Geology and Geochemistry of K-feldspar Veins in Lamprophyre at the Zhenyuan Gold Deposit,Yunnan,Southwest China:Implications for Gold Mineralization

Lamprophyres typically appear in hydrothermal gold deposits.The relationship between lamprophyres and gold deposits is investigated widely.Some researchers suggest that the emplacement of lamprophyres triggers gold mineralization,whereas others hypothesize that the formation of lamprophyres increases the fertility of mantle sources and ore-forming fluids.K-feldspar veins,with ages between those of lamprophyres and gold deposits,appear in lamprophyres in Zhenyuan.Therefore,K-feldspar veins are ideal for investigating the relationship between lamprophyres and gold deposits.Phlogopite in K-feldspar veins has lower Mg#,Ni,and Cr contents and higher TiO2,Li,Ba,Sr,Sc,Zr,Nb,and Cs contents than phlogopite in lamprophyres.The in-situ Sr isotopic values of apatites(0.7063–0.7066)in K-feldspar veins are within the range for apatites(0.7064–0.7078)from lamprophyres.High large-ion lithophile element concentrations and low Nb and Ta concentrations in phlogopite from lamprophyres,in addition to high(87Sr/86Sr)i values of apatite(0.7064–0.7078),indicate that the magma parental to these phlogopite and apatite crystals is derived from an enriched mantle.Kfeldspar veins are genetically correlated with lamprophyres,whereas sulfide mineral assemblage and trace element compositions of pyrite in K-feldspar veins suggest that K-feldspar veins in lamprophyres are not directly related to gold mineralization of the Zhenyuan deposit.

Further study on the genesis of lamellar calcite veins in lacustrine black shale--A case study of Paleogene in Dongying Depression, China

Lamellar calcite veins are prevalent in carbonate-rich,lacustrine dark shale.The formation mechanisms of these veins have been extensively debated,focusing on factors such as timing,depth,material source,and driving forces.This paper examines dark lacustrine shale lamellar calcite veins in the Paleogene strata of Dongying Depression,using various analytical techniques:petrography,isotope geochemistry,cathodoluminescence,inclusion thermometry,and electron probe micro-analysis.Two distinct types of calcite veins have been identified:granular calcite veins and sparry calcite veins.These two types differ significantly in color,grain structure,morphology,and inclusions.Through further investigation,it was observed that vein generation occurred from the shallow burial period to the maturation of organic matter,with a transition from granular calcite veins to sparry calcite veins.The granular calcite veins exhibit characteristics associated with the shallow burial period,including plastically deformed laminae and veins,the development of strawberry pyrite,the absence of oil and gas,weak fractionation in oxygen isotopes,and their contact relationship with sparry calcite veins.These granular calcite veins were likely influenced by the reduction of sulfate bacteria.On the other hand,sparry calcite veins with fibrous grains are antitaxial and closely linked to the evolution and maturation of organic matter.They contain oil and gas inclusions and show a distribution range of homogenization temperature between 90℃ and 120℃ and strong fractionation in oxygen isotopes,indicating formation during the hydrocarbon expulsion period.The carbon isotope analysis of the surrounding rocks and veins suggests that the material for vein formation originates from the shale itself,specifically authigenic micritic calcite modified by the action of methanogens.The opening of horizontal fractures and vein formation is likely driven by fluid overpressure resulting from undercompaction and hydrocarbon expulsion.Veins may form rapidly or through multi-stage composite processes.Early veins are predominantly formed in situ,while late veins are a result of continuous fluid migration and convergence.Furthermore,the veins continue to undergo modification even after formation.This study emphasizes that the formation of lamellar calcite veins in shale is a complex diagenetic process influenced by multiple factors:biology,organic matter,and inorganic processes,all operating at various stages throughout the shale's diagenetic history.

Modeling Blood Flow in Veins of Uniform Properties (Giraffe Jugular Vein)

This paper models the giraffe’s jugular veins as a uniform collapsible tube from a rigid skull. The equations governing one-dimensional steady flow through such a tube for various conditions have been developed. The effects of inertial and inclination angles that have not been discussed previously have been included. It has been shown that different flows for a uniform tube (vein) are possible. However, this flow matches that of a jugular vein which is supercritical, and the steady solution has been given by the balance between the driving forces of gravity and the viscous resistance to the flow at the right atrium of the heart must be sub-critical for a fixed right-atrium pressure which means that an elastic jump is required to return the flow to sub-critical from the supercritical flow upstream this type of relationship gives rise to flow limitation at the same time given any right atrium fixed pressure there exists a maximum flow rate which when exceeded the boundary conditions of the flow do not hold boundary conditions at the right atrium are not satisfied hence making the steady flow impossible this mechanism of flow limitation is slightly different from the other one in that causes airways through forced expiration from the observation made it is clearly shown that there is an intravascular pressure difference with a change in height.

