Calculation of Ecological Footprint Based on Modified Method and Quantitative Analysis of Its Impact Factors——A Case Study of Shanghai

Ecological footprint （EF） has attracted much attention internationally as a potential indicator for sustainable development. In China, EF has also gained recognition in related fields and disciplines. Moreover, some scholars in these fields have proposed alternative methods to calculate EF and have made some progress. This paper, therefore, begins with the introduction and development of EF in China. However, the established methods of EF calculation hold some limitations, such as indicator variance and result abnormality. In order to resolve those problems, the authors make a further modification considering the demand of EF as a comprehensive indicator： 1） More accurate analysis has been done to divide EF into several parts： imported EF, exported EF, and producible EF, which is the solution to the problem of abnormality in original EF results and can explain abnormal phenomena reasonably. 2） Considering the actual situa- tion of Shanghai, emended equivalence factor is brought forward and a matrix is formed with equivalence factors. The measure can reduce the deviation between the fact and the results. 3） The calculation compares local yield with global average yield to analyze the effects of yields. And based on local yields in different years, the results are more accurate. Finally, the calculation method is applied to calculating EF of Shanghai from 1980 to 2003, and the subsequent detailed analysis is presented. Available data and results suggest a statistically significant correlation coefficient between EF and GDP, population density and urbaniTation level. Through analyzing the process of calculating EF and its results, it can be seen that EF, as a macro-indicator, can not exactly indicate whether development within a region can meet the re- quests of sustainable development, which can be explained by the fact that the result of EF is impacted greatly by sub- jective factors including national policy,available technology, population, etc. Nevertheless, EF can demonstrate, at least to some degree, the regional status in terms of resources and energy consumption, as well as developmental potential. The calculation of EF, therefore, deserves further research to achieve more far-reaching significance in application.

A quantitative BP neural network analysis of the relationships between ΣREE content and impact factors in the Beibu Gulf

The distribution characteristics of rare earth elements （REE） in bottomsediments are influenced by many factors. Hence, conducting a quantitative analysis isdifficult. A qualitative analysis of the relationships between ΣREE content andprovenance, hydrodynamics, grain size and mineral distribution in the Beibu Gulf showsthat terrestrial rocks control the ΣREE composition. Both weaker hydrodynamics andfiner grain size lead to a higher ΣREE content. Relative curves revealing therelationships between individual impact factors and ΣREE content were obtained fromthe combination of qualitative and quantitative analyses of the BP neural network,which trained the position of samples, gravel content, sand content, silt content, claycontent and clay mineral content. The results are consistent with those of thequantitative analysis. The self-learning algorithm is automatically determined andcalculated quantitatively. The impact of each factor on REEs and how each factorcontrols the ΣREE distribution is identified. Thus, environmental changes and thegeological evolution of the region can be inferred based on curve variation and the geological evolution of the region can be inferred based on curve variation and theactual situation. This method also provides useful theoretical guidance for the analysisof REE enrichment and dispersion.

Evaluation of vertical impact factor coefficients for continuous and integral railway bridges under high-speed moving loads

In the railway bridge analysis and design method,dynamic train loads are regarded as static loads enhanced by an impact factor(IF).The IF coefficients for various railway bridges have been reported as a function of span length or frequency of the bridges in Eurocode(2003).However,these IF coefficient values neglect the effects of very high speeds(>200 km/h)and soil-structure interaction(SSI).In this work,a comprehensive study to assess the impact factor coefficients of mid-span vertical displacements for continuous and integral railway bridges subjected to high-speed moving loads is reported.Three different configurations,each for the three-dimensional(3D)continuous and integral bridge,are considered.Also,single-track(1-T)and two-track(2-T)“real train”loading cases for both these bridge types are considered.Subsequently,finite element analysis of the full-scale 3D bridge models,to identify their IF values,considering the effects of SSI for three different soil conditions,is conducted.The IF values obtained from the study for both bridge types are comparable and are greater than the values recommended by Eurocode(2003).The results reveal that with a loss of soil stiffness,the IF value reduces;thus,it confirms the importance of SSI analysis.

