基于Extra Tree Classifier的水质安全建模预测

随着工业化和城市化的快速发展,水质安全问题日益受到关注。本研究利用一个包含7999条数据记录的水质分析数据集,涵盖多种化学物质浓度测量值与安全阈值,以及“是否安全”分类变量,运用Extr aTree Classifier模型进行水质安全建模预测及数据分析。本研究目的在于提供一个可靠的模型,以帮助决策者和相关部门更好地监测和维护水质安全,从而保障公众健康和环境可持续发展。

Protective effects of oleic acid and polyphenols in extra virgin olive oil on cardiovascular diseases

The Mediterranean diet has long been recognized as one of the most effective ways to prevent and improve cardiovascular disease.Extra virgin olive oil(EVOO)is the typical sources of fat in the Mediterranean diet which have been shown to have noteworthy nutritional value and positive impact on human health.It is worth noting that EVOO owes its superior nutritional value to its bioactive composition.The main component of EVOO is monounsaturated fatty acids(MUFAs)in the form of oleic acid.Oleic acid accounts for up to 70%-80%of EVOO.Secondly,EVOO contains approximately more than 30 phenolic compounds,of which HT is essential for the protection against cardiovascular diseases.In this review,we focused on the potential mechanisms of oleic acid and polyphenols combat cardiovascular diseases risk in terms of oxidative stress,inflammation,blood pressure,endothelial function and cholesterol.This review might provide a reference for the studies on cardiovascular protective effects of EVOO.

Clinical outcomes in patients diagnosed with extra-nodal Hodgkin lymphoma: a 20-year retrospective analysis of the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) database

Background:Hodgkin lymphoma refers to a malignancy of the lymphatic tissue.Extra-nodal Hodgkin lymphoma(ENHL)is a rare variant consisting of Hodgkin lymphoma occurring outside the lymphatic system.Studies investigating the epidemiology associated with ENHL are rare.Methods:618 ENHL cases were analyzed using the National Cancer Institute’s Surveillance,Epidemiology,and End Results(SEER)database(2000–2020).Demographics including sex,race/ethnicity,rural-urban continuum,age group(categorized as adolescent and young adult(AYA)if between years of 15 and 39,and adult if over the age of 40),and living status(alive/deceased)were examined,with survival status as the main outcome.Results:This study included 335 males(54.2%)and 283 females(45.8%).Of this total,47.9%were in the AYA group.In terms of ethnicity the distribution was 12.5%non-Hispanic Black,67.5%non-Hispanic White,5.2%non-Hispanic Asian/Pacific Islander,and 14.9%Hispanic.Bivariate analyses evidenced significant differences in survival by age group with 91.6%in AYA vs.72.4%in adults(P<0.001)alive by the end of the study period.Multivariable analyses identified age as a key predictor of survival,as the AYA patients had a lower odds ratio for death(odds ratio=0.25,P<0.001).In addition,survival outcomes were also impacted by race,with non-Hispanic Blacks showing higher survival probabilities.Regarding treatment,27.0%of patients underwent surgery,with 10.2%receiving post-surgery radiation,reducing odds of mortality(odds ratio=0.32,P=0.046).Conclusion:The background research as such,tends to affirm that these two factors–age and race are quite crucial in the prognosis as well as management of ENHL.Compared to adults,AYA patients had significantly lower odds of death,while non-Hispanic Black individuals exhibited reduced survival probabilities.It should be noted that 27.0%of patients underwent surgery with 10.2%receiving post-operative radiation which led to decrease in mortality rates.Thus,these results reiterate the necessity for tailor-made treatment methods according to demographic characteristics to boost patient outcomes effectively.For better ENHL care,future studies could shed light on these disparities and improve treatment regimens as needed.

