SOME EXAMPLES OF TRANSITION SPANS MINERALIZING AND ANALYSIS OFTHEIR DYNAMICS

The transitional span is a special environment for deposits. Taking peat, oil gas, metallic deposits as examples, this paper discusses the spatial temporal transitional characteristics of mineralization in transitional regions, points out the importance of the mineralization in transition spans, and analyses their dynamics finally.

TIBET ARCHIVES:Rich Collection Spans Some 700 Years

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Safe mining practices under wide spans in underground non-caving mines——Case studies

Mining under wide span is of concern as it increases the probability of back caving causing personnel injury and equipment damage in underground mines in open stoping and underhand drift-and-fill methods.Though restricting personnel access to well supported lateral development is commonly practiced,it is not always possible to implement this requirement due to various factors such as ore loss control,drilling equipment limitations,availability of remote operating capacity and consideration of productivity.Even with rules implemented to limit personnel entry into openings with wide spans,the hazards of equipment damage and back caving still exist.Over the years,different practices have been reported and adopted to minimize risks associated with exposure to large spans in various underground mines.Lessons from these practices are beneficial to current and future mines with challenges of safe extraction of thick deposits in a non-caving setting.This paper briefly summarizes practices in mining wide orebodies using the open stoping method without personnel access and underhand mining using the drift-andfill method with personnel exposure in the industry and presents cases from Kinross mines where the hanging pillar design was tested,and stope backs were naturally and artificially supported for extraction under wide spans using the open stoping method.

基于对span的预判断和多轮分类的实体关系抽取

针对自然语言处理领域中的实体识别和关系抽取任务,提出一种对词元序列(Token Sequence,又称span)进行预测的模型Smrc。模型整体上利用BERT预训练模型作为编码器,另外包含实体预判断(Pej)、实体多轮分类(Emr)和关系多轮分类(Rmr)3个模块。Smrc模型通过Pej模块的初步判断及Emr模块的多轮实体分类来进行实体识别,再利用Rmr模块的多轮关系分类来判断实体对间的关系,进而完成关系抽取任务。在CoNLL04、SciERC和ADE 3个实验数据集上,Smrc模型的实体识别F1值分别达到89.67%,70.62%和89.56%,关系抽取F1值分别达到73.11%,51.03%和79.89%,相较之前在3个数据集上的最佳模型Spert,Smrc模型凭借实体预判断和实体及关系多轮分类,在2个子任务上其F1值分别提高了0.73%,0.29%,0.61%及1.64%,0.19%,1.05%,表明了该模型的有效性及其优势。

Corrigendum to“Nitrosamines crisis in pharmaceuticals-Insights on toxicological implications,root causes and risk assessment:A systematic review”[J.Pharm.Anal.14(2024)100919]

Original statement in the Section 2:2.Literature search Our primary screening of 180 articles yielded the relevant data for this study.2.1.Study selection A total of 180 articles spanning from 1960 to the present day,including original research,reviews,case reports and studies reporting nitrosamine impurities above the no-observed-adverse-effect levels(NOAEL)established by regulatory agencies,were initially screened.During the primary screening,we considered factors such as relevance,publication date,access to the full article text,and content.

Hepatic Morphometric Correlation with Biophysical Profiling of Height

Introduction: Clinical assessment of hepatic span is usually subjective. And is based on the experience of the clinician. This is what has led to this study in using Biophysical profiling of Heights, Weights, and Body mass index to find the normal hepatic span of every individual. This study was conducted at HMG Hospital Limited, Abonnema in Rivers State in affiliation with the University of Port Harcourt. Methodology: The biophysical sampling method was instituted to select respondents. At the same time, a radiological formula was used to calculate the sample size, and subjects’ weight, height and hepatic span where measured while the BMI was calculated and the data was analyzed using python programming language for data science. Results: The data obtained were subjected to descriptive statistics and the Pearson correlation coefficient. P value greater than or equal to 0.05 was taken as statistically significant. The respondents were mainly aged 30 to 63 years. Conclusion: The null hypothesis was rejected;hence this research has stated the law known as Belema’s Law of hepatic-height correlation, which states that the hepatic span of an individual is directly proportional to the height of that individual except in disease conditions affecting the liver directly or indirectly.

A Review of the Key Points in the Design of Small-Radius Curved Ramp Bridges

This article explores the fundamentals of small-radius curved ramp bridges.It covers the selection of box girder spans,support methods,and forms,along with design optimization techniques for this type of bridge structure.The purpose of this paper is to provide robust support for enhancing the design quality of these bridges and ensuring their efficacy in real-world applications.

