Glass-Ceramics with High Strength and High Transmittance Obtained by Multi-Factor Controlling

The presence of Li_(2)Si_(2)O_(5) and LiAlSi_(4)O_(10) could effectively improve the elastic modulus and transmittance of lithium disilicate(LD)glass-ceramics.Through synergistically modulation of the crystal content and grain size,we obtained high strength and high transmittance of LD glass-ceramics.The optimal sample had a high transmittance of 90.3%,the hardness was 7.72 GPa,the fracture toughness was 1.07 MPa·m^(1/2),and the elastic modulus was 103.1 GPa.

Two-Stream Approximation to the Radiative Transfer Equation:A New Improvement and Comparative Accuracy with Existing Methods

Mathematical modeling of the interaction between solar radiation and the Earth's atmosphere is formalized by the radiative transfer equation(RTE), whose resolution calls for two-stream approximations among other methods. This paper proposes a new two-stream approximation of the RTE with the development of the phase function and the intensity into a third-order series of Legendre polynomials. This new approach, which adds one more term in the expression of the intensity and the phase function, allows in the conditions of a plane parallel atmosphere a new mathematical formulation of γparameters. It is then compared to the Eddington, Hemispheric Constant, Quadrature, Combined Delta Function and Modified Eddington, and second-order approximation methods with reference to the Discrete Ordinate(Disort) method(δ –128 streams), considered as the most precise. This work also determines the conversion function of the proposed New Method using the fundamental definition of two-stream approximation(F-TSA) developed in a previous work. Notably,New Method has generally better precision compared to the second-order approximation and Hemispheric Constant methods. Compared to the Quadrature and Eddington methods, New Method shows very good precision for wide domains of the zenith angle μ 0, but tends to deviate from the Disort method with the zenith angle, especially for high values of optical thickness. In spite of this divergence in reflectance for high values of optical thickness, very strong correlation with the Disort method(R ≈ 1) was obtained for most cases of optical thickness in this study. An analysis of the Legendre polynomial series for simple functions shows that the high precision is due to the fact that the approximated functions ameliorate the accuracy when the order of approximation increases, although it has been proven that there is a limit order depending on the function from which the precision is lost. This observation indicates that increasing the order of approximation of the phase function of the RTE leads to a better precision in flux calculations. However, this approach may be limited to a certain order that has not been studied in this paper.

A review of ToF-based LiDAR

In recent years,propelled by the rapid iterative advancements in digital imaging technology and the semiconductor industry,encompassing microelectronic design,manufacturing,packaging,and testing,time-of-flight(ToF)-based imaging systems for acquiring depth information have garnered considerable attention from both academia and industry.This technology has emerged as a focal point of research within the realm of 3D imaging.Owing to its relatively straightforward principles and exceptional performance,ToF technology finds extensive applications across various domains including human−computer interaction,autonomous driving,industrial inspection,medical and healthcare,augmented reality,smart homes,and 3D reconstruction,among others.Notably,the increasing maturity of ToF-based LiDAR systems is evident in current developments.This paper comprehensively reviews the fundamental principles of ToF technology and LiDAR systems,alongside recent research advancements.It elucidates the innovative aspects and technical challenges encountered in both transmitter(TX)and receiver(RX),providing detailed discussions on corresponding solutions.Furthermore,the paper explores prospective avenues for future research,offering valuable insights for subsequent investigations.

Quantitative method for calculating spatial release region for laser-guided bomb

The laser-guided bomb(LGB)is an air-to-ground pre-cision-guided weapon that offers high hit rates,great power,and ease of use.LGBs are guided by semi-active laser ground-seek-ing technology,which means that atmospheric conditions can affect their accuracy.The spatial release region(SRR)of LGBs is difficult to calculate precisely,especially when there is a poor field of view.This can result in a lower real hit probability.To increase the hit probability of LGBs in tough atmospheric situa-tions,a novel method for calculating the SRR has been pro-posed.This method is based on the transmittance model of the 1.06μm laser in atmospheric species and the laser diffuse reflection model of the target surface to determine the capture target time of the laser seeker.Then,it calculates the boundary ballistic space starting position by ballistic model and gets the spatial scope of the spatial release region.This method can determine the release region of LGBs based on flight test data such as instantaneous velocity,altitude,off-axis angle,and atmospheric visibility.By more effectively employing aircraft release conditions,atmospheric visibility and other factors,the SRR calculation method can improve LGB hit probabi-lity by 9.2%.