Sclerotherapy as the Only Treatment for Varicose Veins

Background: Chronic venous insufficiency (CVI) is a widespread and underdiagnosed condition that affects more than 20% of the general population. The most prevalent manifestation of CVI is varicose veins (VVs), which affect up to 25% of women and 15% of males. Sclerotherapy is a minimally invasive procedure used primarily in treating telangiectasias, reticular veins, and small varicose veins. Objectives: This study aims to evaluate the efficacy and safety of various sclerotherapy techniques in treating varicose veins-related complications. Methods: We conducted a cross-sectional observational interventional study at Jordan University Hospital (JUH) from September 2022 to January 2023. The study involved patients with lower limb varicose veins, assessing their clinical response and monitoring potential treatment complications. Statistical analyses were performed using SPSS software version 21.0. Results: Of 567 patients with diagnosed VVs, 544 were female (95.94%), and 23 were male (4.06%). The primary complaints were pain and cosmetic concerns. Treatments included Foam Aethoxysklerol® 3% (polidocanol) and Micro-foam Aethoxysklerol® 1%. Improvement in symptoms was reported by 538 patients (94.89%). The most common adverse event was hyperpigmentation, reported in 120 patients (21.16%), followed by post-procedural pain in 104 patients (18.34%). Notably, one patient (0.18%) experienced deep vein thrombosis (DVT), one (0.18%) reported telangiectatic matting, and there were two cases (0.36%) of visual disturbances and one allergic reaction. Conclusion: Sclerotherapy is effective and safe for treating VVs with minimal adverse events. It is a viable standalone treatment, reducing complications linked to other methods like radiofrequency ablation and surgery.

Benefit in physical function and quality of life to nonsurgical treatment of varicose veins: Pilot study

BACKGROUND Studies on varicose veins have focused its effects on physical function;however,whether nonsurgical treatments alter muscle oxygenation or physical function remains unclear.Moreover,the differences in such functions between individuals with varicose veins and healthy individuals remain unclear.AIM To investigate changes in physical function and the quality of life(QOL)following nonsurgical treatment of patients with varicose veins and determine the changes in their muscle oxygenation during activity.METHODS We enrolled 37 participants(those with varicose veins,n=17;healthy individuals,n=20).We performed the following measurements pre-and post-nonsurgical treatment in the varicose vein patients and healthy individuals:Calf muscle oxygenation during the two-minute step test,open eyes one-leg stance,30 s sit-to-stand test,visual analog scale(VAS)for pain,Pittsburgh sleep quality index,physical activity assessment,and QOL assessment.RESULTS Varicose veins patients and healthy individuals differ in most variables(physical function,sleep quality,and QOL).Varicose veins patients showed significant differences between pre-and post-nonsurgical treatment—results in the 30 sit-to-stand test[14.41(2.45)to 16.35(4.11),P=0.018],two-minute step test[162.29(25.98)to 170.65(23.80),P=0.037],VAS for pain[5.35(1.90)to 3.88(1.73),P=0.004],and QOL[39.34(19.98)to 26.69(17.02),P=0.005];however,no significant difference was observed for muscle oxygenation.CONCLUSION Nonsurgical treatment improved lower extremity function and QOL in varicose veins patients,bringing their condition close to that of healthy individuals.Future studies should include patients with severe varicose veins requiring surgery to confirm our findings.

Multidetector computer tomography and magnetic resonance imaging of double superior mesenteric veins:A case report

BACKGROUND This study aimed to describe the findings of double superior mesenteric veins(SMVs),a rare anatomical variation,on multidetector computer tomography(MDCT)and magnetic resonance imaging(MRI)images.CASE SUMMARY We describe the case of a 34-year-old male,who underwent both MDC and MRI examinations of the upper abdomen because of liver cirrhosis.MDCT and MRI angiography images of the upper abdomen revealed an anatomic variation of the superior mesenteric vein(SMV),the double SMVs.CONCLUSION The double SMVs are a congenital abnormality without potential clinical manifestation.Physicians need to be aware of this anatomical variation during abdominal surgery to avoid iatrogenic injury.

