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What besides redox conditions? Impact of sea-level fluctuations on redox-sensitive trace-element enrichment patterns in marine sediments

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Science China Earth Sciences 2022年第10期65卷 1985-2004页

作者： junwen peng Bureau of Economic Geology Jackson School of GeosciencesThe University of Texas at AustinAustinTexas 78713USA

Concentrations of redox-sensitive trace-element(RSTE) in marine shales have long been interpreted simply as redox proxies. However, the impact of other non-redox factors(e.g., sea-level fluctuation and seawater chemistry) on the enrichment of RSTE, especially molybdenum(Mo) and uranium(U), in sediments has been rarely reported. This study presents newly obtained RSTE datasets from the Upper Pennsylvanian organic-rich Cline Shale in the silled Midland Basin, U.S., to illustrate the influence of sea-level fluctuation on the authigenic accumulation of RSTE in marine sediments. A previously established transgressive-regressive sequence of the Cline Shale, a well-constrained high-amplitude glacio-eustatic fluctuation curve, and an accompanying episodic resupply of aqueous RSTE from the Panthalassic Ocean provide an ideal stratigraphic framework for determining the spatial and temporal variations of sediment RSTE enrichment patterns that responded to the episodic variations of seawater chemistry in this marginal silled paleomarine basin. Results suggest that although slightly higher median RSTE concentrations were observed in sediments from more reducing environments, the overall variation ranges of RSTE concentrations largely overlap among sediments deposited from a wide redox spectrum(from oxic to euxinic conditions) or different sea-level statuses in the Cline Shale. In contrast to the sediment RSTE enrichment patterns, the variations of sediment Mo/TOC and U/TOC ratios are coupled with glacio-eustatic fluctuation. The highest Mo/TOC and U/TOC ratios are commonly observed in sediments deposited during the highest relative sea-level(RSTE resupply), whereas the lowest Mo/TOC and U/TOC ratios usually appear in sediments deposited during the lowest relative sea-level(RSTE depletion). Our findings suggest that the benthic redox conditions recorded in sediment Mo and U concentrations can be greatly obscured and weakened by depleted aqueous Mo and U concentrations in highly restricted basins. Thus, the use of sediment Mo a

关键词： Molybdenum Uranium Glacio-eustatic fluctuation Pennsylvanian Cline Shale Midland Basin

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Stability analysis of intermittently jointed rock slopes based on the stepped failure mode

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Journal of Mountain Science 2024年第3期21卷 1019-1035页

作者： LI Dejian FU junwen LI Hekai CHENG Xiao ZHAO Lianheng ZHANG Yingbin peng Xinyan School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China Institute for Disaster Management and Reconstruction College of Architecture&EnvironmentSichuan UniversityChengdu 610065China School of Civil Engineering Key Laboratory of Heavy-Haul Railway Engineering StructureMinistry of EducationHunan Provincial Key Laboratory for Disaster Prevention and Mitigation of Rail Transit Engineering StructureCentral South UniversityChangsha 410075China

In practical engineering,due to the noncontinuity characteristics of joints in rock slopes,in addition to plane failure,stepped sliding failure may occur for intermittently jointed rock slopes.Especially for intermittently bedding jointed rock slopes,the correlation and difference in strength parameters between joints and rock bridges,along with the various failure modes and intermittency of rock bridges,contribute to the complexity of stepped failure modes and the unpredictability of failure regions.Based on the upper-bound limit analysis method and multi-sliders step-path failure mode,considering the shear and tensile failure of rock bridges and the weakened relationship between the strength parameters of rock bridges and jointed surfaces,by introducing the modified M-C failure criterion and the formula for calculating the energy consumption of tensile failure of rock bridges,two failure mechanisms are constructed to obtain the safety factor(F_(s))of intermittently jointed rock slopes.The sequential quadratic programming method is used to obtain the optimal upper-bound solution for F_(s).The influence of multiple key parameters(slope height H,horizontal distance L,Slope angleβ,shear strength parameters of the rock bridgeφr and cr,Dimensionless parameter u,weakening coefficients of the internal friction angle and cohesion between the rock bridges and joint surfaces Kφand Kc)on the stability analysis of intermittently jointed rock slopes under the shear failure mode of rock bridges as well as under the tensile failure mode is also explored.The reliability of the failure mechanisms is verified by comparative analysis with theoretical results,numerical results,and landslide cases,and the variation rules of F_(s)with each key parameter are obtained.The results show that F_(s) varies linearly withφr and cr of the rock bridge and with K_(φ)and K_(c),whereas F_(s)changes nonlinearly with H and L.In particular,with the increase in Kφand Kc,Fs increases by approximately 52.78%and 171.02%on average,respectively.For rock b

