240 nm AlGaN-based deep ultraviolet micro-LEDs:size effect versus edge effect

240 nm AlGaN-based micro-LEDs with different sizes are designed and fabricated.Then,the external quantum efficiency(EQE)and light extraction efficiency(LEE)are systematically investigated by comparing size and edge effects.Here,it is revealed that the peak optical output power increases by 81.83%with the size shrinking from 50.0 to 25.0μm.Thereinto,the LEE increases by 26.21%and the LEE enhancement mainly comes from the sidewall light extraction.Most notably,transversemagnetic(TM)mode light intensifies faster as the size shrinks due to the tilted mesa side-wall and Al reflector design.However,when it turns to 12.5μm sized micro-LEDs,the output power is lower than 25.0μm sized ones.The underlying mechanism is that even though protected by SiO2 passivation,the edge effect which leads to current leakage and Shockley-Read-Hall(SRH)recombination deteriorates rapidly with the size further shrinking.Moreover,the ratio of the p-contact area to mesa area is much lower,which deteriorates the p-type current spreading at the mesa edge.These findings show a role of thumb for the design of high efficiency micro-LEDs with wavelength below 250 nm,which will pave the way for wide applications of deep ultraviolet(DUV)micro-LEDs.

能源化学工程专业的无机化学课程思政特色建设

对能源化学工程专业无机化学课程的课程思政建设进行了系统的设计、探索与实践。主要举措包括从能源化学工程专业视角充分挖掘无机化学的课程思政元素,采用绪论引领、随堂引入或引导、案例研讨、专题分享、在线推文和交流等方式进行课程思政教育,实现全程和全方位促学,激发学生的专业使命感和社会责任感,提升了学生的综合能力和专业素养。

Modeling and Optimization of Capacitive Converter for Energy Scavenging System

A new converter with spherical cap for energy scavenging is proposed. Based on the method of separated variables within the torrid coordinate system, a corresponding analytical model for spherical cap converter is further established so as to obtain the analytic expressions of the topology capacitance and the output voltage. The concept of energy increment factor is specifically defined to denote the improvement of energy storage efficiency. With regard to spherical cap converters of different dimensions, the measured values of energy increment factor coincide well with the theoretical equivalents, indicating an effective verification of the proposed analytical model for the spherical cap converter topology.

Study on Eco-climate Type Regionalization of Wheat Growing Areas in Yunnan Province

In order to provide an objective and scientific theoretical basis for rational distribution of wheat growth in Yunnan Province,according to the relationship between Yunnan weather conditions and wheat growth adaptability,a study on eco-climate type regionalization of wheat growing areas in Yunnan was conducted using principal component analysis and GIS technology. The results show that Yunnan Province could be divided into four types,namely southern warm and humid wheat growing area,central semi-arid wheat growing area,central semi-humid wheat growing area and north-central cold wheat growing area.

Design and Application of Optimization Software for Substation Operation Mode Based on EMS

This paper proposes a kind of optimization software for substation operation mode, which can not only read data on-line from EMS, but also calculate total loss of substations in parallel operation, split operation or individual operation mode. It can also select the most optimized way and feed the conclusion back to EMS to make substations operate in the most optimized way. The software is suitable for optimization of substation in rural power grid.

Studies on the Time of Accumulation and Elimination of Alexandrium tamarense Toxins in Argopectens irradias

Using a PSP （paralytic shellfish poisoning） toxin-producing strain of4lexandrium tamarense, it studied the timing of toxin accumulation and elimination of PSP toxins in Argopectens irradias. The PSP toxicity was studied by following the standard PSP mouse bioassay developed by the Association of Official Analytical Chemists （AOAC）. Alexandrium tamarense was cultured to an average density of 1.26 × 10^4/mL for a total of about 50 L culture. The toxicity of the alga was 2.18 ×10^-6 MU/cell. The results show that PSP content increased with time in both visceral and muscle tissue during a two-week accumulation period during which scallops were fed with ,4. tamarense. The average toxin level in scallop＇s viscera was 49.4 MU/g, with an average of 10.0 MU/g in muscle tissue. This level is 2.5 times higher than the sanitation standard （4.0 MU/g of muscles）. The highest value was 61.0 MU/g in the viscera. In summary, the viscera accumulated greater concentrations of toxin than muscle tissue. Scallops that had accumulated toxins were transplanted for two weeks into a field environment containing no toxic algae. The PSP content of the scallops decreased to 7.9 MU/g viscera and 1.6 MU/g muscles two weeks after being transplanted, but did not reach the sanitation standard. Under the experimental conditions, the toxin depuration rate of shellfish toxin was 12% daily. This study worked toward the development of a sanitary shellfish industry and better management of PSP toxin-impacted shellfish in China.

