Direct Flights Allow China and Mexico to Become Neighbors

This year marks the 52nd anniversary of the establishment of diplomatic relations between China and Mexico and the 11th anniversary of the China-Mexico Comprehensive Strategic Partnership.The relationship between these two countries has maintained a steady momentum of development,with political mutual trust increasingly being consolidated and practical cooperation in economy,trade,humanities and other areas constantly expanding.China has been Mexico’s second largest trading partner for many consecutive years,while Mexico steadily ranks as China’s second largest trading partner in Latin America.

Bivariate Analysis of Pollutants Monthly Maxima in Mexico City Using Extreme Value Distributions and Copula

In the present work, we are interested in studying the joint distributions of pairs of the monthly maxima of the pollutants used by the environmental authorities in Mexico City to classify the air quality in the metropolitan area. In order to obtain the joint distributions a copula will be considered. Since we are analyzing the monthly maxima, the extreme value distributions of Weibull and Fréchet are taken into account. Using these two distributions as marginal distributions in the copula a Bayesian inference was made in order to estimate the parameters of both distributions and also the association parameters appearing in the copula model. The pollutants taken into account are ozone, nitrogen dioxide, sulphur dioxide, carbon monoxide, and particulate matter with diameters smaller than 10 and 2.5 microns obtained from the Mexico City monitoring network. The estimation was performed by taking samples of the parameters generated through a Markov chain Monte Carlo algorithm implemented using the software OpenBugs. Once the algorithm is implemented it is applied to the pairs of pollutants where one of the coordinates of the pair is ozone and the other varies on the set of the remaining pollutants. Depending on the pollutant and the region where they were collected, different results were obtained. Hence, in some cases we have that the best model is that where we have a Fréchet distribution as the marginal distribution for the measurements of both pollutants and in others the most suitable model is the one assuming a Fréchet for ozone and a Weibull for the other pollutant. Results show that, in the present case, the estimated association parameter is a good representation to the correlation parameters between the pair of pollutants analyzed. Additionally, it is a straightforward task to obtain these correlation parameters from the corresponding association parameters.

Comparison of Methods for Nitrate Interpolation in Wells in Aguascalientes, Mexico

The accuracy of interpolation models applied to groundwater depends, among other factors, on the interpolation method chosen. Therefore, it is necessary to compare different approaches. For this, different methods of interpolation of nitrate concentrations were contrasted in sixty-seven wells in an aquifer in Aguascalientes, Mexico. Four general interpolation methods were used in ArcGIS 10.5 to make the maps: IDW, Kriging, Natural Neighbor and Spline. In the modeling, only method type was varied. The input parameters (location, temporality, and nitrate concentration) were the same in the four interpolations;despite this, different maximum and minimum values were obtained for each interpolation method: for IDW, 0.2 to 22.0 mg/l, for Kriging, 3.5 to 16.5 mg/l, for Natural Neighbor, 0.3 to 21.7 mg/l and for Spline −30.8 to 37.2 mg/l. Finally, an assessment of the maps obtained was conducted by comparing them with the Official Mexican Standard (OMS), where 24 of the 67 wells were found outside the 10 mg/l that the OMS establishes as maximum permissible limit for human consumption. Taking as a starting point the measured values of nitrates (0.25 to 22.12 mg/l), as well as the spatial distribution of the interpolated values, it was determined that the Krigging method best fitted the data measured in the wells within the studied aquifer.

Gravity anomalies determined from mean sea surface model data over the Gulf of Mexico