Discipline Impact Factor: Some of Its History, Some of the Author's Experience of Its Application, the Continuing Reasons for Its Use and… Next Beyond

Purpose: This work aims to consider the role and some of the 42-year history of the discipline impact factor(DIF) in evaluation of serial publications. Also, the original "symmetric" indicator called the "discipline susceptibility factor" is to be presented. Design/methodology/approach: In accordance with the purpose of the work, the methods are analytical interpretation of the scientific literature related to this problem as well as speculative explanations. The information base of the research is bibliometric publications dealing with impact, impact factor, discipline impact factor, and discipline susceptibility factor.Findings: Examples of the DIF application and modification of the indicator are given. It is shown why research and university libraries need to use the DIF to evaluate serials in conditions of scarce funding for subscription to serial publications, even if open access is available. The role of the DIF for evaluating journals by authors of scientific papers when choosing a good and right journal for submitting a paper is also briefly discussed. An original indicator "symmetrical" to the DIF(the "discipline susceptibility factor") and its differences from the DIF in terms of content and purpose of evaluation are also briefly presented.Research limitations: The selection of publications for the information base of the research did not include those in which the DIF was only mentioned, used partially or not for its original purpose. Restrictions on the length of the article to be submitted in this special issue of the JDIS also caused exclusion even a number of completely relevant publications. Consideration of the DIF is not placed in the context of describing other derivatives from the Garfield impact factor. Practical implications: An underrated bibliometric indicator, viz. the discipline impact factor is being promoted for the practical application. An original indicator "symmetrical" to DIF has been proposed in order of searching serial publications representing the external research fields that might fit for potential applications of the results of scientific activities obtained within the framework of the specific research field represented by the cited specialized journals. Both can be useful in research and university libraries in their endeavors to improve scientific information services. Also, both can be used for evaluating journals by authors of scientific papers when choosing a journal to submit a paper.Originality/value: The article substantiates the need to evaluate scientific serial publications in library activities—even in conditions of access to huge and convenient databases(subscription packages) and open access to a large number of serial publications. It gives a mini-survey of the history of one of the methods of such evaluation, and offers an original method for evaluating scientific serial publications.

Co-expression network analysis predicts a key role of microRNAs in the adaptation of the porcine skeletal muscle to nutrient supply

Background:The role of non-coding RNAs in the porcine muscle metabolism is poorly understood,with few studies investigating their expression patterns in response to nutrient supply.Therefore,we aimed to investigate the changes in microRNAs(miRNAs),long intergenic non-coding RNAs(lincRNAs)and mRNAs muscle expression before and after food intake.Results:We measured the miRNA,lincRNA and mRNA expression levels in the gluteus medius muscle of 12 gilts in a fasting condition(AL-T0)and 24 gilts fed ad libitum during either 5 h.(AL-T1,N=12)or 7 h.(AL-T2,N=12)prior to slaughter.The small RNA fraction was extracted from muscle samples retrieved from the 36 gilts and sequenced,whereas lincRNA and mRNA expression data were already available.In terms of mean and variance,the expression profiles of miRNAs and lincRNAs in the porcine muscle were quite different than those of mRNAs.Food intake induced the differential expression of 149(AL-T0/AL-T1)and 435(AL-T0/AL-T2)mRNAs,6(AL-T0/AL-T1)and 28(AL-T0/AL-T2)miRNAs and none lincRNAs,while the number of differentially dispersed genes was much lower.Among the set of differentially expressed miRNAs,we identified ssc-miR-148a-3p,ssc-miR-22-3p and ssc-miR-1,which play key roles in the regulation of glucose and lipid metabolism.Besides,co-expression network analyses revealed several miRNAs that putatively interact with mRNAs playing key metabolic roles and that also showed differential expression before and after feeding.One case example was represented by seven miRNAs(ssc-miR-148a-3p,ssc-miR-151-3p,ssc-miR-30a-3p,ssc-miR-30e-3p,ssc-miR-421-5p,ssc-miR-493-5p and ssc-miR-503)which putatively interact with the PDK4 mRNA,one of the master regulators of glucose utilization and fatty acid oxidation.Conclusions:As a whole,our results evidence that microRNAs are likely to play an important role in the porcine skeletal muscle metabolic adaptation to nutrient availability.

