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Purpose: Explore the effect of resection of different parts of the maxilla on the prognosis of patients with nasal malignant tumors and promote its clinical selection of nasal endoscopic maxillectomy. Methods: The clinical data of patients with maxillary sinus tumors who underwent endoscopic maxillary resection from January 2013 to May 2020 were analyzed retrospectively and the surgical methods, tumor margin, recurrence and complications are summarized. Results: Among 30 patients (all available follow-up; mean: 17.8 months, range: 2–64 months; pT: T1–T4a), 17 (56.6%) underwent partial maxillary resection, nine (30.0%) total resection, two (6.7%) subtotal resection and two (6.7%) extended resection. There was no significant difference (Log Rank; P > 0.05) in the recurrence rate between endoscopic-assisted maxillectomy and trans-facial surgery. Conclusions: According to the range of tumor lesions and the possible base, different parts of the maxillary sinus can be removed selectively assisted by endoscopy. With the application of endoscopic-assisted maxillectomy, the function can be preserved as far as possible without increasing complications or recurrence rate, and the surgical field of view will be exposed more clearly.

A plasmonic waveguide system composed of metal-insulator-metal (MIM) stub coupled with circular cavity resonator was proposed to produce ultra sharp Fano resonances, which resulted from the coupling between the ultra narrow discrete resonances and the ultra broad spectrum of the plasmonic circular cavity and stub resonator, respectively. The spectral line shapes of the Fano resonances can be easily adjusted by changing the structure parameters. And the transmittance of the system can sharply decrease from peak (“on state”) to valley (“off state”) with wavelength shifts of only about 8 nm. Due to the sharp phase change of the ultra asymmetric Fano resonance, a maximum group index of about 180 can be realized. Also, the ultra sharp spectrum contributes to a highly efficient plasmonic refractive index sensor, which can yield a linear sensitivity of 1277 nm/RIU and figure of merit of about 2.1 × 104. The proposed structure may have potential applications in nanoscale filter, slow light, and refractive index sensor.

A low cost polymer sampled waveguide Bragg grating which can be fabricated by using the simple contact lithography is proposed. By using the contact lithography and reactive ion etching, the sampled Bragg grating structures were fabricated on the waveguide bottom cladding, where a channel waveguide was fabricated on top of it as the waveguide core to form the polymer sampled waveguide Bragg grating working at around 1550 nm. The measured transmission and reflection spectra of the fabricated polymer sampled waveguide Bragg grating exhibit multiple dips and peaks, respectively. And the wavelength interval among the peaks is 0.376 nm, which shows good agreement with the theoretical predictions.

Collecting data like location information is an essential part of concepts like the “IoT” or “Industry 4.0”. In the case of the development of a precise localization system and an integrated navigation system, indoor location technology receives more and more attention and has become a hot research topic. Common indoor location techniques are mainly based on wireless local area network, radio frequency tag, ZigBee technology, Bluetooth technology, infrared technology and ultra-wideband (UWB). However, these techniques are vulnerable to various noise signals and indoor environments, and also the positioning accuracy is easily affected by the complicated indoor environment. We studied the problem of real-time location tracking based on UWB in an indoor environment in this paper. We have proposed a combinational filtering algorithm and an improved Two-Way Ranging (ITWR) method for indoor real-time location tracking. The simulation results prove that the real-time performance and high accuracy of the presented algorithm can improve location accuracy. The experiment shows that the combinational algorithm and ITWR method which are applied to the positioning and navigation of the smart supermarket, have achieved quiet good results in positioning accuracy. The average positioning error is less than 10[Formula: see text]cm, some of the improvements can elevate the positioning accuracy by 17.5%. UWB is a suitable method for indoor real-time location tracking and has important theoretic value and practical significance.

Waveguide ring resonators (WRRs) operating at a telecom window of 1.4∼1.6 μm based on asymmetric Au-(Pb, La)(Zr, Ti)O3-Au structure is proposed and investigated. Electro-optical control of such WRRs is conducted by introducing epitaxial (Pb, La)(Zr, Ti)O3 (PLZT) thin films as the core layer deposited between the upper and lower gold slabs with different widths. The long-term reliability, large electro-optic (EO) coefficients, and spontaneous polarization properties of PLZT thin films have ensured high performance of our WRRs. It has been demonstrated that the footprint of WRR can be fabricated less than 20 μm2 with the radius of ring resonator around 1 μm through combining PLZT thin films with surface plasmons (SPs). Furthermore, the large extinction ratio (∼43 dB), as well as comparatively low insertion loss (