With the improvements in the density and quality of satellite altimetry data,a high-precision and high-resolution mean sea surface model containing abundant information regarding a marine gravity field can be calculated from long-time series multi-satellite altimeter data.Therefore,in this study,a method was proposed for determining marine gravity anomalies from a mean sea surface model.Taking the Gulf of Mexico(15°–32°N,80°–100°W)as the study area and using a removal-recovery method,the residual gridded deflections of the vertical(DOVs)are calculated by combining the mean sea surface,mean dynamic topography,and XGM2019e_2159 geoid,and then using the inverse Vening-Meinesz method to determine the residual marine gravity anomalies from the residual gridded DOVs.Finally,residual gravity anomalies are added to the XGM2019e_2159 gravity anomalies to derive marine gravity anomaly models.In this study,the marine gravity anomalies were estimated with mean sea surface models CNES_CLS15MSS,DTU21MSS,and SDUST2020MSS and the mean dynamic topography models CNES_CLS18MDT and DTU22MDT.The accuracy of the marine gravity anomalies derived by the mean sea surface model was assessed based on ship-borne gravity data.The results show that the difference between the gravity anomalies derived by DTU21MSS and CNES_CLS18MDT and those of the ship-borne gravity data is optimal.With an increase in the distance from the coast,the difference between the gravity anomalies derived by mean sea surface models and ship-borne gravity data gradually decreases.The accuracy of the difference between the gravity anomalies derived by mean sea surface models and those from ship-borne gravity data are optimal at a depth of 3–4 km.The accuracy of the gravity anomalies derived by the mean sea surface model is high.

Air Quality Estimation Using Nonhomogeneous Markov Chains: A Case Study Comparing Two Rules Applied to Mexico City Data

A nonhomogeneous Markov chain is applied to the study of the air quality classification in Mexico City when the so-called criterion pollutants are used. We consider the indices associated with air quality using two regulations where different ways of classification are taken into account. Parameters of the model are the initial and transition probabilities of the chain. They are estimated under the Bayesian point of view through samples generated directly from the corresponding posterior distributions. Using the estimated parameters, the probability of having an air quality index in a given hour of the day is obtained.

2023‘Happy Chinese New Year'Series of Activities in Mexico: ‘Bicycle Zodiac Decoration Competition'

"Bicycle Zodiac Decoration Competition"is a Mexican local brand under the framework of the global brand"Happy Chinese New Year",It was first established in Mexico City in 2017 and has been successfully held in Mexico City for 6 times.

墨西哥第一支柱养老金制度结构性改革及其反思

受智利改革成就、世界银行建议和国内经济危机等影响,1997年墨西哥养老金制度结构性改革,将公共养老金制度由现收现付制待遇确定型转向完全基金制缴费确定型个人账户制。墨西哥此次改革与拉美其他国家相比有着显著不同的特点。但改革实施后,逐渐暴露出道德风险、代际公平、财政风险、可持续性和管理不善等问题,改革效果甚微,财务危机严重。2007年,墨西哥再次进行养老金制度改革,基本形成三支柱的现行养老保险体系。这两次养老金改革在实现一定经济目标的同时,也导致老年贫困和收入不平等等问题。通过剖析墨西哥养老金制度改革,我们应该重新审视养老金制度的性质和定位;认识到养老金制度改革必须考虑非正规就业及其带来的劳动力市场结构性变化;重视缴费型养老金与非缴费型最低保障养老金的匹配,认识到养老金改革应结合本国人口、经济和社会发展等基本国情,制度的管理质量和效率事关改革成效、管理与运行成本以及重视文化的作用。

基于BDWT的运动目标识别及Mexico小波核mean shift跟踪算法(英文)

提出了一种应用于智能交通监控系统的运动目标识别和跟踪方法。针对帧间差分提取运动目标的缺陷与不足,提出了一种基于二进小波变换的运动目标识别算法,即直接在二进小波变换域提取运动区域,从而检测出运动目标。对于检测出来的运动目标,对mean-shift跟踪算法进行了改进,采用以Mexico小波核函数自适应mean-shift算法对目标进行跟踪。实验结果表明,提出的算法可以有效地提取运动目标,即使目标与背景具有较高的相似度,也可以较准确的提取出前景运动信息,效果要好于传统的帧差法;跟踪目标准确度高,不受目标大小变化的影响。本算法具较高的实用价值和应用前景。

台风“艾克”(2008)的海面风场模型研究

台风风场模拟的准确性对台风风场后报工作具有重要意义,目前通过参数模型构建台风边界层的海面风场是较快速且常用的方法之一。以2008年侵入墨西哥湾的大西洋第8号台风“艾克”为例,选取多种参数模型对比研究台风风场模拟的效果。实验结果表明,台风风场模型的选择对台风风场模拟效果具有显著影响。采用Jelesnianski-1风廓线模型即可较好地再现“艾克”台风风场的时空特征;此外,具有可变系数的Holland等气压模型风场和Miller等风廓线模型风场则具有较好的适用性,通过调整可变系数使得参数风场的风廓线贴合实际台风案例。整体而言,基于理想模型的参数风场能基本反映台风核心区域的海面风场特征,但对外围背景风场模拟效果不甚理想,而分析及再分析风场数据则能较好地反映台风外围的背景风场,因此采用参数风场与分析及再分析风场融合的方式构建台风风场,可显著提高台风“艾克”风场的数值模拟效果。