Extra-Axial Anaplastic Pleomorphic Xanthoastrocytoma Mimicking Meningioma: A Case Report with Literature Review

Background: A number of meningeal neoplastic lesions may radiologically and clinically simulate meningioma, include hemangiopericytomas, solitary fibrous tumors, schwannomas, hematolymphoid lesions, metastases, and others very rarely, also may clinically mimic meningiomas. Case Description: We present the case of A 28-year-old male patient, with no notable medical history, who presented with worsening headaches for 3 months, imbalance, and visual deficits, An initial MRI revealed extra-axial lesion involving the right Parieto-occipital, The tumor was hypointense on T1-weighted MR images, hyperintense signals on T2-weightedMR images, and heterogeneously enhanced suggestive of a meningioma, total resection was achieved, and the histopathological analysis confirmed the diagnosis of an angioblastic meningioma. However, 15 months later, the patient presented with the same initial visual complaints. A subsequent MRI showed lesion recurrence, leading to a second surgical intervention. The histopathological analysis confirmed the diagnosis of an anaplastic xanthoastrocytoma. Conclusion: This represents an unusual location for an anaplastic pleomorphic xanthoastrocytoma, which should broaden the differential diagnosis of extra-axial lesions.

Analysis of the Risk of Water Breakout in the Bottom Plate of High-Intensity Mining of Extra-Thick Coal Seams

In order to clarify the danger of water breakout in the bottom plate of extra-thick coal seam mining, 2202 working face of a mine in the west is taken as the research object, and it is proposed to use the on-site monitoring means combining borehole peeping and microseismic monitoring, combined with the theoretical analysis to analyze the danger of water breakout in the bottom plate. The results show that: 1) the theoretically calculated maximum damage depth of the bottom plate is 27.5 m, and its layer is located above the Austrian ash aquifer, which has the danger of water breakout;2) the drill hole peeping at the bottom plate of the working face shows that the depth of the bottom plate fissure development reaches 26 m, and the integrity of the water barrier layer has been damaged, so there is the risk of water breakout;3) for the microseismic monitoring of the anomalous area, the bottom plate of the return air downstream channel occurs in the field with a one-week lag, which shows that microseismic monitoring events may reflect the water breakout of the underground. This shows that the microseismic monitoring events can reflect the changes of the underground flow field, which can provide a reference basis for the early warning of water breakout. The research results can provide reference for the prediction of sudden water hazard.

Vanadis 4 Extra模具钢的干滑动摩擦性能

采用"销-盘"摩擦磨损试验测试不同滑动速度下Vanadis 4 Extra和Cr12MoV模具钢干滑动严重磨损的临界载荷,通过SEM、EDS、OM观察磨损形貌并分析磨损机理及原因。结果表明:滑动速度增大,两种钢严重磨损的临界载荷均减小,Vanadis 4Extra和Cr12MoV两种钢严重磨损的临界载荷分别为:0.691 m/s范围内为900 N和600 N;0.921 m/s时为700 N和300 N。载荷小于临界载荷时以磨粒磨损为主,大于临界载荷之后Vanadis 4 Extra以氧化磨损为主,Cr12MoV为氧化磨损和塑性变形。在不同滑动速度及载荷下,Vanadis 4 Extra模具钢的耐磨性均高于Cr12MoV钢3~18.3倍。

Analysis on the Production Advantages of USA Pima Extra Long Staple Cotton

This paper defines the following advantages of ELS （Extra Long Staple） also known as Pima cotton planted in the United States： first, the only variety which is concentrated in the planting area with good soil moisture and fertilizer retention performances and abundant light and heat resources; second; advanced and practi- cal material equipment and technology; third; high yield and good quality, significant planting scale benefit; fourth, feasible and reliable modernized intensive farm man- agement mode with large-scale agricultural machinery operation; fifth, high-efficient social services and policy support system, as well as reasonable planting layout, good brand influence, synchronization of high yield and good quality with large-scale benefits. Although the production capability of Pima cotton in the United States is considered to be the largest and most powerful country in the world, compared with the ELS production in China, both have their own advantages and characteristics. Therefore, it is suggested that by using the ELS production experience ol the Unit- ed Stages for reference, China should make use of the modern breeding technJques to accelerate the modification of synthetic genetic features of ELS variety, try its best to breed the ELS variety which is suitable for mechanical plucking as soon as possible, actively develop new technology to simplify the whole cost saving cultiva- tion, reform ELS production organization, vigorously develop the social service sys- tem, and adjust and optimize the ELS industry support policies, so as to fundamen- tally improve the competitiveness of China＇s ELS in international market.