Communication System Transmission Performance Tester, as a digital communication system design and testing equipment, plays an important role in the construction and daily maintenance of the communication system. The paper presents a kind of tester, which is designed using Cyclone IV FPGA (Field Programmable Gata Array) and VHDL (Very High Speed Integrated Circuits Hardware Description Language). According to the features in the eye diagram, the system performance can intuitively and qualitatively evaluated. The results prove that the system accurately displayed the eye diagram, thereby reflected the performance of the baseband transmission system truthfully

To help first year students adapt to their college lives and to enhance student learning, freshman seminar courses have been popular in many advanced countries. However, seminar courses in China are still in the beginning stage and are mainly for elective courses considering the large number of students in many majors. In this paper, implementation of a new required freshman seminar course, “Introduction to learning in the specialty of electronics and information” in Southeast University, is introduced. The course is composed of three education stages, i.e., lecture, investigation and project, during which the students can have closer and closer views to the applications of electronic science and engineering, and gain in-depth experience of relevant projects step by step. In addition, by making use of flexible class forms, various teaching methods, composite evaluation methods, and collaboration of a teacher team, the seminar course has been successfully run for about 170 students for the first time.

Precipitation intensity is strong and often lasts for a long time in the Xiangjiang river basin. However, the distribution of time and space is uneven. Moreover, the main stream and tributaries of the Xiangjiang river constitute asymmetric water system on two sides, Which leads the spatial variation of river hydrology and flow gathered fast and downstream flooding. All along, the Xiangjiang river basin has been frequently threatened by floods. The Xiangjiang River is the largest of the Dongting Lake water system and the middle and lower reaches of the Xiangjiang river is China's major grain production bases. So it is a great significance to do mid-to-long-term hydrological forecasting on the Xiangjiang river basin. Because mid-to-long-term hydrological forecasting have a longer period foreseen, people can take early measures to co-ordinate arrangements when solving flood control and fight a drought, water storage and disposal and the contradiction between the various departments. It is very important to hydropower plant production planning, flood prevention and drought control, water resources management and comprehensive utilization. The thesis, based on the mid-to-long-term hydrological phenomena is a typical fuzzy system of the basic thinking, combines cause-and-effect and statistical analysis with fuzzy analysis and chooses predictors such as rainfall and atmospheric circulation in earlier stage which effect the annual maximum peak discharge. Then sets up the fuzzy model of pattern recognition that used to the Xiangtan station of the Xiangjiang river. The high accuracy prediction result shows that models are reasonable and worth popularization and application.

A symmetric dielectric loaded surface plasmon polariton waveguide is proposed and numerically analyzed. The characteristics of the symmetric and asymmetric bound modes, including the effective mode indices, propagation lengths, mode sizes and mode shapes at telecom wavelength 1.55 microm are investigated in detail. The simulation results show that the sub-wavelength confinement (about1.45 microm ) and a long propagation (about 820 microm ) can be realized. Although the mode sizes are a bit larger than that of the dielectric loaded surface plasmon polariton waveguide, an order longer propagation length can be achieved. The proposed symmetric dielectric loaded surface plasmon polariton waveguide provides a potential for low loss and high density photonic integration.

A nanometric and high sensitive refractive index sensor based on the metal-insulator-metal plasmonic Bragg grating is proposed. The wavelength encoded sensing characteristics of the refractive index sensor were investigated by analyzing its transmission spectrum. The numerical results show that a good linear relationship between the Bragg wavelength and the refractive index of the sensing material can be obtained, which is in accordance with the analytical results very well. A high refractive index sensitivity of 1,488 nm/RIU around Bragg resonance wavelength of 1,550 nm was obtained. Besides, the simulation results show that the sensitivity is depended on the Bragg resonance wavelength and the longer the Bragg resonance wavelength, the higher sensitivity can be obtained. Furthermore, the figure of merit of the refractive index sensor can be greatly increased by introducing a nano-cavity in the proposed plasmonic Bragg grating structure. This work pave the way for high sensitive nanometric refractive index sensor design and application.