墨西哥黄绿色磷灰石的宝石学和光谱学研究

墨西哥Durango地区是宝石级氟磷灰石最丰富的产地之一,对该地磷灰石的研究集中于地质年代学和矿物学标准,宝石学和光谱学资料较少。作为一种发光材料,早期学者主要利用激光诱导的光致发光光谱对未知产地的磷灰石进行研究,缺乏三维荧光光谱的研究。采用基础的宝石学测试、 LA-ICP-MS化学成分分析、红外吸收光谱、激光拉曼光谱、显微紫外-可见-近红外吸收光谱以及三维荧光光谱测试,系统性地对收集到的9颗墨西哥Durango磷灰石进行宝石学和谱学研究,旨在丰富墨西哥磷灰石的光谱学研究数据,并为产地鉴别提供科学依据。化学成分研究表明墨西哥磷灰石中稀土元素丰富,含量较高的La、 Ce、 Pr、 Nd和Sm元素,平均含量分别达3 956、 5 430、 472、 1 596和213μg·g^(-1),具有明显的轻稀土元素富集,重稀土元素亏损的特点,δEu平均值为0.29,负Eu异常显著,Ca/P摩尔比接近岩浆磷灰石的标准值1.68,为岩浆作用的产物,且形成岩浆处于中等还原状态。红外吸收光谱指纹区606和575 cm^(-1)吸收峰强度随方向的变化具有明显的规律性,能为晶体定向提供依据,官能团区显示3 482、 3 538和3 556 cm^(-1)结构水相关的吸收峰。紫外-可见-近红外吸收光谱中,由Nd^(3+)导致的528 nm的单峰和578和585 nm的双峰共同造成了黄绿区明显的透过窗,推测黄绿色体色由Nd^(3+)造成;紫外光区298 nm的吸收峰是造成可见光紫区吸收边的原因,推测由Ce^(3+)导致。三维荧光光谱最强荧光峰(λ_(ex)300 nm/λ_(em)356 nm)由Ce^(3+)的电子跃迁造成,红光区603和647 nm的发射峰由Pr^(3+)和Sm^(3+)的电子跃迁造成,与紫外灯下观察到的暗红色荧光现象相对应,推测暗红色荧光由Pr^(3+)和Sm^(3+)造成。该研究中系统的光谱学特征丰富了墨西哥产地磷灰石的谱学数据,并为产地溯源提供了科学依据。

Mexico草帽小波与电离层CT反演

电离层ＣＴ技术中由于数据采集系统的几何结构存在局限性，致使探测所得数据不完全，导致其成为不完全数据重建问题（有限角度层析）。投影中的采样点不均匀，且由投影谱通过Ｆｏｕｒｉｅｒ中心切片原理组合而得的二维谱平面不完全可知，若要用变换方法重建成象，需要对其进行估计。可以利用小波外推方法估值，但是小波函数的选择具有多样性，文中选用比较常用的Ｍｅｘｉｃｏ 草帽小波进行外推。给出了必要的推导过程和数值模拟结果。

墨西哥青少年心理健康教育和社会服务体系研究

儿童和青少年的心理健康一直是墨西哥政府和社会高度关注的热点问题。文章在概括墨西哥儿童和青少年心理健康状况与政策基础上,重点介绍了墨西哥儿童和青少年心理健康服务的实施策略和路径,包括开展社会情感培训,提升教师心理健康素养,以及开展家庭教育指导和多种社会心理健康支持等。总的来说,墨西哥通过政府、社会、学校和家庭等多个层面提升了心理健康服务的普及性和有效性,并为全球其他国家在心理健康服务领域的实践提供了宝贵的经验和案例。