利用Extra.FLV建设教学资源库

FLV是当前网络上最流行的视频格式,然而针对FLV格式文件进行剪辑、合并及转换等的操作并不是很方便。本文简单介绍了Extra.FLV软件在建设FLV格式视频教学资源库中的作用。

热处理对Vanadis 4 Extra模具钢组织与性能的影响

研究了热处理工艺对Vanadis 4 Extra模具钢组织、硬度、冲击韧性和耐磨性的影响。结果表明:淬火处理后的显微组织为马氏体、残留奥氏体和碳化物;硬度随奥氏体化温度的升高先升后降,在1 020℃时硬度最高;残余奥氏体随奥氏体化温度的升高而升高;随回火温度的升高,硬度和冲击韧性变化趋势相反,在500℃回火后,硬度达到最高值62.1HRC,而冲击韧性达到最低值50.1J/cm^2;磨损率随回火温度的升高先变化不大,但在600℃时急速增大。

The Relationship between Fractures and Tectonic Stress Field in the Extra Low-Permeability Sandstone Reservoir at the South of Western Sichuan Depression

The formation and distribution of fractures are controlled by paleotectonic stress field, and their preservative status and effects on development are dominated by the modern stress field. Since Triassic, it has experienced four tectonic movements and developed four sets of tectonic fractures in the extra low-permeability sandstone reservoir at the south of western Sichuan depression. The strikes of fractures are in the S-N, NE-SW, E-W, and NW-SE directions respectively. At the end of Triassic, under the horizontal compression tectonic stress field, for which the maximum principal stress direction was NW.SE, the fractures were well developed near the S-N faults and at the end of NE-SW faults, because of their stress concentration. At the end of Cretaceous, in the horizontal compression stress fields of the NE-SW direction, the stress was obviously lower near the NE-SW faults, thus, fractures mainly developed near the S-N faults. At the end of Neogene-Early Pleistocene, under the horizontal compression tectonic stress fields of E-W direction, stress concentrated near the NE-SW faults and fractures developed at these places, especially at the end of the NE-SE faults, the cross positions of NE-SW, and S-N faults. Therefore, fractures developed mostly near S-N faults and NE-SW faults. At the cross positions of the above two sets of faults, the degree of development of the fractures was the highest. Under the modern stress field of the NW-SE direction, the NW-SE fractures were mainly the seepage ones with tensional state, the best connectivity, the widest aperture, the highest permeability, and the minimum opening pressure.

STRESS FIELD ANALYSIS OF EXTRA-HEIGHT FORGING DIE USING FINITE ELEMENT METHOD

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On Restricted Connectivity and Extra Connectivity of Hypercubes and Folded Hypercubes

Given a graph G and a non-negative integer h, the h-restricted connectivity κh（G） of G is the minimum cardinality of a set of vertices of G, in which at least h neighbors of any vertex is not included, if any, whose deletion disconnects G and every remaining component has the minimum degree of vertex at least h; and the h-extra connectivity κh（G） of G is the minimum cardinality of a set of vertices of G, if any, whose deletion disconnects G and every remaining component has order more than h. This paper shows that for the hypercube Qn and the folded hypercube FQn, κ1（Qn）=κ（1）（Qn）=2n-2 for n≥3, κ2（Qn）=3n-5 for n≥4, κ1（FQn）=κ（1）（FQn）=2n for n≥4 and κ（2）（FQn）=4n-4 for n≥8.