Analysing Delay Impact from Potential Risk Factors on Project Delivery of Oil and Gas Pipeline:A Case Study in IRAQ

The aim of this paper is to present the design and specifications of an integrated Delay Analysis Framework(DAF),which could be used to quantify the delay caused by the Risk Factors(RFs)in Oil and Gas Pipelines(OGPs)projects in a simple and systematic way.The main inputs of the DAF are(i)the potential list of RFs in the projects and their impact levels on the projects and the estimated maximum and minimum duration of each task.Monte Carlo Simulation integrated within@Risk simulator was the key process algorithm that used to quantify the impact of delay caused by the associated RFs.The key output of the DAF is the amount of potential delay caused by RFs in the OGP project.The functionalities of the developed DAF were evaluated using a case study of newly developed OGP project,in the south of Iraq.It is found that the case study project might have delayed by 45 days if neglected the consideration of the RFs associated with the project at the construction stage.The paper concludes that identifying the associated RFs and analysing the potential delay in advance will help in reducing the construction delay and improving the effectiveness of the project delivery by taking suitable risk mitigation measures.

On indexing in the Web of Science and predicting journal impact factor

We discuss what document types account for the calculation of the journal impact factor （JIF） as published in the Journal Citation Reports （JCR）. Based on a brief review of articles discussing how to predict JIFs and taking data differences between the Web of Science （WoS） and the JCR into account, we make our own predictions. Using data by cited-reference searching for Thomson Scientific＇s WoS, we predict 2007 impact factors （1Fs） for several journals, such as Nature, Science, Learned Publishing and some Library and Information Sciences journals. Based on our colleagues＇ experiences we expect our predictions to be lower bounds for the official journal impact factors. We explain why it is useful to derive one＇s own journal impact factor.

Factors affecting soil organic carbon in a Phyllostachys edulis forest

Phyllostachys edulis plays an important role in maintaining carbon cycling.We examined the effects of soil properties on organic carbon content in a P.edulis forest on Dagang Mountain,Jiangxi Province,China.Based on correlation and stepwise multiple regression analyses,the effects of seven soil factors on organic carbon and their sensitivities to change were studied using path and sensitivity analyses.The results revealed differences in the interconnections and intensities of soil factors on organic carbon.Soil porosity,field capacity,and ammonium nitrogen levels were the main factors affecting organic carbon in the ecosystem.Soil porosity had a strong direct effect on organic carbon content and a strong indirect effect through field capacity.Field capacity and ammonium nitrogen levels mainly affected organic carbon directly.Field capacity,soil porosity,and ammonium nitrogen content,as well as bulk density,b-glucosidase activity,and invertase activity,were sensitive factors.Polyphenol oxidase activity was insensitive.Our study provides a theoretical basis for understanding the effects of soil factors on organic carbon,which can be utilised to improve P.edulis forest management strategies and promote carbon sequestration capacities.

东北三省耕地利用格局变化对粮食全要素生产率的影响

耕地是粮食生产最基本的要素,当前粮食需求扩大与粮食生产区域性不足矛盾突出,寻求更合理的耕地利用格局来实现粮食全要素生产率的提升具有重要意义。本研究基于土地利用/土地覆被变化(LUCC)遥感监测数据,应用GIS软件提取东北三省2000、2005、2010、2015年耕地利用格局相关数据,同时运用数据包络分析模型估算了2000、2005、2010年和2015年东北三省区域和市域粮食全要素生产率。在耕地利用格局变化分析和粮食全要素生产率测算的基础上,从耕地利用格局变化的角度选取指标构建面板数据模型,定量分析其对粮食全要素生产率的影响。结果表明:东北三省市域粮食全要素生产率4个时期均值分别为0.81、0.78、0.82和0.83,粮食全要素生产率空间分布从最初的相对均匀到局部集聚;耕地转出率和耕地斑块破碎度与粮食全要素生产率呈负相关关系,耕地面积比例、耕地转入率和耕地斑块聚合度与粮食全要素生产率呈正相关关系;东北三省粮食全要素生产率提高主要源于耕地面积增加、林地和未利用地向耕地的转入以及耕地在流域的聚合,粮食全要素生产率的降低主要源于耕地转入减少和建设用地对耕地的嵌入式占用。研究表明,严格规划耕地利用格局、持续开展土地整理、提高耕地聚合度,可在保证耕地有效数量的同时,提高耕地利用格局的集聚性和合理性,促进粮食全要素生产率的提升。

