For thousands of years, human beings have obtained various information from the objective world in the practical activities of transforming nature and society. This information has been refined and processed by the human brain and gradually transformed into knowledge. But knowledge must rely on a certain material carrier to exist. In the early society, humans stored and transmitted knowledge through their own brains. Due to the influence and constraints of various factors, it is difficult for the knowledge stored in the human brain to span space and time. With the development of social productivity, human beings have broken their own constraints and found a material carrier that exists outside the human body and transforms knowledge into some regular information symbols, which are recorded on the carrier. This new material carrier is literature. Literature, as a product of the combination of human spirit and material, is a record of human knowledge, information and activities, and a form of the existence and expression of scientific knowledge.
The construction of information resources is a core basic work for libraries and other types of information institutions to carry out various business and service work. As an important information center of higher education, one of the main tasks of university library is to construct the document information resource system of the whole university, and provide literature information insurance for teaching, scientific research and discipline construction. It can be seen that the construction of information resources directly determines the level and quality of universities. In particular, the proposal of “double first-class” construction puts forward new opportunities and challenges for the construction of university library information resources. With the development of information technology, the formation of network environment and the advent of the “Internet+” era, fundamental changes have taken place in the theoretical system, acquisitioning work, organization and management, development and utilization, resource evaluation, guarantee system and sharing system of information resources construction. In the new era, how to effectively construct the construction and management of information resources in university libraries, and to maximize the co-construction and sharing of information resources construction, has always been one of the important topics studied by the library community.
前 言
几千年来,人类在改造自然和社会的实践活动中,获得了来自客观世界的各种信息,这些信息经过人类大脑的提炼和加工,逐渐转变为知识。但知识必须依赖一定事实上的物质载体才能存在。早期社会,人类是通过自身的大脑来存储和传播知识的,由于各种因素的影响和制约,存储在人类大脑的知识很难跨越空间和时间。随着社会生产力的发展,人类打破了自身的束缚,寻找到了一种自身身体外的物质载体,将知识转化为一些有规律的信息符号记录在载体上,这种新的物质载体就是文献。文献作为人类精神与物质相结合的产物,是人类知识信息及活动的记录,是科学知识存在和表现的形式。
信息资源建设是图书馆和其他类型信息机构开展各项业务工作和服务工作的一项核心性基础性工作。高校图书馆作为高等教育的重要信息中心,其主要任务之一是建设全校的文献信息资源体系,为教学、科研和学科建设提供文献信息保障,可见信息资源建设工作直接决定着高校办学水平和办学质量。特别是“双一流"建设的提出, 为高校图书馆信息资源建设提出了新的机遇和挑战。 随着信息技术的发展,网络环境的形成和“互联网+”时代的到来,信息资源建设的理论体系、采访工作、组织管理、开发利用、资源评价、保障体系和共建共享都发生了根本性变化。如何有效构建新时期高校图书馆信息资源建设与管理,最大限度地实现信息资源建设的共建共享等相关问题,一直是图书馆界积极研究的重要课题之一。
The quality of water conservancy and hydropower projects is related to the national economy and people’s livelihood and the safety of urban and rural people’s lives and property, whether water conservancy and hydropower projects are to harness rivers, build urban flood control, remove waterlogging in low-lying areas, or store water for irrigation, solve drinking water, prevent pollution and develop hydropower. Project quality is not only related to project benefits, but also directly affects the sustainable, healthy and rapid development of national economy. Many years of construction engineering practice has proved that it is an important measure to make clear the responsibilities of all parties involved in the water conservancy project construction, implement the project quality responsibility system, strengthen the project quality management, and improve the overall quality of the quality control and quality assurance personnel of all parties involved in the construction, which is an important measure to ensure the safety of national property and the life and property of the residents, enhance the reputation of enterprises, and improve the economic benefits.
Water conservancy and hydropower project construction project has the characteristics of large scale, long construction period, many production links, many participants, and many factors affecting the project quality. No matter which subject or link has problems, it will lead to quality defects and even major quality accidents. Therefore, it is necessary to strengthen quality supervision and quality inspection. Water conservancy project quality inspection is an essential means of project quality process control and an important basis for project quality acceptance.