Analysis of the Relationship between the Number of Traffic Accidents and the Traffic Flow &Section Location in Extra Long Tunnel

In order to study the influence of the traffic characteristics on traffic accidents in extra long tunnel, the main measurement indicators of traffic flow during the time of traffic accidents are matched with the accident information to form a data set of the number of traffic accidents and the hourly traffic flow of the accident. Vehicle ratio and the number of accidents are mainly used as the characteristic indicators of traffic flow. At the same time, the longitudinal distribution law of the average speed of traffic flow and the number of traffic accidents in the extra long tunnel is studied. Based on the superposition principle, the extra long tunnel is divided into 5 traffic safety zones. This paper analyzes the distribution of time, morphology, cause of accident, and other characteristics in different traffic safety zones, finding that the shape of traffic accidents in extra long tunnel is mainly rear-end collisions. Improper operation and illegal lane changes are the main causes of accidents.

Extra dimensions and atomic transition frequencies

New unification theories predict large extra dimensions （LEDs）. If that is the case, gravity would be stronger at short ranges than what Newtonian gravity predicts. LEDs could also have effects at atomic level. In this paper we propose a new method to constrain the size of ‘gravity-only’ LEDs by analysing how these LEDs modify the energy of the atomic transitions 1s-2s and 2s-2p （Lamb shift）, in the particular case of the hydrogen and muonium atoms. We estimate these effects by using Bethe＇s non-relativistic treatment of Lamb shift. In the particular case of three LEDs, which may be a candidate to explain the interaction mechanism of dark matter particles, we have found that current knowledge in atomic spectroscopy could constrain their sizes to less than 10 μm. Although our contributions do not reach the sensitivity given by SN1987a, they are still slightly better than recent constraints given by Inverse Square Law tests of the Eoet-Wash group at Washington University, which gave R3 〈 36.6 μm.

On the extra edge-connectivity of hypercubes

The classical hypercube structure is a popular topological architecture in parallel computing environments and a large number of variations based on the hypercube were posed in the past three decades. Reliability evaluation of systems is important to the design and maintenance of multiprocessor systems. The h-extra edge-connectivity of graph G（V, E） is a kind of measure for the reliability of interconnection systems, which is defined as the minimum cardinality of a subset of edge set, if any, whose deletion disconnects G and such that every re- maining component has at least h vertices. This paper shows that the h-extra edge-connectivity 2n-1 2n-1 of the hypercube Qn is a constant 2n-1 for 2n-1/3≤ h2n-1, and n ≥ 4, which extends the result of [Bounding the size of the subgraph induced by m vertices and extra edge-connectivity of hypercubes, Discrete Applied Mathematics, 2013, 161（16）： 2753-2757].

Mechanism and control technology of strong ground pressure behaviour induced by high-position hard roofs in extra-thick coal seam mining

This work aimed at revealing the mechanism of strong ground pressure behaviour(SGPB)induced by high-position hard roof(HHR).Based on the supporting structures model of HHR,a modified voussoir beam mechanical model for HHR was established by considering the gangue support coefficient,through which the modified expressions of limit breaking span and breaking energy of HHR were deduced.Combined with the relationship between the dynamic-static loading stress of supporting body(hydraulic support and coal wall)and its comprehensive supporting strength,the criteria of ground pressure behaviour(GPB)induced by HHR were discussed.The types of Ⅰ_(1),Ⅰ_(2),Ⅱ_(1),andⅡ_(2) of GPB were interpreted.Results showed that types Ⅰ_(1) and Ⅰ_(2) were the main forms of SGPB in extra-thick coal seam mining.The main manifestation of SGPB was static stress,which was mainly derived from the instability of HHR rather than fracture.Accordingly,an innovative control technology was proposed,which can weaken static load by vertical-well separated fracturing HHR.The research results have been successfully applied to the 8101 working face in Tashan coal mine,Shanxi Province,China.The results of a digital borehole camera observation and stress monitoring proved the rationality of the GPB criteria.The control technology was successful,paving the way for new possibilities to HHR control for safety mining.

