Highly Integrated Perovskite Solar Cells-Based Photorechargeable System with Excellent Photoelectric Conversion and Energy Storage Ability

Perovskite solar cells have emerged as a promising technology for renewable energy generation.However,the successful integration of perovskite solar cells with energy storage devices to establish high-efficiency and long-term stable photorechargeable systems remains a persistent challenge.Issues such as electrical mismatch and restricted integration levels contribute to elevated internal resistance,leading to suboptimal overall efficiency(η_(overall))within photorechargeable systems.Additionally,the compatibility of perovskite solar cells with electrolytes from energy storage devices poses another significant concern regarding their stability.To address these limitations,we demonstrate a highly integrated photorechargeable system that combines perovskite solar cells with a solid-state zinc-ion hybrid capacitor using a streamlined process.Our study employs a novel ultraviolet-cured ionogel electrolyte to prevent moisture-induced degradation of the perovskite layer in integrated photorechargeable system,enabling perovskite solar cells to achieve maximum power conversion efficiencies and facilitating the monolithic design of the system with minimal energy loss.By precisely matching voltages between the two modules and leveraging the superior energy storage efficiency,our integrated photorechargeable system achieves a remarkableηoverall of 10.01%while maintaining excellent cycling stability.This innovative design and the comprehensive investigations of the dynamic photocharging process in monolithic systems,not only offer a reliable and enduring power source but also provide guidelines for future development of self-power off-grid electronics.

外推法天线增益测量系统的暗室反射影响评估

介绍了外推法技术,在此基础上提出一种基于几何光学的吸波材料影响评估方法.该方法可以在数字滤波后有效模拟并引入反射信号,通过比较两次外推后的数据,得到对增益测量的影响评估结果.在中国计量科学研究院(National Institute of Metrology,NIM)的外推法装置中进行实验验证,结果表明:该方法可以有效模拟吸波材料的影响,并给出由吸波材料引入的增益测量不确定度分量.该方法目前已应用到NIM和英国国家物理研究院(National Physical Laboratory,NPL)的外推法测量结果评定中,不仅对于外推法,对于在暗室中进行的其他天线测量结果的评估也具有很好的参考价值.

聚合物透镜的远红外色差和有效透射光谱

在50～500cm^(-1)光谱范围,计算了用高密度和低密度聚乙烯,聚4-甲基戊烯1(TPX),聚丙烯,聚四氟乙烯(PTFE)和聚苯乙烯制作的平面-凸透镜的色差和有效功率透射光谱。计算基于由色散傅里叶交换光谱测量结果推导出的光学参数。

喷雾热解法制备高产率石墨／炭纳米纤维及其特征研究

基于石墨／炭纳米纤维（GNFs）的克量级（〉1g）制备及其特征表征，通过苯的喷雾热解制备了GNFs，并采用XRD，TEM及SEM对GNFs进行了表征。结果表明：高产率GNFs的最佳生长条件是：喷管内径～0．52mm，苯液流量～5mL／min，反应温度-750℃，载气H2流量-1500mL／min。所制GNFs的典型长度和直径分别为～60μm和-250nm，大部分GNFs样品呈现螺圈／螺旋纤维状。喷雾热解生长模式中GNFs的产率为克量级（1．45g）／产程。

Effective Doping of Rare-earth Ions in Silica Gel:A Novel Approach to Design Active Electronic Devices

Eu^(3+)luminescence spectroscopy has been used to investigate the effective doping of alkoxide-based silica(SiO_2) gels using a novel pressure-assisted sol-gel method. Our results pertaining to intense photoluminescence(PL) from gel nanospheres can be directly attributed to the high specific surface area and remarkable decrease in unsaturated dangling bonds of the gel nanospheres under pressure. An increased dehydroxylation in an autoclave resulted in enhanced red(~611 nm) PL emission from europium and is almost ten times brighter than the SiO_2 gel made at atmospheric pressure and^50 using conventional St¨ober-Fink-Bohn process. The presented results are entirely different from those reported earlier for SiO_2:Eu3+gel nanospheres and the origin of the enhanced PL have been discussed thoroughly.

