Emerging perovskite materials for supercapacitors:Structure,synthesis,modification,advanced characterization,theoretical calculation and electrochemical performance

As a new generation electrode materials for energy storage,perovskites have attracted wide attention because of their unique crystal structure,reversible active sites,rich oxygen vacancies,and good stability.In this review,the design and engineering progress of perovskite materials for supercapacitors(SCs)in recent years is summarized.Specifically,the review will focus on four types of perovskites,perovskite oxides,halide perovskites,fluoride perovskites,and multi-perovskites,within the context of their intrinsic structure and corresponding electrochemical performance.A series of experimental variables,such as synthesis,crystal structure,and electrochemical reaction mechanism,will be carefully analyzed by combining various advanced characterization techniques and theoretical calculations.The applications of these materials as electrodes are then featured for various SCs.Finally,we look forward to the prospects and challenges of perovskite-type SCs electrodes,as well as the future research direction.

A theoretical model to predict the rising trajectory of single bubble with zigzagging path in still water

The rising motion of single bubble in still liquid is a natural phenomenon,which has high theoretical research significance and engineering application prospect.Experimental observations and numerical simulations for prediction of the rising trajectory of a single bubble in still liquid are being carried out,while the concise but accurate theoretical or mechanism model is still not well developed.In this article,a theoretical model of a single bubble based on experimental observation of flow around bluff body is proposed to predict the rising trajectory of zigzagging bubbles in still water.The prediction correlation of bubble lateral movement frequency and bubble steer angle are established based on three degrees of freedom frame.The model has achieved good trajectory prediction effect in the bubble rising experiment.The average simulation time per unit moving time of bubble is 2.5 s.

Evaluation of Medical Prescribers’ Theoretical Knowledge on Medical Imaging in the Northern Region of Burkina Faso

Introduction: Medical imaging is a medical specialty that involves producing images of the human body and interpreting them for diagnostic, therapeutic purposes, and for monitoring the progress of pathologies. We aimed to assess the theoretical knowledge of doctors and interns in medical imaging in the northern region of Burkina Faso. Methodology: This was a descriptive cross-sectional survey based on a self-administered questionnaire. Prescribers knowledge was estimated based on scores derived from questionnaire responses. Results: We collected 106 questionnaires out of 163, i.e. a participation rate of 65.03%. The average knowledge score was 81.71% for the contribution of medical imaging to patient management. It was 60.02% for the indications/counter-indications of radiological examinations and 72.56% for the risks associated with exposure to radiation during these examinations. The score was 59.83% for the methods used to select the appropriate radiological examination. As regards the completeness of the clinical and biological information on the forms requesting imaging examinations, the score was 96.65%. Specialist doctors had the highest overall level of knowledge (74.68%). Conclusion: Improved technical facilities, good initial and in-service training, and interdisciplinary collaboration will help to ensure that imaging tests are properly prescribed, leading to better patient care.

Theoretical Modeling and Surface Roughness Prediction of Microtextured Surfaces in Ultrasonic Vibration-Assisted Milling

Textured surfaces with certain micro/nano structures have been proven to possess some advanced functions,such as reducing friction,improving wear and increasing wettability.Accurate prediction of micro/nano surface textures is of great significance for the design,fabrication and application of functional textured surfaces.In this paper,based on the kinematic analysis of cutter teeth,the discretization of ultrasonic machining process,transformation method of coordinate systems and the cubic spline data interpolation,an integrated theoretical model was established to characterize the distribution and geometric features of micro textures on the surfaces machined by different types of ultrasonic vibration-assisted milling(UVAM).Based on the theoretical model,the effect of key process parameters(vibration directions,vibration dimensions,cutting parameters and vibration parameters)on tool trajectories and microtextured surface morphology in UVAM is investigated.Besides,the effect of phase difference on the elliptical shape in 2D/3D ultrasonic elliptical vibration-assisted milling(UEVAM)was analyzed.Compared to conventional numerical models,the method of the cubic spline data interpolation is applied to the simulation of microtextured surface morphology in UVAM,which is more suitable for characterizing the morphological features of microtextured surfaces than traditional methods due to the presence of numerous micro textures.The prediction of surface roughness indicates that the magnitude of ultrasonic amplitude in z-direction should be strictly limited in 1D rotary UVAM,2D and 3D UEVAM due to the unfavorable effect of axial ultrasonic vibration on the surface quality.This study can provide theoretical guidance for the design and fabrication of microtextured surfaces in UVAM.