Electro-Optical Model of Soiling Effects on Photovoltaic Panels and Performance Implications

In this paper,a detailed model of a photovoltaic(PV)panel is used to study the accumulation of dust on solar panels.The presence of dust diminishes the incident light intensity penetrating the panel’s cover glass,as it increases the reflection of light by particles.This phenomenon,commonly known as the“soiling effect”,presents a significant challenge to PV systems on a global scale.Two basic models of the equivalent circuits of a solar cell can be found,namely the single-diode model and the two-diode models.The limitation of efficiency data in manufacturers’datasheets has encouraged us to develop an equivalent electrical model that is efficient under dust conditions,integrated with optical transmittance considerations to investigate the soiling effect.The proposed approach is based on the use of experimental current-voltage(I-V)characteristics with simulated data using MATLAB/Simulink.Our research outcomes underscores the feasibility of accurately quantifying the reduction in energy production resulting from soiling by assessing the optical transmittance of accumulated dust on the surface of PV glass.

Trends in Global Solar Radiation and Sunshine Duration in Past Two Decades in Japan

Global solar radiation (GSR) is an essential physical quantity for agricultural management and designing infrastructures. Because GSR has often been modeled as a function of sunshine duration (SD) and day length for a given set of locations and calendar days, analyzing interannual trends in GSR and SD is important to evaluate, predict or regulate the cycles of energy and water between geosphere and atmosphere. This study aimed to exemplify interannual trends in GSR and SD, which had been recorded from 2001 to 2022 in 40 meteorological stations in Japan, and validate the applicability of an SD-based model to the evaluation of GSR. Both the measured GSR and SD had increased in many of the stations in the study period with averaged rates of 0.252 [W·m−2·y−1] and 0.015 [h·d−1·y−1], respectively. The offset and the slope of the SD-based model were estimated by fitting the model to the measured data sets and were found to have been almost constant with the averages of 0.201[-] and 0.566[-], respectively, indicating that characteristics of the SD-GSR relation had not varied for the 22-year period and that the model and its parameter set can be stationarily applicable to the analyses and predictions of GSR in recent years. The stable trends in both parameters also implied that the upward trend in SD can be a main explanatory factor for that in the measured GSR. The upward trend in SD had coincided with the increase in the frequency of heavy-shortened rains, suggesting that the time period of each rainfall event had gradually decreased, which may be attributable to the obtained upward trend in SD. Further studies are required to clarify if there is some cause-effect relation between the changes in rainfall patterns and the standard level of solar radiation reaching the land surface.

Green,Sustainable Architectural Bamboo with High Light Transmission and Excellent Electromagnetic Shielding as a Candidate for Energy-Saving Buildings

Currently,light-transmitting,energy-saving,and electromagnetic shielding materials are essential for reducing indoor energy consumption and improving the electromagnetic environment.Here,we developed a cellulose composite with excellent optical transmittance that retained the natural shape and fiber structure of bamboo.The modified whole bamboo possessed an impressive optical transmittance of approximately 60%at 6.23 mm,illuminance of 1000 luminance(lux),water absorption stability(mass change rate less than 4%),longitudinal tensile strength(46.40 MPa),and surface properties(80.2 HD).These were attributed to not only the retention of the natural circular hollow structure of the bamboo rod on the macro,but also the complete bamboo fiber skeleton template impregnated with UV resin on the micro.Moreover,a multilayered device consisting of translucent whole bamboo,transparent bamboo sheets,and electromagnetic shielding film exhibited remarkable heat insulation and heat preservation performance as well as an electromagnetic shielding performance of 46.3 dB.The impressive optical transmittance,mechanical properties,thermal performance,and electromagnetic shielding abilities combined with the renewable and sustainable nature,as well as the fast and efficient manufacturing process,make this bamboo composite material suitable for effective application in transparent,energy-saving,and electromagnetic shielding buildings.