物料冲击对椭圆振动筛筛分性能的动态影响

为了研究物料冲击对振动筛动态特性的影响,加工了某型三轴椭圆振动筛样机。首先,建立简化后的筛机模型,采用离散元法与多体动力学相结合的方法对椭圆振动筛的筛分过程进行数值模拟;其次,引入有限元法对物料冲击下的筛面进行分析,以筛分效率、物料运输速度、筛上物质量和最大冲击力为筛分性能的评价指标;最后,通过试验对其不同工况下的结构振动和应变信号进行了测试和分析,研究了振幅、振频、筛面倾角以及入料速度对筛分性能的影响,揭示了常规筛机评价指标与振动参数之间的关系,为多目标评价和振动筛机优化设计提供了参考。

新版CSSCI新增与剔除期刊的定量分析与对策研究

分析高校学报类期刊的论文出版与影响力现状并提出对策,对于学术期刊的健康成长和发展具有重要意义。文章对最新版CSSCI来源期刊(2021—2022)新增6种与剔除2种高校学报期刊从载文量、年被引次数、复合影响因子、综合影响因子、两年他引影响因子、学科分布及基金发表论文等方面进行定量分析,探究期刊发展规律和趋势。研究结果表明:新增与剔除期刊的论文发文量呈下降趋势,影响因子呈现差异,剔除期刊存在自引现象,期刊基金论文占比与其影响因子不相关,各期刊发文所属学科存在差异。基于以上研究结果提出的对策建议可为优化学术期刊提供重要参考。

UHPC梁抗冲击性能影响因素有限元分析

为研究配箍率、纵筋率、UHPC强度对UHPC梁抗冲击性能的影响,采用LS-DYNA软件,建立落锤冲击下的UHPC梁有限元模型,进行数值计算,分析对比其破坏形态、位移时程。结果表明UHPC中的钢纤维提高了梁的抗剪能力,导致配箍率对UHPC梁的冲击响应影响较小;当纵筋率小于1.0%时,破坏形态为少筋破坏,随着纵筋率增大,梁抗冲击能力增强,破坏形态转变为适筋破坏,跨中最大位移减少,但影响程度随着纵筋率增加而逐渐减少;UHPC抗压强度不同,梁的破坏模式有差异,当强度从100MPa增加到140MPa时,梁体破坏形态从落锤两侧出现斜向损伤转变为跨中受拉损伤。对于UHPC梁抗冲击设计,可减少箍筋的配置,而提高纵筋率或UHPC强度。

克里雅河流域中游绿洲蒸散发的时空演变与驱动因素分析

蒸散发是评估荒漠绿洲水热循环的关键因素,其时空变化监测及驱动力研究可为水资源的精准调控与生态环境保护提供科学依据。以克里雅河流域中游绿洲地区为研究区域,本文基于Landsat遥感影像与SEBS模型分析了2010—2022年蒸散发的时空变化,通过蒸发皿实测数据和Penman-Monteith模型进行了估算结果的精度验证,并进一步探讨了蒸散发的影响因素。结果表明:①蒸散发的SEBS模拟值与蒸发皿观测值的相关系数和R 2分别为0.93和0.87,RMSE为0.96 mm/d;与彭曼公式观测值的相关系数和R 2分别为0.90和0.81,RMSE为0.64 mm/d。②2010—2022年的实际蒸散发呈下降趋势,其变化速率为14.75 mm/a;在春季、夏季和秋季呈下降趋势,在冬季则呈上升趋势。③蒸散发的空间异质性明显,高值主要集中在克里雅河沿岸附近,低值则分布在绿洲边缘地区的沙地;近13年整个研究区约有70.2%的像元呈无显著下降趋势,10.4%的像元呈显著下降趋势。④蒸散发与气温、气压、日照时数、地表温度和NDVI呈显著相关关系,与风速和地表反照率呈弱相关关系。总体而言,研究结果能够较好地模拟克里雅河流域中游绿洲的蒸散发时空异质特征,有助于流域水资源合理规划与调控政策的制定。

