“循源而学”理论视域下的小学数学教学:看见数学、理解数学、学通数学、用好数学

如何提高小学生数学学习兴趣、提升学生数学学习力、体悟数学的价值是当前小学数学教育三大待解难题。解决之道在于让学生看见数学、理解数学、学通数学、学好数学、用好数学、爱上数学,“循源而学”应运而生。它倡导顺着数学产生、发展、应用的“源”与“流”而学,其核心内容包括循数学发展之源而学、循人生成长之源而学、循生存生活之源而学,体现为从数学学习走向人生成长、从人生成长走向完整生活,这是一切学科学习的基本“源”与“流”,是系列内化与外化、专与博、立己与达人、出发与归宿、基础与发展的自然生长、生发、生态过程。“情境与问题、体验与实践、关联与综合、拓展与长程、创造与成长”是“循源而学”的五大设计与实施要义。

高中生学通文理的必要性及将《梦溪笔谈》部分内容引入教材浅探

笔者认为高中生应着重在＂学通文理＂上下工夫,使学生＂学通文理＂,在知识、能力、审美和创新方面既提升个人才能,又服务于我国社会主义现代化建设的进程,实现中华民族的伟大复兴;在教学内容上,可将沈括《梦溪笔谈》的部分内容引入教材。

安藤正次《国语学通考》(1931):日本昭和初期国语学建构

日本安藤正次《国语学通考》(1931)明显不同于上田万年《国语のため》(1897)与《国语学の十讲》(1916),研究理论与方法已经相当成熟,其成就为:对国语学对象及概念内涵有所界定,从理论上将国语学范畴化,由此,给进一步研究相关学术问题的学者提供了先决条件;构筑国语学体系,使得国语学研究框架得到完善,梳理其内部各种关系与职责;具有强烈的理论与方法论意识,研究的操作程序与方式科学有序;国语文献学基础雄厚,让人感到,其国学的"功力"非同一般;在具体问题的研究上,安藤正次取得了突出的成就。比如"史的国语学"研究,在《国语学通考》中,有所突破;学术视野开阔,吸取国内外新的国语学学术信息,引证文献十分丰富,使得其国语学研究代表了那个时代日本国语学的最高学术水平;在许多日本国语学者"大东亚国语学意识"甚嚣尘上之际,安藤正次算是比较冷静地看待日本"国语"的作用的。《国语学通考》与中国等国家国语学著作具有清楚的"相通性",但对中国学术在日本国语学中所应该具有的作用估计不足。

小学数学“见解通用”理念课堂应用例探

“见解通用”指“见到、理解、学通、用好”,强调在数学教学中将抽象的概念转变为可视的素材,深入理解定理,学通不同要素之间的逻辑关系并强化生活应用。将“见解通用”教学理念引入小学数学课堂教学中,不仅能够切实提升学生的学习兴趣,更能够综合培养学生的数学能力、拓展数学思维,形成学生主动学习、生活化学习、研究型学习的发展态势。

桑椹菌核病研究进展

桑椹是一种营养丰富的果实,富含花青素等抗氧化物质,不仅可以直接食用,还可用于制作果酱、酿造果酒和饮料,具有极高的经济价值。然而,近年来由于缺乏有效的抗性品种,我国果桑种植地区的桑椹菌核病发生日益严重,已严重影响到了桑椹的产量和品质。已确认桑椹菌核病的病原真菌有4种,不同地区的优势菌株不尽相同,可能由单一种类组成,也可能是由2种及以上的菌株复合侵染。由于桑椹菌核病的发病机制复杂,防治难度大,因此,本文主要从桑椹菌核病的类型、特征和侵染循环过程,桑树与病原菌相互作用的分子机制以及防治措施3个方面对该病的研究进展进行综述,以期为今后桑椹菌核病的研究重点以及科学防治提供理论指导。

A hybrid ventilation scheme applied to bidirectional excavation tunnel construction with a long inclined shaft