Heat stroke alters hippocampal and cerebellar transmitter metabonomics

BACKGROUND:The mechanisms underlying heat stroke(HS)-induced hippocampal injury remain unclear.This study aimed to evaluate the HS-induced metabonomics of hippocampal and cerebellar transmitters.METHODS:The HS model was established with male Sprague-Dawley rats subjected to heat exposure of up to 42℃ at a humidity of(55.0±5.0)%.The hippocampal and cerebellar transmitters and metabolites of rats were tested via ultra-high-performance liquid chromatography–mass spectrometry(UPLC-MS/MS).The primary transmitters and metabolites were identified by principal component analysis(PCA)and orthogonal partial least square-discriminant analysis(OPLS-DA).The major metabolic pathways for HS were selected after enrichment.The brain injury was evaluated by histological tests.RESULTS:HS induced hippocampal and cerebellar injuries in rats.HS upregulated the protein levels of hippocampal glutamate,glutamine,gamma-aminobutyric acid,L-tryptophan(Trp),5-hydroxy-indoleacetic acid,and kynurenine;however,it downregulated asparagine,tryptamine,5-hydroxytryptophan,melatonin,3,4-dihydroxyphenylalanine(L-DOPA),and vanillylmandelic acid.HS also sharply elevated the protein levels of cerebellar methionine and Trp,and decreased the levels of serotonin,L-alanine,L-asparagine,L-aspartate,cysteine,norepinephrine,spermine,spermidine,and tyrosine.Hippocampal glutamate,monoamine transmitters,cerebellar aspartate acid,and catecholamine transmitters’metabolic pathways were identified as the main metablic pathways in HS.CONCLUSION:The hippocampus and cerebellum were injured in rats with HS,possibly induced the disorder of hippocampal glutamate and serotonin metabolism,cerebellar aspartate acid and catecholamine transmitter metabolism,and related metabolic pathways.

Structural and Physicochemical Properties of Dust and Their Effect on Solar Modules Efficiency in Agadir-Morocco

Experiments of soiling effects on the performances of a PV panel have been performed using dust collected from two sites in the region of Agadir-Morocco.The optical transmittance of the front glass was found to depend on the nature and density of dust.The nature of dust was studied by means of scanning electron microscopy and energy dispersive x-ray spectroscopy.It was found that the granulometry of dust particles depends on the study area.For a dust density of around 20 g/m^(2),the maximum power Pmax of the solar panel decreases drastically from 30 to 20 W for the(HP)site,and no more than 14 W for the(AD)site.The diversity of the behavior of the soiled panel was explained in terms of the size of the particles collected from each area.The transmission of light across the front glass of the PV panel is more affected when the sizes of particles are small.

High efficiency of broadband transmissive metasurface terahertz polarization converter

Terahertz wave is between microwave and infrared bands in the electromagnetic spectrum with the frequency range from 0.1 THz to 10 THz. Controlling and processing of the polarization state in terahertz wave are the focus due to its great influence on the characteristics. In this paper, a transmissive metasurface terahertz polarization converter is designed in 3D structure with an upper surface of ruler-like rectangular, an intermediate dielectric layer and a lower surface of metal grid wires. Numerical simulations of the converter show that the polarization conversion ratio(PCR) is above 99.9% at 0.288 THz–1.6 THz, the polarization rotation angle(PRA) is close to 90° at 0.06 THz–1.4 THz, and the ellipticity angle(EA) is close to 0° at 0.531 THz–1.49 THz. The origin of the efficient polarization conversion is explained by analyzing the electric field intensity, magnetic field intensity, surface current, electric field energy density, and magnetic field energy density distributions of the converter at 1.19 THz and 0.87 THz, which are consistent with the energy transmittance and transmittance coefficient. In addition, the effects of different thickness and material of intermediate layer, thickness of upper surface material, polarized wave incidence angle, and metasurface materials on the performance of the polarization converter are discussed, and how they affect the conversion performance of the polarization converter are also explained.Our results provide a strong theoretical basis and technical support to develop high performance transmission-type terahertz polarization converters, and play an important role to promote the development of terahertz science and technology.