Effect of hydrogen plasma treatment on the growth and microstructures of multiwalled carbon nanotubes

The effect of hydrogen plasma treatment of iron oxide films on the growth and microstructure of carbon nanotubes(CNTs)by microwave plasma enhanced chemical vapor deposition process has been investigated.Microwave plasma was characterized in-situ using optical emission spectrometer.Morphology of the films was examined by scanning electron microscopy.Structural analysis was carried out by high resolution transmission electron microscopy(HRTEM)equipped with energy dispersive X-ray spectroscopy(EDS)and micro-diffraction attachments.It is found that oxide films without H_2 plasma pretreatment or treated for lesser time resulted in CNT films with high percentage of carbonaceous particles and with embedded particles/nanorods distributed discontinuously in the cavity of the nanotubes.The embedded particles were found to be of iron carbide(Fe-C)as confirmed by HRTEM,EDS and micro-diffraction analysis.Experimental observations suggested that the iron oxide particles had poor catalytic action for CNT growth and in-situ reduction of oxide clusters to Fe by hydrogen plasma plays a key role in discontinuous filling of the nanotubes by the catalytic particles.

Revisiting the Concentration Observations and Source Apportionment of Atmospheric Ammonia

While China’s Air Pollution Prevention and Control Action Plan on particulate matter since 2013 has reduced sulfate significantly,aerosol ammonium nitrate remains high in East China.As the high nitrate abundances are strongly linked with ammonia,reducing ammonia emissions is becoming increasingly important to improve the air quality of China.Although satellite data provide evidence of substantial increases in atmospheric ammonia concentrations over major agricultural regions,long-term surface observation of ammonia concentrations are sparse.In addition,there is still no consensus on whether agricultural or non-agricultural emissions dominate the urban ammonia budget.Identifying the ammonia source by nitrogen isotope helps in designing a mitigation strategy for policymakers,but existing methods have not been well validated.Revisiting the concentration measurements and identifying source apportionment of atmospheric ammonia is thus an essential step towards reducing ammonia emissions.

A direct laser-synthesized magnetic metamaterial for low-frequency wideband passive microwave absorption

Microwave absorption in radar stealth technology is faced with challenges in terms of its effectiveness in low-frequency regions.Herein,we report a new laser-based method for producing an ultrawideband metamaterial-based microwave absorber with a highly uniform sheet resistance and negative magnetic permeability at resonant frequencies,which results in a wide bandwidth in the L-to S-band.Control of the electrical sheet resistance uniformity has been achieved with less than 5%deviation at 400Ωsq^(-1)and 6%deviation at 120Ωsq^(-1),resulting in a microwave absorption coefficient between 97.2%and 97.7%within a1.56–18.3 GHz bandwidth for incident angles of 0°–40°,and there is no need for providing energy or an electrical power source during the operation.Porous N-and S-doped turbostratic graphene 2D patterns with embedded magnetic nanoparticles were produced simultaneously on a polyethylene terephthalate substrate via laser direct writing.The proposed low-frequency,wideband,wide-incident-angle,and high-electromagnetic-absorption microwave absorber can potentially be used in aviation,electromagnetic interference(EMI)suppression,and 5G applications.

Influence of Binary Oxidant (FeCl₃:APS) Ratio on the Spectroscopic and Microscopic Properties of Poly(2,5-Dimethoxyaniline)

Poly(2,5-dimethoxyaniline) (PDMA) has been synthesized by chemical oxidative polymerization technique using varying ratio (wt/wt) of binary oxidants;ferric chloride (FeCl3) and ammonium persulfate (APS). Fourier transform infrared (FT-IR) and ultraviolet-visible (Uv-vis) spectroscopic investigations provide the evidence of the presence of both benzenoid and quinoid ring units. The thermal analysis and structural characterization data suggests that the oxidant ratio greatly controls the molecular ordering in PDMA. Surface morphology shows the existence of both amorphous and crystalline domains wherein the crystalline domain size depends on the oxidant ratio. The dc conductivity (σdc) of PDMA is also a function of binary oxidant ratio and at FeCl3:APS (50:50), it increases by two orders of magnitude. Films of PDMA synthesized using FeCl3:APS (50:50) binary oxidant exhibits a decrease in the surface current on exposure to ammonia gas.

Second Harmonic Generation in Some Donor-Acceptor Substituted Chalcone Derivatives

A series of five chalcone derivatives with different substituents in para and meta posions have been synthesized, and single crystals were successfully grown in aceton solution by slow evaporation solution growth technique (SESGT). Single crystal X-ray studies revealed that all the crystals crystallized in noncentrosymmetric space group with their molecular dipoles perfectly aligned in a direction-favorable for large nonlinear optical effects. Kurtz powder tests revealed that all five materials have second-harmonic-generating properties with maximum efficiencies of approximately 14 times that of urea standard. UV-vis-NIR spectroscopy and thermogravimetric analyses are also presented for all of the reported materials. Among the five chalcones, high quality single crystals of 4-Methoxy-4'-chlorochalcone were grown by SESGT, and its crystalline perection were studied by using a high resolution X-ray diffractometry (HRXRD).