Automatic Detection and Characterization of Human Veins Using Infra-Red Image Processing

The detection and characterization of human veins using infrared (IR) image processing have gained significant attention due to its potential applications in biometric identification, medical diagnostics, and vein-based authentication systems. This paper presents a low-cost approach for automatic detection and characterization of human veins from IR images. The proposed method uses image processing techniques including segmentation, feature extraction, and, pattern recognition algorithms. Initially, the IR images are preprocessed to enhance vein structures and reduce noise. Subsequently, a CLAHE algorithm is employed to extract vein regions based on their unique IR absorption properties. Features such as vein thickness, orientation, and branching patterns are extracted using mathematical morphology and directional filters. Finally, a classification framework is implemented to categorize veins and distinguish them from surrounding tissues or artifacts. A setup based on Raspberry Pi was used. Experimental results of IR images demonstrate the effectiveness and robustness of the proposed approach in accurately detecting and characterizing human. The developed system shows promising for integration into applications requiring reliable and secure identification based on vein patterns. Our work provides an effective and low-cost solution for nursing staff in low and middle-income countries to perform a safe and accurate venipuncture.

Construction of Anti-breaking Models of the Main Veins of Flue-cured Tobacco Leaves and Principal Component Analysis

[Objective] This study aimed to explore the related mechanisms of the breaking of flue-cured tobacco leaves. [Method] Anti-breaking models of the main veins of flue-cured tobacco leaves were constructed for principal component analysis on the anti-breaking index, leaf traits and cellulose contents. [Result] The results showed that the growth traits had certain relevance with the cellulose contents while the leaf weight assumed a significant negative correlation with the anti-breaking index, indicating that the heavier the leaf weight was, the weaker the anti-breaking capacity of flue-cured tobacco would be; the cross-sectional area of main veins and the cellulose contents had shown a positive correlation with the anti-breaking index, indicating that the thicker the main vein of flue-cured tobacco was, the higher the cellulose contents would be, and the stronger the anti-breaking capacity of flue-cured tobacco leaves would be. [Conclusion] This study provided theoretical basis and reference to improve tobacco production and enhance the quality of flue-cured tobacco.

基于Veins的交通路径优化算法研究

智能交通系统是未来智慧城市中不可缺少的一部分,而交通路径优化是智能交通重要的组成部分。文中主要研究了在Veins平台中交通路径优化算法。通过VANET(车载自组网)每台车辆都在同一个局域网互连互通,当前车遇到拥堵时通过拥塞躲避机制不断通知后方车辆,后方车辆通过设计的路径规划算法进行路径变更,直至拥堵结束。通过分析车辆通过的情况和交通数据,不断优化算法,最终达到减缓拥堵和提高交通效率的目的。

Persistent and advanced reddening of sweetgum leaves after major veins severing

The effects of major veins severing on morphological and physiological features of sweetgum （Liquidambar styraciflua L.） leaves were investigated by observing leaf color change and measuring leaf temperature, green/luminance （G/L） value of half-lobes, leaf stomata conductance, and water content in Yamaguchi University, Japan. The palmately veined leaves of sweetgum （Liquidambar styraciflua L.） were found more sensitive to the major vein severing than that of other species Major veins severing resulted in serious water stresses, as indicated by the persistent reddening and/or advanced reddening of local leaf, lower leaf stomatal conductance, and higher leaf temperature, etc. Severed leaf can be clearly divided into non-severed area, transitional area, and stressed area, which the three areas have different colours and temperature. The major vein barrier can also be seen clearly. The persistent reddening and advanced reddening seem consistent with the phenomenon of red crown top of some sweetgum trees and may have similar mechanism.