A Friendship That Spans Generations

As China and Pakistan mark 55 years of diplomatic relations, the two countries are enhancing their strategic cooperation May 21 marks the 55th anniversary of the establishment of diplomatic ties between China and Pakistan. After more than a half century, the time-tested relationship between the two countries has developed into an "all-weather friendship" and "all-around cooperation" featuring a

A Village Spans Two Nations

The play Lost Village,a collaboration between Chinese and Japanese artists that is being performed in both countries, presents individuals' differing per-spectives on

Revisiting the nonlinear Gaussian noise model for hybrid fiber spans

We rederive from first principles and generalize the theoretical framework of the nonlinear Gaussian noise model to the case of coherent optical systems with multiple fiber types per span and ideal Nyquist spectra.We focus on the accurate numerical evaluation of the integral for the nonlinear noise variance for hybrid fiber spans.This task consists in addressing four computational aspects:(1)Adopting a novel transformation of variables(other than using hyperbolic coordinates)that changes the integrand to a more appropriate form for numerical quadrature;(2)Evaluating analytically the integral at its lower limit,where the integrand presents a singularity;(3)Dividing the interval of integration into subintervals of size and approximating the integral over each subinterval by using various algorithms;and(4)Deriving an upper bound for the relative error when the interval of integration is truncated in order to accelerate computation.We apply the proposed analytical model to the performance evaluation of coherent optical communications systems with hybrid fiber spans composed of quasi-single-mode and single-mode fiber segments.More specifically,the model is used to optimize the lengths of the optical fiber segments that compose each span in order to maximize the system performance.We check the validity of the optimal fiber segment lengths per span provided by the analytical model by using Monte Carlo simulation,where the Manakov equation is solved numerically using the split-step Fourier method.We show that the analytical model predicts the lengths of the optical fiber segments per span with satisfactory accuracy so that the system performance,in terms of the Q-factor,is within 0.1 dB from the maximum given by Monte Carlo simulation.

基于上下文语义增强的实体关系联合抽取

基于span的联合抽取模型在实体和关系抽取(RE)任务中共享实体span的语义表示,能有效降低流水线模型带来的级联误差,但现有模型无法充分地将上下文信息融入实体和关系的表示中。针对上述问题,提出一个基于上下文语义增强的实体关系联合抽取(JERCE)模型。首先通过对比学习的方法获取句子级文本和实体间文本的语义特征表示;然后,将该表示加入实体和关系的表示中,对实体关系进行联合预测;最后,动态调整两个任务的损失以使联合模型的整体性能最优化。在公共数据集CoNLL04、ADE和ACE05上进行实验,结果显示JERCE模型与触发器感知记忆流框架(TriMF)相比,实体识别F1值分别提升了1.04、0.13和2.12个百分点,RE的F1值则分别提升了1.19、1.14和0.44个百分点。实验结果表明,JERCE模型可以充分获取上下文中的语义信息。

基于BERT-WWM预训练的跨文档三元组提取

关于跨文档三元组(Subject Predicate Object,SPO)抽取任务,当前的研究主要基于句子级别的分析。然而很多场景下SPO元素可能分散于文档的各个位置,句子级别的抽取技术远远无法满足需求,因此提出一种Doc2SpSPO联合SPO抽取模型。该模型通过Span候选集模型生成初始实体信息,基于BERT-WWM预训练模型得到上下文以及候选实体相关Embedding信息进行分类任务从而实现SPO的联合提取。实验结果表明,该模型实体识别可达到F1值44.4%、关系分类准确率66.9%的较好效果。