关键词： Jointed rock slopes Stepped sliding failure Weakening characteristics Modified M‒C failure criterion

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Experimental and numerical study on atmospheric-pressure air dielectric barrier discharge via 50 Hz/5000 Hz dual-frequency excitation

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High Voltage 2024年第2期9卷 391-402页

作者： junwen He Bangfa peng Guanglin Yu Ronggang Wang Nan Jiang Jie Li Yan Wu School of Electrical Engineering Dalian University of TechnologyDalianChina Canmax Technologies Co. Ltd.SuzhouChina

A dual-frequency(DF)dielectric barrier discharge,excited by the superposition of a 50 Hz low frequency(LF)and a 5000 Hz intermediate frequency(IF),is proposed to enhance discharge.The effect of the LF voltage component on the breakdown behaviour of the DF discharge during different periods has been studied both experimentally and numerically.The number of high-current pulses rises as the LF voltage increases.The statistical analysis shows that the number of the current pulse amplitude above 80 mA in the DF discharge reaches nearly 6 times that in the IF discharge.Additionally,the total discharge energy in the DF discharge is significantly higher than that in the IF discharge.The simulation re-produces the temporal variation of the breakdown behaviours in the DF discharge.The simulated results reveal that the maximal electric field strength of the breakdown process is greater in the DF discharge compared to the IF discharge during a half-period of DF.Finally,the comparison between the IF and DF discharges exhibits that the LF voltage regulates the accumulation of residual charged species on the dielectric surface after the breakdown by modulating the residual voltage between the air gap.

关键词： dielectric excitation excited

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Crustal structure in the Anyuan Coal Mine and its adjacent areas of Jiangxi Province by P-wave receiver functions

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Earthquake Research Advances 2024年第1期4卷 47-58页

作者： Xingmian Zhang Meng Gong Jian Lü Hongxing Li Jie Hu junwen He Jianhua peng Bingyue Liu State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang330013China Nanchang Key Laboratory of Intelligent Sensing Technology and Instruments for Geological Hazards East China University of TechnologyNanchang330013China Jiangxi Earthquake Agency Nanchang330026China East China University of Technology School of Geophysics and Measurement-Control TechnologyNanchang330013China Hunan Earthquake Agency Changsha410004China

We collected high-quality teleseismic events recorded by 12 broadband seismographs deployed in the Anyuan Coal Mine and its adjacent areas in Pingxiang City,Jiangxi Province for nearly two years.The H-κ-c stacking method was employed to obtain the crustal thickness and Poisson's ratio distribution,then the characteristics of crustal structure below the stations were obtained by using the time-domain linear inversion method.The crustal thickness in the Anyuan Coal Mine and its adjacent areas ranges from approximately 32~35 km,with an average thickness of 33 km,which is consistent with the crustal thickness results in South China from previous studies using the receiver function method.The average Poisson's ratio of the crustal bulk composition in the study area varies between 0.22 and 0.25,which is lower than the global value with a 0.27 average,indicating a predominantly intermediate-acidic or felsic crustal composition.There is a weak negative correlation between Poisson's ratio and crustal thickness estimates in the Anyuan Coal Mine and its adjacent areas,suggesting that the absence of mafic-ultramafic materials in the lower crust is associated with the process of crustal delamination.The velocity inversion results indicate that the crustal structure including three velocity discontinuity interfaces,with the first at a depth of approximately 1.5 km,the second at about 10~15 km,and the third being the Moho.The study also indicates that the results obtained by the H-κ-c stacking method are significantly better than those obtained by the H-κmethod,effectively reducing the standard deviation and dispersion of crustal thickness and vP/vSratio.