The breakage and bending of ducts result in a difficulty to cope with ventilation issues in bidirectional excavation tunnels with a long inclined shaft using a single ventilation method based on ducts.To discuss the hybrid ventilation system applied in bidirectional excavation tunnels with a long inclined shaft,this study has established a full-scale computational fluid dynamics model based on field tests,the Poly-Hexcore method,and the sliding mesh technique.The distribution of wind speed,temperature field,and CO in the tunnel are taken as indices to compare the ventilation efficiency of three ventilation systems(duct,duct-ventilation shaft,duct–ventilated shaft-axial fan).The results show that the hybrid ventilation scheme based on duct-ventilation shaft–axial fan performs the best among the three ventilation systems.Compared to the duct,the wind speed and cooling rate in the tunnel are enhanced by 7.5%–30.6%and 14.1%–17.7%,respectively,for the duct-vent shaft-axial fan condition,and the volume fractions of CO are reduced by 26.9%–73.9%.This contributes to the effective design of combined ventilation for bidirectional excavation tunnels with an inclined shaft,ultimately improving the air quality within the tunnel.

Mid-infrared Optical Frequency Comb-based Fourier Transform Spectrometer for Broadband Molecular Spectroscopy

Optical frequency combbased Fourier transform spectroscopy has the features of broad spectral bandwidth,high sensitivity,andmultiplexed trace gas detection,which has valuable application potential in the fields of precision spectroscopy and trace gas detection.Here,we report the development of a mid-infrared Fourier transform spectrometer based on an optical frequency comb combined with a Herriott-type multipass cell.Using this instrument,the broadband absorption spectra of several important molecules,including methane,acetylene,water molecules and nitrous oxide,are measured by near real-time data acquisition in the 2800-3500 cm^(-1)spectral region.The achieved minimum detectable absorption of the instrument is 4.4×10^(-8)cm^(-1)·Hz^(-1/2)per spectral element.Broadband spectra of H_(2)0 are fited using the Voigt profile multispectral fitting technique and the consistency of the concentration inversion is 1%.Our system also enables precise spectroscopic measurements,and it allows the determination of the spectral line positions and upper state constants of N_(2)O in the(0002)-(1000)band,with results in good agreement with those reported by Toth[Appl.Opt.30,5289(1991)].

Visualizing Aphasia in Linguistics From 2000 to 2019

This paper aims to visualize the research of aphasia from a linguistic perspective for the two decades from 2000 to 2019,identifying the changes in research focus and the future emerging trends of aphasia studies in linguistics.Applying the bibliometric approach,the present study reviewed 3,004 publications with the topic word“aphasia”in the framework of linguistics.The dataset was created from the Web of Science database ranging from 2000 to 2019.Using the CiteSpace tool,document co-citation analysis,betweenness centrality(BC)measurement and citation burst detection were conducted to explore and determine the thematic patterns,critical studies,and emerging trends of this knowledge domain.Twelve thematic patterns in these two decades were identified,indicating that researchers have focused on language impairment in aphasia,aphasia therapy and other topics associated with aphasia.Meanwhile,papers with high BC reveal the connections among different research clusters.In addition,bursts of detected citations demonstrate that treatment aiming at the enhanced quality of daily life,the utilization of discourse tasks and treatments at the discourse level,deeper exploration of primary progressive aphasia in terms of clinical data and the application of working memory assessment,and the role of working memory(WM)training in rehabilitation will possibly attract more attention in the future.On the basis of the cluster landscape,BC and citation bursts,the review found that scholars paid extensive attention to the alleviation of communication deficits in the linguistic exploration of aphasia.

Lecturers’Efforts in Building Rapport in the English-Medium Instruction(EMI)Context:Focus on the Use of Communication Strategies

Past studies reveal the prevalence of anxiety,coupled with low motivation and disengagement among students in English-medium instruction(EMI)programs.Given the detrimental impact these negative emotions can have on learning outcomes,it is imperative that teachers establish positive emotional rapport with their students.This study explores how experienced and highly rated EMI lecturers at a Chinese university’s overseas campus use communication strategies to build rapport with their students during interactive academic activities.It identifies the strategies used by these lecturers and examines how the strategies facilitate the teaching-learning process.The data,consisting of 10 hours of tutorials and 10 hours of supervisor-student supervision meetings,is analyzed using an adapted Conversation Analysis(CA)approach.The analysis reveals three types of communication strategies(CSs)frequently used by lecturers:back-channeling,codeswitching,and co-creation of messages.By employing these strategies,the lecturers established a strong rapport with the students,which created an encouraging and supportive learning environment.Consequently,this positive atmosphere facilitated students’learning of content knowledge through English.The findings of this study have implications for the training of lecturers who encounter difficulties in establishing rapport with multilingual students in the EMI setting.

