生物群落的一般概念是
【填空题】开放式浇筑系统，内浇口应放置在横浇口( )端。
【判断题】对于粘土湿砂，当水分合适时，粘土含量越高，强度越高。
【判断题】压实造型时，压实比大于压实 O.7 MPa 称为高压造型。
【判断题】铸件上的宽水平面浇筑时应朝下。
【单选题】~をはじめ
在使用中GIF在优化图像时，选择以下参数( )图像中透明像素的优化方法可以指定。
如图所示，要将波动曲线处理成重复的网状纹理效果，准确快捷的制作方法是( )。
【填空题】目前主要有树脂砂芯 3 硬化方法，即( )、( )和( )。
自定义图案时，正确的操作步骤是( )。
【填空】铸件应力过大会导致铸件应力过大 ( ) 等待缺陷。因此，在设计铸件结构时应注意铸件( )尽量均匀。
浇注位置是指造型时的浇注位置( )它影响铸件的质量。
【单选题】~とはいえ
化学粘砂是由金属氧化物、砂、粘土相互作用产生的低熔点化合物。
【填空】球墨铸铁中石墨呈现 ( ) 状。
水玻璃砂硬化的方法有( )和( )等。
【填空题】铸件浇铸位置的选择必须正确，如重要加工面、大平面、薄壁等，浇铸时应尽量选择( ),而且厚的部位要尽量( ),为了安装冒口( )。
化学粘砂层中的金属氧化物越厚，越难清洗。
单选题将图像存储为JPEG格式时，可以从0设置质量参数~当数值设置越大，图像压缩时，12之间的值( )。
【判断题】铸铁用粘土湿砂必须全部采用新砂混合砂。
影响自硬砂使用时间和起模时间的因素主要是砂温和环境温度。
铸铁根据石墨形态可分为石墨形态( )、( )、( )和( )。
阅读理解What is renewable energy? Renewable energy is energy that is environment -friendly because it is collected from renewable resources, which are naturally replenish ed. Examples of these renewable resources include sunlight, wind, rain, tides, waves, and geothermal heat (i.e.the thermal energy generated and stored in the Earth). There is a distinction between renewable energy and alternative energy . The latter is generate d from alternatives to fossil fuels and need not be renewable. Renewable energy often supplies energy in four essential sectors: · The generation of electricity; · Cooling and heating of air; · Means of transport, · Rural energy services. Investing in renewable energy Global investments in renewable technologies were estimated to be more than US$286 billion in 2015. Countries like China and the United States invest heavily in wind, hydro, solar and biofuels. Globally, there are an estimated 7.7 million jobs associated with the renewable energy industries, with solar photovoltaics being the largest renewable employer. As of 2015 worldwide, more than half of all new electricity capacity installed was renewable. Benefits of renewable energy There are a lot of benefits to using renewable energy. First, naturally replenished energy resources are found over wide geographical areas, in contrast to non-renewable resources , which exist only in a limited number of countries. In addition to that, rapid deployment of renewable energy and energy efficiency is resulting in significant energy security, climate change mitigation , and economic benefits. The results of a recent review of the literature concluded that as greenhouse gas emitters begin to be held liable for damages resulting from greenhouse gas emissions resulting in climate change, a high value for liability mitigation would provide powerful incentive s for deployment of renewable energy technologies. There are other undeniable advantages of renewable energy. Renewable technologies are also suited to rural and remote areas and developing countries, where energy is often crucial in human development. Former United Nations Secretary-General Ban Ki-moon has said that renewable energy has the ability to lift the poorest nations to new levels of prosperity . Besides, as most renewables provide electricity, renewable energy deployment is often applied in conjunction with further electrification, which has several benefits: · Electricity can be converted to heat (where necessary generating higher temperatures than fossil fuels); · Electricity can be converted into mechanical energy with high efficiency; · Electricity from renewable resources is clean at the point of consumption. Deployment of renewable energy In international public opinion surveys, there is label support for promoting renewable sources such as solar power and wind power. At the national level, at least 30 nations around the world already have renewable energy contributing more than 20 percent of energy supply. National renewable energy markets are projected to continue to grow labelly in the coming decade and beyond. Some places and at least two countries, Iceland and Norway generate all their electricity using renewable energy already, and many other countries have set a goal to reach 100% renewable energy in the future. For example, in Denmark, the government decided to switch the total energy supply (electricity, mobility and heating/cooling) to 100% renewable energy by 2050. Conclusion Renewable energy systems are rapidly becoming more efficient and cheaper. Their share of total energy consumption is increasing. Growth in consumption of coal and oil could end by 2020 due to increased uptake of renewables and natural gas.
如何理解软件生命周期的内在特征？
铸铁中碳的存在形式有( )和( )。
影响铸铁石墨化的主要因素是( )和( )。
【单选题】生物群落是
镁砂是由菱镁矿高温锻烧冉破碎分选而成，主要成分为( )。
【单选题】在玻璃 ( 折射率 n 3 = 1.60) 表面镀一层 MgF 2 ( 折射率 n 2 = 1.38) 薄膜作为增透膜.为了使波长为 500 nm 的光从空气 ( n 1 = 1.00) 正入射时尽可能少反射, MgF 2 薄膜的最小厚度应是
【判断题】用于热芯盒工艺的树脂砂的发气量较大,但发气速度较快,因此,砂芯不需要加强排气措施。
【填空题】对砂型铸件进行结构设计时,必须考虑合金的( )和铸造( )对铸件结构提出的要求。
【单选题】生物群落是
【判断题】铸件的主要加工面和重要的工作面浇注时应朝上。
【判断题】铸造热应力最终的结果是薄壁或表层受拉。
【填空题】封闭式浇注系统,内浇口应置于横浇口( )部。
【填空题】影响合金充型能力的因素有( )、( )、( )。
【填空题】水玻璃砂的常用物理再生方法包括( )和( )两种。
【单选题】~ものの
【填空题】ZG200-400 中 “ZG 表示 ( ) ,数 字 400 表示 ( ) 。 HT150 表示 ( ). QT450-10 的含义 ( ). , KTH300-06 表示( )。
【填空题】可锻铸铁中石墨呈( )状。
【简答题】群落的基本特征有哪些?
【单选题】~た上で
【填空题】灰铸铁中主要以( )的形式存在,呈( )状。
【填空题】铸件上各部分壁厚相差较大,冷却到室温,厚壁部分的残余应力为( )应力,而薄壁部分的残余应力为( )应力。
【单选题】下列工具箱中的选取工具中,能用于定义图案的是( )。
【多选题】妊娠期妇女乳房的特点是
【填空题】铸造应力按产生的原因不同,主要可分为( )和( )( )三种。
【判断题】热芯盒工艺中的树脂砂的强度高低,主要决定于树脂本身的性质,但也与原砂质量、芯盒温度、混制质量等有关。
【单选题】Inspectors were appointed to _____ into the affairs of the company.
【填空题】水玻璃砂存在的突出问题是( )、( )、( )和( )等。