关键词： Anyuan Coal Mine Receiver function H-κ-c stacking Crustal thickness Poisson's ratio

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Demonstration of radar-aided flexible communication in a photonics-based W-band distributed integrated sensing and communication system for 6G

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Chinese Optics Letters 2024年第4期22卷 119-124页

作者：贾俊连董博宇陶理施剑阳迟楠张俊文 Key Laboratory of EMW Information(MoE) Fudan UniversityShanghai 200433China Shanghai ERC of LEO Satellite Communication and Applications Shanghai CIC of LEO Satellite Communication TechnologyShanghai 200433China Science and Technology on Electromagnetic Compatibility Laboratory China Ship Development and Design CentreWuhan 430000China peng Cheng Laboratory Shenzhen 518055China

This paper experimentally demonstrates a distributed photonics-based W-band integrated sensing and communication(ISAC) system, in which radar sensing can aid the communication links in alignment and data rate estimation. As a proof-of-concept, the ISAC system locates the users, guides the alignment, and sets a communication link with the estimated highest data rate. A peak net data rate of 68.6 Gbit/s and a target sensing with a less-than-1-cm error and a sub-2-cm resolution have been tested over a 10-km fiber and a 1.15-m free space transmission in the photonics-based W-band ISAC system. The achievable net data rates of the users at different locations estimated by sensing are experimentally verified.

关键词： integrated sensing and communication photonics-aided technique W-band radar-aided flexible communication

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封装型Ni基催化剂制备及其原位提质煤热解焦油的性能

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洁净煤技术 2024年第4期30卷 179-186页

作者：贾鹏王明义王玉高王俊文王焦飞太原理工大学化学工程与技术学院山西太原030024 华阳新材料科技集团有限公司山西阳泉045000 宁夏大学省部共建煤炭高效利用与绿色化工国家重点实验室宁夏银川750021

为实现煤热解焦油原位轻质化,分别用原位封装法和浸渍法制备Ni基催化剂,并考察这两种催化剂对热解焦油原位催化提质的影响。与不加催化剂相比,Ni含量2%Ni/HZSM-5可使焦油中轻质组分产率由5.8%提至6.9%,而相同Ni含量的Ni@HZSM-5可使轻质... 详细信息

为实现煤热解焦油原位轻质化,分别用原位封装法和浸渍法制备Ni基催化剂,并考察这两种催化剂对热解焦油原位催化提质的影响。与不加催化剂相比,Ni含量2%Ni/HZSM-5可使焦油中轻质组分产率由5.8%提至6.9%,而相同Ni含量的Ni@HZSM-5可使轻质焦油产率提至7.6%。进一步分析Ni/HZSM-5和Ni@HZSM-5催化剂对焦油各馏分产率的影响,结果表明,2种催化剂均使焦油中重质组分明显降低,沥青质产率分别由5.4%降至1.3%和2.0%,但相较Ni/HZSM-5,Ni@HZSM-5使焦油中轻油和酚油产率分别上升38.5%和25.5%,萘油产率也有所上升,说明封装法制备的Ni基催化剂可使焦油中轻质组分最大程度保留。因为在Ni/HZSM-5中焦油裂解和热解气中富氢组分活化均发生在Ni表面,在促进富氢气体活化的同时也造成焦油过度裂解。而Ni@HZSM-5中Ni主要分布于分子筛孔道内,其良好择形催化性可使富氢气体分子进入HZSM-5分子筛内部与Ni接触产生·H和·CH x等富氢自由基,而焦油中大分子无法进入HZSM-5孔道,其裂解仅发生在分子筛外表面酸性位点上,避免了金属Ni参与焦油裂解,从而定向调控焦油裂解碎片和富氢自由基数量,达到体系内氢碳平衡,有效避免焦油碎片过度裂解,提高轻质焦油产率。

关键词：煤热解焦油催化提质封装型催化剂 HZSM-5分子筛

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12Cr2Mo1V钢凸台附加填充丝埋弧堆焊工艺研究

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压力容器 2024年第4期41卷 16-21,79页

作者：王雪骄何鹏晏君文吴成林二重(德阳)重型装备有限公司四川德阳618000

针对12Cr2Mo1V钢加氢反应器壳体凸台采用单丝埋弧焊进行堆焊、制造效率低的问题,研究了采用附加填充丝埋弧焊的焊接方法堆焊12Cr2Mo1V材质凸台本体的工艺可行性。研究结果表明,在12Cr2Mo1V钢上采用附加填充丝埋弧焊进行本体堆焊,焊接工... 详细信息

