查询词典 variable compression ratio

In order to improve the high-performance concrete quality of longer brittleness, lower tensile strength, particularly the less descending branch in stress-strain curve compared with that of ordinary concrete. The breakthrough of this thesis lies in the mixture of short carbon fiber. Four factors such as water-binder ratio, volume ratio of short carbon fiber and blending value of high efficiency water-reducing admixture were selected as variable. Experiment was carried out by utilizing uniform design. Regression equation was established by regression analysis of the compression strength and the split tensile strength separately utilizing SPSS software. The process of optimization was obtained with the aid of MATLAB. Finally the optimized ratio was acquired.

为了改善高强混凝土由於水泥自缩、湿涨造成的脆性大、抗拉强度低，特别是应力－应变曲线的下降段不及普通混凝土的特点，本文以掺入短碳纤维为突破口，选取水胶比、砂率、短碳纤维的体积比、高效减水剂掺量四个因素作为变量，利用均匀设计安排试验，用SPSS软件对抗压强度和劈拉强度分别进行回归分析而得到回归方程，用MATLAB进行优化处理，进而求出最优配比。

The main work and innovation1 In general , a image compression method has different effect to different image . Some are fit for image which has much high frequency . Some are fit for image which has much low frequency .This paper analysis the applicability of fractal algorithm . In this dissertation , an improved algorithum is given . The basic algorithum without eight change and the joint use of quantitative coding , The compression ratio and PSNR can be adjusted , and it can get more quickly speed of coding .2 To a group of exact fractal code , the decoding image can be any resolution .With this characteristic ,choose the proper domain block and range block,this paper get an algorithum which can get higher decoding PSNR and speed than the basic fractal algorithum.3 Give a new method to calculate the scale factor . The calculation of basic algorithum is complex and enormous . The factor of scale is an important variable of the basic algorithm. Now there are two methods to calculate the factor of scale .A new method was given to calculate the factor of scale. The calculation load and complexity are reduced by the new method. Compared with the basic algorithm , the method can reduce coding time.4 The basic fractal algorithum is based on the Collage theorem and contraction mapping theorem . A mathematic model based on basic fractal algorithum is given .

本文的主要工作及创新点主要包括以下几点：1一般情况下，一种图像压缩的方法对不同特点的图像，压缩效果会有所不同，本文利用分形压缩编码对不同特点的图像进行编码，分析了分形编码对不同图像的编码适用性，利用去掉8种变换的分形编码算法与简单的均匀量化编码方案相结合，得到了一种可以调节压缩比与解码质量的分形编码方案，该提高编码速度6倍以上。2分形编码的特点之一是分形解码的分辨率无关性，即对于一组分形编码可以将其解码到任意分辨率下，本文利用分形编码的这一特点，结合不同的量化编码方案，选择合适的定义域块与值域块及适当的编解码分辨率，得到了一种提高解码质量，编码速度提高12倍以上的加速算法。3比例因子是基本分形算法中的一个重要变量，目前有两种计算比例因子的方法，文中给出了一种新的求比例因子的方法，该方法简化了求比例因子的计算，从整体上减小了基本分形算法的计算量，简化了算法4分形压缩的数学基础是不动点定理与拼贴定理，本文根据基本的自动分形编码方法，建立数学模型对其进行推导，得到了用普通数学的极限理论解释分形编码的数学表达式，从而对由基本分形编码得到的解码图像中的像素点的值给出了确定的表达式。

Camshaftless valve actuation includes electromagnetic,electrohydraulic,electropneumatic and electromechanical types.it could vary valve timing agilely,simplify the engine's structure,deactivate some of the engine's cylinders selectively and vary the effective compression ratio flexibly to adapt different fuels.So it could offer more advantages than general variable valve timing.

阐述了在发动机上以电磁、电液、电气或其他方式驱动气门，实现无凸轮轴气门驱动，可以灵活改变气门正时，简化发动机结构，能有选择地闭缸，灵活改变发动机有效压缩比以适应多种燃料要求，使发动机获得比采用一般可变气门驱动更多的好处。

In order to increase the compression ratio of color video,a new coding method context-based four-dimensional matrix variable length coding was proposed according to four-dimensional matrix theory.

为了进一步提高彩色视频的压缩比，根据四维矩阵理论，提出了基于上下文的四维矩阵变长编码方法。

MWM engine makes the conversion among two-stroke mode, four-stroke mode and six-stroke mode of one engine come true in theory, filles in the blank with 1/3 which is the ratio of total strokes to working strokes in single working cycle of engine, possessing the continuous variable compression ratio of a certain range at the same time, combines the advantages of two-stroke engine and four-stroke engine, expandes the working range of engine greatly.

MWM发动机在理论上实现了一台发动机在二冲程、四冲程与六冲程工作模式之间的相互转换，填补了发动机单工作循环作功行程数与总行程数比值中1/3的空白，同时具备一定范围连续可变的压缩比，整合了二冲程与四冲程发动机的优点，拓展了发动机的工作范围。

Through the flue gas and air characteristic analysis in supercharged boiler,the results showed that the value of parameters would increase with the increase of fuel consumption.And volume heat load of the furnace, fuel consumption, heat change between flue gas and convective heating surface and evaporation value would increase with the increase of compression ratio.The heat calculation would be different because of dissimilar thermal calculation in the turbo-compressor when the boiler load was changed.As the boiler load increased,heat loss in the turbo-compressor would increase and the efficiency of the boiler would decrease.The results of the boiler start-up simulation showed that the time of start-up would decrease with the increase of flue consumption ,but instantaneous pressure amplitude would increase.Steam water"s dymamic diversification would be more complex than flue gas"s,and dynamic characters of their parameters would be changed due to different boiler load and disturbance variable,which was shown by results of the simulation when boiler load was changed.

通过分析增压锅炉内的空气、烟气参数特性，发现随着锅炉负荷的增加，空气和烟气的各项参数值都相应的增加；炉膛容积热负荷、锅炉的燃料负荷随着增压比的提高成比例增加；随着增压比的增大，烟气与对流受热面的换热增加，蒸发量随之增加；由于涡轮增压机组在不同负荷下的热力计算不同而造成增压锅炉在不同负荷下的热平衡计算的不同；锅炉增压机组的总的热损失随着锅炉负荷的增加而增加，而增压锅炉的热效率随着锅炉负荷的增加而减少；锅炉启动模拟仿真结果中发现，锅炉启动时燃料量增加，锅炉的启动时间就会减少，但是瞬时升压速度会增加；而动态负荷变化模拟仿真结果中发现，锅炉汽水侧的变化相比烟气侧更为复杂，且在不同负荷和不同扰动量下，烟气侧和汽水侧的重要参数动态特性是不同的。

Stirling engines generally operate with low compression ratios, even if they respond simultaneously to a thermal compression ratio and a geometric compression ratio (both are time variable, and the product of both ratios gives the real ratio).

一般经营斯特林发动机压缩比低，即使他们回应，同时向一热压缩比和几何压缩比（无论是时间变量，产品的比例都给人的真实比例）。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。