Evaluation of the Effectiveness of the “1 + 1 + 1” Method in Theoretical Teaching of Emergency Pericardiocentesis

Background: Pericardial effusion may progress to cardiac tamponade when pressure around the heart increases to a level comparable to that of the right and left atria. Patients with cardiac tamponade need timely completion of emergency pericardiocentesis to relieve the threat to the patient’s life, and to save valuable time for patients who need emergency thoracotomy and pericardial window drainage. Pericardiocentesis is a necessary clinical skill for residents in standardized training. In addition, nurses who are familiar with this technology can better assist clinicians to perform this operation. In order to make the medical staff quickly master the theoretical knowledge of emergency pericardiocentesis, we designed a “1 + 1 + 1” teaching method for the theoretical teaching of emergency pericardiocentesis. Objective: This study aims to explore the effectiveness of the “1 + 1 + 1” teaching method in the theoretical teaching of emergency pericardiocentesis. Methods: We used an English teaching video of emergency pericardiocentesis and applied the “1 + 1 + 1” teaching method for theoretical teaching. A questionnaire survey was conducted before and after the lecture among 19 medical staff of different years of service to understand their mastery of the theoretical content of emergency pericardiocentesis before and after the lecture. According to the years of service, the medical staff were divided into three groups: 1 - 3 years (Group A), 4 - 10 years (Group B), and over 10 years (Group C), and the changes in the mastery of various contents by the overall medical staff and each group were statistically analyzed. Results: Before the lecture, the number of people who mastered the indications, contraindications, most commonly used methods, and common complications of emergency pericardiocentesis were 15, 12, 16, and 17, respectively, whereas after the lecture, these numbers increased to 17, 19, 19, and 19, respectively. The overall mastery before and after the lecture was statistically significant (p Conclusion: The “1 + 1 + 1” teaching method can effectively improve the overall mastery level of medical staff’s theoretical knowledge of emergency pericardiocentesis, especially in improving the mastery of contraindications of this operation.

Research on the Upper Limit of Accuracy for Predicting Theoretical Tandem Mass Spectrometry

In recent years, numerous theoretical tandem mass spectrometry prediction methods have been proposed, yet a systematic study and evaluation of their theoretical accuracy limits have not been conducted. If the accuracy of current methods approaches this limit, further exploration of new prediction techniques may become redundant. Conversely, a need for more precise prediction methods or models may be indicated. In this study, we have experimentally analyzed the limits of accuracy at different numbers of ions and parameters using repeated spectral pairs and integrating various similarity metrics. Results show significant achievements in accuracy for backbone ion methods with room for improvement. In contrast, full-spectrum prediction methods exhibit greater potential relative to the theoretical accuracy limit. Additionally, findings highlight the significant impact of normalized collision energy and instrument type on prediction accuracy, underscoring the importance of considering these factors in future theoretical tandem mass spectrometry predictions.

Systematic and Theoretical Unfolding of Research on Xi Jinping’s Discourses on Respecting and Protecting Human Rights

Xi Jinping’s discourses on respecting and protect-ing human rights stand as a shining example of the sinicization and modernization of Marxist human rights theory,embodying profound theoretical,political,practical,and cultural logic.Existing research has conducted comprehensive and systematic theoretical analysis and academic extractions on the following contents:the core essence in-herent in these important discourses,including the“theory of human rights concepts,”the“theory of human rights paths,”the“theory of human rights practices,”the“theory of human rights protection,”and the“theory of human rights governance,”along with their profound theoretical significance,practical significance,and global signifi-cance.In the future,researchers should emphasize efforts on studying the original texts and understanding the original principles.While focusing on the precision of concepts,the scientific nature of the prop-ositions,the maturity of theoretical systems,and the rigor of internal logic related to Xi Jinping’s discourses on respecting and protecting human rights,researchers should also pay attention to constructing a discourse system on human rights from the dimensions of discourse power,discourse cluster,and discourse field.Researchers should be adept at drawing innovative insights into human rights theory from China’s vibrant human rights practices and the vast masses of people.This approach will facilitate the systematic unfolding,academic trans-formation,and innovative development of Xi Jinping’s discourses on respecting and protecting human rights.

Theoretical analysis on springback of L-section extrusion in rotary stretch bending process

The theoretical analysis of springback in rotary stretch bending process of L-section extrusion was studied. The models for characterizing the springback angle after unloading were established based on the stress and strain distributions in the cross-section of the part. With the proposed model, analysis of the effect of pre-stretch force and post-stretch force on springback angle shows that springback decreases as the pre-stretch force or post-stretch force increases. Comparative study with experiments clearly demonstrates that the prediction of springback can resort to the current model without the loss of accuracy.