高校辅导员学习领会十九大精神的途径探析

为了更好地引导大学生深入学习十九大精神,确实抓好高校意识形态教育,辅导员应通过认真研读《习近平谈治国理政》、反复揣摩《三十讲》、深入领会系列讲话以及严守政治规矩四方面学通弄懂坐实党的十九大精神。

Age Differences in Behavioral Responses of Male Giant Pandas to Chemosensory Stimulation

Chemical communication plays an important role in survival and reproductive success in mammalian species. In the present study, we examined the ontogenetic pattern of behavioral responses of male giant pandas （Ailuropoda melanoleuca ） to urine odors of conspecific individuals. Our data showed that exposure to the urine of adult females induced a significant increase in sniffing and environmental sniffing/licking behaviors, but a decrease in biting behavior, in males. Males of different ages displayed specific behaviors to female urine odors. Adult males spent more time licking than juvenile and sub-adult males. Further, sub-adult and adult males displayed high levels of environmental sniffing/licking, which was absent in the juvenile males. Juvenile males displayed scent rubbing behavior significantly more frequently than sub-adult and adult males, and also spent more time showing biting behavior than sub-adult males. Finally, juvenile and sub-aduh males showed no difference in response to female and male urine odors. Together, these data suggest that chemosensory cues from conspecific urines induce age-specific responses in male giant pandas.

PCCC for the performance improvement of the wireless optical communication system

In wireless optical communication, effects of scintillation make average Bit Error Rate （BER） deteriorate. To improve system performance,PCCC （Parallel Concatenated Convolutional Code） encoding scheme is employed,and upper bound on the bit error rate is given by considering the effects of scintillation,APD noise and thermal noise. Simulation results show that the POOC encoding scheme can relieve turbulenceinduced intensity fluctuations and the system performance is improved remarkably.

Mechanical properties and microstructures of Al alloy tensile samples produced by serpentine channel pouring rheo-diecasting process

An innovative one-step semi-solid processing technique of A356 Al alloy,the serpentine channel pouring rheo-diecasting process （SCRC）,was explored.The mechanical properties and microstructures of the tensile samples made by the SCRC technique were tested in the as-cast and T6 heat treatment conditions.The experimental results show that the as-cast ultimate tensile strength can reach about 250MPa and the elongation is 8.6%？13.2%.The ultimate tensile strength can increase approximately 30% higher than that of the as-cast one but there is some slight sacrifice of the plasticity after T6 heat treatment.Under these experimental conditions,the semi-solid A356 Al alloy slurry with primary α1（Al） grains,which have the shape factor of 0.78？0.89 and the grain diameter of 35？45μm,can be prepared by the serpentine channel pouring process.The primary α2（Al） grains are very fine during the secondary solidification stage.Compared with the conventional HPDC process,the SCRC process can improve the microstructures and mechanical properties of the tensile test samples.The advantages of the SCRC process include easily incorporating with an existing HPDC machine,cancelling the preservation and transportation process of the semi-solid alloy slurry,and a higher cost performance.

Design of buffer structure at core nodes in optical burst switching

Reasonable and effective buffer structures are proposed in core routers /nodes of optical burst switching.Based on the model of burst traffics and their contentions,the basic qualifications for the design of buffer structures are concluded.With these qualifications,buffer and switch integrated structures are proposed;and by conclusion and expansion,the classification rules of buffer structures are also proposed from different angles.The schemes to integrate structures are analyzed and simulated.

New scheme of optical switch technology of time division

The optical time division switch scheme using optical scanning was proposed in this paper.Quick switching can be realized by the optical element and optical system based on the proposed scheme.The modulation velocity of the proposed scheme can be of the order of nanosecond,which is quick enough for the next generation of optical communication.This scheme will be a key technology in the optical network.The principle of the scheme is studied.The structure of the scheme is proposed and the performance is analyzed.