A Volt-Second Source for Calibration of Integrator in a Pulsed Field Magnetometer

A volt-second （Vs） source intended for absolutely calibrating the integrator in a pulsed field magnetometer （PFM） is designed and proven to be with accurate rising and falling edges and reasonable lower uncertainty. A comparison experiment shows that the difference between the magnetic fluxes generated respectively by the Vs source and the mutual inductor is within ±0.04%. The PFM is then calibrated in an absolute way of the Vs source. The calibrated PFM gives the measured results in good agreement with a static BH tracer supplied by National Institute of Metrology of China and provides a convenient way of studying the effect of mathematic process on the dynamic measuring curve of PFMs.

Degradation Diagnostics from the Subsurface of Lithium-Ion Battery Electrodes

Despite the long-established rocking-chair theory of lithium-ion batteries(LIBs),developing novel characterization methodology with higher spatiotemporal resolution facilitates a better understanding of the solid electrolyte interphase studies to shape the reaction mechanisms.In this work,we develop a Xenon ion plasma focused ion beam(Xe+PFIB)-based characterization technique to probe the cross-sectional interface of both ternary cathode and graphite anode electrodes,with the focus on revealing the chemical composition and distribution underneath the electrode surface by in-depth analysis of secondary ions.Particularly,the lithium fluoride is detected in the pristine cathode prior to contact with the electrolyte,reflecting that the electrode degradation is in the form of the loss of lithium inventory during electrode preparation.This degradation is related to the hydrolysis of the cathode material and the decomposition of the PVDF binder.Through the quantitative analysis of the transition-metal degradation products,manganese is found to be the dominant element in the newly formed inactive fluoride deposition on the cathode,while no transition metal signal can be found inside the anode electrode.These insights at high resolution implemented via a PFIB-based characterization technique not only enrich the understanding of the degradation mechanism in the LIBs but also identify and enable a high-sensitivity methodology to obtain the chemical survey at the subsurface,which will help remove the capacity-fade observed in most LIBs.

Thermodynamic Properties of Sodium:A First-Principles Study

The Thermal expansion,Hugoniot state and 300 K isotherm of sodium have been calculated on the basis of:(i)the accurate calculations of 0 K total energies with the full-potential linearized augmented plane wave method within the generalized gradient approximation to exchange-correlational functional and(ii)the newly developed classical mean-field statistics where both the cold and thermal parts of the Helmholtz free-energy are entirely derived from the 0 K total energy.A quite satisfactory agreement between calculation and experiment has been observed.Our approach does not invoke any empirical parameter,which has long been a desirability on the field of material science.

Influence of Picric Acid on the SHG Efficiency of L-Prolinium Tartrate Crystals

Single crystals of the NLO material L-Prolinium tartrate (LPT) have been grown in the presence and absence of picric acid, by slow evaporation technique. Good quality crystals were harvested within 30 days. The grown crystals were characterized by single crystal X-ray diffraction. The quality of the crystals grown in the presence and absence of picric acid was examined by high resolution X-ray diffractometry (HRXRD). Fourier transform infrared spectroscopy (FTIR) and Fourier transform Raman spectroscopy were used to confirm the presence of the functional groups of L-Prolinium tartrate and the absence of picric acid in the crystals. The thermal stability and the trend of decomposition of the grown crystals were analyzed by thermo gravimetric analysis (TGA). The influence of picric acid on the second harmonic generation efficiency was studied by Kurtz and Perry method. It was observed that the SHG efficiency increased by about 2.3 times compared to that of normal LPT crystals. The results are discussed in detail.

Analysis of Clinical Effect of Concurrent Chemo/radiotherapy in the Treatment of Advanced Cervical Cancer

The study aimed to analyze the efficacy and adverse effects of concurrent chemo/radiotherapy in the treatment of advanced cervical cancer,and the efficacy and safety of concurrent chemo/radiotherapy were evaluated to standardize the treatment.First of all,retrospective analysis was carried out,and 30 cases of advanced cervical cancer treated in hospitals from 2013 to 2018 were included in the study.30 cases of concurrent chemo/radiotherapy were included in the synchronous group,and 30 cases of radical radiotherapy alone were included in the radiotherapy group.The results showed that the CR rate and remission rate in the synchronous group were 43.3%and 93.3%,which were higher than those in the radiotherapy group(26.7%and 80.0%).The 3-year survival rate of the synchronous group was 80.0%,which was higher than that of the radiotherapy group,with a statistically significant difference(P<0.05).There was no significant difference in 3-year all-cause mortality,5-year survival and 5-year allcause mortality between the two groups.The tumor-free survival time in the synchronous group was(24.4±8.2)months,which was higher than that in the radiotherapy group(17.0±8.5)months,and the difference was statistically significant(P<0.05).Therefore,compared with radiotherapy alone,concurrent chemo/radiotherapy in the treatment of advanced cervical cancer can improve the 3-year survival rate and prolong the tumor-free survival time.However,it did not increase 5-year survival rate,and bone marrow suppression and gastrointestinal reactions were increased.

