Coupled DEM-FDM analyses of the effects of falling rock’s shape and impact angle on response of granular cushion and rock shed

Rock shed is an effective protection measure against rockfall.To investigate the influences of falling rock’s shape and impact angle on the impact effect of the cushioned rock shed,a modeling approach for a rock shed with a cushion layer using PFC-FLAC.The granular cushion is modeled as an aggregate of discrete non-cohesion particles,while the concrete plate and the beam are modeled as zones.The falling rock with different sphericities and impact angles is modeled as a rigid assembly.The numerical model is validated by comparing the simulation results with experimental and numerical results from previous literature.This model is applied to analyze the effects of rock shape and impact angle on the dynamic interaction effects between falling rock and cushioned rock shed,including the impact force,transmitted bottom force,penetration depth,and plate deflection.The numerical results show that the variation in the falling rock’s shape has different effects on the falling rock with different impact angles.These findings could support rock shed design by revealing the limitations of the assumptions in the past research,which may result in unsafe rock sheds for some rockfall cases.

The Impact of Comment Style on Learners’ Essay Revisions

This paper investigates how the type of written feedback provided by teachers affects learners’ ability to revise essays. A total of 120 participants participated in two rounds of essay composition and feedback delivery. The findings indicate that learners who receive comments in the form of questions are more prone to make revisions compared to those receiving statements or imperatives. These results hold significant implications for educators and the ways they utilize written feedback to enhance learners’ writing skills.

售货机升降系统S型速度控制策略

在传统三闭环控制方式下,售货机升降接货系统易因启停过程中加速度突变产生冲击,导致系统运行不平稳。针对这一问题,文中对传统升降系统加减速控制策略进行改进,加入前馈和微分负反馈,提出一种S型速度曲线控制算法。根据路径规划判别条件将S型速度曲线分为七段式、六段式和四段式3种,并给出各路径约束条件下的参数求解方法和具体执行流程。将该算法运用到升降控制系统中进行仿真和实际工况测试,实验结果表明,与传统三闭环控制相比,文中所提控制策略可以提高售货机升降系统运行的平稳性,减小冲击,使速度曲线更加柔和,并能够保持较好的跟踪性能。

Google Scholar University Ranking Algorithm to Evaluate the Quality of Institutional Research

Education quality has undoubtedly become an important local and international benchmark for education,and an institute’s ranking is assessed based on the quality of education,research projects,theses,and dissertations,which has always been controversial.Hence,this research paper is influenced by the institutes ranking all over the world.The data of institutes are obtained through Google Scholar(GS),as input to investigate the United Kingdom’s Research Excellence Framework(UK-REF)process.For this purpose,the current research used a Bespoke Program to evaluate the institutes’ranking based on their source.The bespoke program requires changes to improve the results by addressing these methodological issues:Firstly,Redundant profiles,which increased their citation and rank to produce false results.Secondly,the exclusion of theses and dissertation documents to retrieve the actual publications to count for citations.Thirdly,the elimination of falsely owned articles from scholars’profiles.To accomplish this task,the experimental design referred to collecting data from 120 UK-REF institutes and GS for the present year to enhance its correlation analysis in this new evaluation.The data extracted from GS is processed into structured data,and afterward,it is utilized to generate statistical computations of citations’analysis that contribute to the ranking based on their citations.The research promoted the predictive approach of correlational research.Furthermore,experimental evaluation reported encouraging results in comparison to the previous modi-fication made by the proposed taxonomy.This paper discussed the limitations of the current evaluation and suggested the potential paths to improve the research impact algorithm.

基于FIS模型的学者学术代表作遴选研究

[目的/意义]在“大力推行优秀成果和代表作评价”的背景下,如何科学地遴选学术代表作是摆在所有学者面前的一个重要研究问题,尤其是一般学者的代表作遴选更加值得关注。[方法/过程]在阐述了模型构建基本思想的基础上,文章从期刊影响因子、即时被引频次和内容相似度三个方面构建了适合一般学者代表作遴选的FIS模型。利用陕西省自然科学优秀论文获得者的学术论文进行学术代表作遴选实证研究,并从内部和外部两个方面进行了对比分析。[结果/结论]构建的FIS模型具有一定的比较优势和实际意义,能够更科学地遴选代表作,在一定程度上有助于推动学术繁荣和进步。