A narrow band waveguide Fabry?Perot filter at 1550 nm, which is composed of two polymer waveguide Bragg gratings as reflectors, is presented. By using conventional lithography, a low-loss polymer channel waveguide was fabricated, and the submicron Bragg grating structure was transferred onto the waveguide surface using a nanoimprinting technique. The transmission spectrum of the device was measured, and the results show that there is a very narrow transmission peak, with a 3 dB bandwidth of 0.011 nm in the 0.38 nm rejection band of the waveguide Bragg grating. A quality factor of Q???1.41???105 is achieved. The insertion loss and the extinction ratio of the Fabry?Perot filter are about ?12.5 dB and 17 dB, respectively. In addition, the measured transmission spectrum is in excellent accordance with the numerical simulation.

A hybrid surface plasmonic waveguide with nanometric confinement is proposed. With interactions between high-index-contrast dielectric waveguide modes and surface plasmon modes of a very thin metal film, nanometric hybrid surface plasmon modes with high optical intensities can be formed. Characteristics of the symmetric and asymmetric hybrid surface plasmon modes, including the effective mode indices, propagation lengths, mode sizes, and power intensities at telecom wavelength (1550 nm), are investigated in detail. Simulation results show that nanometric mode confinement and a long propagation length can be realized simultaneously. The high optical power intensity and long propagation length of the nanometric hybrid surface plasmon modes are very promising for high-density photonic integration and nonlinear waveguide applications.

An organic dye salt trans-4-[p-(N-hydroxyethyl-N-methylamino)styryl]-N-methylpyridinium iodide (ASPI) is doped with an electron transport organic molecule tris(8-hydroxyquinoline) aluminium (Alq3) in a host matrix of poly(methylmethacrylate) (PMMA), and the amplified spontaneous emission (ASE) is studied. By efficient Forster energy transfer from Alq3 to ASPI, it is demonstrated that the ASE threshold of ASPI:Alq3:PMMA waveguide (about 11μJ/pulse) is much lower than that of ASPI:PMMA system (about 38μJ/pulse). Meanwhile, the peak position of ASE can be controlled by the effect of film thickness on waveguide modes. We show that the ASE peak position can be tuned over 37nm. These characteristics indicate the ASPI:Alq3 system as a promising gain medium for optical amplifiers and organic semiconductor lasers.

We report the stimulated emission from a dye doped polymer plane waveguide with TiO2 particles. This waveguide consists of a poly (methylmethacrylate) (PMMA) film containing laser dye DCM as a gain medium. The emission spectrum of the film pumped by the Nd:YAG laser is different from the amplified spontaneous emission of the dye-doped film without particles. It is shown that when the excitation intensity reaches the threshold 9.6 ?J, the broad band emission spectrum narrows into multiple separate peaks with central wavelength of 608 nm. The linewidth of the sharp peak is 0.5 nm. According to our analyses, this phenomenon is due to the multiscattering of the disordered TiO2 particles inside the gain polymer film.

Early diagnosis in exhaled breath is a key technology for next-generation personal healthcare monitoring. Current chemiresistive sensors, primarily based on metal oxide (MOx) thin films, have limited applicability in such portable systems due to their high power consumption, long recovery time, poor device-to-device consistency, and baseline drifts. To address these challenges for ammonia ($${{\rm{NH}}}_{3}$$ NH 3 ) detection in exhaled breath, a critical biomarker for a variety of kidney and liver problems, we present a formulation of a graphene–MOx functional ink-based sensing platform. We integrate our sensing layer directly onto miniaturized CMOS microhotplates (μHP) via inkjet printing, potentially enabling scalability and device-to-device performance repeatability. Using stage-by-stage temporal analysis, and a temperature-pulsed modulation (TM) strategy, we achieve ultrahigh responsivity (1500% at 10 ppm pure $${{\rm{NH}}}_{3}$$ NH 3 ), fast response and recovery time (28 and 43 s), ultralow power consumption (~6 mW), negligible baseline drift ($${{\rm{WO}}}_{3}$$ WO 3 ) device as part of the sensor array. Our dual graphene–MOx formulations and their integration with ultralow power CMOS through inkjet printing represent a significant step towards reliable and portable multi-analyte breath diagnostics.