针对12Cr2Mo1V钢加氢反应器壳体凸台采用单丝埋弧焊进行堆焊、制造效率低的问题,研究了采用附加填充丝埋弧焊的焊接方法堆焊12Cr2Mo1V材质凸台本体的工艺可行性。研究结果表明,在12Cr2Mo1V钢上采用附加填充丝埋弧焊进行本体堆焊,焊接工艺性良好;其工艺评定试验的各项力学性能完全满足母材的要求,特别是-30℃夏比KV_(2)型缺口冲击试验冲击值均≥54 J,抗回火脆化倾向评定试验结果均满足v Tr54+3Δv Tr54≤0℃的要求。与单丝埋弧堆焊相比,两枪六丝附加填充丝埋弧堆焊凸台可提高生产效率200%~250%。该项工艺研究在满足加钒钢凸台性能的前提条件下,能极大缩短凸台制造周期、节能减排,为加氢反应器先进绿色制造的发展提供了新的制造手段。

关键词：附加填充丝埋弧焊 12Cr2Mo1V钢凸台堆焊

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Lens-free wavefront shaping method for a diffuse non-lineof-sight link in visible light communication

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Chinese Optics Letters 2024年第2期22卷 81-87页

作者：陈超旭周晓萌李子薇沈超张俊文施剑阳迟楠 Key Laboratory for Information Science of Electromagnetic Waves(MoE) Fudan UniversityShanghai 200433China peng Cheng Laboratory Shenzhen 518038China

In this Letter,we propose and experimentally demonstrate a lens-free wavefront shaping method that utilizes synchronized signal block beam alignment and a genetic algorithm(SSBGA)for a diffuse non-line-of-sight(NLOS)visible light communication(VLC)system.The proposed method effectively controls the position and mobility of visible light beams by partitioning spatial light modulator pixels and manipulating beams to converge at distinct spatial positions,thereby enhancing wavefront shaping efficiency,which achieves a significant 23.9 dB optical power enhancement at+2 mm offset,surpassing the lens-based continuous sequence(CS)scheme by 21.7 dB.At+40°angle,the improvement reaches up to 11.8 dB and 16.8 dB compared to the results with and without lens-based CS,respectively.A maximum rate of 5.16 Gbps is successfully achieved using bit-power loading discrete multi-tone(DMT)modulation and the proposed SSBGA in an NLOS VLC system,which outperforms the lens-based CS by 1.07 Gbps and obtains a power saving of 55.6%during the transmission at4 Gbps.To the best of our knowledge,this is the first time that high-speed communication has been realized in an NLOS VLC system without a lens.

关键词： non-line-of-sight lens-free wavefront shaping visible light communication

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A unified model for the formation and distribution of both conventional and unconventional hydrocarbon reservoirs

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Geoscience Frontiers 2021年第2期12卷 695-711页

作者： Xiongqi Pang Chengzao Jia Junqing Chen Maowen Li Wenyang Wang Qinhong Hu Yingchun Guo Zhangxin Chen junwen peng Keyu Liu Keliu Wu State Key Laboratory of Petroleum Resources and Prospecting Beijing 102249China College of Geosciences China University of Petroleum-BeijingBeijing 102249China Exploration&Development Research Institute China National Petroleum CorporationBeijing 100724China College of Science China University of Petroleum-BeijingBeijing 102249China State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development Beijing 100083China Chemical and Petroleum Engineering Schulich School of EngineeringUniversity of CalgaryCalgary T2N 1N4Canada The University of Texas at Arlington ArlingtonTX 76019USA Institue of Geomechanics China Academy of Geological ScienceBeijing 100081China Bureau of Economic Geology University of Texas at AustinAustin TX 78713USA CSIRO Energy 26 Dick Perry AveKensingtonWA 6151Australia