探讨SPAN指数、wSPAN指数和SC评分对急性缺血性卒中血管内治疗患者的临床预后

目的探讨术前年龄和NIHSS两者相结合的指标SPAN指数、wSPAN指数、SC评分对急性缺血性卒中(AIS)患者血管内治疗术后临床预后之间的关系。方法连续收集2015年8月—2021年10月就诊于中国3个综合性卒中中心接受血管内治疗的AIS患者889例,以门诊或电话方式随访90天。根据术后90天改良Rankin量表(90 d mRS)评分评估患者预后,分为预后良好组(mRS≤2分)和预后不良组(mRS>2分)。同时记录患者术后症状性颅内出血(sICH)、颅内出血转化的发生率及术后90天死亡率。结果在纳入的889例患者中,预后不良组血管内治疗前的SPAN指数、wSPAN指数、SC评分均显著高于预后良好组(P<0.001)。在调整潜在的混杂因素后,SPAN、wSPAN、SC均与EVT患者90天预后独立相关(SPAN:OR=0.961,95%CI=0.948-0.975、wSPAN:OR=0.968,95%CI=0.959-0.976、SC:OR=0.767,95%CI=0.713-0.826)。SPAN、wSPAN、SC与sICH之间没有统计学差异(P=0.220,P=0.088,P=0.072),而与颅内出血转化风险增加(SPAN:OR=1.03,95%CI=1.02-1.05,P<0.001、wSPAN:OR=1.03,95%CI=1.02-1.03,P<0.001、SC:OR=1.25,95%CI=1.14-1.36,P<0.001)和死亡率(P<0.001,P<0.001,P<0.001)相关。结论术前SPAN指数、wSPAN指数、SC评分与AIS患者血管内治疗90天临床预后、颅内出血转化发生率和高死亡率相关,但与sICH无关。

Learning-Based Dynamic Connectivity Maintenance for UAV-Assisted D2D Multicast Communication

Unmanned aerial vehicles(UAVs) enable flexible networking functions in emergency scenarios.However,due to the movement characteristic of ground users(GUs),it is challenging to capture the interactions among GUs.Thus,we propose a learningbased dynamic connectivity maintenance architecture to reduce the delay for the UAV-assisted device-todevice(D2D) multicast communication.In this paper,each UAV transmits information to a selected GU,and then other GUs receive the information in a multi-hop manner.To minimize the total delay while ensuring that all GUs receive the information,we decouple it into three subproblems according to the time division on the topology:For the cluster-head selection,we adopt the Whale Optimization Algorithm(WOA) to imitate the hunting behavior of whales by abstracting the UAVs and cluster-heads into whales and preys,respectively;For the D2D multi-hop link establishment,we make the best of social relationships between GUs,and propose a node mapping algorithm based on the balanced spanning tree(BST) with reconfiguration to minimize the number of hops;For the dynamic connectivity maintenance,Restricted Q-learning(RQL) is utilized to learn the optimal multicast timeslot.Finally,the simulation results show that our proposed algorithms perfor better than other benchmark algorithms in the dynamic scenario.

Brain Functional Network Based on Small-Worldness and Minimum Spanning Tree for Depression Analysis

Since the outbreak and spread of corona virus disease 2019(COVID-19),the prevalence of mental disorders,such as depression,has continued to increase.To explore the abnormal changes of brain functional connections in patients with depression,this paper proposes a depression analysis method based on brain function network(BFN).To avoid the volume conductor effect,BFN was constructed based on phase lag index(PLI).Then the indicators closely related to depression were selected from weighted BFN based on small-worldness(SW)characteristics and binarization BFN based on the minimum spanning tree(MST).Differences analysis between groups and correlation analysis between these indicators and diagnostic indicators were performed in turn.The resting state electroencephalogram(EEG)data of 24 patients with depression and 29 healthy controls(HC)was used to verify our proposed method.The results showed that compared with HC,the information processing of BFN in patients with depression decreased,and BFN showed a trend of randomization.

基于改进Prefix Span的结构超手册修理方法推荐

针对当前民机结构超手册修理能力提升的迫切需求,提出了一种基于改进Prefix Span的结构超手册修理方法推荐模型。以某型国产民机结构超手册修理案例数据为样本,构建案例特征指标层次并对数据分级和结构化预处理,基于改进Prefix Span算法对案例损伤信息和修理方法频繁序列进行充分挖掘,生成超手册修理关联规则集,通过目标案例和频繁序列间相似度匹配,实现了超手册修理方法的智能推荐。测试结果表明,模型超手册修理方法推荐总准确率可达85.3%,显著高于改进前算法,具备良好的准确性和可用性,可为结构超手册修理决策、方案制定等提供一定的参考依据。

复配药剂强化低阶煤浮选的试验研究

针对低阶煤浮选困难的问题,以复配药剂配比、捕收剂用量和起泡剂用量为影响因子,利用Design Expert 8.0软件进行响应曲面法优化试验设计及数据分析,研究了不同复配捕收剂对浮选效果的影响。结果表明:捕收剂和起泡剂用量对浮选效果影响显著,在复配药剂-Span80质量分数为20%、捕收剂用量为3600 g/t、起泡剂用量为770 g/t条件下,浮选精煤产率为83.06%,精煤灰分为11.62%,尾煤灰分为67.99%,精煤可燃体回收率达到93.12%,较未采用复配药剂时的浮选效果显著提高。通过对药剂作用前后试样的XPS测试结果和接触角变化情况进行分析,认为复配药剂的加入,可减少煤表面含氧官能团数量,增大接触角,提高疏水性,从而促进煤样与煤油的作用,提高浮选效果。