Clinical studies on inferior right hepatic veins

BACKGROUND: Many small veins are called accessory, short hepatic veins in addition to the right, middle and left hepatic veins. The size of these veins varied from a pinhole to 1 cm; the size of inferior right hepatic veins (IRHVs) is thicker than that of short hepatic veins or more than 1 cm. occasionally. Adults have a higher incidence rate of the IRHV. DATA SOURCES: A literature search of the PubMed database was conducted and research articles were reviewed. RESULTS: The size of IRHVs is related to the size of the right hepatic vein, i.e. the larger the diameter of the right hepatic vein, the smaller the diameter of the IRHVs, and vice versa. The IRHVs are divided into superior, medial and inferior groups, separately named the superior, medial and inferior right hepatic veins according to the position of the IRHV entering the inferior vena cava. The superior right hepatic vein mainly drains the superior part of segment VII, and the medial right hepatic vein drains the middle part of segment VII. A thicker IRHV mainly drains segment VI and the inferior part of segment VII and a thinner IRHV drains the inferior part of segment V. CONCLUSIONS: The clinical significance of these studies on IRHVs is varied: (1) Hepatic caudate lobe resection could be introduced after study on the veins of that lobe. (2) It is very important to identify the draining region of the IRHV for guiding hepatic segmentectomy. The postero-inferior area of the right lobe can be preserved along with the hypertrophic IRHV even if the entire main right hepatic vein is resected during segmentectomy of VII and VIII with right hepatic vein resection for patients with primary liver cancer. (3) The ligation of the major hepatic vein for the treatment of juxtahepatic vein injury is recommended because of severe hemorrhagic shock and difficulty in exposure. (4) It is very helpful to decide therapeutic modalities for Budd-Chiari syndrome.

U-Pb SHRIMP Dating of Zircon from Quartz Veins of the Yangshan Gold Deposit in Gansu Province and Its Geological Significance

The Yangshan gold deposit is a super-large fine-grained disseminated gold deposit located in southern Gansu Province. Its metallogenic age has been determined by using the cathodoluminescence image and ion probe U-Pb dating techniques. It is found that zircons from quartz veinlet of the fine-grained disseminated gold ore show characters of magmatic origin with prism idiomorphism, oscillatory zoning and dominant Th/U ratios of 0.5-1.5. Three main populations of zircons are obtained, giving average 206Pb/238U ages of 197.6±1.7 Ma, 126.9±3.2 Ma and 51.2±1.3 Ma respectively. The first age corresponds to the K-Ar age of the plagiogranite dike, while the latter two ages indicate that buried Cretaceous and Tertiary intrusives exist in the orefield, suggesting that the Yangshan gold deposit was genetically related to the three magmatic hydrothermal activities. By contrast, zircons from coarse gold-bearing quartz vein in the mining area are much older than the host rock, indicating that the vein was formed earlier and was not contaminated by later magmatic fluids. It is concluded that the coupling of multiperiodic hydrothermal activities in the mining area has contributed a lot to mineralization of the Yangshan gold deposit.

Early control of short hepatic portal veins in isolated or combined hepatic caudate lobectomy

BACKGROUND:Caudate lobectomy has long been considered technically difficult.This study aimed to elaborate the significance of early control of short hepatic portal veins(SHPVs) in isolated hepatic caudate lobectomy or in hepatic caudate lobectomy combined with major partial hepatectomy,and to describe the anatomical characteristics of SHPVs.METHODS:The data of 117 patients who underwent either isolated or combined caudate lobectomy by the same team of surgeons from 2005 to 2009 were retrospectively analyzed.From 2005 to 2007(group A,n=55),we carried out early control of short hepatic veins(SHVs) only;from 2008 to 2009(group B,n=62),we carried out early control of both SHVs and SHPVs.The two groups were compared to evaluate which surgical procedure was better.A detailed anatomical study was then carried out on the last 25 consecutive patients in group B to study the number and distribution of SHPVs during surgery.RESULTS:Patients in group B had less intra-operative blood loss,less impairment of liver function,shorter postoperative hospital stay,fewer postoperative complications and required less blood transfusion(P<0.05).The number of SHPVs in the 25 patients was 183,with 7.3±2.7 per patient.The diameters of SHPVs were 1 to 4 mm.On average,3.4 SHPVs/patient came from the left portal vein,2.2 from the bifurcation,1.4 from the right portal vein,and 0.3 from the main portal vein.On average,3.3 SHPVs/patient supplied segment I of the liver,0.4 for segment II,2.1 for segment IV,1.4 for segment V and 0.1 for segment VI.CONCLUSION:Early control of SHPVs in isolated or combined hepatic caudate lobectomy may be a useful method to decrease surgical risk and improve postoperative recovery.