The discovery and large-scale exploration of unconventional oil/gas resources since 1980s have been considered as the most important advancement in the history of petroleum geology;that has not only changed the balance of supply and demand in the global energy market,but also improved our understanding of the formation mechanisms and distribution characteristics of oil/gas reservoirs.However,what is the difference of conventional and unconventional resources and why they always related to each other in petroliferous basins is not clear.As the differences and correlations between unconventional and conventional resources are complex challenging issues and very critical for resources assessment and hydrocarbon exploration,this paper focused on studying the relationship of formations and distributions among different oil/gas reservoirs.Drilling results of 12,237 exploratory wells in 6 representative petroliferous basins of China and distribution characteristics for 52,926 oil/gas accumulations over the world were applied to clarify the formation conditions and genetic relations of different oil/gas reservoirs in a petroliferous basin,and then to establish a unified model to address the differences and correlations of conventional and unconventional reservoirs.In this model,conventional reservoirs formed in free hydrocarbon dynamic field with high porosity and permeability located above the boundary of hydrocarbon buoyancy-driven accumulation depth limit.Unconventional tight reservoirs formed in confined hydrocarbon dynamic field with low porosity and permeability located between hydrocarbon buoyancy-driven accumulation depth limit and hydrocarbon accumulation depth limit.Shale oil/gas reservoirs formed in the bound hydrocarbon dynamic field with low porosity and ultra-low permeability within the source rock layers.More than 75%of proved reserves around the world are discovered in the free hydrocarbon dynamic field,which is estimated to contain only 10%of originally generated hydrocarbons.Most of undiscovered resourc

关键词： Fossil fuels Hydrocarbon resources Unified model of reservoirs formation Hydrocarbon reservoirs Hydrocarbon accumulation Hydrocarbon dynamic field

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乳腺X线和MRI参数联合外周血RLR水平预测乳腺癌改良根治术后复发转移的价值

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中华内分泌外科杂志（中英文） 2024年第3期18卷 404-408页

作者：叶建刚彭俊文李莉浙江大学医学院附属二院建德分院建德市第一人民医院放射科建德311600

目的探讨乳腺X线和MRI参数联合外周血红细胞分布宽度-淋巴细胞比值(red cell distribution width to lymphocyte ratio,RLR)水平预测乳腺癌改良根治术后复发转移的价值。方法纳入2021年6月至2023年12月在建德市第一人民医院接受改良根... 详细信息

目的探讨乳腺X线和MRI参数联合外周血红细胞分布宽度-淋巴细胞比值(red cell distribution width to lymphocyte ratio,RLR)水平预测乳腺癌改良根治术后复发转移的价值。方法纳入2021年6月至2023年12月在建德市第一人民医院接受改良根治术的104例女性乳腺癌患者作为研究对象。术前对每位受试者使用韩国GENORAY MX300乳腺数字化摄影钼靶机进行检查,记录原发肿瘤病灶的X线征象,包括最大直径、乳腺密度、钙化、肿块形态、血管征象和肿瘤边缘。使用飞利浦Achieva磁共振成像仪和专用乳腺检查线圈对肿瘤原发灶进行MRI评估,测量并自动计算出表观扩散系数(apparent diffusion coefficient,ADC)值,并记录RLR。结果术后复发转移者31例,未复发转移者73例。术后复发转移组中腋窝淋巴结转移和Ki67>14%者的比例相较于未复发转移患者显著升高。术后复发转移组中出现钙化、血管增粗、增多、肿块边缘毛刺者的比例相较于未复发转移患者显著升高。乳腺癌术后复发转移患者的ADC值为0.93±0.12,未复发转移患者的ADC值为1.08±0.15,前者显著低于后者,差异有统计学意义(t=5.64,P<0.001)。乳腺癌术后复发转移患者的外周血RLR为21.36±2.39,未复发转移患者外周血RLR为19.93±2.14,前者显著高于后者,差异有统计学意义(t=4.37,P<0.001)。多因素Logistic回归分析结果显示,Ki67高表达、血管增多、增粗、肿块边缘毛刺、较小的ADC值、较大的外周血RLR是乳腺癌术后发生复发转移的独立危险因素(P<0.05)。ROC曲线结果显示基于上述因素构建的logistic回归模型预测乳腺癌术后复发转移的曲线下面积为0.860(0.798~0.921),灵敏度为80.4%,特异度为81.8%。结论乳腺X线、MRI参数联合外周血RLR水平预测乳腺癌改良根治术后复发转移有一定价值。

关键词：乳腺癌复发转移乳腺X线表观扩散系数红细胞分布宽度与淋巴细胞比值

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