An chromatic dispersion monitoring method based on spectral-shift of SOA

A remnant dispersion monitoring method based on spectral-shift of SOA in high speed optical communication system with CSRZ format and single channel speed of 40 Gbit/s is proposed. The system performance can be optimized by careful choosing bandwidth and center wavelength of the optical fiber grating filter. The dynamical monitoring range is ±60 ps/nm and the monitoring precision is about 5 ps/nm. This method can be suitable for the application in dynamical dispersion compensation of high speed optical communication systems.

Research on the Correlation between Meteorological Factors and Flue-cured Tobacco Chemical Components in Different Altitudes of Lincang Region

In this study, the relationship between major meteorological factors and tobacco chemical components in different altitudes of Yongde County, Lincang Region of Yunnan Province was studied using correlation analysis and path analysis methods.The results showed that there was a difference on meteorological factors in different altitudes, causing different impacts on chemical components of flue-cured tobacco; contents of nicotine and total nitrogen decreased with the rising of altitude, conversely, total sugar and reducing sugar contents increased with the rising trend of altitude, and the differences on the contents of potassium （K） and chlorine（CI）, and the ratio of K to CI in different altitudes were not significant, at the altitude of 1 250-1 450 m, each chemical component indicator was better. The correlation between main meteorological factors and conventional chemical components of tobacco leaves was as follows： contents of reducing sugar and total sugar increased with the increase of rainfall and relative humidity, and decreased with the increase of sunshine duration; nicotine content increased with the increase of accumulated temperature and sunshine duration; total nitrogen （N） content increased with the increase of daily mean temperature and accumulated temperature; sugar-alkali ratio increased with the increase of rainfall. Path analysis showed that the direct effect of sunshine duration on reducing sugar and total sugar of tobacco leaves was faint, but the indirect effect was obvious; meanwhile, the direct and indirect effects of it on nicotine and total N were the greatest.

Channel Arrangement for optical communication subsystems with 12 parallel channels

This paper devoted to report the design and the achievement of an optical communication subsystem with 12 parallel channels in one chip.The system is capable of transmitting 10 Gbps bidirectional date over hundreds of meters.It can provide error detection and correction by using 8B/10B encoding and Cyclical Redundancy Checking (CRC) encoding when only single-channel fails.The design scheme has already passed the simulation in FPGA.This technique is useful to enhance the capability and the reliability of the very short reach (VSR) transmission systems.

Hardware-in-loop Simulation(HLS) of Homing Anti-tank Missile

The simulation techniques of hardware-in-loop simulation(HLS) of homing antitank missile based on the personal computer (PC) are discussed. The PC and MCS-96 chip controller employ A/D and D/A boards (with photoelectricity isolation) to transfer measur ment and control information about homing head, gyro and rudder and utilize the digital hand shaking board to build correct communication communication protocol. In order to satisfy the real-time requirement of HLS, this paper first simplifies the aerodynamic data file reasonably, then builds a PC software with C language. The program of the controller part is made with PL/M language. The simulation of HLS based on PC is done with the same sampling period of 10ms as that of YH-F1 and the experiment results are identical to those of digital simulation of the homing anti-tank guided missile.

Uniaxial compressive behavior of equal channel angular pressing Al at wide temperature and strain rate range

Uniaxial compressive experiments of ultrafine-grained Al fabricated by equal channel angular pressing(ECAP) method were performed at wide temperature and strain rate range. The influence of temperature on flow stress, strain hardening rate and strain rate sensitivity was investigated experimentally. The results show that both the effect of temperature on flow stress and its strain rate sensitivity of ECAPed Al is much larger than those of the coarse-grained Al. The temperature sensitivity of ultrafine-grained Al is comparatively weaker than that of the coarse-grained Al. Based on the experimental results, the apparent activation volume was estimated at different temperatures and strain rates. The forest dislocation interactions is the dominant thermally activated mechanism for ECAPed Al compressed at quasi-static strain rates, while the viscous drag plays an important role at high strain rates.