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Switchable frequency selective rasorbers (FSRs) have been extensively studied recently due to their out-of-band stealth and in-band electromagnetic wave manipulation abilities. Nevertheless, the vast majority of the reported FSRs are incapable of in-band waves control, including simultaneous transmission, reflection, and absorption. Herein, this article proposes a multifunctional switchable FSR that is capable of switching among all three transmission modes at the operation band. This FSR consists of two periodic layers embedded with p-i-n diodes that are separately controlled by bias voltages. By changing the states of the p-i-n diodes in each layer, the incident wave within the operation band can be manipulated continuously (transmission mode in the on–on state, reflection mode in the on–off state, absorption mode in the off–off state). Furthermore, the broad region below the operation band retains high absorptivity throughout all states. The physical properties of the multifunctional switchable FSR are investigated with an equivalent circuit model. The measured results show that a switchable operation frequency is located at 10.15 GHz, and an effective absorption band ranges from 3.8 GHz to 8.6 GHz. The proposed design has promising potential for multiple applications, such as communication for the transmission mode, protection of high-power microwaves for the reflection mode, and stealth and electromagnetic compatibility for the absorption mode.

This article presents a series of intensity high-pass devices (IHPDs) that are designed and investigated to prevent the propagation of high-power microwaves (HPMs) in RF front-end systems. The IHPDs function as a band-stop filter for low-intensity waves and a bandpass filter for high-intensity waves. By combining an IHPD, a circulator, and a matched load, an intensity-dependent nonreciprocal component (IDNC) is created. The IDNC exhibits unidirectional transmission characteristics with high power backward input, thus achieving HPM protection. This article investigates and verifies the mechanisms and designs of IHPDs through measurements to meet various performance requirements. First, circuit models for diodes, circuit units, and IHPDs are established successively. Next, a standardized design procedure is presented, which clearly outlines the steps from specifications to implementation. The optimal values of the circuit components are determined by comparing them with the results of circuit and full-wave simulations. The measured results, including the $S$ -parameters, bandwidths, and thresholds, closely match the designed results. This method provides a new perspective and is suitable for high-power in-band full-duplex (IBFD) applications.

Superhydrophobic coatings for umbrella canopies have the potential to solve the issue of rain residue. However, achieving both impalement resistance and mechanical robustness in these coatings poses a significant challenge and limits their practical applications. In this study, we propose a similar “pole erecting” method utilizing perfluorodecyl polysiloxane modified SiO2nanoparticles (F-silica) as the pole and poly(dimethylsiloxane) (PDMS) as the screw to enhance impalement resistance and mechanical robustness, which is attributed to the three-tier hierarchical micro-/micro-/nanostructure bonded by PDMS, along with a reduction in aspect ratio. The obtained PDMS0.5-F-silica could withstand 150 min of water drop impacting (equivalent to approximately 19,000 water drops) and 60 s of 50 kPa water jetting, also showed exceptional endurance against various mechanical tests, including 200 cycles of reciprocating abrasion, 1000 cycles of Martindale abrasion and 200 cycles of tape peeling. Moreover, when applying the PDMS0.5-F-silica coating to umbrella canopies, we observed an absence of rain residue after subjecting the umbrella to 20 h rain. These findings are promising for the development and practical implementation of superhydrophobic coatings.

In this article, a wideband energy selective surface (ESS) with quasi-elliptic response and high shielding effectiveness is proposed for providing out-of-band rejection and high-power microwave protection at the same time for wideband systems. By cascading three layers of structures and loading diodes, wideband quasi-elliptic response and nonlinear transmission property are realized. The ESS has a wide pass-band and high out-of-band rejection simultaneously with turned off diodes under a low-power incidence. On the contrary, under a high-power incident wave, diodes are turned on adaptively, leading to a high shielding in wideband. An equivalent circuit model is first designed in which a three-order Chebyshev filter with a serial LC and diodes is schemed. ESS structure is then constructed based on the circuit model. Field-circuit cosimulation is employed to analyze the power-dependent transmission property. In addition, two prototypes are designed and measured in rectangular waveguides, where it can be seen that the simulation and measurement findings agree well. The proposed ESS has a wide pass-band of 6–10 GHz and great out-of-band rejection with one transmission zero at 11.6 GHz under a low-power incidence, whereas high shielding in wideband is observed for high-power incidence.