Theoretical prediction of forming limit diagram of AZ31 magnesium alloy sheet at warm temperatures

A theoretical prediction on forming limit diagram（FLD） of AZ31 magnesium alloy sheet was developed at warm temperatures based on the M-K theory. Two different yield criteria of von Mises and Hill＇48 were applied in this model. Mechanical properties of AZ31 magnesium alloy used in the prediction were obtained by uniaxial tensile tests and the Fields-Backofen equation was incorporated in the analysis. In addition, experimental FLDs of AZ31 were acquired by conducting rigid die swell test at different temperatures to verify the prediction. It is demonstrated from a comparison between the predicted and the experimental FLDs at 473 K and 523 K that the predicted results are influenced by the type of yield criterion used in the calculation, especially at lower temperatures. Furthermore, a better agreement between the predicted results and experimental data for AZ31 magnesium alloy sheet at warm temperatures was obtained when Hill＇48 yield criterion was applied.

Theoretical Framework for Circular Agricultural Science and Technology Park Planning

In the paper, theoretical framework of Circular Agricultural Science and Technology Park planning was constructed based on circular agriculture, modern agriculture, garden landscape and management of agriculture SciTech park, and the concerning meaning and characteristics were introduced, providing theoretical bases and guidance for circular agriculture SciTech park.

A Number Theoretic Function and Its Mean Value Computation

Let p be a prime, n be any positiv e integer, α(n,p) denotes the power of p in the factorization of n! . In this paper, we give an exact computing formula of the mean value ∑ n<Nα(n,p).

香榧酯分子及晶体结构、热力学和电子性质的理论研究

香榧子假种皮中含有丰富的活性物质,挥发油、萜类、黄酮类等物质.香榧酯作为一种二萜类物质,具有抗氧化活性、抗病毒作用.本文采用量子化学计算方法对香榧酯的分子及晶体结构进行研究,得到其微观结构参数、红外光谱、晶胞参数.根据统计热力学原理,计算了标题物的标准热力学函数,包括摩尔热容(C_(p,m)^(o))、摩尔熵(S_(m)^(o))和摩尔焓(H_(m)^(o)).在DFT优化分子结构的基础上,采用力场方法得到香榧酯的最可能堆积方式属于P21空间群,进一步采用DFT GGA-RPBE方法优化其晶体结构,并计算能带结构和态密度,发现其带隙较宽(3.324 eV),表明其具有较好的稳定性.在Fermi能级附近,香榧酯晶体中的导带主要来自于O原子和C原子的2p轨道的贡献,而价带主要来自于H原子的s轨道.

Theoretical investigations on CO oxidation reaction catalyzed by gold nanoparticles

It is crucial to understand the mechanism of low temperature CO oxidation reaction catalyzed by gold nanoparticles so as to find out the origin of the high catalytic reactivity and extend the indus‐trialization applications of nano gold catalysts. In this work, some theoretical works on CO adsorp‐tion, O2 adsorption, atomic oxygen adsorption, formation of surface gold oxide films, reaction mechanisms of CO oxidation involving O2 reaction with CO and O2 dissociation before reacting with CO on gold surfaces and Au/metal oxide were summarized, and the influences of coordination number, charge transfer and relativity of gold on CO oxidation reaction were briefly reviewed. It was found that CO reaction mechanism depended on the systems with or without oxide and the strong relativistic effects might play an important role in CO oxidation reaction on gold catalysts. In particular, the relativistic effects are related to the unique behaviors of CO adsorption, O adsorption, O2 activation on gold surfaces, effects of coordination number and the wide gap between the chem‐ical inertness of bulk gold and high catalytic activity of nano gold. The present work helps us to understand the CO oxidation reaction mechanism on gold catalysts and the influence of relativistic effects on gold catalysis.

Theoretical Study on Raman Spectra of Aqueous Peroxynitric Acid

Using density functional theory and polarizable continuum models, we study the Raman spectra of aqueous peroxynitric acid. The calculated results indicate that the solvent effect has significant influence on the electric dipole transition moments between the ground and excited electronic state and Raman polarizabilities. The theoretical Raman spectra agree well with the experimental results. From the experimental depolarization ratio, we can conclude that peroxynitric acid is not a plane molecule. We also find that the hydrogen bond can enhance IR intensity of hydroxyl group by several times.