前 言
水利水电工程无论是治理江河、兴建城市防洪、低洼地区除涝,还是蓄水灌溉、解决饮水、防治污染、开发水电,其质量好坏都关系到国计民生,关系到城乡人民生命财产的安全。工程质量不仅关系到工程效益,而且直接影响到国民经济可持续健康快速发展,可以毫不夸张地说“质量责任重于泰山”。多年建设工程实践证明,明确水利工程参建各方责任、落实工程质量责任制、加强工程质量管理、提高建设各方质量控制和质量保证人员的整体素质,是保障国家财产及入民生命财产安全,增强企业信誉,提高经济效益的重要举措。
水利水电工程建设项目具有规模大、建设周期长、生产环节多、参与方多、影响工程质量的因素多等特点,不论是哪个主体出了问题,哪个环节出了问题,都会导致质量缺陷,甚至造成重大质量事故。因此防患于未然,加强质量监督,加强质量检测就显得尤为必要。水利工程质量检测是工程质量过程控制的必备手段,也是工程质量验收的重要依据。
With the development of human society and the improvement of living standards, consumers have higher requirements for food. Food is not only rich in nutrition and delicious, but also safe and hygienic.
With the development of food quality and safety detection technology, it has become an important part of promoting the progress of food production enterprises. It is mainly reflected in the improvement of food quality and the whole process verification activities, and coordinated with the management activities of food production enterprises, thus effectively ensuring the steady improvement of food quality and constantly meeting the needs of social development and the improvement of people’s material living standards.
Food quality and safety testing is one of the important means to ensure food quality and improve food safety. With the development of science and technology and the improvement of people’s requirements for food, food detection instruments are constantly updated, the level of detection technology, detection sensitivity and detection limit are constantly improved, and the detection methods are also constantly updated, especially for the rapid detection of toxic and harmful substances. Therefore, it is the responsibility and obligation of food testing institutions, food quality inspectors, quality control personnel and relevant scientific and technological personnel to fully understand and master the food quality and safety testing technology.
前 言
随着人类社会的发展和生活水平的提高,消费者对食品的要求更高,食品除营养丰富、美味可口外,还要安全、卫生。
食品质量安全检测技术发展至今,已成为全面推进食品生产企业进步的重要组成部分。它突出地体现在通过提高食品质量和全过程验证活动,并与食品生产企业各项管理活动相协同,从而有力地保证了食品质量的稳步提高,不断满足社会日益发展和人们对物质生活水平提高的需求。
食品的质量与安全性检测是确保食品质量,提高食品安全性的重要手段之一。随着科学技术的发展和人们对食品要求的提高,食品检测仪器不断换代,检测技术水平、检测灵敏度及检测限不断提高,检测方法也在不断更新,尤其是针对有毒有害物质的快速检测新方法不断推出。因此,全面了解和掌握食品质量与安全检测技术,是食品检测机构、食品质量检测人员、 品控人员及有关科技人员的责任和义务。
Pump is a general machine developed with the development of industry. By the 19th century, the foreign industrial developed countries had a relatively complete form and variety of pumps. Pumps are widely used, ranging from airplanes in the sky to drilling, mining and coal mining on the ground, automobiles, tanks on land, ships on the sea, urban and rural buildings, residents’ lives, factories’ boilers and pump stations, and agricultural drainage and irrigation. In order to ensure the normal operation of the pump, it is necessary to master the structure, use method and maintenance skills of the pump.Therefore, we have compiled the book: Research on the Use and Operation of Pumps.