This study aimed to investigate the indocyanine green (ICG) dose in real‐time fluorescent cholangiography during laparoscopic cholecystectomy (LC) with a 4K fluorescent system. A randomized controlled clinical trial was conducted in patients who underwent LC for treatment of cholelithiasis. Using the OptoMedic 4K fluorescent endoscopic system, we compared four different doses of ICG (1, 10, 25, and 100 µg) administered intravenously within 30 min preoperatively and evaluated the fluorescence intensity (FI) of the common bile duct and liver background and the bile-to-liver ratio (BLR) of the FI at three timepoints: before surgical dissection of the cystohepatic triangle, before clipping the cystic duct, and before closure. Forty patients were randomized into four groups, and 33 patients were fully analyzed, with 10 patients in Group A (1 µg), 7 patients in Group B (10 µg), 9 patients in Group C (25 µg), and 7 patients in Group D (100 µg). The preoperative baseline characteristics were compared among groups (p> 0.05). Group A showed no or minimal FI in the bile duct and liver background, while Group D showed extremely high FIs in the bile duct and in the liver background at the three timepoints. Groups B and C presented with visible FI in the bile duct and low FI in the liver background. With increasing ICG doses, the FIs in the liver background and bile duct gradually increased at the three timepoints. The BLR, however, showed no increasing trend with an increasing ICG dose. A relatively high BLR on average was found in Group B, without a significant difference compared to the other groups (p> 0.05). An ICG dose ranging from 10 to 25 µg by intravenous administration within 30 min preoperatively was appropriate for real‐time fluorescent cholangiography in LC with a 4K fluorescent system. Registration: This study was registered in the Chinese Clinical Trial Registry (ChiCTR No: ChiCTR2200064726).

In this article, a novel nonreciprocal energy selective surface (ESS) concept is proposed against high-intensity radiation field (HIRF) threat, which has unidirectional HIRF isolation performance in ultra-broadband. The nonreciprocal ESS consists of an electromagnetic (EM) detector, a controlling module, and a controllable surface. The EM detector is used to monitor the forward electric field. When HIRF irradiation comes from the front, the controllable surface is triggered by the detector from transparent to opaque, thus isolating the HIRF to protect the back-end sensitive equipment. On the contrary, the backward HIRF cannot trigger the controllable surface, thus ensuring that the HIRF can radiate out. To illustrate this concept, an ultrabroadband nonreciprocal ESS prototype is designed and fabricated. The results of the simulation and measurement prove that the designed ESS has low insertion loss for small signals and shows nonreciprocal high shielding effectiveness under HIRF. Furthermore, the ESS can work in an ultrabroadband covering 3.5–8.5 GHz. The proposed method can be used to protect HIRF-sensitive equipment that requires high-power EM radiation.

This study reports the synthesis of CdS/WS2composites via a green and ultra-low-cost hydrothermal method. By controlling the relative mass ratio between WS2and CdS, an n–n type CdS/WS2heterostructure, with excellent NH3gas-sensitive properties, was developed and investigated at room temperature. Compared with pristine WS2and CdS, the CdS/WS2-40%wt composite exhibited excellent selectivity of more than 4 orders of magnitude for sensing NH3, a very short recovery time of 3 s, and ultrahigh selectivity at room temperature. The large specific surface area of the CdS/WS2composite increased the active sites for the gas-sensitive reaction. Additionally, the 2D morphology of CdS/WS2and the heterojunction formed between WS2and CdS contributed to the improved performance. Anti-humidity interference tests showed that the CdS/WS2sample remained stable under real-time monitoring of NH3at different ambient humidity values. This study paves the way for designing high-performance gas sensors operating at room temperature.

Field-induced nonlinear materials, with extended abilities of manipulating electromagnetic waves, have been widely employed in electromagnetic protection, absorption, and detection. Until now, it was found that the field-induced nonlinearity mainly shows in the optical and terahertz frequency bands. Applying the microwave band into such technical activities is hampered due to a lack of investigations on the nonlinearity caused by microwave electric fields, especially in the ultrawideband and microwave high-frequency bands. In this paper, a nonlinear metamaterial (NLMM) concept based on the integration of metamaterial structures and a semiconductor on the same wafer is proposed, which shows nonlinear behavior to the electromagnetics’ field energy in the microwave band. The designed NLMM is transparent to low-density electromagnetic radiation fields, while it adaptively becomes opaque to high-density electromagnetic radiation fields. Two types of NLMM are designed to verify the nonlinear characteristics of ultrawide and narrow bands in the microwave band, respectively. The concept of NLMM can be used for the application of the microwave frequency band in electromagnetic protection and detection.

The development of a green and non-polluting gas-sensitive material for N2H4detection at room temperature (RT) remains a challenge. Guided by the concept of green and sustainable development, we have prepared a novel porous carbon material (LSC) for high-performance N2H4detection at RT. This was achieved through a green and environmentally friendly one-step carbonization method, using Laetiporus sulphureus (LS), a tree pathogen abundant in amino acids and proteins, as a precursor for nitrogen self-doping. Through optimization of the carbonization temperature, the LSC-600 sensor achieves highly sensitive and selective detection of N2H4at RT, with a response of 32.11k%–500 ppm N2H4and exhibits a faster response (∼20.1 s) and recovery (∼1.5 s). The LSC-600 sensor shows good long-term stability, with a response to N2H4varying less than 8.4 % after 30 days. Moreover, its gas-sensitive mechanism is discussed in detail. This research not only presents a green and sustainable approach for the valuable utilization of biomass waste but also furnishes a valuable reference for the development of high-performance sensors. In addition, it expands the scope of bio-manufacturing and opens up new avenues for research and development in materials science.