Efficient and stable hybrid perovskite-organic light-emitting diodes with external quantum efficiency exceeding 40 per cent

Light-emitting diodes(LEDs)based on perovskite semiconductor materials with tunable emission wavelength in visible light range as well as narrow linewidth are potential competitors among current light-emitting display technologies,but still suffer from severe instability driven by electric field.Here,we develop a stable,efficient and highcolor purity hybrid LED with a tandem structure by combining the perovskite LED and the commercial organic LED technologies to accelerate the practical application of perovskites.Perovskite LED and organic LED with close photoluminescence peak are selected to maximize photon emission without photon reabsorption and to achieve the narrowed emission spectra.By designing an efficient interconnecting layer with p-type interface doping that provides good opto-electric coupling and reduces Joule heating,the resulting green emitting hybrid LED shows a narrow linewidth of around 30 nm,a peak luminance of over 176,000 cd m^(−2),a maximum external quantum efficiency of over 40%,and an operational half-lifetime of over 42,000 h.

共建与区域产学研联合办学背景下应用化学专业建设与成效

针对地方高校学科、专业与课程建设各自为政,难于提升人才培养质量的现象,挖掘区域特色优势,在共建与区域产学研联合办学背景下,对标"双一流"和"新工科"及"双万计划",开展学科、专业与课程一体化建设,构建基于导师加团队、平台、培养方案的科研教学协同三全育人生态体系,建设应用化学国家一流专业,培养复合创新人才。

浅析质谱中的广义麦式重排

麦氏重排是对质谱分析中分子离子的重排反应提出的经验规则。对经典麦式重排的概念、裂解过程及其应用做进一步拓展,形成了广义麦式重排。在广义麦式重排中,γ-H的经典麦式重排是一步完成的六元环协同裂解,分子离子亦可通过六元环或五元环过渡态进行协同重排裂解,发生相应的γ-R、β-H(或R)的迁移,产生不同的碎片离子。这种广义麦氏重排在各种常见官能团化合物中均可发生,其在质谱解析和化合物结构研究中具有广泛应用。

Assessment of the Spatial and Temporal Water Eutrophication for Lake Baiyangdian Based on Integrated Fuzzy Method

Water quality evaluation entails both randomness and fuzziness. Considering that water eutrophication evaluation involves many indices, different classifications and interval values, fuzzy variable sets theory was developed to Lake Baiyangdian as a study case. Taking reference to eutrophication standard of Chinese lakes and local characteristic of Lake Baiyangdian, eutrophication degree of lake was divided into 8 levels. Total phosphorus, total nitrogen, and CODMn were selected as evaluation indices in this research. Based on the measured data, index feature value matrix of sample was built. Index weights were determined by means of pure threshold value method. Relative membership degree of each index to each classification was calculated with relative difference function model. Then the stability of feature value of classification corresponding was received by the comprehensive calculation with the relative membership degree and index weights. The results show that the proposed models are effective tools for generating a set of realistic and flexible optimal solutions for complicated water quality evaluation issues. It concluded that the model was reasonable and practical.