Theoretical Study on Dissociation Potential Energy Surface of Peroxynitric Acid

The lowest energy structures of peroxynitric acid have been studied with B3LYP/6-311＋ G（2d,2p） method. The potential energy surfaces （PES） along the O-N and O-O bonds have been scanned at CCSD（T）/aug-cc-pVDZ level, respectively. The calculated results show that on the O-N PES, the O3-N4 bond length of the loose transition state is 2.82A^° and the corresponding energy barrier is 25.6 kcal/mol, while on the O-O PES, the loose transition state with of O2-O3 bond length of 2.35A^° has the energy barrier of 37.4 kcal/mol. Thus the primary reaction path for peroxynitric acid is the dissociation into HO2 and NO2.

二维GaN中带电缺陷性质的第一性原理研究

带电缺陷形成能与电荷转移能级对探索材料中n-type或p-type掺杂具有重要指导意义.基于第一性原理方法,本文结合二维带电缺陷校正理论,将半局域泛函电荷转移能级有效转换到杂化泛函精度,对六方二维氮化镓(Hexagonal gallium nitride,h-_(Ga)N)12种n-type和p-type带电掺杂体系结构性质、磁学性质及缺陷性质进行系统研究.n-type体系包括C_(Ga),Si_(Ga),Ge_(Ga),O_(N),S_(N),Se_(N),p-type体系包括Be_(Ga),Mg_(Ga),Ca_(Ga),C_(N),Si_(N),Ge_(N),结果表明Ge_(Ga)和Be_(Ga)分别是n-type和p-type中最稳定缺陷.n-type体系最稳定价态为0和1+价,施主离子化能分布在低于导带底~0.4到~0.6 eV能量区间,表现为深施主能级特性,会捕获p型h-GaN中空穴,影响空穴导电率;p-type体系最稳定价态为1-,0(Ge_(N)除外),1+价,受主离子化能分布在高于价带顶~1.25到2.85 eV能量区间,表现为深受主能级特性,会捕获n(p)型h-GaN中电子(空穴),影响n(p)载流子导电率.研究结果表明,二维h-GaN体系很难通过单缺陷实现n或p-type掺杂,实验上需要考虑复合缺陷实现双极型掺杂.

Application of Evolution Sequential Number Theoretic Optimization in Global Optimization

Synthesis of chemical processes is of non-convex and multi-modal. Deterministic strategies often fail to find global optimum within reasonable time scales. Stochastic methodologies generally approach global solution in probability. In recogniting the state of art status in the discipline, a new approach for global optimization of processes, based on sequential number theoretic optimization (SNTO), is proposed. In this approach, subspaces and feasible points are derived from uniformly scattered points, and iterations over passing the corner of local optimum are enhanced via parallel strategy. The efficiency of the approach proposed is verified by results obtained from various case studies.

The theoretical expressions of wood thermal diffusivity

From viewpoint of chemical element and microstructure of wood, this paper makes a discussion on thermal diffusivity of wood and two theoretical expressions of thermal diffusivity for the choral and radial directions were derived. The thermal diffusivities of the choral and radial directions for about 20 species of trees were calculated with the derived theoretical expressions and compared with the experimental values. The average error of the theoretical values of thermal diffusivity was 7.5% for choral direction and 6.2% for radial direction.

习近平关于新质生产力重要论述的理论体系和实践指向研究

习近平总书记关于新质生产力重要论述深刻阐明了新质生产力的基本内涵、本质特征、鲜明标志、核心要素、形成规律以及实现路径等重大理论和实践问题,是具有重大原创性、标识性、系统性、实践性的理论创新成果,是习近平新时代中国特色社会主义思想的重要组成部分。习近平总书记关于新质生产力重要论述是在推进中国式现代化进程中形成的新的生产力理论,是指导我国经济社会高质量发展的学理化、体系化的理论体系,是具有深邃而丰富辩证法则的实践指向。

A Theoretical Analysis on Features of Linguistic Decategorization

Liu Zhengguang made a conclusion about features of linguistic decategorization on the semantic,morphonological,textual and categorial attributes levels.However,these features were too specific to reflect the holistic characteristics of linguistic decategorization.Taking a holistic point of view,this paper will make a tentative study to summarize the features of linguistic decategorization.This paper maintains that 1) linguistic decategorization is a dynamic and gradual process;2) linguistic decategorization is uneven at multilevel;3) linguistic decategorization is context-dependent and unpredictable.