Subduction channel fluid-rock interaction:Indications from rutile-quartz veins within eclogite from the Yuka terrane,North Qaidam orogen

High-pressure(HP)or ultrahigh-pressure(UHP)rutile-quartz veins that form at mantle depths due to fluid-rock interaction can be used to trace the properties and behavior of natural fluids in subduction zones.To explore the fluid flow and the associated element mobility during deep subduction and exhumation of the continental crust,we investigated the major and trace elements of Ti-rich minerals.Additionally,U–Pb dating,trace element contents,and Lu–Hf isotopic composition of zircon grains in the UHP eclogite and associated rutile-quartz veins were examined in the North Qaidam UHP metamorphic belt,Yuka terrane.The zircon grains in the rutile-quartz veins have unzoned or weak oscillatory zonings,and show low Th/U ratios,steep chondrite-normalized patterns of heavy rare earth elements(HREEs),and insignificant negative Eu anomalies,indicating their growth in metamorphic fluids.These zircon grains formed in 431
3 Ma,which is consistent with the 432
2 Ma age of the host eclogite.As for the zircons in the rutile-quartz veins,they showed steep HREE patterns on one hand,and were different from the zircons present in the host eclogite on the other.This demonstrates that their formation might have been related to the breakdown of the early stage of garnet,which corresponds to the abundance of fluids during the early exhumation stage.The core-rim profile analyses of rutile recorded a two-stage rutile growth across a large rutile grain;the rutile core has higher Nb,Ta,W,and Zr contents and lower Nb/Ta ratios than the rim,indicating that the rutile domains grew in different metamorphic fluids from the core towards the rim.The significant enrichment of high field strength elements(HFSEs)in the rutile core suggests that the peak fluids have high solubility and transportation capacity of these HFSEs.Furthermore,variations in the Nb vs.Cr trends in rutile indicate a connection of rutile to mafic protolith.The zircon grains from both the rutile-quartz veins and the host eclogite have similar Hf isotopic compositions,indicating that the vein-forming fluids are internally derived from the host eclogite.These fluids accumulated in the subduction channel and were triggered by local dehydration of the deeply subducted eclogite during the early exhumation conditions.

Application of the Trivex system in the treatment of primary severe superficial varicose veins of the lower extremity

Purpose:The aim of this study was to evaluate the clinical effects of the Trivex system in the treatment of primary severe superficial varicose veins of the lower extremity and compare Trivex to the point-form-stripping combined with foam sclerotherapy(FS).Methods:A total of 64 patients(35 females,29 males;mean age,57?11 years[range,29–79 years])with primary severe superficial varicose veins of the lower extremity involving 64 legs were included between October 2015 and July 2019.The maximum diameter of the vein branches was>20 mm,which appeared to be cystic dilatation and forms large-scale in the crus or the thigh.All patients underwent high ligation and endovenous laser ablation or stripping of the trunk under general anesthesia.The surgical time,pain/phlebitis,number of incisions,amount of bleeding,recurrence of varicose vein,incidence of surgical site infections(SSIs),satisfaction score,and improvement in clinical symptoms were evaluated respectively with the patients in two groups:Group A,with patients who underwent treatment with the Trivex system,and Group B,patients who underwent treatment by point-form-stripping combined with FS.Results:All procedures were performed successfully.The average operative time in Group A was 56?11 min,whereas that of Group B was 90?33 min,which was a significant difference(p<0.05).Group A patients felt little pain after surgery,whereas in Group B the level of pain peaked on postoperative day 30,mostly due to thrombophlebitis after FS.There was no recurrence of varicose vein was observed in any patient,however,there were some residual effects in Group B,including the amount of bleeding volume,in-hospital stays,pain/phlebitis,and number of incisions(P<0.05).There were no significant differences with respect to SSIs,improvement in clinical symptoms,and satisfaction scores observed(p>0.05).Conclusions:This study shows that patients benefited from both treatment options.However,primary severe superficial varicose veins of the lower extremity treated with the Trivex system suffered less pain with fewer incisions than severe branches treated with the point-form-stripping combined with foam sclerotherapy(FS).In summary,the Trivex system is a suitable treatment prior to point-form-stripping combined with foam sclerotherapy(FS)for those who demand a high level of appearance,and especially for young patients,the Trivex system is recommended.

Quantifying the carbon source of pedogenic calcite veins in weathered limestone: implications for the terrestrial carbon cycle