墨西哥湾万米级特深井钻完井实践与启示

目前,我国陆上钻井能力已达9000 m水平,且随着深地塔科1井钻深突破万米,成为全球第二个实现陆上万米钻探的国家,初步具备万米深地油气资源勘探开发能力。但是,目前我国仅完钻5口井深超过9000 m的特深井,万米深地钻完井技术仍处于起步与探索阶段。美国墨西哥湾是世界上超深特深井数量最多的地区,并在钻井−完井−开发一体化设计理念、井身结构优化与拓展、关键装备与工具仪器、强化钻井参数提速和井下事故复杂防控等方面已形成先进理念与成熟做法。为此,系统总结分析了美国墨西哥湾万米级特深井钻井周期、钻完井成本、原油产量、钻完井方案、成熟应用装备、工艺技术等,认为我国在地质条件、地层可钻性等方面存在差异,万米级特深井的数量、钻井周期及机械钻速与美国墨西哥湾相比仍存在一定差距。结合我国万米深地油气资源钻探面临的工程难题与挑战,提出了万米深地钻探工程技术及装备发展方向及建议,为实现我国万米深地油气资源勘探开发,推动钻完井关键技术装备迭代升级提供参考借鉴。

Intermodal Competition: Cargo Airships versus Long-Haul Trucking for Perishable Commodities

Intermodal competition changes with changes in technology, economics, and environmental concerns. Trucks and airships are generally considered not to be competitors, but this depends on the distance of haul. The tonne-kilometer cost of trucking rises much more quickly with distance than it does the cost of a cargo airship. At some distance, the two modes are direct substitutes. The costs of the Mexico-Canada refrigerated truck supply chain are compared with the costs of a 100t-lift, electrically-powered airship. The flight characteristics of the Hindenburg Zeppelin are used as a model for a modern cargo airship. The supply chain cost of trucking tomatoes is used to test the theorical proposition. The cost difference works out to about US10￠/kg (5￠/lb) advantage for trucking Mexican tomatoes to Canada. However, this cost disadvantage of the airship could be made up by their vibrationless ride, better air circulation and one-day service versus four days by truck. This alternative form of transportation could have a positive impact on worldwide north-south distribution of food. Airships can overcome trade barriers and distance to open new markets for perishable food exports. In addition, they would reduce the carbon emissions of transport. Canada imports 160,000 refrigerated truckloads of fruits and vegetables by from the southern US and Mexico. With an average driving distance of 3,000 km, these trucks emit 606,000 MT of CO2 annually. Airships powered by hydrogen fuel cells would have zero-carbon emissions. Markets are not yet incorporating the environmental advantage of airships in any freight comparison, but inevitably this will be important.

探析墨西哥高等教育阶段的跨文化教育——以跨文化大学为例

墨西哥是一个多元文化国家,人口主要由印欧混血人和印第安人组成。印第安人由于历史问题和在经济上所处的弱势地位,长期处于社会的边缘,并遭受社会的歧视。为了扩大墨西哥高等教育覆盖面,加强墨西哥主体群体和印第安人的跨文化交流,2003年墨西哥政府筹划建立一种新型教育机构,即跨文化大学。本文通过对此类大学建立的背景、目标、创新点和成效进行简要介绍和分析,指出跨文化大学在经费、师资以及学校自治权等方面存在着一系列困难与挑战,并建议其通过扩大经费来源,建立一支高水平、稳定的教师队伍以及提高印第安人的参与度,推动跨文化大学的可持续发展。

墨西哥气候政策变迁的演进逻辑——基于历史制度主义的分析

墨西哥是全球南方国家中探索与实践气候政策的先行者,考察墨西哥气候政策演变的因果机制,对理解发展中国家参与全球气候治理的行为具有重要意义。基于历史制度主义的理论视角,可以从历史情境与结构要素两个维度分析墨西哥气候政策变迁大致经历的萌芽、探索和深化三个阶段。研究发现,在这一政策演变过程中,国际气候治理潮流、外部施压、执政者的重视以及多元社会主体的参与共同构成了政策变迁的结构性逻辑;《能源转型法》颁布的关键节点、利益诉求与变革驱动形塑的路径依赖以及传统政治文化弊病的“历史否决点”,共同构成了政策变迁的历史性逻辑。运用历史制度主义分析墨西哥气候政策变迁的关键驱动因素和面临的挑战,有助于我们深刻认识以墨西哥为代表的拉丁美洲发展中国家气候政策演进的底层逻辑,为加强南方国家气候合作提供启发。