The creation of crystal phase heterostructures of transition metal chalcogenides, e.g., the 1T/2H heterostructures, has led to the formation of metal/semiconductor junctions with low potential barriers. Very differently, post-transition metal chalcogenides are semiconductors regardless of their phases. Herein, we report, based on experimental and simulation results, that alloying between 1T-SnS2 and 1T-WS2 induces a charge redistribution in Sn and W to realize metallic Sn0.5W0.5S2 nanosheets. These nanosheets are epitaxially deposited on surfaces of semiconducting SnS2 nanoplates to form vertical heterostructures. The ohmic-like contact formed at the Sn0.5W0.5S2/SnS2 heterointerface affords rapid transport of charge carriers, and allows for the fabrication of fast photodetectors. Such facile charge transfer, combined with a high surface affinity for acetone molecules, further enables their use as highly selective 100 ppb level acetone sensors. Our work suggests that combining compositional and structural control in solution-phase epitaxy holds promises for solution-processible thin-film optoelectronics and sensors., Controlling the composition and crystal phase of layered heterostructures is important. Here, the authors report the liquid-phase epitaxial growth of Sn0.5W0.5S2 nanosheets with 83% metallic phase on SnS2 nanoplates, which are used as 100 ppb level chemiresistive gas sensors at room temperature.

Understanding of the fundamental photoresponse of carbon nanotubes has broad implications for various photonic and optoelectronic devices. Here, Z-scan and pump-probe spectroscopy performed across 600-2400 nm were combined to give a broadband 'degenerate' mapping of the nonlinear absorption properties of single-wall carbon nanotubes (SWNTs). In contrast to the views obtained from non-degenerate techniques, sizable saturable absorption is observed from the visible to the near-infrared range, including the spectral regions between semiconducting excitonic peaks and metallic tube transitions. In addition, the broadband mapping unambiguously reveals a photobleaching to photoinduced absorption transition feature within the first semiconducting excitonic band ∼2100 nm, quantitatively marking the long-wavelength cut-off for saturable absorption of the SWNTs investigated. Our findings present a much clearer physical picture of SWNTs' nonlinear absorption characteristics, and help provide updated design guidelines for SWNT based nonlinear optical devices.

Ultrafast fiber lasers with broad bandwidth and short pulse duration have a variety of applications, such as ultrafast time-resolved spectroscopy and supercontinuum generation. We report a simple and compact all-fiber thulium-doped femtosecond laser mode-locked by carbon nanotubes. The oscillator operates in slightly normal cavity dispersion at 0.055 ps2 and delivers 152 fs pulses with 52.8 nm bandwidth and 0.19 nJ pulse energy. This is the shortest pulse duration and the widest spectral width demonstrated from Tm-doped all-fiber lasers based on 1 or 2 dimensional nanomaterials, underscoring their growing potential as versatile saturable absorber materials.

We demonstrate a ytterbium (Yb) and an erbium (Er)-doped fiber laser Q-switched by a solution processed, optically uniform, few-layer tungsten disulfide saturable absorber (WS2-SA). Nonlinear optical absorption of the WS2-SA in the sub-bandgap region, attributed to the edge-induced states, is characterized by 3.1% and 4.9% modulation depths with 1.38 and 3.83 MW/cm2 saturation intensities at 1030 and 1558 nm, respectively. By integrating the optically uniform WS2-SA in the Yb- and Er-doped laser cavities, we obtain self-starting Q-switched pulses with microsecond duration and kilohertz repetition rates at 1030 and 1558 nm. Our work demonstrates broadband sub-bandgap saturable absorption of a single, solution processed WS2-SA, providing new potential efficacy for WS2 in ultrafast photonic applications.

We fabricate a free-standing few-layer molybdenum disulfide (MoS2)-polymer composite by liquid phase exfoliation of chemically pristine MoS2 crystals and use this to demonstrate a wideband tunable, ultrafast mode-locked fiber laser. Stable, picosecond pulses, tunable from 1,535 nm to 1,565 nm, are generated, corresponding to photon energies below the MoS2 material bandgap. These results contribute to the growing body of work studying the nonlinear optical properties of transition metal dichalcogenides that present new opportunities for ultrafast photonic applications.

A binary solvent ink exploiting solutal Marangoni flows to suppress the coffee-ring effect for uniform printing of 2D crystals., Recent advances in inkjet printing of two-dimensional (2D) crystals show great promise for next-generation printed electronics development. Printing nonuniformity, however, results in poor reproducibility in device performance and remains a major impediment to their large-scale manufacturing. At the heart of this challenge lies the coffee-ring effect (CRE), ring-shaped nonuniform deposits formed during postdeposition drying. We present an experimental study of the drying mechanism of a binary solvent ink formulation. We show that Marangoni-enhanced spreading in this formulation inhibits contact line pinning and deforms the droplet shape to naturally suppress the capillary flows that give rise to the CRE. This general formulation supports uniform deposition of 2D crystals and their derivatives, enabling scalable and even wafer-scale device fabrication, moving them closer to industrial-level additive manufacturing.