基于“板块”理论与“周期”理论的比较研究所得的哲学启示

运用文献资料法、比较分析法、逻辑推理法等,对新时期"板块"训练理论与传统"周期"训练理论的背景、基础、核心、层面及应用范围、局限性五个方面进行了深入分析与比较研究。得到若干启示:分析运动训练理论的变迁应以逻辑的、历史的态度;对理论变迁的评价应站在辨证客观的哲学高度;理论的变迁遵循适用—不适用—适用……循环往复、螺旋上升的范式;理论变迁的直接动力是理论和实践之间的矛盾。

依托“周期学习单”开展初中生整本书阅读实践

依托“周期学习单”,通过预学、导学和延学三个阶段的教学,能够提高整本书阅读质量,促进学生阅读力、创新力和实践力的提升。预学阶段,整体把握,激活阅读兴趣;导学阶段,分组布置,保证任务驱动;延学阶段,交流探究,培养迁移能力。三个阶段互为保证、互为促进、环环相扣,做实、做活、做细依托“周期学习单”阅读整本书的三环节工程,以此助力学生阅读素养的培养,助力学生阅读与精神生命的丰盈。

依托“周期学习单”开展小学生整本书阅读及小练笔

当前在小学各学段,整本书阅读的现状存在课堂内的学习比重小、阅读缺乏常态化的氛围营造、忽略了人文性的沉淀等问题。研究表明,“周期学习单”对整本书阅读有引领、推进、吸收、内化的作用。基于“周期学习单”激发学生兴趣,增强阅读欲望;精心设计“周期学习单”,引导学生快乐阅读;通过定时交流,提高阅读效率;注重反刍吸收,突出教学重点;重视学生写作欲望的唤起,指导学生多写小练笔等策略,引导小学生进行整本书阅读,提升学生思想品质。

“周期学习单”运用于小学英语课堂教学的实践探讨

文章分析了“周期学习单”运用小学英语课堂教学的必要性,重点介绍了“周期学习单”运用于小学英语课堂教学的设计方法与步骤,呈现了小学英语“周期学习单”设计示例。期望此研究对提高小学英语课堂教学质量有所帮助。

Techno-economic and Environmental Assessments of SAF from Bioamss:An Review

This review presents a comprehensive techno-economic and life-cycle assessment of sustainable aviation fuel(SAF)production from biomass.The critical need for transitioning towards environmentally sustainable alternatives for liquid fuel and aviation industry is first discussed.Key insights encompass the evolutionary progression of biofuel production from first-generation to second-generation biofuels,with a focus on utilizing non-food sources like woody biomass for enhanced sustainability.Available data from the literature on techno-economic assessments of various SAF production pathways are analyzed including production costs,conversion efficiency,and scalability.Moreover,results of lifecycle assessments associated with different SAF production pathways are presented,providing essential insights for decision-making processes.The challenges of scaling up woody biomass-based SAF production are discussed based on the assessment results,and recommendations are proposed to steer stakeholders towards a greener and more sustainable trajectory for aviation operations.

“周期型”问题如何解?(高一、高二、高三)

“周期型”问题,如匀速圆周运动、简谐振动和波动,以及交变电流的相关问题等.如果没有条件限制时.会有无数组解.这一点容易忽略.从而导致漏解。本文给出这类问题的解法.

Microstructure and indentation toughness of Cr/CrN multilayer coatings by arc ion plating

Cr/CrN multilayer coatings with bilayer periods in the range from 1351 to 260 nm were prepared on 304 stainless steel substrates by arc ion plating to study the microstructure and properties of multilayer coatings and stimulate their application.SEM results confirm the clear periodicity of the Cr/CrN multilayer coatings and the clear interface between individual layers.XRD patterns reveal that these multilayer coatings contain Cr,CrN and Cr_2N phases.Because Cr layer is softer than its nitride layer,the hardness decreases with the shortening of the bilayer period(or increasing volume fraction of Cr layer).The Cr/CrN multilayer coating with 862 nm period possesses the highest indentation toughness due to a proper individual Cr and nitride layer thickness.However,for the Cr/CrN multilayer with the bilayer period of 1351 nm,it possesses the lowest toughness due to more nitride phase.The indentation toughness of Cr/CrN multilayer coatings is related with their bilayer period.A coating with a proper individual Cr and nitride layer thickness possesses the highest indentation toughness.

