Environment monitoring is important for the safety of underground coal mine production, and it also an application Wireless Sensor Networks (WSNs). We put forward integrated environment system mine, which uses existing Cable Monitoring System (CMS) as main body WSN with multi-parameter supplementary technique. As CMS techniques are mature, this paper mainly focuses on interconnection between CMS. In order to implement mines, two work modes designed: periodic inspection interrupt service;...

Curved beams are a class of elements capable bi-stability and can be used to construct multi-stable metamaterials. These materials leverage elastic snap-through in curved transition between multiple stable states, effectively achieving energy absorption trapping. The deformation allows the structure repetitively. However, conventional beam unit cells design process omits influence supporting frames, resulting inadequate constrains fabricated Its mechanical properties number states...

Abstract Broadband photodetectors have a wide range of applications in the fields biomedical sensing, environmental monitoring, optical communications, and space exploration. Since light absorbed by MAPbX 3 perovskite materials is mainly located within visible region, detection limited. To broaden for these types and, thus, enhance number possible application scenarios, non‐fullerene acceptor Y6 introduced that strongly absorbs near‐infrared band alongside PM6 forms an organic bulk...

The IPv6 over Low Power Wireless Personal Area Network (6LoWPAN), a special type of Sensor Networks (WSNs) with mobility, has great potential to be deployed for the convenience people’s life. In 6LoWPAN, group sensor nodes often move together as whole subset, guiding by cluster head. Because low-power requirements mobile devices in seeking low cost schemes manage mobility subset is very essential problem solved. To this end, paper firstly proposes Proxy Mobile (PMIPv6) Aided Mobility (NEMO)...

Though tandem solar cells (TSCs) based on wide-bandgap perovskite (WB-PSCs) as the top sub-cells continuously gain efficiency breakthroughs, low power conversion (PCE) of WB-PSCs caused by defects and interface energy-level mismatch is still a vital issue limiting their performance. Moreover, stability layer against moisture subsequent fabrication process essential to highly stable TSCs. Herein, nonpolar material with an ultra-long chain, didodecyldimethylammonium bromide (DDAB), was...

I–III–VI type semiconductor nanocrystals (NCs) have attracted considerable attention due to their environmental friendly nature and large-scale tunable emission. Herein, we report the successful synthesis of full-spectrum (470 614 nm) Ag–In–Ga–Zn–S (AIGZS) NCs by precisely regulating In/Ga ratios using a facile one-pot method. Intriguingly, photoluminescence (PL) peak width exhibits continuous narrowing trend with extended reaction time, ultimately reaching full at half-maximum (fwhm) 34 nm...

Quasi-two-dimensional (quasi-2D) perovskites exhibit excellent performance when applied to light-emitting diodes (LEDs). However, quasi-2D perovskite films generally have nonuniform n phases and irregular internal crystal structures, which degrade the device's performance. Here, we propose using a Dion-Jacobson (DJ)-type organic spacer modulate phase distribution of Ruddlesden-Popper (RP) perovskite. A DJ-type cation, 1.6-hexamethylenediamine (HDABr2), was introduced into as second cation...

Network connectivity is a fundamental requirement for applying the vehicular ad hoc networks (VANETs) to real traffic systems. The high mobility of vehicles results in rapid changes network topology generating dynamic variation connectivity. Therefore, new approach using Exponential Random Geometric Graphs (ERGGs) analyze VANETs presented considering randomness vehicles' velocity and headway under scenario free flow state on highway. Vehicles enter highway according Poisson distribution,...

Near-infrared photodetectors (NIR-PDs) are widely used in communications, biomedical imaging, and national defense. Here we report a new strategy to prepare short wavelength light filter based NIR-PDs by introducing an interface layer between the perovskite polymer achieve selective passage of carriers. Through synergistic effect layer, component signal spectrum is effectively filtered out. The organic with bulk heterojunction structure applied realize absorption conversion near-infrared...

The development of tandem optoelectronic devices has garnered significant attention as they can potentially enhance the light absorption and power conversion efficiency solar cells. A perovskite/interface layer/organic quasi-tandem system was constructed to develop a series narrowband photodetectors (NPDs) that function in visible near-infrared regions. range response be directionally modulated by adjusting perovskite organic material contents at front back subcells, respectively. This...

