青海省都兰县开荒地区地球化学特征及找矿预测

青海省都兰县开荒地区大地构造位置处于塔柴板块南缘，东昆仑造山带中段，雪峰山—布尔汗布达金、钴、铜成矿带内。为在开荒地区实现找矿突破，于研究区内开展了1∶50 000水系沉积物测量工作，以527件水系沉积物样品数据为基础，采用元素的变异系数、富集系数、浓集比率对Au、Ag、As、Sb、Cu、Pb、Zn、W、Mo 9种元素进行了数理统计分析，分析各元素在空间上的富集规律及其成矿潜力，并结合成矿地质条件对研究区进行了成矿预测。研究表明：Au在研究区内具有较大的成矿潜力，其他元素的成矿潜力较小；通过R型聚类分析及因子分析确立了研究区内与Au成矿有关的元素组合为Au-As-Sb-Pb；运用衬度异常方法在研究区内圈定了2处找矿靶区，KH1靶区与KH2靶区内的Au、As、Sb、Pb异常套合性较好，并且在KH1靶区内发现了白金沟金矿体。由于KH2靶区与KH1靶区内的各元素套合性及成矿地质条件极为相似，故认为KH2靶区也具有较好的找矿潜力。分析结果对于在研究区进一步开展找矿勘探工作及相关成矿预测研究有一定的参考价值。     

视频侦查中人像智能分析应用及算法优化

人像智能分析指的是对视频或录像中的人像进行结构化和可视化分析,对目标人物进行性别、年龄、发型等特征的智能识别,这项技术在视频侦查中有极高的应用价值。人像识别早期的算法是通过人工提取特征,通过学习低级视觉特征来针对不同属性进行分类学习,这种基于传统方法的模型表现常常不尽如人意。在计算机视觉领域,通过海量图像数据学习的神经网络比传统方法有更丰富的信息量和特征可以被提取。文章尝试通过深度学习技术训练神经网络模型对行人进行检测和识别,对于衣着不同的行人进行智能识别,具有更好的鲁棒性,提升了视频人像识别的准确率,拓展了人工智能技术在身份识别领域的应用。     

青海都兰县双雪包银多金属矿地球化学特征及找矿前景探讨

近年来的化探找矿实例证明,化探在干旱高山景观区是行之有效的找矿方法,以1∶2.5万地球化学测量对1∶5万水系沉积物异常进行检查,可达到快速、经济、准确圈定矿化范围的目的。该文通过对青海都兰县双雪包地区1∶5万水系沉积物AS14号异常的分析研究,利用1∶2.5万地球化学测量对该异常较好的分解和重现,圈出综合异常14处,异常总体分布受F3断裂构造控制;重点对GA2和GA5等2个1∶2.5万地球化学测量综合异常进行检查,发现矿化破碎蚀变带2条,通过地表工程揭露,圈出AgPbZn矿体2条,矿体与异常中心位置套合,异常为矿致异常。综合分析双雪包地区的找矿前景,为下一步工作提供参考。     

多组元钛合金电子束冷床炉熔炼挥发规律研究

利用电子束冷床炉(EB炉)一次熔炼制备TC4、Ti6242、TA15钛合金铸锭,采用Langmuir定律对熔炼过程中Al、Sn、Zr、Mo等元素的挥发规律做了简要的数值分析,并与实际挥发规律进行了对比分析。结果表明:EB炉熔炼TC4、Ti6242、TA15钛合金过程中,Al元素在3种合金中的挥发率有所不同,挥发率由大到小顺序为TC4>Ti6242>TA15;Al元素是TC4钛合金中主要的挥发元素;Ti6242钛合金中,Al、Sn元素之间存在联合挥发的问题;TA15钛合金中,Al、Zr元素之间亦存在联合挥发的问题,Al元素带动了Zr元素(难挥发元素)的挥发。     

青海省格尔木市西大滩东多金属矿控矿因素及找矿前景

青海省格尔木市西大滩东多金属矿出露地层主要为早-中三叠世昌马河地层走向呈北西~南东向,与区域构造线方向基本一致。是测区的主要矿源层,为后期矿化提供了物质基础。比较发育的北西向、北西西向逆断层具有明显的多期活动特点,多形成破碎带,为热液活动、成矿元素富集提供了良好空间,对本区矿化起着一定的控制作用,破碎蚀变带控制了土壤异常展布。本文对西大滩东多金属矿控矿因素及找矿前景进行分析探讨。     

Boosted photogenerated carriers separation in Z-scheme Cu3P/ZnIn2S4 heterojunction photocatalyst for highly efficient H2 evolution under visible light