Influence of Ti_(3)C_(2)T_(x)(MXene)on the generation of dielectric barrier discharge in air

The formation of homogeneous dielectric barrier discharge(DBD)in air is a key scientific problem and core technical problem to be solved for the application of plasmas.Here,we report the effect of two-dimensional(2D)nanomaterial Ti_(3)C_(2)T_(x)(Tx=-F,-O and/or-OH)on regulating the electrical discharge characteristics.The field emission and weak bound state property of Ti_(3)C_(2)T_(x)can effectively increase the seed electrons and contribute to the generation of atmospheric pressure homogeneous air DBD.The electron avalanche development for the uneven electrode structure is calculated,and the discharge mode transition is modeled.The comparative analyses of discharge phenomena validate the regulation of Ti_(3)C_(2)T_(x)on the discharge characteristics of DBD.The light emission capture and the voltage and current waveforms verify that the transition of Townsend discharge to streamer discharge is effectively inhibited.The optical emission spectra are used to characterize the plasma and confirm that it is in a non-equilibrium state and the gas temperature is at room temperature.This is the first exploration of Ti_(3)C_(2)T_(x)on the regulation of electrical discharge characteristics as far as we know.This work proves the feasibility of Ti_(3)C_(2)T_(x)as a source of seed electrons to form homogeneous DBD,establishing a preliminary foundation for promoting the application of atmospheric pressure non-equilibrium plasma.

Enhancing bioactivity and stability of polymer-based materialtissue interface through coupling multiscale interfacial interactions with atomic-thin TiO2 nanosheets

Stable and bioactive material-tissue interface(MTF)basically determines the clinical applications of biomaterials in wound healing,sustained drug release,and tissue engineering.Although many inorganic nanomaterials have been widely explored to enhance the stability and bioactivity of polymer-based biomaterials,most are still restricted by their stability and biocompatibility.Here we demonstrate the enhanced bioactivity and stability of polymer-matrix bio-composite through coupling multiscale material-tissue interfacial interactions with atomically thin TiO_(2)nanosheets.Resin modified with TiO_(2)nanosheets displays improved mechanical properties,hydrophilicity,and stability.Also,we confirm that this resin can effectively stimulate the adhesion,proliferation,and differentiation into osteogenic and odontogenic lineages of human dental pulp stem cells using in vitro cell-resin interface model.TiO_(2)nanosheets can also enhance the interaction between demineralized dentinal collagen and resin.Our results suggest an approach to effectively up-regulate the stability and bioactivity of MTFs by designing biocompatible materials at the sub-nanoscale.

Trends of Mortality in End-Stage Liver Disease—China,2008–2020

Introduction:Liver cancer and cirrhosis represent the most prevalent forms of end-stage liver diseases(ESLDs).Notably,in China,deaths attributed to ESLDs contribute significantly to the global mortality rate of these disorders.Enhanced comprehension of the mortality profile associated with ESLDs in China could provide crucial insights into intervention prioritization,which could in turn help reduce the overall global burden of these diseases.Methods:Data were obtained from China’s Disease Surveillance Points system.The presentation includes both crude and age-standardized mortality rates,stratified by sex,residential location,and region.Using Joinpoint Regression,trends in annual mortality rates were estimated from the period of 2008 to 2020 and expressed as the average annual percentage change(AAPC).Results:In 2020,the gross mortality rate of ESLD stood at 30.08 cases per 100,000 individuals.A higher age-standardized ESLD mortality rate was observed in males and rural populations in comparison to their female and urban counterparts,respectively.Noticeably,the highest mortality rates associated with liver cancer and cirrhosis were reported in South and Southwest China,respectively.A positive correlation was noticed between age-specific ESLD mortality rates and advancing age.Interestingly,an annual decrease in the ESLD mortality rate was observed from 2008 to 2020.In urban contexts,the AAPC of cirrhosis was noted to be higher than that of liver cancer.Conclusions:The mortality rate associated with ESLDs in China decreased between 2008 and 2020.Nevertheless,the death burden attributable to ESLD continues to be alarmingly high.Future initiatives should prioritize the reduction of ESLD mortality in particular populations:males,elderly individuals,and those residing in rural regions of South and Southwest China.The emphasis of future interventions should beplaced on antiviral therapy for adults diagnosed with viral hepatitis,and on the prevention of hepatitis B virus(HBV)infection across all demographics.

