landmark prediction in both static images and video frames. It should be emphasized that the proposed detection system exhibits better performance than others without requiring heavy computational loadings.

Liver fibrosis is currently a global health challenge with no approved therapy, with the activation of hepatic stellate cells being a principal factor. Lipophilic constituents in Salvia miltiorrhiza (LS) have been reported to improve liver function and reduce the indicators of liver fibrosis for patients with chronic hepatitis B induced hepatic fibrosis. However, the pharmacological mechanisms of LS on liver fibrosis have not been clarified. In this study, 71 active compounds, 342 potential target proteins and 22 signaling pathways of LS were identified through a network pharmacology strategy. Through text mining and data analysis, the JAK1/STAT3 signaling pathway was representatively selected for further experimental validation. We firstly confirmed the protective effect of LS on liver fibrosis in vivo by animal experiments. Hepatic stellate cells, which proliferated and displayed a fibroblast-like morphology similar to activated primary stellate cells, were applied to evaluate its underlying mechanisms. The results showed that LS could inhibit the cell viability, promote the cell apoptosis, decrease the expression of liver fibrosis markers, and downregulate the JAK1/STAT3 signaling pathway. These results demonstrated that LS could exert anti-liver-fibrosis effects by inhibiting the activation of HSCs and regulating the JAK1/STAT3 signaling pathway, which is expected to benefit its clinical application.

This study designs and implements a wheeled bipedal robot (WBR) that combines the mobility of wheeled robots and the dexterity of legged robots. The designed WBR has extra knee joints to maintain body balance when encountering uneven terrain. Because of the robot’s highly nonlinear, dynamic, unstable, and under-actuated nature, an intelligent motion and balance controller (IMBC) based on a fuzzy logic approach is proposed to maintain the balance of the WBR while it is standing and moving on the ground. It should be emphasized that the proposed IMBC system does not require prior knowledge of system dynamics and the controller parameters are tuned using the qualitative aspects of human knowledge. Furthermore, a 32-bit microcontroller that has memory, programmable I/O peripherals, and a processor core is used to implement the IMBC method. Finally, moving and rotating, height-changing, posture-keeping, and “one leg on slope” movement scenarios are tested to demonstrate the feasibility of the proposed IMBC system. The experimental results show that, by using the proposed IMBC system, the WBR can not only balance and move well both on flat ground and in complex terrain but also extend each leg independently to maintain body balance.

Abstract Background This study aimed to describe the design and present the baseline characteristics of a web-based lifestyle intervention program, which comprises of sequentially and simultaneously delivered intervention modules targeting physical activity (PA) and fruit and vegetable consumption (FVC) in Chinese college students. Methods The study adopted a randomized placebo-controlled trial, using the Health Action Process Approach (HAPA) and the Compensatory Carry-Over Action Model (CCAM) as the theoretical backdrops. 556 Chinese college students participated in the 8-week web-based lifestyle intervention program. All eligible participants were randomly assigned to one of four groups: 1) the PA-first arm which received a 4-week intervention addressing PA followed by a 4-week intervention addressing FVC; 2) the FVC-first arm which received a 4-week intervention addressing FVC followed by a 4-week intervention addressing PA; 3) the PA + FVC simultaneous arm that received an 8-week intervention addressing both PA and FVC at the same time; and 4) the placebo-control arm that received 8 weeks of general health information, which is not relevant for changing actual PA and FVC behaviors. Data collection includes four time-points: at the beginning and end of the intervention, and a 3-month and 12-month follow-up after the intervention. Results At baseline, 41.7% of participants were male and 58.3% were female. 41.0% of the participants did not meet the standard PA-recommendations, while 69.6% did not adhere to the standard FVC-recommendations. In total, only 19.6% of participants met both PA and FVC recommendations. Baseline characteristics across the four groups had no significant differences (all P = .17–.99), indicating successful randomization. Conclusions The preliminary results indicate a high prevalence of unhealthy lifestyles in college students in China, which further supports the need for web-based health intervention programs. This is also the first study that examines the comparative effectiveness of simultaneously and sequentially delivered lifestyle interventions in the Chinese population. These findings may contribute to the creation of future web-based health behavior change interventions. Trial registration ClinicalTrails.gov: NCT03627949, 14 August, 2018.

This study Development a high-speed data acquisition (DAQ) device by using AD9226 analog-to-digital converters, a field programmable gate array, and an ARM Cortex-A8 microprocessor for a self-designed synchronous 6-channel high-speed DAQ card that was able to transmit data to a computer through its network interface. Its cost was approximately 10% that of a commercial model, the National Instruments PXI-5105, and thus overcame the prohibitively high cost of commercial DAQ cards. A high-frequency current transformer (HFCT) was used to measure three types of typical partial discharge (PD) in self-made models to compare the performance of the self-designed DAQ card and that of the National Instruments PXI-5105. The HFCT signals were converted into three-dimensional PD patterns, and mean discharge was chosen as the feature to be extracted for the application of extension theory in the recognition of discharge models. The results revealed that the self-designed DAQ card was comparable to the commercial model in the recognition of high-frequency PD signals. Given the high price of commercial high-speed DAQ devices, the self-designed DAQ card was deemed to have considerable advantages in cost and expandability.

The block samples of a Ni-based superalloy named GH4169 were prepared by laser melting deposited method using the corresponding GH4169 alloy powders,and then were heat treated with solution treatment followed by double aging.The microstructure and element segregation analysis of both as-deposited and heat treated samples were studied by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).The microhardness as well as tensile properties at room and elevated temperatures were tested.The results indicate that the microstructure of as-deposited sample mainly consists of columnar dendritic crystals that grow along with different directions.Grains are refined after solution and aging heat treatment,but remain dendritic crystals substructure inside.Compared with the as-deposited sample,the microhardness and tensile strength of the heat treated sample increase substantially,but the plasticity somewhat decreases.Nonetheless the tensile properties are superior to the standard values of forgings.The fracture surface exhibits ductile transcrystalline fracture mode.