Current Situation and Countermeasures of the Construction of “Double-Qualified” Teachers in Higher Vocational Colleges

The construction of“double-qualified”teachers is the basic premise for the high-quality development of higher vocational education,and it is also the key force for higher vocational colleges to cultivate high-quality skilled talents.This paper probes into the positioning of the construction of“double-qualified”teachers in higher vocational colleges,deeply analyzes the current situation of the construction of“double-qualified”teachers in higher vocational colleges,and provides the countermeasures of the construction of“double-qualified”teachers.

Discussions on the Construction of“Double-Qualified”Teachers in Higher Vocational Colleges

Creating a“double-qualified”teacher team is an important content in the construction of a higher vocational college teacher team.This paper probes into the significance of the construction of“double-qualified”teachers in higher vocational colleges,and deeply analyzes the problems existing in the construction of“double-qualified”teachers’training base,the institutionalization of“double-qualified”teacher rotation training,the regularization of cooperation with enterprises,and the rationalization of incentive mechanism.Therefore,it is of great practical significance to strengthen the theoretical research and practical exploration of the construction of“double-qualified”teachers.

3D printed fiber-optic nanomechanical bioprobe

Ultrasensitive nanomechanical instruments,e.g.atomic force microscopy(AFM),can be used to perform delicate biomechanical measurements and reveal the complex mechanical environment of biological processes.However,these instruments are limited because of their size and complex feedback system.In this study,we demonstrate a miniature fiber optical nanomechanical probe(FONP)that can be used to detect the mechanical properties of single cells and in vivo tissue measurements.A FONP that can operate in air and in liquids was developed by programming a microcantilever probe on the end face of a single-mode fiber using femtosecond laser two-photon polymerization nanolithography.To realize stiffness matching of the FONP and sample,a strategy of customizing the microcantilever’s spring constant according to the sample was proposed based on structure-correlated mechanics.As a proof-of concept,three FONPs with spring constants varying from 0.421 N m^(−1)to 52.6 N m^(−1)by more than two orders of magnitude were prepared.The highest microforce sensitivity was 54.5 nmμN^(−1)and the detection limit was 2.1 nN.The Young’s modulus of heterogeneous soft materials,such as polydimethylsiloxane,muscle tissue of living mice,onion cells,and MCF-7 cells,were successfully measured,which validating the broad applicability of this method.Our strategy provides a universal protocol for directly programming fiber-optic AFMs.Moreover,this method has no special requirements for the size and shape of living biological samples,which is infeasible when using commercial AFMs.FONP has made substantial progress in realizing basic biological discoveries,which may create new biomedical applications that cannot be realized by current AFMs.

老年心力衰竭住院患者衰弱风险动态诺谟图的构建及验证

目的 旨在建立一个动态在线诺谟图模型并进行验证,以预测老年心力衰竭住院患者的衰弱风险.方法 2021年12月至2022年11月,选取山东省潍坊市1所三级甲等医院心血管内科住院的451例老年心力衰竭患者为研究对象.采用Bartherl指数、工具性日常生活活动能力量表、迷你营养评估简表、匹兹堡睡眠质量指数量表、Morse跌倒评估量表及一般资料量表收集数据,并通过电子病历收集患者的脑钠肽和超声心动图指标.所有数据使用R软件按7:3的比例随机分为训练集(n=319)和验证集(n=132).采用最小绝对收缩和选择算子(Least Absolute Shrinkage and Selection Operator,LASSO)回归方法筛选建模变量,然后使用多变量逻辑回归建立诺谟图.采用受试者工作特征曲线下面积(area under the curve,AUC)、Hosmer-Lemeshow检验、校准图和决策曲线分析(decision curve analysis,DCA)评估模型性能.结果 衰弱的总体发生率为50.6%.在训练集和验证集中,衰弱发生率分别为51.4%和48.5%.LASSO回归结果显示,饮酒、握力、纽约心脏协会心功能分级、多发疾病、心力衰竭住院史、日常生活活动能力、工具性日常生活活动能力、营养状况、睡眠、跌倒风险和左心房舒张末直径为模型纳入变量.诺谟图的AUC为0.920,敏感性为86.8%,特异性为84.4%.H-L检验P值为0.742,DCA表明诺谟图具有良好的临床适用性.结论 在线动态诺谟图适用于预测老年心力衰竭住院患者的衰弱程度,可以帮助医护人员及时诊断衰弱高危人群,以减轻心力衰竭住院负担.