AFFINE SPINOR DECOMPOSITION IN THREE-DIMENSIONAL AFFINE GEOMETRY

Spin group and screw algebra,as extensions of quaternions and vector algebra,respectively,have important applications in geometry,physics and engineering.In threedimensional projective geometry,when acting on lines,each projective transformation can be decomposed into at most three harmonic projective reflections with respect to projective lines,or equivalently,each projective spinor can be decomposed into at most three orthogonal Minkowski bispinors,each inducing a harmonic projective line reflection.In this paper,we establish the corresponding result for three-dimensional affine geometry:with each affine transformation is found a minimal decomposition into general affine reflections,where the number of general affine reflections is at most three;equivalently,each affine spinor can be decomposed into at most three affine Minkowski bispinors,each inducing a general affine line reflection.

Development of an Ultrasonic Nomogram for Preoperative Prediction of Castleman Disease Pathological Type

An ultrasonic nomogram was developed for preoperative prediction of Castleman disease(CD)pathological type(hyaline vascular(HV)or plasma cell(PC)variant)to improve the understanding and diagnostic accuracy of ultrasound for this disease.Fifty cases of CD confirmed by pathology were gathered from January 2012 to October 2018 from three hospitals.A grayscale ultrasound image of each patient was collected and processed.First,the region of interest of each gray ultrasound image was manually segmented using a process that was guided and calibrated by radiologists who have been engaged in imaging diagnosis for more than 5 years.In addition,the clinical characteristics and other ultrasonic features extracted from the color Doppler and spectral Doppler ultrasound images were also selected.Second,the chi-square test was used to select and reduce features.Third,a naïve Bayesian model was used as a classifier.Last,clinical cases with gray ultrasound image datasets from the hospital were used to test the performance of our proposed method.Among these patients,31 patients(18 patients with HV and 13 patients with PC)were used to build a training set for the predictive model and 19(11 patients with HV and 8 patients with PC)were used for the test set.From the set,584 high-throughput and quantitative image features,such as mass shape size,intensity,texture characteristics,and wavelet characteristics,were extracted,and then 152 images features were selected.Comparing the radiomics classification results with the pathological results,the accuracy rate,sensitivity,and specificity were 84.2%,90.1%,and 87.5%,respectively.The experimental results show that radiomics was valuable for the differentiation of CD pathological type.

Inferential Statistics and Machine Learning Models for Short-TermWind Power Forecasting

The inherent randomness,intermittence and volatility of wind power generation compromise the quality of the wind power system,resulting in uncertainty in the system’s optimal scheduling.As a result,it’s critical to improve power quality and assure real-time power grid scheduling and grid-connected wind farm operation.Inferred statistics are utilized in this research to infer general features based on the selected information,confirming that there are differences between two forecasting categories:Forecast Category 1(0-11 h ahead)and Forecast Category 2(12-23 h ahead).In z-tests,the null hypothesis provides the corresponding quantitative findings.To verify the final performance of the prediction findings,five benchmark methodologies are used:Persistence model,LMNN(Multilayer Perceptron with LMlearningmethods),NARX(Nonlinear autoregressive exogenous neural networkmodel),LMRNN(RNNs with LM training methods)and LSTM(Long short-term memory neural network).Experiments using a real dataset show that the LSTM network has the highest forecasting accuracy when compared to other benchmark approaches including persistence model,LMNN,NARX network,and LMRNN,and the 23-steps forecasting accuracy has improved by 19.61%.

Screening of Slow Release Solvents for Plant Volatiles

[Objective] The paper was to study the slow release effects of eight common kinds of slow release solvents on n-hexane, and to provide a reference for the construction of slow release system of attractants or repellents synthesized by plant volatiles. [Method] The effect of slow release solvents on volatile quantity and release rate of n-hexane was compared by weight loss method. [Result] Under indoor natural conditions [(22±2) ℃,RH 50%±10%], the slow release effect of lubricating oil on n-hexane was the best, followed by liquid paraffin. The best ratio of slow release solvent(lubricating oil and liquid paraffin) and n-hexane was 5∶1 and the best mixing time was 3 h, which improved the slow release effects of n-hexane by6.3 and 4.7 times, and prolonged the half-life of n-hexane by 1.3 and 1.0 times, respectively. Slow release solvents mainly affected the post-half-life period of n-hexane, and the release rates of n-hexane mixed with lubricating oil and liquid paraffin were decreased by 10.4 and 7.7 times, respec-tively. During the half-life period, the release rates of n-hexane were decreased by 1.3 and 1.0 times, respectively. [Conclusion] Two kinds of slow release solvents with good slow release effect on volatile n-hexane are screened out, and the proportion and mixing time of slow release solvent and volatile are determined, which will provide technical support for the construction of plant volatile slow release system.