临床分析标本溶血对生化检验中AST、GPT、LDH、K^(+)的影响

目的 临床分析标本溶血对生化检验中天门冬氨酸氨基转移酶(AST)、谷丙转氨酶(GPT)、乳酸脱氢酶(LDH)、钾离子(K^(+))的影响情况。方法 选取本院门诊部收治的健康体检者共计80例,时间跨度为2020年1月—2023年2月,将受检者血液标本分成2份,分别进行常规生化检测与引发溶血后的生化检测,对两种不同血清标本天门冬氨酸氨基、谷丙转氨酶、乳酸脱氢酶、钾离子、总胆固醇、碱性磷酸酶、甘油三酯、尿素氮、肌酐、血糖、血尿酸、总胆红素生化指标检测值进行对比观察,随后把标本血清溶血后再测定上述生化指标,分析溶血前后检验结果。结果 在溶血标本中天门冬氨酸氨基转移酶检测值、谷丙转氨酶检测值、乳酸脱氢酶检测值、钾离子检测值、总胆固醇检测值,相较于非溶血标本明显偏高,且碱性磷酸酶、总胆红素与非溶血标本相比明显偏低,差异有统计学意义(P<0.05)。结论 标本溶血容易造成生化检验的天门冬氨酸氨基转移酶、谷丙转氨酶、乳酸脱氢酶、钾离子、总胆固醇以及碱性磷酸酶检测结果出现异常,运用血清血红蛋白浓度校对,有较高的运用价值,可为临床医师提供重要的参考依据。

基于奇异值分解和S变换的齿轮故障诊断研究

为了在强背景噪声干扰下能从核电行星齿轮箱齿轮故障振动信号中提取出冲击特征进行故障诊断,文章将奇异值分解与S变换相结合,并借助MATLAB软件辅助来处理信号中的噪声,提取突出故障信息的冲击特征。采用的方法为:从含有噪声的信号中建立Hankel矩阵,使用3种不同的奇异值选择方法,即奇异值中值法、特征均值法以及奇异值差分谱法,对Hankel矩阵进行奇异值处理后,再重构信号,达到降低信号噪声的目的;对重构信号进行S变换,获得该重构信号的时频谱图;对时频谱图进行S逆变换,得到重构信号的冲击特征。研究结果表明:将奇异值差分谱法与S变换相结合提取出冲击特征的效果最佳,可以为核电行星齿轮箱齿轮相关故障的诊断提供先验信息。

Pathogenesis of Parkinson＇s disease： oxidative stress, environmental impact factors and inflammatory processes

Current hypothesis of neuronal degeneration in Parkinson＇s disease （PD） have been proposed, including formation of free radicals and oxidative stress, mitochondrial dysfunction, excitotoxicity, trophic factor deficiency, inflammatory processes, genetic factors, environmental impact factors, toxic action of nitric oxide, apoptosis, and so on. This review mainly discussed oxidative stress, environmental impact factors, and inflammatory processes in PD.

Pathogenesis of Parkinson’s disease: oxidative stress, environmental impact factors and inflammatory processes

Current hypothesis of neuronal degeneration in Parkinson’s disease (PD) have been proposed, including formation of free radicals and oxidative stress, mitochondrial dysfunction, excitotoxicity, trophic factor deficiency, inflam- matory processes, genetic factors, environmental impact factors, toxic action of nitric oxide, apoptosis, and so on. This review mainly discussed oxidative stress, environmental impact factors, and inflammatory processes in PD.

The withdrawal of the U.S. from the Paris Agreement and its impact on global climate change governance

The global community has prepared for the withdrawal of the U.S. from the Paris Agreement since Donald Trump was elected as the president of the U.S. However, Trump's formal declaration of withdrawal still caused worldwide reaction. Trump will use the withdrawal to build his political reputation and to renegotiate the Paris Agreement despite its negative effects on the political credibility, international relationships, and potential long-term economic growth of the U.S. In general, the withdrawal of the U.S. from the Paris Agreement will not change the development of low-carbon technologies and the transformation trend of the global climate governance regime. However, the long-term goals and international cooperation on climate change will be affected by budget cuts in American climate change research and the cancelation of donations from the multilateral environmental fund of the U.S. If the Paris Agreement is renegotiated, the common but differentiated principle of responsibility of the United Nations Framework Convention on Climate Change will be challenged again. Nevertheless, climate change governance remains a main theme of future sustainable development. Instead of national governments, local governments and non-governmental organizations will develop strategies for technical innovation and emphasize pragmatic cooperation, thus expanding their roles in climate change governance. The capacity building on climate change research and public awareness should be enhanced as a long-term objective of global climate change governance.

The core-merging giant impact in Earth's accretion history and its implications

The Earth’s accretion process is accompanied by a large number of collisions.It is widely accepted that collisions dominate the Earth’s late accretion stage.Among all these collisions,there is a special type of collision called Core-merging giant impact(CMGI),in which much or most the impactor’s core merges directly with the protoEarth’s core.This core-merging scenario plays an important role in the Earth’s accretion process and deeply affects the formation of the Earth’s core and mantle.However,because CMGI is a small probability event,it has not been fully studied.Here we use the SPH method to comprehensively study all possible CMGIs in the Earth’s accretion history.We find that CMGI only occurs in the initial conditions with small impact angle,small impact velocity and big impactor.We further discuss the implications of CMGI.We are confident that CMGI inevitably causes the chemical disequilibrium of the Earth’s core and mantle.The CMGI process also brings many light elements into the Earth’s core.In particular,if the Moon-forming giant impact is a CMGI,then CMGI can also explain the abnormal content of HSEs in the Earth’s current mantle.