Developing low-cost, highly efficient and robust photocatalystic hydrogen evolution system is a promising solution to environmental and energy crisis. Herein, a Z-scheme Cu₃P/ZnIn₂S₄ heterojunction photocatalyst was successfully constructed for the first time via a facile solution-phase hybridization method. The optimized Cu₃P/ZIS composite exhibited the highest H₂ production rate of 2561.1 μmol g⁻¹ h⁻¹ under visible light irradiation (>420 nm), which was 5.2 times greater than that of bare ZnIn₂S₄ and even exceeded the photocatalytic performance of Pt/ZIS composite. The apparent quantum yield of 10 wt% Cu₃P/ZnIn₂S₄ can reach 22.3% at 420 nm. The huge boost of photocatalytic hydrogen evolution activity is ascribed to the formation of heterojunction with the built in electric field within Cu₃P/ZnIn₂S₄ and Z-scheme charge carriers transfer pathway, which result in efficient separation and migration of charge carriers. In addition, both experimental and theoretical calculation confirmed that the charge-carriers transfer pathway of Cu₃P/ZnIn₂S₄ photocatalyst follows the Z-scheme mechanism instead of conventional type-Ⅱ heterojunction mechanism. This work is considered helpful for getting a great deal of insight into constructing high-activity and cost-effective transition metal phosphides (TMPs) based photcatalytic hydrogen production system and rationally designing Z-scheme heterojunction photocatalyst.     

In2S3-NiS co-decorated MoO3@MoS2 composites for enhancing the solar-light induced CO2 photoreduction activity

In₂S₃-NiS co-decorated MoO₃@MoS₂ (INS/MoO₃@MoS₂) heterojunctions were prepared in nonthermal plasma via the in-situ sulfurization for enhancing the solar-light photocatalytic conversion of CO₂ into CH₄ and CO at 423 K. In contrast with hexagonal h-MoO₃ nanorods, CH₄ and CO yields were enhanced by h-MoO₃@MoS₂ and In₂S₃/MoO₃@MoS₂, while the increased CH₄ yield and decreased CO yield were obtained by INS/MoO₃@MoS₂ and NiS/MoO₃@MoS₂. The optimal 3-INS/MoO₃@MoS₂ with a nominal NiS-In₂S₃ content of 5.0 wt% and a In/Ni molar ratio of 2:1 exhibited the best photoreduction activity of CO₂, of which CH₄ and CO yields were 49.11 and 6.19 μmol g⁻¹ h⁻¹, respectively. It's ascribed to the tight interface for enhancing the visible-light absorption capacity and reinforcing the transfer and separation of charge carriers. S-rich sites and O vacancies were favorable for the adsorption and photoreduction of reactants on the bulks surface. The nonthermal plasma induced in-situ sulfurization was thus a promising route to fabricate metal sulfides-based heterojunctions.     

Santo Domingo: City profile of the Caribbean's metropolis

As the oldest city of the New World, Santo Domingo has undergone major institutional, political, economic and urban restructuring in five centuries of urban history. This city profile article investigates first the historical urban development of the city and then scrutinizes contemporary urban policies and projects that respond to challenges of rapid growth, inequality, and vulnerability to climate change. The article highlights how centralized policies initiated by divergent political regimes have resulted in a segregated city where Presidents used urban space to leave their legacies without adhering to planning mechanisms. The article also uncovers how rapid growth and absence of urban planning have produced two city making approaches, the “formal” and the “informal” cities converging parallel to each other. Furthermore, as the capital city of a Small Island Developing State, Santo Domingo's recent urban policies are embedded in global frameworks such as the Sustainable Development Goals and the Paris Climate Agreement; in this line, inequality and climate change vulnerabilities continue to be the city's main challenges in the 21rst century.     

High-temperature sulfurized synthesis of MnxCd1-xS composites for enhancing solar-light driven H2 evolution

In recent years, tremendous efforts have been devoted to develop new photocatalyst with wide spectrum response for H₂ generation from water or aqueous solution. In this paper, Mn_xCd_1-xS composites were in-situ fabricated via the high-temperature sulfurization to enhance the solar-light photocatalytic capacity of H₂ evolution. Benefiting from the S defects and junction interface between MnS and CdS, Mn_xCd_1-xS composites exhibited the better H₂ evolution rate than pure MnS. The H₂ evolution rate of optimal Mn_0.5Cd_0.5S with a Mn(II) content of 22.52% and a Mn/Cd mole ratio of 0.95:1 was 9.27 mmol g^?1 h^?1, which was 35.65 and 2.38 times higher than pure MnS (0.26 mmol g^?1 h^?1) and CdS (3.89 mmol g^?1 h^?1), respectively. In addition, H₂ evolution capacity of Mn_0.5Cd_0.5S decreased from 44.83 to 41.66 mmol g^?1 after three cycles. Mn_0.5Cd_0.5S prepared via the high-temperature sulfurization was thus a potential material for solar-light induced H₂ generation.     

电感耦合等离子体发射光谱法测量青海地区矿泉水中锶含量的不确定度

采用电感耦合等离子体发射光谱(ICP-AES)法测定矿泉水中锶的不确定度。分析了标准溶液配制过程及仪器测定过程的各种不确定度影响因素,对各不确定度分量进行了评定与计算,当锶的质量浓度为0.8373 mg/L时,测量结果的扩展不确定度为0.0192 mg/L(k=2)。该法适合于以线性回归法得出检测结果的不确定度评估。