Study on the Characteristics of Atmospheric Dry and Wet Deposition in the Upper Reaches of Baiyangdian

To study the characteristics of atmospheric dry and wet deposition in the upper reaches of Baiyangdian,two sampling sites in Baoding City were monitored for 1 year from September 2018 to August 2019.The results showed that the dry and wet deposition fluxes of total nitrogen(TN)during the monitoring period were 6.87 and 6.46 kg/(hm^(2)·a),respectively.The ratio of wet to dry deposition of TN was approximately 1∶1,with wet deposition being dominated by ammonium nitrogen deposition.The dry and wet deposition fluxes of total phosphorus(TP)were 0.228 and 0.125 kg/(hm^(2)·a),and it was dominated by dry deposition.The average concentration of TN in wet deposition exceeded the standard threshold for eutrophic waters,and its ecological effects on the Baiyangdian basin should be concerned.Wet deposition fluxes of nitrogen and phosphorus had a significantly positive correlation with rainfall,while their deposition concentrations were negatively correlated with rainfall.The dry deposition of atmospheric nitrogen and phosphorus was influenced by the amount of dustfall and climatic factors such as rainfall,temperature,and humidity,which mainly occurred from April to August.

A comprehensive review on the development of data-driven methods for wind power prediction and AGC performance evaluation in wind–thermal bundled power systems

The wind–thermal bundled power system achieves energy complementarity and optimized scheduling, which is an important way to build a new type of energy system. For the safe and stable operation of the wind–thermal bundled power system, accurate data-driven analysis is necessary to maintain real-time balance between electricity supply and demand. By summarizing the development and characteristics of wind–thermal bundled power system in China and different countries, current research in this field can be clearly defined in two aspects: short-term wind power prediction for wind farms and performance evaluation of automatic generation control (AGC) for thermal power generation units. For short-term wind power prediction, it is recommended to focus on historical data preprocessing and artificial intelligence methods. The technical characteristics of different data-driven wind power prediction methods have been compared in detail. For performance evaluation of AGC units, a comprehensive analysis was conducted on current evaluation methods, including the “permitted-band” and “regulation mileage” methods, as well as the issue of evaluation failure in traditional evaluation methods in practical engineering. Finally, the relative optimal dynamic performance of AGC units was discussed and the future trend of data-driven research in wind–thermal bundled power system was summarized.

Virus-Host Interactions Drive Contrasting Bacterial Diel Dynamics in the Ocean

Marine organisms perform a sea of diel rhythmicity.Planktonic diel dynamics have been shown to be driven by light,energy resources,circadian rhythms,and the coordinated coupling of photoautotrophs and heterotrophic bacterioplankton.Here,we explore the diel fluctuation of viral production and decay and their impact on the total and active bacterial community in the coastal and open seawaters of the South China Sea.The results showed that the night-production diel pattern of lytic viral production was concurrent with the lower viral decay at night,contributing to the accumulation of the viral population size during the night for surface waters.The diel variations in bacterial activity,community composition,and diversity were found highly affected by viral dynamics.This was revealed by the finding that bacterial community diversity was positively correlated to lytic viral production in the euphotic zone of the open ocean but was negatively related to lysogenic viral production in the coastal ocean.Such distinct but contrasting correlations suggest that viral life strategies can not only contribute to diversifying bacterial community but also potentially piggyback their host to dominate bacterial community,suggesting the tightly synchronized depth-dependent and habitat-specific diel patterns of virus-host interactions.It further implies that viruses serve as an ecologically important driver of bacterial diel dynamics across the ocean,highlighting the viral roles in bacterial ecological and biogeochemical processes in the ocean.