Optical and Mechanical Properties of Ramie Fiber/Epoxy Resin Transparent Composites

The residual resources of ramie fiber-based textile products were used as raw materials.Ramie fiber felt(RF)was modified by NaClO_(2) aqueous solution and then impregnated with water-based epoxy resin(WER).RF/WER transparent composite materials were prepared by lamination hot pressing process.The composite materials’color difference,transmittance,haze,density,water absorption,and mechanical properties were determined to assess the effects of NaClO_(2) treatment and the number of ramie fiber layers on the properties of the prepared composites.The results showed significantly improved optical and mechanical properties of the RF/WER transparent composites after NaClO_(2) treatment.With the increase of ramie fiber layers,the composites’whiteness,transmittance,and water absorption decreased while the haze increased.For material with three layers,the optical transmittance in the visible light region was 82%,and the haze was 96%,indicating the material has both high transmittance and high haze characteristics.The tensile strength increases with the increase of the number of layers,and the tensile strength of the composite with six layers is 243 MPa.This study broadens the scope of application of ramie fiber as a new option for home decoration materials.

A Review on Conductive and Transparent Materials Used in the Design of Transparent Antennas

In this review, we highlight the essential parameters of some transparent materials for use in the design of transparent antennas. ITO films with a sheet resistance of Rs = 10 Ω/sq and a T = 90% transmittance, we turn to materials that can be serious alternatives for ITO, such as graphene T = 97% for Rs = 60 Ω/sq and the micro-mesh metal. Wire mesh seems to be the best alternative T = 93% for Rs Rs = 0.022 Ω/sq at T = 81%, this is the micrometric pitch mesh.

A 1.25Gb/s InP-Based Vertical Monolithic Integration of an MQW Laser Diode and an HBT Driver witha Lateral Buffer Mes a Structure

A novel fabrication process related to a smoothly wet chemical etching profile o f InP-based epitaxial layers in the crystal direction of [01for an InP-based monol ithic vertically integrated transmitter with an MQW laser diode and a heterojunction bipolar tran sistors driver circuit is described.A clear eye output diagram via an O/E converter is demonstrat ed und er a 1.25Gb/s non-return-zero pseudorandom code with a pattern length of 2 the integrated transmitter has a power dissipation of about 120mW with an optical output of 2dBm.

溶胶-凝胶法制备Al^3＋掺杂ZnO薄膜的结构和光学性能

采用无机盐溶胶-凝胶方法在载玻片衬底上制备了ZnO:Al薄膜,利用X射线衍射(XRD)、紫外-可见光透射光谱(UV-Vis transmittance spectrum)和扫描电镜(SEM)研究了退火温度和Al3+掺杂浓度对ZnO:Al薄膜结构和光学性能的影响。结果表明,随退火温度的升高或进行适当浓度的Al3+掺杂,可使(002)衍射峰的强度增强,晶粒尺寸增大,半高宽减小,薄膜的结晶质量明显改善,且可见光透过率高。

Modified Malkmus band model for clear-sky atmospheric transmittance calculation

The Malkmus band model has been widely used in remote sensing and climate studies. However, its accuracy is not high. To solve this problem, a modified Malkmus band model was proposed by introducing a correction item. The HITRAN (High-resolution TRANsmission) 2008 database and the atmospheric models provided by the Air Force Geophysics Laboratory (AFGL) were used to calculate the molecular transmittances. By fitting the calculated transmittances to those by MODTRAN (MODerate resolution atmospheric TRANsmission) package with the least-squares method, the fitting coefficients of the correction item were obtained under different atmosphere models. The experimental results show that the root mean square errors (RMSE) of the modified model are significantly less than that of the traditional Malkmus band model by 1-2 orders of magnitude. In addition, the modified method is suitable for different atmospheric models and molecules.

