begin vi. (began; begun; beginning) 1.开始 (opp. end); 着手,动手。 2.始于,源于 (from). School begins on Monday. 星期一开课。 vt. 1.开始,创始;动手,着手。 2.创建。 It has begun to be done. = It has been begun. 工作开始了。 He began (to speak). 他开口了。 a book I began (to read) 开始读的书。 begin a dynasty 开创一个朝代。 begin again 重做,从头另做。 begin at 从…开始 (begin at the wrong end 开错了头。 begin at page 10 从第10页开始)。 begin by (doing ...)从(做…)开始,先做…。 begin on [upon] 着手,动手 (He has begun on a new book. 他已开始读[写]另一本新书)。 begin the world 开始为人[处世];开始独立生活。 begin with 从…开始,先做 (A little caviar to begin with, madame 先吃一点鱼子酱怎么样,女士?)。 not begin to (do) 〔口语〕决不会,完全不 (It does not begin to meet the specifications. 这完全不合规格。 I can't begin to tell you how grateful I am. 我不知道怎样感激你才好)。 to begin with 首先,第一,第一个理由是;本来〔插入语〕 (To begin with, he is too young. 首先[第一],他太年轻了)。
So the dissertation is began with the scientific and economic analysis 因此,我们的研究以对能源的科技、经济分析为切入点。
The azeotropic distillation of the system acetic acid - water - azeotropic agent ( isopropyl acetate and butyl acetate ) is simulated . due to the non - ideal behavior , nrtl - hoc and uniquac - hoc model is used to depict vapor - liquid phase equilibrium behavior of this system . concerning the liquid in the decanter , the stability is checked by tangent plane stability analysis , and the initialization of phase splitting calculation is produced . a good estimate of the phase fration is gotten by successive substitution with newton ' s method , and every component of two phase is gotten by mass equilibrium equation . finally , the solution of this equation is produced with successive substitution calcultion . the naphtali - sandholm method is used to simulation of azeotropic distillation . by virtue of this combined calculation method , the simulation is begun with operational data as basical data . the results of simulation accord with the operating data , which proved that the combined calculation method is credible 该体系具有高度非理想性,气液相平衡模型采用nrtl - hoc和uniquac - hoc模型,采用切平面判据法对进入分层器中的液相进行液相稳定性测试,提供液液相分离计算的初值,再结合牛顿拉夫森迭代法运算求得相分割系数,根据物料衡算求出各相组成,循环迭代可求得分层各组分数据,共沸精馏模拟计算采用那夫塔列-山德荷姆全变量迭代算法。
This section begins with the important position of the non - coercive means of environmental administration and comes to the descriptions to the creation of the non - coercive means of environmental administration . and these descriptions are begun with several important factors about the creation of the non - coercive means of environmental administration 本部分在强调国家行政权在环境管理中的重要地位的同时,通过非强制行政的勃兴、环境意识和环境文化背景、持续发展对环境行政管理手段的基本要求、解决环境问题对行政管理手段的理想选择等角度,对环境行政非强制性管理手段的产生背景进行了阐述。