There are four aspects that affect the efficiency of pump equipment: First, the design and processing is not up to standard, which means that the design of the selected pump is unreasonable, and the manufacturing process control is improper, resulting in the loss of machinery and volume, resulting in the increase of pump operation energy consumption. Second, the production operation is continuous and uninterrupted. In this process, the equipment is scoured by the water flow for a long time, which increases the roughness of the impeller surface and the inner wall of the channel, increases the resistance of the inner channel, and reduces the operation efficiency of the equipment and increases the loss of the equipment. Third, in the production process, the pump blade back surface will produce a certain negative pressure, if not treated for a long time, it will gradually form honeycomb or cavitation. Fourth, in order to improve the water production effect, the relevant drugs will be put into the pump shell during the production process, and the raw water quality will also have a certain degree of impact on the pump components. After a long time of operation, dirt will be generated in the pump shell. In serious cases, the wall thickness of the pump shell will be increased and the operation efficiency of the equipment will be reduced. Therefore, it is very important to master the operation specification of pump, and to install, inspect and maintain the pump in the correct way.
前 言
泵是伴随着工业发展而发展起来的通用机械。 到 19 世纪, 国外工业发达国家已有了比较完整的泵的形式和品种。泵的应用范围非常广泛,从天上的飞机,到地上的钻井、采矿、掘煤;从陆地的汽车、各种机动车、坦克,到海上的舰船;从城乡建筑、居民生活、工厂的锅炉、泵站,到农业的排灌等,到处都能见到泵在工作。为了保证泵的正常运转,必须掌握泵的结构、使用方法及维修技能。为此,我们编写了《泵类设备使用与运行研究》这本书。
影响机泵设备使用效能可从四个方面分析:第一,设计加工不过关,指所选机泵其设计不合理,加上制作工艺控制不当,使得机械、容积出现损失,造成机泵运行能耗增加。第二,生产作业具有持续不间断特点,在这个过程中,设备长期受水流冲刷作用,使得叶轮过水面以及流道内壁粗糙度增加,加大了内流道阻力,进而会降低设备运行效率,并造成设备损耗增加。第三,在生产过程中,机泵叶片背水面会产生一定负压,如果长时间未处理,会逐渐形成蜂窝或者气穴。第四,为提高制水效果,会在生产过程中向泵壳内投入相关药物,且原水水质也会对机泵构件产生一定程度的影响,长时间运行后会在泵壳内产生污垢,情况严重时会造成泵壳壁厚增加,降低设备运行效率。因此掌握机泵运行规范,并对机泵按照正确方式安装、检查与维修对机泵实现高效运行具有非常重要的意义。
Over the past 20 years of reform and opening up, China’s construction industry has developed rapidly, and the construction market has initially formed. In order to meet the needs of market economy, the construction industry has carried out a series of major reforms.
The implementation of construction management is a great change in the production and operation activities of construction enterprises. Its significance lies in: through the implementation of the construction project manager responsibility system, the separation of management and operation level, and the market-oriented management of internal resources, we can promote the internal structural adjustment of the enterprise, and finally realize the transformation from extensive operation to intensive operation, from speed type to efficiency type, from labor intensive type to the combination type of labor intensive and technology intensive. Through this transformation, the quality of construction enterprises can be improved as a whole to meet the objective needs of national economic development and reform and opening up to the international construction market.
Construction enterprise is the main body of construction project management, and its production and operation activities are implemented in the construction market environment. The optimization of internal organization and management system, engineering contracting system, construction planning system and production factor management system of enterprises is the basis for improving the construction project management and even the production and operation activities of enterprises, and is also the necessary condition for survival and development in the fierce market competition.
前 言
改革开放 20 多年来,我国的建筑业发展很快,建筑市场已初步形成。为适应市场经济的需要,建筑业进行了一系列重大改革。
推行施工管理是建筑施工企业生产经营活动的一次大变革。其意义在于:通过实行施工项目经理负责制、管理层与作业层分离、内部资源的市场化管理等,推动企业内部的结构调整,最终实现企业从粗放型经营向集约型经营的转变,从速度型向效益型的转变,从劳务密集型向劳务密集与技术密集结合型的转变。通过这种转变,从整体上提高施工企业的素质,以适应国民经济发展和改革开放走向国际建筑市场的客观需要。
施工企业是施工项目管理的主体,其生产经营活动是在建筑市场大环境下实施的。企业内部的组织管理体制、工程承发包体制、施工计划体制、生产要素管理体制等的优化是使施工项目管理,乃至企业的生产经营活动完善和健全的基础,也是市场激烈竞争中生存和发展的必备条件。