Induction of apoptosis and G2/M cell cycle arrest by oridonin in human gastric cancer BGC-823 cells

Aim To investigate in vitro apoptosis-induction effects of oridonin on gastric tumor cells BGC-823 and its effects on cell cycle, mitochondrial membrane potential and intracellular Ca^2＋ to shed light on the mode of its anticancer action. Methods The MTT method was used to investigate the inhibitory effect of oridonin on BGC-823 cells. The apoptosis-induction effect was evaluated by confocal laser microscopy and flow cytometry. The change of mitochondrial membrane potential and the increase of intracellular Ca^2＋ were assessed by fluorescence probe rhodamine123 and Fluo 3-AM, respectively, with flow cytometry. The expression of apoptosis and cell cycle related proteins was studied using western blotting. Results Oridonin inhibited BGC-823 cells growth with IC50 of 22.21 p, mol.L^-1. It induced apoptosis in a dose-dependent manner. In addition, it decreased mitochondria membrane potential, increased intracellular Ca^2＋, and activated pro-caspase 3. BGC-823 cells were arrested in G2/M cell cycle phase with lower expression of cyclin A protein. The up-regulation of p53 was observed before apoptosis and cell cycle arrest occurred. Conclusion Oridonin inhibits the proliferation of BGC-823 cells through G2/M cell cycle arrest and apoptosis induction, which is mediated by influx of Ca^2＋, up-regulation of p53, activation of caspase-3, and down-regulation of cyclin A.

Microstructure and tribological behavior of Mg-Gd-Zn-Zr alloy with LPSO structure

A Mg-14.28Gd-2.44Zn-0.54Zr （mass fraction, %） alloy was prepared by conventional ingot metallurgy （I/M）. The microstructure differences in as-cast and solution-treated alloys were investigated. Sliding tribological behaviors of the as-cast and solution-treated alloys were investigated under oil lubricant condition by pin-on-disc configuration. The wear loss and friction coefficients were measured at a load of 40 N and sliding speeds of 30-300 mm/s with a sliding distance of 5000 m at room temperature. The results show that the as-cast alloy is mainly composed ofα-Mg solid solution, the lamellar 14H-type long period stacking ordered （LPSO） structure within matrix, andβ-[（Mg,Zn）3Gd] phase. However, most of theβ-phase transforms to X-phase with 14H-type LPSO structure after solution heat treatment at 773 K for 35 h （T4）. The solution-treated alloy presents low wear-resistance, because the hard β-phase is converted into thermally-stable, ductile and soft X-Mg12GdZn phase with LPSO structure in the alloy.

Microstructure and mechanical properties of Mg_(94)Zn_2Y_4 extruded alloy with long-period stacking ordered structure

The microstructure and mechanical properties of Mg94Zn2Y4 extruded alloy containing long-period stacking ordered structures were systematically investigated by SEM and TEM analyses. The results show that the 18R-LPSO structure and α-Mg phase are observed in cast Mg94Zn2Y4 alloy. After extrusion, the LPSO structures are delaminated and Mg-slices with width of 50-200 nm are generated. By ageing at 498 K for 36 h, the ageing peak is attained andβ′phase is precipitated. Due to this novel precipitation, the microhardness ofα-Mg matrix increases apparently from HV108.9 to HV129.7. While the microhardness for LPSO structure is stabilized at about HV145. TEM observations and SAED patterns indicate that the β′ phase has unique orientation relationships betweenα-Mg and LPSO structures, the direction in the close-packed planes ofβ′precipitates perpendicular to that ofα-Mg and LPSO structures. The ultimate tensile strength for the peak-aged alloy achieves 410.7 MPa and the significant strength originates from the coexistence ofβ′precipitates and 18R-LPSO structures.

Decomposition laws of tungsten prices fluctuation since 1900 and its applications

Tungsten current price was transformed yearly to its constant price since 1900, which is roughly decomposed into four components as trend, cycle, impact and random. The core prices, consisting of the trend and the cycle, present regularities that a long-run cycle is embedded within two major cycles, and major cycle is composed of low-price period and high-price period, along with the rapid rise into a tower, and along with deep down into next trough; three sharply upward shocks occur by the events in a tower. Fluctuations in prices trend to slow cycles and expand the bands. It can be expected that tungsten price will highly stand over 17 a, and is is a advice that reducing production and restricting export maybe maintain a high price level.

New LCA Approach with Fuzzy Evaluation

A quantitative and comprehensive method of product life cycle assessment(LCA) with fuzzy theory is developed, which will help designers to select the optimum design scheme for product life cycle design(LCD). Based on the theory of multiple attribute decision making, an algorithm of comprehensive and comparative evaluation for product environmental adaptability is presented. A program is built and used in an example of design improvement. The result shows that the proposed method and algorithm are practical and effective to the development of green products.