Edge Computing Task Scheduling with Joint Blockchain and Task Caching in Industrial Internet

Deploying task caching at edge servers has become an effectiveway to handle compute-intensive and latency-sensitive tasks on the industrialinternet. However, how to select the task scheduling location to reduce taskdelay and cost while ensuring the data security and reliable communicationof edge computing remains a challenge. To solve this problem, this paperestablishes a task scheduling model with joint blockchain and task cachingin the industrial internet and designs a novel blockchain-assisted cachingmechanism to enhance system security. In this paper, the task schedulingproblem, which couples the task scheduling decision, task caching decision,and blockchain reward, is formulated as the minimum weighted cost problemunder delay constraints. This is a mixed integer nonlinear problem, which isproved to be nonconvex and NP-hard. To solve the optimal solution, thispaper proposes a task scheduling strategy algorithm based on an improvedgenetic algorithm (IGA-TSPA) by improving the genetic algorithm initializationand mutation operations to reduce the size of the initial solutionspace and enhance the optimal solution convergence speed. In addition,an Improved Least Frequently Used algorithm is proposed to improve thecontent hit rate. Simulation results show that IGA-TSPA has a faster optimalsolution-solving ability and shorter running time compared with the existingedge computing scheduling algorithms. The established task scheduling modelnot only saves 62.19% of system overhead consumption in comparison withlocal computing but also has great significance in protecting data security,reducing task processing delay, and reducing system cost.

Laser-Chirp Controlled Terahertz Wave Generation from Air Plasma

We report the laser-chirp controlled terahertz(THz) wave generation from two-color-laser-induced air plasma.Our experimental results reveal that the THz wave is affected by both the laser energy and chirp,leading to radiation minima that can be quantitatively reconstructed using the linear-dipole-array model.The phase difference between the two colors,determined by the chirp and intensity of the laser,can account for the radiation minima.Furthermore,we observe an asynchronous variation in the generated THz spectrum,which suggests a THz frequency-dependent phase matching between the laser pulse and THz wave.These results highlight the importance of laser chirp during the THz wave generation and demonstrate the possibility of modulating the THz yields and spectrum through chirping the incident laser pulse.This work can provide valuable insights into the mechanism of plasma-based THz wave generation and offer a unique means to control THz emissions.

美国养蜂业历史与现状浅析

受国家外专局出国培训项目资助，笔者于2017年8月28日～2018年2月23日赴美国农业部农业研究局Beltsville蜜蜂实验室进行交流学习。

转地养蜂蜜蜂授粉在美国农业经济中的作用

在全球范围内,人类消费农业生产总值的9.5%来自昆虫授粉。我们吃的1/3的食物依赖蜜蜂授粉。提供全球90%食物的100种作物中,有70多种是由蜜蜂授粉的。在北美,蜜蜂为近90~130种农作物授粉,比如苹果、蔓越莓、草莓、西瓜、柑橘等,而杏仁和鳄梨等则是100%依靠蜜蜂授粉(表1),否则颗粒无收。根据美国农业部2013年5月的一份报告,每年授粉为农业带来200亿至300亿美元的经济价值,而蜂产品价值约1.5亿美元,两者相距100倍。

NUMERICAL ANALYSIS FOR VOLTERRA INTEGRAL EQUATION WITH TWO KINDS OF DELAY

In this article, we study the Volterra integral equations with two kinds of delay that are proportional delay and nonproportional delay. We mainly use Chebyshev spectral collocation method to analyze them. First, we use variable transformation to transform the equation into an new equation which is defined in [-1,1]. Then, with the help of Gronwall inequality and some other lemmas, we provide a rigorous error analysis for the proposed method, which shows that the numerical error decay exponentially in L~∞ and L_(ω~c)~2-norm. In the end, we give numerical test to confirm the conclusion.

