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1.
This work offers an overview of the state of the art and future state of environmental health in our country from a viewpoint of the impact of the commercial opening established in the Free Trade Agreement among Mexico, the USA, and Canada. In the first section of this work, we analyze the expected economic changes resulting from the implementation of the FTA and foretells the way in which those changes will influence the present environmental and epidemiologic profiles of this country in the medium and long term. The main changes predicted by the analysis are, in the epidemiologic context, the acceleration of the transference of occupational, consumption, environmental and population risks, characteristic of industrialized countries, to the country's polarized epidemiologic profile; and, in the environmental context, a transition consisting of a broadening and composition of the spectrum of pollutants, including and important lagging of bacteriologic control. The second section offers an analysis of the predicted response capacity facing the new environmental risk dynamics in the country, encompassing regulation, normativeness and enforcement of environmental and consumer protection, as well as obstacles found in health services to the implementation of surveillance, detection and treatment of health damages caused by environmental factors. The analysis of the organized social response to these problems discloses a relative flexibility of the normativeness and enforcement functions in comparison with our northern neighbors, a paramount factor for the possible transference of environmental risks, as well as the informational and research deficiency about environmental issues, basic elements for sustaining environmental health in the country, aiming at speeding up the development and transference of technologies for prevention, detection and management of environmental risks in the country, drawing upon the systematization of our experience and that of our neighbors. This speeding process ought to match, in the medium term, the velocity of risk transference produced by the commercial opening. In this way, the commercial integration of North America will become a favorable context for the development of the environmental health infrastructure of the country.  相似文献   

2.
在“碳达峰”、“碳中和”的目标背景下,绿色低碳、清洁高效成为资源开采的新要求,也对科学开采这一复杂系统问题的研究提出了新的方向。阐述了矿产资源开采理念的发展演化,综述了近年来国内外在科学开采方面的研究现状,构建了安全、高效、绿色、低碳、经济、科学管理“六位一体”的科学开采体系,丰富了科学开采的内涵和框架。从复杂科学问题的判断标准、科学开采体系的特征两方面进行推断,得出科学开采属于复杂问题,承载科学开采复杂问题的系统是复杂系统。以复杂科学的思路研究科学开采的复杂性,构建科学开采复杂系统模型,从顶层设计、中层连接和底层基础3个层次思考了实现科学开采的新途径,为实现矿产资源的科学开采提供了新的发展方向。  相似文献   

3.
We studied the absorbing peripheral lymphatic vessel with the light microscope, the transmission electron microscope, the scanning electron microscope, and three-dimensional models of the diaphragm of several rodents and insectivores under normal and experimental conditions (lymphatic stasis and dehydration). To clarify the delicate and complex mechanism that permits drainage of the abdominal cavity contents into the lymphatic circulatory system, we introduced Polystyrene latex spherules, China ink, and Trypan blue into the abdominal cavities. After anatomical comparisons of the superficial and deep networks of absorbing peripheral lymphatic vessels at the tendinous and muscular portions of the diaphragm and after classification of lymphatic vessels into absorbing and conducting functions, we examined the stomata, which, owing to morphologic and topographic findings, we defined as stable structures. Furthermore, we observed that the stomata and submesothelial connective channel are fundamental elements that facilitate the flow of the corpuscular and liquid contents of the peritoneal cavity to the submesothelial absorbing lymphatic vessel wall. Also, we underlined that the genesis of the connective channel depends on the secondary cytoplasm extensions of two distinct adjacent endothelial cells, which, to facilitate the flow of the absorbed abdominal contents, completely coat this channel. Additionally, our observations illustrate that the secondary cytoplasm extensions do not engage in continuous relationships with the basal lamina of the mesothelium and with the margins of the stoma, and, hence, the hypothesis of "lymphatic stomata" as an expression of the anchoring of the borders of the open interendothelial junctions to the orifice margins of the stoma cannot be confirmed. Moreover, we describe the presence and formation of intraendothelial channels in the lymphatic endothelial wall. We affirm that this morphological entity is a dynamic unit, because its numerical density varies according to different physiological and experimental conditions to degrees of hydrostatic and colloidal osmotic pressure and, perhaps, also to the particular characteristics of the substances that the connective channel liberates into the endothelial wall of the lymphatic vessel. In conclusion, we affirm that the absorbing peripheral lymphatic vessels of the diaphragm, by way of intraendothelial channel formations, membrane diffusion, and the vesicular path of the endothelial cells, constitute the fundamental draining elements for the corpuscular and liquid contents of the abdominal cavity.  相似文献   