SUBSAMPLE TIME DELAY ESTIMATION BASED ON PHASE SPECTRUM OF BAND LIMITED STOCHASTIC SIGNALS

The accuracy of conventional time delay estimation （TDE） algorithms is limited by the sampling interval. A novel algorithm of subsample TDE suitable for widehand signals is presented to improve the accuracy. This algorithm applies periodogram and parabolic interpolation to the cross correlation spectrum of band limited stochastic signals, and can obtain a continuous time delay estimator. Simulations are carried out to compare the performance of the proposed algorithm with that of other subsample TDE algorithms. Results show that the proposed algorithm outperforms other algorithms and reachs the Cramer-Rao lower bound （CRLB） at a high signal- to-noise ratio. For the wideband characteristic and the randomness of the transmitting signal, the proposed algo- rithm is suitable for the low probability of intercept radars.

IMMUNE FUNCTION OF IMMATURE RAINBOW TROUT ( Oncorhynchus mykiss ) RELATED WITH PHOTOPERIOD

Radioimmunoassay,enzyme linked immunospot assay and enzyme immunoassay were used for the determinations of plasma steroid hormone's level,antibody producing cell's counting and IgM level in this study.The decreased number of antibody producing cells and low IgM levels were observed in sexual immature rainbow trout during the spawning season.These fish were reared under almost constant water temperature and natural photoperiod.Moreover,low IgM level was also observed in immature rainbow trout,which were reared under short photoperiod,and IgM level was not changed by treatment of testosterone.The results suggest that photoperoid may cause the changes in immune competence.It is possible that circadian rhythm accompanied with photoperiod may influence physiological function of fish,so that immune competence is changed.

体育实践教学内容体系研究

在《中小学体育与健康课程标准》与《全国普通高等学校体育课程教学指导纲要》精神的指导下,在保持课程灵活性原则的基础上,横向以体育教材排列"周期循环"理论,纵向以学生身心发展特点为依据来划分体育教学项目与内容,建立体育实践教学内容新体系,使体育实践教学内容适度"细化",使其安排和选择在理论层面上更加科学,在实践层面上更加具有可操作性。

Identification of Differentially Expressed MicroRNAs During the Development of Chinese Murine Mammary Gland

MicroRNAs （miRNAs） are endogenous -22 nucleofide-long noncoding RNAs. In this study, to investigate miRNA expression profiles and their functions in mammary gland development, we have used microarray as well as qRT-PCR, to analyze the miRNA expression changes along the murine mammary cycle during pregnancy, particularly on transition from pregnancy to lactation. It shows that every developmental stage of the mammary gland has its own mjRNA expression pattern. Compared with virgin and involution, some miRNAs such as miR-138 and miR-431 are downregulated, whereas, some miRNAs such as miR-133 and miR-133a-133b are upregulated during pregnancy and lactation. These results indicate that miRNAs are functionally involved in mammary gland development.

Effects of Low Dose Radiation on Tumor Apoptosis, Cell Cycle and Apoptosis-Related Protein Bcl-2 in Tumor-Bearing Mice

To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcutaneously with S180 sarcoma cells in the left inguenas an in situ experimental animal model. Seven days later, the mice were subjected to 75 mGywhole-body γ-irradiation. At 24 and 48 h after the irradiation, all mice were sacrificed. The tumorsizes were measured, and tumor cell apoptosis and cell cycle progression were analyzed by flowcytometry. The expression of apoptosis-related protein Bcl-2 and the apoptotic rate of tumor cellswere observed by immunohistochemistry and electron microscopy. Results: Tumors grew significantlyslower after LDR (P 【 0.05). The tumor cells were arrested in G1 phrase and the expression of Bcl-2protein decreased at 24 h. Apoptotic rate of tumor cells was increased significantly at 48 h afterLDR (P 【 0.01). Conclusion: LDR could cause a G1-phase arrest and increase the apoptosis of tumorcells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. Theorganized immune function and anti-tumor ability are markedly increased after LDR. Our studyprovides practical evidence of clinical application to cancer treatment.

Immunohistochemical Analysis of IAA in Anthers of the Photoperiod-sensitive Genic Male-sterile Rice

The immunohistochemical localization of IAA and the comparison of their relative levels were carried out for the first time in the anthers of Nongken 58S and its wild type Nongken 58 (Oryza sativa subsp. japonica) after long_day and short_day treatments. The distribution of free_IAA in anthers and its dynamic variation could be reflected by this method. The results showed that the IAA level in the anthers of Nongken 58S after long_day treatment was much lower than that in short_day_treated Nongken 58S and those in wild type Nongken 58 in five stages from pistil and stamen primordia formation to late uninucleate stage. The possible reasons for IAA deficiency in Nongken 58S_LD anthers and its relationship with fertility alteration were also discussed.