基于Web of Science数据库中影响因子研究文献的计量分析

文章运用文献计量方法,以美国科学情报研究所开发的Web of Science数据库为数据源基础,检索了有关研究影响因子的文献,并从文献量、著者、机构、核心期刊、引文等角度进行了统计和分析,以定量数据从侧面反映了影响因子这一评价期刊质量的指标在其被提出之后30余年内的发展情况。

基于ISI Web of Science的《中国地理科学》(英文版)影响力分析及提升举措

本文以Web of Knowledge为检索平台,从总被引频次、发表文章数量、单篇文章被引用次数、引用作者分布等方面,基于地理学学科特点和文献计量学方法,统计分析了《中国地理科学》(英文版)近年来影响因子的变化情况和影响因子下降的原因,总结了该刊为提高影响因子和总被引频次所采取的改进措施,为该刊未来的发展提供指导,也为其他同类刊物提供借鉴。

基于logistic回归分析下颌第三磨牙近中、垂直阻生的危险因素

目的:探讨下颌第三磨牙近中、垂直阻生的危险因素,并基于logistic回归分析构建预测模型。方法:收集2021年6月—2023年12月天津市口腔医院243颗下颌第三磨牙的临床资料,根据萌出类型分为萌出组和阻生组,阻生组包括近中阻生和垂直单侧阻生。单因素分析筛选出具有统计学意义的因素后,采用logistic回归分析方法进行多因素分析,进一步绘制列线图,预测下颌第三磨牙阻生的风险因素。采用SPSS 27.0软件包对数据进行统计学分析。结果:243颗下颌第三磨牙中,萌出组75例(30.86%),阻生组168例(69.14%)。2组年龄、性别、牙根数、Co-Go、Co-Cop、W2、W3、W4和L相比,差异无统计学意义(P>0.05)。萌出组与阻生组Nolla、L-6缺失、L-E缺失、Co-Pog、Co-Go/Co-Pog、L6-MP、α和W1相比,差异有统计学意义(P<0.05)。多因素回归分析显示,Nolla、L-6缺失、L-E缺失、Co-Pog、Co-Go/Co-Pog、L6-MP、α和W1是下颌第三磨牙发生近中、垂直阻生的独立危险因素(P<0.05)。列线图构建显示较高的预测准确性。受试者工作特征曲线(ROC)分析结果表明,独立危险因素联合预测下颌第三磨牙近中、垂直阻生的曲线下面积(AUC)为0.924,95%CI为0.887~0.960,灵敏度为86.9%,特异度为86.7%。结论:Nolla、L-6缺失、L-E缺失、Co-Pog、Co-Go/Co-Pog、L6-MP、α和W1是影响下颌第三磨牙近中、垂直阻生的主要危险因素,利用logistic回归分析和列线图可有效预测阻生风险,为临床治疗提供科学依据。