Absorption of the long-wave infrared from human beings and surroundings is a key step to imaging sensing. Here we demonstrate flexible transparent broadband absorber using photoresist-assisted metamaterials fabricated by one-step laser direct writing. The photoresist patterned as an insulator layer well mask build complementary bilayer without lithography. average absorptivity 94.5% 8 14 μm in experiment due destructive interference reflected beam explained Fabry-Perot cavity model. proposed...

Electrochemical hydrogenation reactions demand rapid proton-coupled electron transfer at the electrode surface, kinetics of which depend closely on pH. Buffer electrolytes are extensively employed to regulate pH over a wide range. However, specific role buffer species should be taken into account when interpreting intrinsic dependence, is easily overlooked in current research. Herein, we report electrochemical hydroxyacetone, derived from glycerol feedstock, propylene glycol with faradaic...

Dual-band photodetectors (PDs) have attracted extensive research attention due to their great potential for diverse and refreshing application scenarios in full-color imaging, optical communication, imaging detection. Here, a self-driven dual-band PD without filters other auxiliary equipment achieve narrowband response Mode 1 broadband 2 was designed based on carrier-selective transmission narrowing (CSTN). The polymer material poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), which...

This paper investigates the energy efficient resource allocation for OFDM relay networks, where K users receive information via L helping relays. For such a system, an optimization problem is formulated to maximize system efficiency (EE) by jointly optimizing selection, subcarriers assignment and power under proportional rate constraints available constraint. Since this non-convex with integer variables, which nontrivial be solved using known methods, we design low- complexity algorithm...

Multihop question answering has attracted extensive studies in recent years because of the emergence human annotated datasets and associated leaderboards. Recent have revealed that systems learn to exploit annotation artifacts other biases current datasets. Therefore, a model with strong interpretability should not only predict final answer, but more importantly find supporting facts’ sentences necessary answer complex questions, also known as evidence sentences. Most existing methods...

In this paper, we present a measurement campaign of indoor massive MIMO channels by using wideband channel sounder and rectangular large-scale array with 256 elements. The measurements are conducted at 11 GHz, bandwidth 200 MHz, the light-of-sight (LOS) scenario is considered. Some basic parameters, including shadow fading, delay spread coherence bandwidth, extracted. non-stationarity radio channels, which reflected variations over different locations, discussed. results would be useful for...

Physical layer network coding (PNC), where relay node is allowed to process the superimposed signal directly, can improve throughput and spectral efficiency greatly. In this paper, we extent nearest neighbor approximation investigate symbol error rate (SER) of PNC over AWGN channels. SER for BPSK QPSK modulation derived, an algorithm designed calculate high order modulations. Simulation results validate derived expressions characterize performance

The dependability of the train localization based on Global Navigation Satellite System (GNSS) is fundamental for railway applications. In stations and similar harsh environments, skyscraper station ceilings have created obstacles to reception GNSS signals. Multipath non-line-of-sight (NLOS) signals a strong influence positioning accuracy. 3D digital track map aided can identify NLOS signal caused by obstacles. Then accuracy improvement identification analytical method be applied. This paper...

This paper investigates the relay beamforming design for quality of service (QoS) discrimination in two‐way networks. The purpose is to keep legitimate users exchange their information via a helping multiantenna with QoS guarantee while avoiding exchanged overhearing by unauthorized receiver. To this end, we propose physical layer method, where jointly designed artificial noise (AN) which used interfere user’s reception. We formulate joint and AN (BFA) into an optimization problem such that...

To connect wireless sensor networks and WiMAX accessing system, a system is proposed in this paper. It composed of two parts. The first part used to establish P2P network multiple (WSNs) named as ¿WSN Peer Group (WPG)¿. This implemented by using JXTA platform. In the WPG, informations can be shared peer networks. second WPG which Gateway (WG). As WG developed for not certain WSN, new proposes way WSNs access WiMAX, avoids developing various gateways different types WSNs. performances on...