4.
王新东 《钢铁》2022,57(11):1-10
 绿色化、智能化已成为钢铁行业未来发展的共识,是中国钢铁行业引领世界钢铁行业的重要方向。针对“绿色化、智能化、品牌化”的新一代流程钢厂建设面临的全流程数字孪生、绿色技术集成、工程管理创新等诸多问题,河钢集团积极探索钢铁工程的绿色化、数字化转型路径,在工程实践中建立了全流程多要素“融合协同”的绿色工程管理方法。形成了钢铁工程数字虚拟工厂与现实工厂的协同、绿色技术与工程设计的协同、过程管控与全要素资源动态的协同、工程数字与模块建造的协同等“四个协同”的具体方法支撑。据此方法建成的唐钢新区,从设计、建设到交付的全过程遵循冶金流程工程学理论,按照“绿色化、智能化、品牌化”的建设目标,以物质流、能量流、信息流的最优网络结构为方向,运用最新的钢厂动态精准设计、集成理论和流程界面技术,通过工序功能集解析优化、工序间关系集协调优化和流程工序集重构优化,构建信息物理融合系统,实现了唐钢新区产线连续紧凑、动态有序和产品质量窄窗口稳定运行。唐钢新区是在同时期、同类型钢铁工程中吨钢投资最低、建设工期最短、环保水平最高的新一代流程钢厂。全流程多要素“融合协同”的绿色工程管理方法的建立为钢铁工程的绿色化、智能化转型提供了借鉴。  相似文献   

5.
通过对南平巨口钼矿床控矿地质条件分析,认为北东向的政和-大埔断裂带和南北向浦城-嵩口断裂带复合交会部位控制了成矿小岩体群,强调了南北向构造迭加为成矿母岩侵位提供了通道和赋存空间,同时其次级断裂构造控制矿体的分布产状及规模;控矿母岩-黑云母花岗岩,高硅、高碱、高钾,低钙、镁对成钼有利.文章总结矿(体)床特征,分析围岩蚀变...  相似文献   

6.
矿山编录是矿山生产中重要的地质技术工作之一,编录工作的规范性和严谨性、编录资料的真实性和准确性,直接影响到后期地质工作研究的精度。面对井下工作环境差、重复工作量大、效率低和成果利用不便等问题,亟待采用信息技术进行解决。本文阐述选择采用C/S架构搭建矿山编录系统,分析系统架构、业务功能和关键技术后对系统进行设计,通过规范编录数据采集标准,利用移动端APP离线采集编录数据,实现编录信息快速采集、自动成图和数据集中管理,实时动态模拟展示采掘工程控制下编录地质体的三维空间状态。实例研究表明:基于C/S架构的矿山编录系统开发、使用便捷,具有实时性好、安全性高等特点,编录结果具有三维可视性,可以方便、灵活、全面地展示编录成果及地质信息,指导矿山地质探勘和安全生产。  相似文献   

7.
讨论了空间机械臂在轨插、拔孔操作的阻抗控制问题。为此,结合系统动量守恒关系,空间机械臂替换部件末端输出插、拔孔主动力与孔内所受摩擦阻力作用关系,以及第二类拉格朗日方程,推导得到了载体位置、姿态均不受控制情况下,空间机械臂在轨插、拔孔操作过程系统动力学方程。同时,根据相关操作控制系统设计需要,利用系统位置几何关系分析、建立了空间机械臂替换部件末端相对基联坐标系的相对运动雅可比关系。之后,由空间机械臂替换部件末端位姿与末端输出插、拔孔主动力之间的动态关系并结合阻抗控制原理,建立了二阶线性阻抗模型。在上述工作基础上,针对空间机械臂在轨插、拔孔操作过程同时存在运动学与动力学不确定性的情况,设计了空间机械臂替换部件末端力/位姿跟踪指数型阻抗控制策略;并通过李雅普诺夫理论,证明了控制系统的稳定性。提到的控制策略具有结构简单、收敛速度快、稳定性好的特点。系统数值仿真,验证了上述控制策略的有效性。   相似文献   