Drivers of the differentiation between broad-leaved trees and shrubs in the shift from evergreen to deciduous leaf habit in forests of eastern Asian subtropics

In eastern Asian subtropical forests,leaf habit shifts from evergreen to deciduous broad-leaved woody plants toward higher latitudes.This shift has been largely explained by the greater capacity of deciduous broad-leaved plants to respond to harsh climatic conditions(e.g.,greater seasonality).The advantages of deciduous leaf habit over evergreen leaf habit in more seasonal climates have led us to hypothesize that leaf habits would shift in response to climate changes more conspicuously in forest canopy trees than in forest understory shrubs.Furthermore,we hypothesize that in the forests of the subtropics,plants at higher latitudes,regardless of growth form,would better tolerate seasonal harsh climates,and hence show less differentiation in leaf habit shift,compared to those at lower latitudes.To test these two hypotheses,we modelled the proportion of deciduous broad-leaved species and the incidence of deciduous and evergreen broad-leaved species in woody angiosperm species compositions of ten largesized forest plots distributed in the Chinese subtropics.We found that the rate of leaf habit shift along a latitudinal gradient was higher in forest trees than in forest shrubs.We also found that the differentiation in leaf habit shift between trees and shrubs is greater at lower latitudes(i.e.,warmer climates)than at higher latitudes(i.e.,colder climates).These findings indicate that specialized forest plants are differentially affected by climate in distinct forest strata in a manner dependent on latitudinal distribution.These differences in forest plant response to changes in climate suggest that global climate warming will alter growth forms and geographical distributions and ranges of forests.

Bridge plating in the setting of radiocarpal instability:Does distal fixation to the second or third metacarpal matter?A cadaveric study

BACKGROUND Radiocarpal dislocations are rare but potentially devastating injuries.Poorer outcomes are associated with inadequate or lost reduction,such as ulnar translocation,but no consensus exists on the ideal fixation technique.Dorsal bridge plate fixation has been described for various settings in the treatment of complex distal radius fractures and can be fixed distally to the second or third metacarpal,but its application for radiocarpal dislocations has not been established.AIM To determine whether distal fixation to the second or third metacarpal matters.METHODS Using a cadaveric radiocarpal dislocation model,the effect of distal fixation was studied in two stages:(1)A pilot study that investigated the effect of distal fixation alone;and(2)a more refined study that investigated the effect of described techniques for distal and proximal fixation.Radiographs were measured in various parameters to determine the quality of the reduction achieved.RESULTS The pilot study found that focusing on distal fixation alone without changing proximal fixation results in ulnar translocation and volar subluxation when fixing distally to the second metacarpal compared with the third.The second iteration demonstrated that anatomic alignment in coronal and sagittal planes could be achieved with each technique.CONCLUSION In a cadaveric radiocarpal dislocation model,anatomic alignment can be maintained with bridge plate fixation to the second metacarpal or the third metacarpal if the described technique is followed.When considering dorsal bridge plate fixation for radiocarpal dislocations,the surgeon is encouraged to understand the nuances of different fixation techniques and how implant design features may influence proximal placement.

A method for calculating strand tension in the anchor span of a suspension bridge considering the rotation of a splay saddle

This paper reports a method for strand tension in anchor spans considering rotation.A kind of co-moved coordinate system,a saddle local coordinate system,was set up.This system implemented the rotation of the splay saddle through the rotation of the coordinate system,and all calculations proceeded in this coordinate system.Considering the rotation of the anchoring surface by the rotation of the local coordinate system of the anchoring surface,the anchorage point coordinates of strands were transformed to the local sadle coordinate system.There was a two-layer iteration adopted in the calculation.In the inner iteration,the cable force at the end of the vertical bend was taken as the variable,and the ordinate of the anchorage point was taken as the target value.In the outer iteration,the vertical tangential angle at the end of the vertical bend was taken as the variable,and the ordinate of the anchorage point was taken as the target value.The method carried out the rotation of the splay saddle and anchor surface and was simple,convenient and without approximation.The effect of rotation was considered precisely;it showed stability during the process of two-layer iteration,powerful adaptation and higher efficiency and had been successfully applied in the construction control of the Wufengshan Yangtze River Bridge,the world's first kilometer-level combined highway and railway suspension bridge.