The continent is the second largest carbon sink on Earth’s surface.With the diversification of vascular land plants in the late Paleozoic,terrestrial organic carbon burial is represented by massive coal formation,while the development of soil profiles would account for both organic and inorganic carbon burial.As compared with soil organic carbon,inorganic carbon burial,collectively known as the soil carbonate,would have a greater impact on the long-term carbon cycle.Soil carbonate would have multiple carbon sources,including dissolution of host calcareous rocks,dissolved inorganic carbon from freshwater,and oxidation of organic matter,but the host calcareous rock dissolution would not cause atmospheric CO2drawdown.Thus,to evaluate the potential effect of soil carbonate formation on the atmospheric p CO2level,different carbon sources of soil carbonate should be quantitatively differentiated.In this study,we analyzed the carbon and magnesium isotopes of pedogenic calcite veins developed in a heavily weathered outcrop,consisting of limestone of the early Paleogene Guanzhuang Group in North China.Based on the C and Mg isotope data,we developed a numerical model to quantify the carbon source of calcite veins.The modeling results indicate that4–37 wt%of carbon in these calcite veins was derived from atmospheric CO2.The low contribution from atmospheric CO2might be attributed to the host limestone that might have diluted the atmospheric CO2sink.Nevertheless,taking this value into consideration,it is estimated that soil carbonate formation would lower 1 ppm atmospheric CO2within 2000 years,i.e.,soil carbonate alone would sequester all atmospheric CO2within 1 million years.Finally,our study suggests the C–Mg isotope system might be a better tool in quantifying the carbon source of soil carbonate.

Hepatic veins anatomy and piggy-back liver transplantation

BACKGROUND:The piggy-back caval anastomosis technique is widely used in orthotopic liver transplantation although it carries an increased risk of complications,including outflow obstruction and Budd-Chiari syndrome.The aim of this study is to clarify the anatomy and variations of hepatic veins(HVs) draining into the inferior vena cava(IVC),and to classify the surgical techniques of piggy-back liver transplantation(PBLT) based on the anatomy of HVs which can reduce the occurrence of complications.METHODS:PBLT was performed in 248 consecutive cases at our hospital from January 2004 to August 2011.The anatomy of recipients’ HVs was determined when removing the native diseased livers.Both anatomy of HVs and short HVs draining into the IVC were recorded.These data were collected and analyzed.RESULTS:We classified anatomic variations of HVs in the 248 livers into five types according to the way of drainage into the IVC:type I(trunk type of left and middle HVs),142(57.3%) patients;type II(trunk type of right and middle HVs),54(21.8%);type III(trunk type of left,middle and right HVs),14(5.6%);type IV(non-trunk type of left,middle and right HVs),of which,type IVa,16(6.5%),in the same horizontal plane;type IVb,18(7.3%),in different horizontal planes;and type V(segment type),4(1.6%).The patients whose HVs anatomy belonged to types I,II and III underwent classical piggy-back liver transplantation.Type IVa patients had classical PBLT via HV venoplasty prior to piggy-back anastomosis,while type IVb patients and type V patients could only have modified PBLT.CONCLUSION:This study demonstrates that HVs can be classified according to the anatomy of their drainage into the IVC and we can use this classification to choose the best operative approach to PBLT.

Geochemical Trace of Silicon Isotopes of Intrusions and Ore Veins Related to Alkali-rich Porphyry Deposits in Western Yunnan, China

Western Yunnan is the well-known polymetallic province in China. It is characterized by copper-gold mineralization related to Cenozoic alkali-rich porphyry. This paper analyzes the silicon isotope data obtained from four typical alkali-rich porphyry deposits based on the dynamic fractionation principle of silicon isotope. The study shows that the ore materials should originate mainly from alkali-rich magmas, together with silicon-rich mineralizing fluids. The process of mineralization was completed by auto-metasomatism, i.e. silicon-rich mineralizing fluids (including alkali-rich porphyry and wall-rock strata) replaced and altered the country rocks and contaminated with crustal rocks during the crystallization of alkali-rich magmas. Such a process is essentially the continuance of the metasomatism of mantle fluids in crust's mineralization. This provides important evidence of silicon isotopic geochemistry for better understanding the mineralization of the Cenozoic alkali-rich porphyry polymetallic deposits

基于Veins平台的城市路口交通信号灯智能控制技术优化研究

针对当前路口交通信号灯智能控制优化方法中存在的响应时间较长等不足,进行基于Veins平台的城市路口交通信号灯智能控制技术优化研究。利用Veins平台与GLD编辑器进行城市交通路网模拟,结合实际交通数据进行参数设置,采用分级模糊控制器对交通信号灯进行控制,调节信号灯各相位时长;根据路口车辆流通数据,以各路口车辆的最小平均延时作为优化目标函数,利用自适应遗传算法寻求最优解,获得信号灯各相位的最优时长分配方案。实验结果表明,与现行方法相比,新方法的优化响应时间更短,能满足时效性需求,准确性高,稳定性好,且能够减少车辆等待延时。