Analysis of Protein Content in Panicum miliaceum L. Using Near Infrared Transmittance Spectroscopy

[Objective] To explore a method for the rapid determination of protein con- tent in grains of Panicum miliaceum L. [Method] The near infrared transmittance spec- troscopy （NITS） was used to build the mathematical models for the quantitative analy- sis of protein content in the grains. Four combinations of treatment that first derivative and second derivative were respectively combined with partial least squares （PLS） and modified partial least squares （MPLS） were set to compare their effects on the original transmission spectrum. [Result] The predicting effects of the 4 combinations were similar. The optimal combination was first derivative with MPLS, in which the average determination coefficient of validation （RSQ） was 0.880 6, correlation coeffi- cient of cross validation （1-VR） was 0.857 0, standard error of calibration （SEC） was 0.342 4, standard error of cross validation （SECV） was 0.375 1, and the standard er- ror of prediction （SEP） was 0.454. [Conclusion] The constructed NITS model is a rapid way for the determination of protein content in grains of P. miliaceum.

A CMOS Power Amplifier with 100% and 18% Modulation Depth for Mobile RFID Readers

Aiming at the specific protocol of RFID technology,a 915MHz CMOS transmitter front-end for OOK modulation is implemented in a 0.18μm CMOS process. The transmitter incorporates a class-E power amplifier （PA）, a modulator, and a control logic unit. The direct-conversion architecture minimizes the required on-and-off-chip components and provides a low-cost and efficient solution. A novel structure is proposed to provide the modulation depth of 100% and 18% ,respectively. The PA presents an output ldB power of 17.6dBm while maintaining a maximum PAE of 35.4%.

Azimuthal cement evaluation with an acoustic phased-arc array transmitter:numerical simulations and field tests

We developed a novel cement evaluation logging tool,named the azimuthally acoustic bond tool（AABT）,which uses a phased-arc array transmitter with azimuthal detection capability.We combined numerical simulations and field tests to verify the AABT tool.The numerical simulation results showed that the radiation direction of the subarray corresponding to the maximum amplitude of the first arrival matches the azimuth of the channeling when it is behind the casing.With larger channeling size in the circumferential direction,the amplitude difference of the casing wave at different azimuths becomes more evident.The test results showed that the AABT can accurately locate the casing collars and evaluate the cement bond quality with azimuthal resolution at the casing-cement interface,and can visualize the size,depth,and azimuth of channeling.In the case of good casingcement bonding,the AABT can further evaluate the cement bond quality at the cementformation interface with azimuthal resolution by using the amplitude map and the velocity of the formation wave.

2.5 Gbit/s monolithic ICs for optical fiber transmitter and receiver in 0.35 μm CMOS process

2.5 Gbit/s monolithic integrated circuits （ICs） for optical fiber transmitter and receiver in 0.35 μm CMOS （complementary metal-oxide-semiconductor transistor） process are presented. The transmitter, which includes a 4： 1 multiplexer and a laser diode driver （LDD）, has four 622 Mbit/s random signals as its inputs and gets a 2.5 Gbit/s driving signal as its output; the receiver detects a 2.5 Gbit/s random signal and gets four 622 Mbit/s signals at the output. The main circuits include a trans-impedance amplifier （TIA）, a limiting amplifier, a clock and data recovery （CDR） unit, and a 1： 4 demultiplexer （DEMUX）. Test results prove the logic functions of the transmitter to be right, and the 10% to 90% rise and fall times of transmitter＇s output data eye diagram are 211.1 ps and 200 ps, respectively. The sensitivity of the receiver is measured to be better than 20 mV. The root mean square jitter of the DEMUX＇s output data is 15.6 ps and that of the clock after 1： 4 frequency dividing is 1.9 ps. Two chips are both applicable to 2.5 Gbit/s optical fiber communication systems.

A 2.4GHz Low Power ASK Transmitter for Wireless Capsule Endoscope Applications

A 2.4GHz ASK transmitter suitable for a low power wireless capsule endoscope system is presented. A mixer-based frequency up-conversion transmitter architecture is employed to achieve a high data rate. A pseudodifferential stacked class-A power amplifier using the current reuse technique is proposed to save power. The transmitter mainly includes two parts： a 20MHz ASK modulator based on a constant amplitude phase lock loop （PLL） and a direct up-conversion RF circuit. This design, implemented in a TSMC 0.25μm CMOS process, achieves a - 23. 217dBm output power with a data rate of 1Mbps and dissipates 3.17mA of current with a single 2.5V power supply.