Russia's New Energy Diplomacy and Its Impact

Since the terrorist attacks of September 11,the world energy mar-kets have witnessed remarkable changes in Russia’s re-emergenceas a major world energy power and its active development of energydiplomacy.As the signing of agreements at the Russia-America summitand Russia-Europe summit last May as well as at the regular

Convergence of Impact Measures and Impact Bundles

Purpose:A new point of view in the study of impact is introduced.Design/methodology/approach:Using fundamental theorems in real analysis we study the convergence of well-known impact measures.Findings:We show that pointwise convergence is maintained by all well-known impact bundles(such as the h-,g-,and R-bundle)and that theμ-bundle even maintains uniform convergence.Based on these results,a classification of impact bundles is given.Research limitations:As for all impact studies,it is just impossible to study all measures in depth.Practical implications:It is proposed to include convergence properties in the study of impact measures.Originality/value:This article is the first to present a bundle classification based on convergence properties of impact bundles.

U.S.Technological Decoupling from China:Process and Impact

Decoupling is becoming a new phenomenon in inter­national relations and the world economy.Of all the areas of decoupling,the most striking is that of technology,given the special feature of high-tech and its close connections with trade.The United States is implementing a policy of decoupling itself from China in the entire range of high-tech.IMF experts predict that technological decoupling will not only define the strategic competition between China and the U.S.,but also in turn have a strong impact on Europe.

An Impact of Hydrostatic Extraction Scheme on BMRC's Global Spectral Model

There are two important features in geophysical fluid dynamics. One is that the atmospheric and oceanic equations of motion include the Coriolis force; another is that they describe a stratified fluid. The hydrostatic extraction scheme, or standard stratification approximation, posed by Zeng (1979), reflects the second aspect of geophysical fluid dynamics. There exist two major advantages in this scheme; accurate computation of the pressure gradient force can be obtained over steep mountain slopes, and the accumulation error in vertical finite differencing can be reduced, especially near the tropopause.Chen et al (1987) introduced the hydrostatic extraction scheme into a global spectral model, which attained preliminary success at low resolution. Zhang and Sheng et al (1990) developed and improved the hydrostatic extraction scheme in a global spectral model, in which C0, the parameter that represents the stratification of the reference atmosphere, changes not only with height, but also with latitude. The scheme has been incorporated BMRC's global spectral model (IAPB). Four 5-day forecasts have been performed to test the IAPB with the hydrostatic extraction scheme. Objective verifications demonstrate a positive effect of the hydrostatic extration scheme on BMRC's model, particularly at upper levels, over the tropics and the Antartic region.

Systematic Synthesis of Impacts of Climate Change on China's Crop Production System

Global climate change is real and already taking place. The most recent Fifth Assessment Report of the Intergov- ernmental Panel on Climate Change （IPCC AR5） stated that global land and ocean surface temperature increased by 0.85℃ over the period of 1880 to 2012 （IPCC Climate Change 2013）. China is among the most affected countries by global climate change.

Review on Possible Factors for Outbreak of Wood Boring Isopod, Sphaeroma spp. Which Causes Destructive Impact on Mangrove Forest in China

The tropical and subtropical mangrove biomes form the foundation of a highly productive and biologically rich ecosystem providing essential goods and services to human beings. Despite its values, the stability and survival of mangroves are consistently threatened by anthropogenic activities and their associated degradation, resulting in their disappearance. After realizing their ecological importance, in recent years, rehabilitation and restoration programs for mangrove forests have been launched globally. Unfortunately, most mangrove restoration efforts yielded negative results and failed to re-establish mangrove forests because of technical and social failures. Besides, the continued outbreak of wood borer, Sphaeroma spp., in mangrove forests has become one of the destructive causes of natural and restored mangrove forests in some nations including China. However, few studies on the biology of Sphaeroma spp. found in Chinese mangrove ecosystem have been done, and little is known concerning the factors affecting their outbreak in China. In this review, we discussed the possible factors that affect the rapid growth and recruitment of Sphaeroma spp. in the mangrove ecosystem by examining the information of the wood borer Sphaeroma spp. from the scattered pieces of literature with great regard. We discussed the relationship between the recruitment of Sphaeroma spp. and the tide and flow of water, food availability from the surrounding water and water quality including salinity, temperature, and the pollution of water. In addition to these factors, the reduced biodiversity of restored mangrove forest could be one of the main reasons for the outbreak of isopod. We also discussed the destructive impact of the isopod’s outbreak and the possible ways to control their outbreak in mangrove forest.

Policy Towards Gender Equality in Employment in a Globalizing Economy——An outline of the analysis report on the impacts of China's economic reform on women employment

1.This study is one of The Applied Economic Institutes Linkages Project(AERIL)which is funded by theCanadian International Development Agency(CIDA)and jiontly managed by The Conference Board of Canada(CBOC)and the International Trade Research Institute in China.It is jointly implemented by the Institute ofEconomic Research of the Chinese State Planning Commission and the North—South Institute of Canada。