Impact coefficient and reliability of mid-span continuous beam bridge under action of extra heavy vehicle with low speed

To analyze the dynamic response and reliability of a continuous beam bridge under the action of an extra heavy vehicle, a vehicle–bridge coupled vibration model was established based on the virtual work principle and vehicle–bridge displacement compatibility equation, which can accurately simulate the dynamic characteristics of the vehicle and bridge. Results show that deck roughness has an important function in the effect of the vehicle on the bridge. When an extra heavy vehicle passes through the continuous beam bridge at a low speed of 5 km/h, the impact coefficient reaches a high value, which should not be disregarded in bridge safety assessments. Considering that no specific law exists between the impact coefficient and vehicle speed, vehicle speed should not be unduly limited and deck roughness repairing should be paid considerable attention. Deck roughness has a significant influence on the reliability index, which decreases as deck roughness increases. For the continuous beam bridge in this work, the reliability index of each control section is greater than the minimum reliability index. No reinforcement measures are required for over-sized transport.

Malignant extra-gastrointestinal stromal tumor of the pancreas:Report of two cases and review of the literature

Gastrointestinal stromal tumors(GISTs)are mesenchymal tumors that arise from the gastrointestinal tract.In rare cases,these tumors are found in intra-abdominal sites unrelated to the gastrointestinal tract,such as the mesentery,omentum and retroperitoneum.However,pancreatic extra-gastrointestinal stromal tumors are extremely rare,with only 14 previous cases reported.A 61-year-old man with no clinical symptoms had a routine check-up,during which an abdominal mass located in the pancreas tail was detected.Abdominal surgery was performed with resection of the pancreas tail and the spleen,and he was diagnosed with lowrisk GISTs.Another 60-year-old man with no clinical symptoms underwent Computed tomography which revealed a well-demarcated tumor,6 cm in diameter,in the head of the pancreas.He was diagnosed with pancreatic GISTs.Here,we describe two rare cases of pancreatic GISTs and review the cases previously reported in the literature.

Kinetic studies on extra heavy crude oil upgrading using nanocatalysts by applying CFD techniques

Regarding the growth of global energy consumption and the paucity of light crude oil, extracting and using heavy and extra heavy crude oil has received much more attention, but the application of this kind of oil is complicated due to its very high molecular weight. High viscosity and low flowability complicate the transportation of heavy and extra heavy crude oil. Accordingly, it is essential to reduce the viscosity of heavy and extra heavy crude oil through in-situ operations or immediate actions after extraction to reduce costs. Numerical simulations are influential methods, because they reduce calculation time and costs. In this study, the cracking of extra heavy crude oil using computational fluid dynamics is simulated, and a unique kinetic model is proposed based on experimental procedures to predict the behavior of extra heavy crude oil cracking reaction. Moreover, the hydrodynamics and heat transfer of the system and influence of nanocatalysts and temperature on the upgrading of crude oil are studied. The geometry of a reactor is produced using commercial software, and some experiments are performed to examine the validity and accuracy of the numerical results. The findings reveal that there is a good agreement between the numerical and experimental results. Furthermore, to investigate the main factors affecting the process, sensitivity analysis is adopted. Results show that type of catalyst and concentration of catalyst are the parameters that influence the viscosity reduction of extra heavy crude oil the most. The findings further revealed that when using a 25 nm SiO_2 nanocatalyst, a maximum viscosity reduction of 98.67% is observed at 623 K. Also, a catalyst concentration of 2.28 wt% is best for upgrading extra heavy crude oil. The results obtained through sensitivity analysis, simulation model, and experiments represent effectual information for the design and development of high performance upgrading processes for energy applications.