Two-grid methods for semi-linear elliptic interface problems by immersed finite element methods

In this paper,two-grid immersed finite element (IFE) algorithms are proposed and analyzed for semi-linear interface problems with discontinuous diffusion coefficients in two dimension.Because of the advantages of finite element (FE) formulation and the simple structure of Cartesian grids,the IFE discretization is used in this paper.Two-grid schemes are formulated to linearize the FE equations.It is theoretically and numerically illustrated that the coarse space can be selected as coarse as H =O(h^1/4)(or H =O(h^1/8)),and the asymptotically optimal approximation can be achieved as the nonlinear schemes.As a result,we can settle a great majority of nonlinear equations as easy as linearized problems.In order to estimate the present two-grid algorithms,we derive the optimal error estimates of the IFE solution in the L^p norm.Numerical experiments are given to verify the theorems and indicate that the present two-grid algorithms can greatly improve the computing efficiency.

THE BOUNDEDNESS OF MULTILINEAR COMMUTATORS FROM L^p(R^n) TO TRIEBEL-LIZORKIN SPACES

Let b^→=（b1,…,bm）,bi∈∧°βi（R^n）,1≤i≤m,0〈βi〈β,0〈β〈1,[B^→,T]f（x）=∫R^n（b1（x）-b1（y））…（bm（x）-bm（y））K（x-y）f（y）dy,where K is a Calder6n-Zygmund kernel. In this paper, we show that [b^→,T] is bounded from L^p（R^n） to Fp^β,∞（R^n）,as well as [b^→,1α]form L^p （R^n） to Fp^β,∞（R^n）,where 1/q=1/p-α/n.

Smoothing Newton-Like Method for the Solution of Nonlinear Systems of Equalities and Inequalities

In this paper,we present a smoothing Newton-like method for solving nonlinear systems of equalities and inequalities.By using the so-called max function,we transfer the inequalities into a system of semismooth equalities.Then a smoothing Newton-like method is proposed for solving the reformulated system,which only needs to solve one system of linear equations and to perform one line search at each iteration. The global and local quadratic convergence are studied under appropriate assumptions. Numerical examples show that the new approach is effective.

Superconvergence analysis of bi-k-degree rectangular elements for two-dimensional time-dependent Schrodinger equation

Superconvergence has been studied for long, and many different numerical methods have been analyzed. This paper is concerned with the problem of superconvergence for a two-dimensional time-dependent linear Schr?dinger equation with the finite element method. The error estimate and superconvergence property with order O(hk+1)in the H1norm are given by using the elliptic projection operator in the semi-discrete scheme. The global superconvergence is derived by the interpolation post-processing technique. The superconvergence result with order O(hk+1+ τ2) in the H1norm can be obtained in the Crank-Nicolson fully discrete scheme.

Identification and Genetic Analysis of a Novel Allelic Variation of Brittle-1 with Endosperm Mutant in Maize

Endosperm mutants are critical to the studies on both starch synthesis and metabolism and genetic improvement of starch quality in maize.In the present study,a novel maize endosperm mutant A0178 of natural variation was used as the experimental material and identified and then characterized.Through phenotypic identification,genetic analysis,main ingredients measurement and embryo rescue,development of genetic mapping population from A0178,the endosperm mutant gene was located.The results showed that the mutant exhibited extremely low germination ability as attributed to the inhibited embryo development,and amounts of sugars were accumulated in the mutant seeds and more sugars content was detected at 23 days after pollination(DAP)in A0178 than B73.Employing genetic linkage analysis,the mutant trait was mapped in the bin 5.04 on chromosome 5.Sequence analysis showed that two sites of base transversion and insertion presented in the protein coding region and non-coding region of the mutant brittle-1(bt1),the adenylate translocator encoding gene involved in the starch synthesis.The single base insertion in the coding region cause frameshift mutation,early termination and lose of function of Brittle-1(BT1).All results suggested that bt1 is a novel allelic gene and the causal gene of this endosperm mutant,providing insights on the mechanism of endosperm formation in maize.

Boundedness for the Singular Integral with Variable Kernel and Fractional Differentiation on Weighted Morrey Spaces

Let T be the singular integral operator with variable kernel, T＊ be the adjoint of T and T# be the pseudo-adjoint of T. Let TIT2 be the product of T1 and T2, T1 o T2 be the pseudo product of T1 and T2. In this paper, we establish the boundedness for commutators of these operators and the fractional differentiation operator D^γ on the weighted Morrey spaces.