The Bovine Tuberculosis Campaign in Mexico： Present and Perspectives

Mexico is considered by different international organizations as a country where the bovine tuberculosis is an endemic problem. However, there are important and consistent improvements in eradicating the disease by the implementation of government policies and with the livestock organization support. The current situation of the program shows good results regarding decreasing the prevalence, and as a consequence, the risk of this disease for public health and animal health, as well as the improvement in animal production and international and national trade. Today, the bovine tuberculosis distribution is almost known in Mexico. In addition, a series of controls and indicators have been established, which allow maintain consistency and reliability in the data that are managed and analyzed.

墨西哥中文教学发展现状与策略研究

区域与国别研究是国际中文教育研究的一个重要方面,近年来,中国和墨西哥的友好关系进一步加强,当地学习中文的人数也在持续增长。本文对当前墨西哥中文教育的现状进行了简要介绍,提出了历史、政治、经济和语言政策四个方面的影响因素,对墨西哥中文教育在教学资源、教学管理制度以及学生学习成果方面的问题进行了总结,并提出了相应的建议和策略。

Comparison of TRMM and Water District Rain Rates over New Mexico

This paper compares monthly and seasonal rain rates derived from the Version 5 （V5） and Version 6 （V6） TRMM Precipitation Radar （TPR, TSDIS reference 2A25）, TRMM Microwave Imager （TMI, 2A12）, TRMM Combined Instrument （TCI, 2B31）, TRMM calibrated IR rain estimates （3B42） and TRMM merged gauge and satellite analysis （3B43） algorithms over New Mexico （NM） with rain gauge analyses provided by the New Mexico water districts （WD）. The average rain rates over the NM region for 1998- 2002 are 0.91 mm d^-1 for WD and 0.75, 1.38, 1.49, 1.27, and 1.07 mm d^-1 for V5 3B43, 3B42, TMI, PR and TCA; and 0.74, 1.38, 0.87 and 0.97 mm d^-1 for V6 3B43, TMI, TPR and TCA, respectively. Comparison of V5 3B43 with WD rain rates and the daily TRMM mission index （TPR and TMI） suggests that the low bias of V5 3B43 for the wet months （summer to early fall） may be due to the non-inclusion of some rain events in the operational gauge analyses that. are used in the production of V5 3B43. Correlation analyses show that the WD rain rates vary in phase, with higher correlation between neighboring WDs. High temporal correlations （〉0.8） exist between WD and the combined algorithms （3B42, 3B43 and TCA for both V5 and V6） while satellite instrument algorithms （PR, TMI and TCI） are correlated best among themselves at the monthly scale. Paired t-tests of the monthly time series show that V5 3B42 and TMI are statistically different from the WD rain rates while no significant difference exists between WD and the other products. The agreements between the TRMM satellite and WD gauge estimates are best for the spring and fall and worst for winter and summer. The reduction in V6 TMI （-7.4%） and TPR （-31%） rain rates （compared to V5） results in better agreement between WD estimates and TMI in winter and TPR during summer.

HBV endemicity in Mexico is associated with HBV genotypes H and G

Hepatitis B virus(HBV)genotypes have distinct genetic and geographic diversity and may be associated with specific clinical characteristics,progression,severity of disease and antiviral response.Herein,we provide an updated overview of the endemicity of HBV genotypes H and G in Mexico.HBV genotype H is predominant among the Mexican population,but not in Central America.Its geographic distribution is related to a typical endemicity among the Mexicans which is characterized by a low hepatitis B surface antigen seroprevalence,apparently due to a rapid resolution of the infection,low viral loads and a high prevalence of occult B infection.During chronic infections,genotype H is detected in mixtures with other HBV genotypes and associated with other co-morbidities,such as obesity,alcoholism and co-infection with hepatitis C virus or human immunodeficiency virus.Hepatocellular carcinoma prevalence is low.Thus,antiviral therapy may differ significantly from the standard guidelines established worldwide.The high prevalence of HBV genotype G in the Americas,especially among the Mexican population,raises new questions regarding its geographic origin that will require further investigation.