A novel design method for ultra-broadband energy selective surface (ESS) is presented in this article based on the equivalent theory from filter circuits to metamaterial units. This method provides a new way of designing ESS in ultra-broadband with low insertion loss (IL) and high shielding efficiency from the perspective of filter circuit topology. It is illustrated and verified with a three layer ultra-broadband ESS. Firstly, a third-order filter with a switching bandpass to bandstop in C to Ku-band is designed and optimized. Then, the filter is mapped to a physical model of a three-layer ESS which has a nonlinear transmission response for low-intensity radiation field (LIRF) and high-intensity radiation field (HIRF) in C/X/Ku-band. The three ESS prototypes are fabricated and measured in three different band waveguides to prove the design method of the ESS proposed in ultra-broadband. Simulated and measured results demonstrate that low IL and high shielding efficiency at the same time can be obtained under low and high incident power levels, respectively, where the 1 dB loss and 23 dB shielding bandwidth cover from 5.4 to 14.45 GHz. Furthermore, the IL is less than 0.5 dB in the frequency band of 5.45–13.8 GHz and maximum shielding effectiveness (SE) reaches 25 dB at 10 GHz.

In this work, sol–gel and chemical etching methods are adopted to synthesize zinc hydroxystannate materials. Cubic tin dioxide and zinc stannate composite materials with a definite structure are successfully prepared at varied annealing temperatures and times by using the synthesized zinc hydroxystannate as a sacrificial template. After a gas sensing test, tin dioxide and zinc stannate composite samples etched at 650 °C and annealed for 4 h exhibit a strong response and outstanding selectivity to hydrogen peroxide. Furthermore, the samples prepared under such conditions demonstrate long-term stability, and also a specified level of tolerance after the humidity stability test. Moreover, because of the simple preparation method and rapid detection of hydrogen peroxide, it is worth noting that samples prepared following the etching process at the 650 °C annealing temperature for 4 h exhibit the significant benefits of tin dioxide and zinc stannate composites. In this modern era, this research emphasizes the sample's potential for the rapid identification and detection of hydrogen peroxide.

Background: The dose and dosing time of indocyanine green (ICG) vary among fluorescence cholangiography (FC) studies. The purpose of this prospective, randomized, exploratory clinical trial was to optimize the dose and dosing time of ICG. Methods: PubMed was searched to determine the optimal dose. To optimize the dosing time of ICG, a clinical trial was designed with two parts. The first part included patients with T tubes for more than 1 month. After the patient was injected with ICG, bile was collected at 10 time points to explore the change and trends of bile fluorescence intensity (FI). In addition, the results of the first experiment were used to setup a randomized controlled trial (RCT) that aimed to find the optimal dosing timing for ICG injections for laparoscopic cholecystectomy (LC). During surgery, imaging data were collected for analysis. Results: After performing a systematic review, the ICG injection dose for each patient in the clinical trial was 10 mg. Five patients were included in the first part of the study. Bile collected 8 h after ICG injection had a higher FI than bile collected at other time points (p< 0.05), and the FI of bile collected 20 h after ICG injection was nearly zero. In the second part of the experiment, 4 groups of patients (6 patients per group) were injected with 10 mg ICG at 8, 10, 12 and 14 h prior to surgery. The distribution of bile duct FI (p= 0.001), liver FI (p< 0.001), and common bile duct (CBD)-to-liver contrast (p= 0.001) were not the same in each group. Further analysis with the Bonferroni method revealed the following: (1) the FI of the CBD in the 8 h group was significantly different from that in the 14 h group (adjusted p< 0.001); (2) the liver FI of the 8 h group was higher than that of the 10 h group (adjusted p= 0.042) and the 14 h group (adjusted p< 0.001); and (3) the CBD-to-liver contrast of the 8 h group was lower than that of the 10 h group (adjusted p= 0.013) and the 14 h group (adjusted p= 0.001). Conclusion: ICG FC enables the real-time identification of extrahepatic bile ducts. The optimal effect of FC can be achieved by performing 10 mg ICG injections 10 to 12 h prior to surgery.