8.
王新东  常金宝  李杰 《钢铁》2020,55(9):125-131
运用冶金流程工程学观点,并结合工厂应用实例对小方坯热送热装技术、直接轧制技术和铸轧型无头轧制技术的发展和应用进行了介绍。以小方坯连铸-轧钢制造流程为例,讨论了冶金制造流程中时间、空间等关键要素的配置方法对整个流程中能量耗散的影响,研究了冶金流程典型耗散系统中物质流、能量流和信息流实现"层流"运行的关键技术以及应用效果。通过理论分析和工厂实例,证明通过优化连铸-轧钢"界面"衔接,建立物质流、能量流、信息流优化的运行网络并且实现高效运行,可以显著降低整个棒线材生产流程的能量耗散,节约大量能源,从而实现降本增效、节能减排、绿色化生产。  相似文献   

9.
Analysis of currently available data on mortality and morbidity indicates that the major organic illnesses of childhood, and their developmental consequences, are susceptible in part to the technical interventions of American medical science. Environmental forces, however, exert a powerful impact on the health of children in the United states, manifested both in the disproportionate toll of most organic diseases on poor and nonwhite populations and in such increasingly important symptoms of familial, social, and behavioral distress as child abuse, accidents, and childhood suicide. Review of the nature, quality, and distribution of child health services demonstrates a systemic inability to reach and treat the children most in need of them. A rational basis for child health policy includes: appropriate concepts of health, disease, and preventive and therapeutic intervention; a capacity to acknowledge, to measure, and to act on the familial and environmental, as well as the medical, sources of illness; an orientation to the developmental and social implications of good and poor child health; and a commitment to enable all children to receive health services. The data and this policy framework lead to these program recommendations: the channeling of resources into a more rational system which guarantees equity and access; a planning and program implementation mechanism which addresses the health needs of diverse local populations and which makes real the advocacy concept; a screening, evaluation, and surveillance methodology; a delivery system which both applies preventive and curative health technology and addresses basic life needs of children; and a coherent program for the training, assignment, and supervision of the several kinds of manpower which such a system would require.  相似文献   

10.
The gene families encoding the immunoglobulin variable regions of heavy (VH) and light (VL) chains in vertebrates are composed of many genes. However, the gene number and the extent of diversity among VH and VL gene copies vary with species. To examine the causes of this variation and the evolutionary forces for these multigene families, we conducted a phylogenetic analysis of VH and VL genes from the species of amniotes. The results of our analysis showed that for each species, VH and VL genes have the same pattern of clustering in the trees, and, according to this clustering pattern, the species can be divided into two groups. In the first group of species (humans and mice), VH and VL genes were extensively intermingled with genes from other organisms; in the second group of species (chickens, rabbits, cattle, sheep, swine, and horses), the genes tended to form clusters within the same group of organisms. These results suggest that the VH and VL multigene families have evolved in the same fashion: they have undergone coordinated contraction and expansion of gene repertoires such that each group of organisms is characterized by a certain level of diversity of VH and VL genes. The extent of diversity among copies of VH and VL genes in each species is related to the mechanism of generation of antibody variety. In humans and mice, DNA rearrangement of immunoglobulin variable, diversity, and joining-segment genes is a main source of antibody diversity, whereas in chickens, rabbits, cattle, sheep, swine, and horses, somatic hypermutation and somatic gene conversion play important roles. The evolutionary pattern of VH and VL multigene families is consistent with the birth-and-death model of evolution, yet different levels of diversifying selection seem to operate in the VH and VL genes of these two groups of species.  相似文献   

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