Magnetic minerals in Mid-Pleistocene sediments on the Caiwei Guyot,Northwest Pacific and their response to the Mid-Brunhes climate event

Seamounts are ubiquitous topographic units in global oceans,and their influences on local oceanic circulation have attracted great attention in physical oceanography;however,previous efforts were less made in paleoclimatology and paleoceanography.The Caiwei Guyot in the Magellan Seamounts of the western Pacific is a typical seamount,and in this study,we investigate a well-dated sediment core by magnetic properties to reveal the relationship between deep-sea sedimentary processes and global climate changes.The principal results are as follows:(1)the dominant magnetic minerals in the sediments are low-coercivity magnetite in pseudo-single domain range,probably including a biogenic contribution;(2)the variabilities of magnetic parameters can be clustered into two sections at~500 ka,and the differences between the two units are evident in amplitudes and means;(3)changes in the grainsize-dependent magnetic parameters can be well correlated to records of global ice volume and atmospheric CO;in the middle Pleistocene.Based on these results,a close linkage was proposed between deep-sea sedimentary processes in the Caiwei Guyot and global climate changes.This linkage likely involves different roles of biogenic magnetite in the sediments between interglacial and glacial intervals,responding to changes in marine productivity and deep-sea circulation and displaying a major change in the MidBrunhes climate event.Therefore,we proposed that the sedimentary archives at the bottom of the Caiwei Guyot record some key signals of global climate changes,providing a unique window to observe interactions between various environmental systems on glacial-interglacial timescales.

A SPECTRAL METHOD FOR A WEAKLY SINGULAR VOLTERRA INTEGRO-DIFFERENTIAL EQUATION WITH PANTOGRAPH DELAY

In this paper,a Jacobi-collocation spectral method is developed for a Volterraintegro-differential equation with delay,which contains a weakly singular kernel.We use a function transformation and a variable transformation to change the equation into a new Volterra integral equation defined on the standard interval[-1,1],so that the Jacobi orthogonal polynomial theory can be applied conveniently.In order to obtain high order accuracy for the approximation,the integral term in the resulting equation is approximated by Jacobi spectral quadrature rules.In the end,we provide a rigorous error analysis for the proposed method.The spectral rate of convergence for the proposed method is established in both the L^(∞)-norm and the weighted L^(2)-norm.

WEIGHTED NORM INEQUALITIES FOR COMMUTATORS OF THE KATO SQUARE ROOT OF SECOND ORDER ELLIPTIC OPERATORS ON R^(n)

Let L=-div(A▽) be a second order divergence form elliptic operator with bounded measurable coefficients in R^(n).We establish weighted L^(p) norm inequalities for commutators generated by √L and Lipschitz functions,where the range of p is different from(1,∞),and we isolate the right class of weights introduced by Auscher and Martell.In this work,we use good-λ inequality with two parameters through the weighted boundedness of Riesz transforms ▽L^(-1/2).Our result recovers,in some sense,a previous result of Hofmann.

Analysis of a two-grid method for semiconductor device problem

The mathematical model of a semiconductor device is governed by a system of quasi-linear partial differential equations.The electric potential equation is approximated by a mixed finite element method,and the concentration equations are approximated by a standard Galerkin method.We estimate the error of the numerical solutions in the sense of the Lqnorm.To linearize the full discrete scheme of the problem,we present an efficient two-grid method based on the idea of Newton iteration.The main procedures are to solve the small scaled nonlinear equations on the coarse grid and then deal with the linear equations on the fine grid.Error estimation for the two-grid solutions is analyzed in detail.It is shown that this method still achieves asymptotically optimal approximations as long as a mesh size satisfies H=O(h^1/2).Numerical experiments are given to illustrate the efficiency of the two-grid method.

Research on the Protection of Vulnerable Groups in Water Pollution Conflicts Based on Binomial Tree Pricing Model

The interests of vulnerable groups can’t be guaranteed due to their weaker capacity and the limited interests demand channels during the water pollution conflicts. The interest protection for the vulnerable people in the water pollution conflicts has attracted attentions of the international scholars. The paper tries to construct the market mechanism which can make the vulnerable people to involve in the emission trading. The vulnerable people can buy American put option in the emission trading market. When the price of the emission runs below the contract price, the vulnerable people can get the benefit through executing the option. When the price of the emission runs above the contract price, the vulnerable people can give up the right. The binomial tree option pricing model can help the vulnerable people to make a decision through the analysis of the worth of the American put option.