基于主成分分析的豫北平原浅层地下水化学特征

地下水是豫北平原的重要工农业水源。为调查豫北平原北部地下水水质的空间分布、成因及其主要影响因子,采集了660个地下水样品,利用水化学分析及数学统计方法得出:研究区地下水TDS值为170.02~6970.30 mg/L,78%的地下水样品为淡水,22%的水样为微咸水、咸水。淡水的水化学类型以HCO_(3)-Ca·Mg、HCO3·Cl-Ca·Mg为主,微咸水、咸水水化学类型以Cl·SO_(4)-Ca·Mg为主。从西北到东南,地下水盐度逐渐增大,咸水呈条带状沿卫河流向展布。采用主成分分析法得出地下水水质的5个主成分,代表了含水层中碳酸盐、硅酸盐以及石膏等矿物的溶解,工农业污染,含锰、氟、铁矿物溶解的原生地质污染以及蒸发浓缩作用。依据主成分得分对地下水控制因素进行划分,发现区内地下水主要受到水岩作用影响,部分区域存在原生地质污染,而在城市周边地下水主要受到人为污染的影响,受污染的地下水零散分布。

京沪高速公路北京—天津段地面沉降时序InSAR监测与影响因素

地面沉降作为平原区主要的地质灾害之一,对高速公路安全运行产生了潜在的影响。为了探究京沪高速公路北京—天津段的地面沉降情况,选取2017年1月至2020年3月70景Sentinel-1B卫星影像,利用SBAS-InSAR技术对该路段沿线地面沉降展开监测,并采用外部水准观测方法对InSAR监测结果进行精度评定;在此基础上,结合3类9个影响因子数据对沿线地面沉降进行空间模拟,通过对比普通最小二乘(OLS)模型、地理加权回归(GWR)模型和多尺度地理加权回归(MGWR)模型的模拟效果,最后选取相对最优模型对各种影响因子进行量化研究。结果表明:京沪高速公路北京—天津段表现出不均匀沉降特征,最大年均沉降速率超过-90 mm·年-1;研究区主要分布有6个明显的沉降中心,京沪高速公路北京—天津段经过其中3个;采用模拟效果相对最优的多尺度地理加权回归模型进行定量分析可知,第四系沉积厚度和地下水位变化对沉降的影响较大,而地形环境因子的影响较小。

古尔班通古特沙漠土壤水分-地形-植被关系研究

土壤水分是固沙植被的主要驱动因子,受地形、植被和气候的相互作用影响。本研究以古尔班通古特沙漠半固定沙丘上的土壤水分为研究对象,采用广义线性、广义加性和随机森林等模型,研究了不同微地貌类型和深度的土壤水分与地形-植被因子之间的关系。结果表明:除了迎风坡上表层(0~40 cm)土壤水分之外,沙丘不同微地貌类型和深度的土壤水分之间差异不显著;与植被因子相比,地形因子对不同深度土壤水分的影响更显著;地形因子坡度和高差与土壤水分含量呈负相关关系,而坡向与土壤水分含量呈正相关关系;植被因子的灌木盖度和生物量也对土壤水分呈现负向趋势;针对不同深度的土壤水分与地形-植被因子的关系建模上,随机森林模型优于广义线性和广义加性模型。研究结果为该地区未来固沙植被保护工作提供了理论指导。

基于多因素耦合量化表征模型的冲击危险区域划分

针对现有冲击危险评价方法不能准确体现冲击危险因素影响下应力集中变化特征等问题,提出了基于多因素耦合量化表征模型的冲击危险区域划分方法。首先,根据地下煤层的地质条件、巷道分布、开采范围等实际情况,分析得出主要的冲击影响因素;其次,分别参考多因素叠加法和应力分析法,确定各类冲击影响因素的影响范围及相对应力集中系数;然后,基于煤岩体内部微元强度分布函数,构建冲击危险多因素耦合量化表征模型;最后,将冲击影响因素的影响范围及相对应力集中系数代入量化表征模型,得到煤层应力分布结果,根据应力分布结果进行冲击危险等级划分,得到冲击危险区域分布情况。以山东新巨龙能源有限责任公司3煤层为例,通过分析叠加断层、大巷和采空区等主要冲击危险因素引起的应力集中,制定合理的冲击危险等级划分标准,得到了3煤层冲击危险区域划分结果,并进行了现场验证。由评价工作完成前后发生的矿震事件可知,冲击震源主要集中在强冲击危险区域,这与区域划分结果较为吻合,从而验证了该方法能够有效地定量划分煤层冲击危险区域。