Laser-Induced Recoverable Fluorescence Quenching of Perovskite Films at a Microscopic Grain Scale

Understanding the fundamental properties of metal-halide perovskite materials is driving the development of novel optoelectronic applications.Here,we report the observation of a recoverable laser-induced fluorescence quenching phenomenon in perovskite films with a microscopic grain-scale restriction,accompanied by spectral variations.This fluorescence quenching depends on the laser intensity and the dwell time under Auger recombination dominated conditions.These features indicate that the perovskite lattice deformation may take the main responsibility for the transient and show a new aspect to understand halide perovskite photostability.We further modulate this phenomenon by adjusting the charge carrier recombination and extraction,revealing that efficient carrier transfer can improve the bleaching resistance of perovskite grains.Our results provide future opportunities to attain high-performance devices by tuning the perovskite lattice disorder and harvesting the energetic carriers.

A First-Principles Study of Structure-Property Correlation and the Origin of Ferrimagnetism in Gallium Ferrite

A first-principles study of structure property correlation and the origin of ferrimagnetism is presented based on LSDA+U method. In particular, the results for the ground state structure, electronic band structure, density of states, Born effective charges, spontaneous polarization and cationic disorder are discussed. The calculations were done using Vienna ab-initio simulation package (VASP) with projector augmented wave method. We find that the ground state structure is orthorhombic and insulating having A-type antiferromagnetic spin configuration. The cationic disorder is found to play an important role. Although the cationic site disorder is not spontaneous in the ground state, interchange of octahedrally coordinated Ga2 and Fe2 sites is most favored. We find that ferrimagnetism? in gallium ferrite is primarily due to this exchange between Ga-Fe sites? such that Fe spins at Ga1 and Ga2 sites are antiferromagnetically aligned? while maintaining ferromagnetic coupling between Fe spins at Ga1 and Fe1? sites as well as between Fe spins at Ga2 and Fe2 sites. Further, the partial density of states shows noticeable hybridization of Fe 3d, Ga 4s,? Ga 4p and O 2p states indicating some covalent character of Ga/Fe-O bonds.? However, the charge density and electron localization functions show largely the ionic character of these bonds. Our calculation predicts spontaneous polarization of ~59 μC/cm2 along b-axis.

Metrology of Optical Communication Systems Using Error Vector Magnitude

Error vector magnitude (EVM) as a performance metric for M-ary quadrature amplitude modulation (QAM) formats in optical coherent systems is presented. It is shown that the calibrated BER, which would otherwise be under-estimated without the correction factor, can reliably monitor the performance of optical coherent systems near the target BER of 10-3 for quadrature phase shift keying (QPSK), 16-QAM, and 64-QAM employing carrier phase recovery with differential decoding to compensate for laser phase noise. The impact on the number of symbols used to estimate the BER from EVM analysis is also presented and compared to the BER obtained by error counting.

Tropical forest canopies and their relationships with climate and disturbance： results from a global dataset of consistent field-based measurements

Background： Canopy structure, defined by leaf area index （LAI）, fractional vegetation cover （FCover） and fraction of absorbed photosynthetically active radiation （fAPAR）, regulates a wide range of forest functions and ecosystem services. Spatially consistent field-measurements of canopy structure are however lacking, particularly for the tropics. Methods： Here, we introduce the Global LAI database： a global dataset of field-based canopy structure measurements spanning tropical forests in four continents （Africa, Asia, Australia and the Americas）. We use these measurements to test for climate dependencies within and across continents, and to test for the potential of anthropogenic disturbance and forest protection to modulate those dependences. Results： Using data collected from 887 tropical forest plots, we show that maximum water deficit, defined across the most arid months of the year, is an important predictor of canopy structure, with all three canopy attributes declining significantly with increasing water deficit. Canopy attributes also increase with minimum temperature, and with the protection of forests according to both active （within protected areas） and passive measures （through topography）. Once protection and continent effects are accounted for, other anthropogenic measures （e.g. human population） do not improve the model. Conclusions： We conclude that canopy structure in the tropics is primarily a consequence of forest adaptation to the maximum water deficits historically experienced within a given region. Climate change, and in particular changes in drought regimes may thus affect forest structure and function, but forest protection may offer some resilience against this effect.

力值测量指南(2013版) 力值的测量方法介绍

各种力值的测量方法、力值传感器及性能说明。