Biomasses are promising precursors of porous carbons. However, the complexity in composition and microstructure of biomasses might result in poor quality reproducibility of biomass-derived porous carbons. It is essential to develop reliable approaches to prepare biomass-derived porous carbons. In this work, a nitrogen-doped porous carbon derived from cellulose microfibers of rice straw was prepared. The cellulose microfibers were first extracted from rice straw by alkali treatment. Then, a hydrochar was fabricated by hydrothermal treatment of the cellulose microfibers. Nitrogen-doped porous carbon was finally obtained by calcination under high temperature with K2CO3and CO(NH2)2as the activating agent and nitrogen dopant, respectively. The prepared carbon material has an ultrahigh specific surface area (∼2800 m2/g) and a moderate nitrogen doping (1.65 atom %). Consequently, rice-straw-derived porous carbon achieves a remarkable specific capacitance (380.1 F/g at 0.5 A/g) and a good rate capability (61.8% capacitance retention at 50 A/g). In addition, the porous carbon exhibits good cycling stability. The loss of capacitance is only 4.6% after 10 000 charge–discharge cycles. This study provides a robust method for the preparation of porous carbons from lignocellulosic biomasses.

Substrate oxidation is inevitable when exposed to ambient atmosphere during semiconductor manufacturing, which is detrimental to the fabrication of state-of-the-art devices. Optimizing the deoxidation process in molecular beam epitaxy (MBE) for random substrates poses a multidimensional challenge and is sometimes controversial. Due to variations in substrates and growth processes, the determination of the deoxidation condition heavily relies on the individual’s expertise, yielding inconsistent results. This study employs a machine learning model that integrates interpolation and vision transformer (Interpolation-ViT) techniques. The model utilizes reflection high-energy electron diffraction videos as input to predict the status of the substrate, enabling automated deoxidation within a controlled architecture for various substrates. Furthermore, we highlight the potential of models trained on data from specific MBE equipment to achieve high-accuracy deployment on different pieces of equipment. In contrast to traditional methods, our approach holds exceptional value, as it standardizes deoxidation temperatures across diverse equipment and substrates. This significantly advances the standardization of the semiconductor process. The concepts and methods presented are expected to revolutionize semiconductor manufacturing processes in the optoelectronic and microelectronic industries.

Counting the cardinality of flows for massive high-speed traffic over sliding windows is still a challenging work under time and space constrains, but plays a key role in many network applications, such as traffic management and routing optimization in software defined network. In this paper, we propose a novel data structure (called LRU-Sketch) to address the problem. The significant contributions are as follows. 1) The proposed data structure adapts a well-known probabilistic sketch to sliding window model; 2) By using the least-recently used (LRU) replacement policy, we design a highly time-efficient algorithm for timely forgetting stale information, which takes constant (O(1)) time per time slot; 3) Moreover, a further memory-reducing schema is given at a cost of very little loss of accuracy; 4) Comprehensive experiments, performed on two real IP trace files, confirm that the proposed schema attains high accuracy and high time efficiency.

This paper describes a method for enhancing the electron transition among carbon nanotubes (CNTs) by integrating CNTs with a polar mineral tourmaline having spontaneous electric fields for conductive polymer composites. The thin polymer layer at the surfaces of CNTs raises the potential barrier of electron transition among CNTs, limiting the electrical properties. The incorporation of tourmaline particles (TPs) enhanced significantly the electrical properties of polyurethane/multiwalled carbon nanotube (PU/MWNT) composites. The electric fields of TPs lower the potential barrier by an applied external electric field. It is proposed that the enhanced electrical properties are due to a reduction in the potential barrier of electron hopping among CNTs. The results have important implications for enhancing the electrical properties of conductive polymer composites, endowing the composites with new fuctions, such as nagetive air ions and far-infrared emission.

The biosensors with flexibility and breathability turn out to be a vital means of non-intrusive detection of multi-components biochemical markers in human sweat. For this end, three-dimensional (3D) structure TiO2nanotube arrays were in-situestablished on Ti mesh by using the anodizing method in the present study. The 3D structure TiO2nanotube arrays@Ti mesh (3D TiO₂ NTs@Ti mesh) exhibited an anatase structure and a nanotube with pore size of 60-80 nm. 3D TiO₂ NTs@Ti mesh with good corrosion resistance made it possible to be a sweat sensor since the tube is capable of penetrating deeper into the pores to absorb more sweat, while mesh substrate exhibits high gas permeability to avoid skin damage. Sweat sensing performance was tested by using cyclic voltammetry (CV) curve, and the response current intensity increasesd with the increase in the concentrations of Na+, K+, urea and lactic acid while the current intensity decreases as the glucose concentration increases in the electrolyte solution. The semi-quantitative analysis was conducted to discriminate sweat component from each other, thereby revealing an effective recognition capability of the 3D TiO₂ NTs@Ti mesh. The density of the states (DOS) for anatase TiO₂ (101) nanotube that adsorbed different components were calculated. As suggested from the results, the adsorbed sweat components narrowed the band gap of anatase TiO2, thereby improving the current intensity.