设G=(V,E)是一个图,一个函数f:V→{-1,1}如果满足∑v∈V(C)f(v)≥1对G中每一个导出圈C均成立,则称f为图G的一个圈符号控制函数,图G的圈符号控制数定义为γsc(G)=min{∑v∈V(G)f(v):f为图G的一个圈符号控制函数}。得到了图的圈符号控制数的若干下界,并刻划了满足δ≥2且γsc(G)=4-V(G)的所有图。

Let G =(V,E)be a graph,a function f:V→{-1 ,1}is said to be a cycle signed domination function (CSDF)of G if∑f(v)≥1 holds for any induced cycle C of G ,where the cycle signed domi-v∈V(C) nation number of G is defined asγsc(G)=min{∑v∈V f(v) fis a CSDF of G}.Some lower bounds of the cycle signed domination number of a graph are obtained,and all graphs G withδ≥2 andγsc(G)=4 -V(G) are characterized.

以果葡糖浆和玉米浆为主要原料,依次通过Plackett-Burman设计、均匀设计、人工神经网络和遗传算法,纤维素产生菌G-29静态培养下的最优条件是:果葡糖浆40g/L,玉米浆23.88g/L,(NH4)2SO43g/L,Na2HPO4·12H2O 4.66g/L,柠檬酸1g/L,醋酸0.5g/L,MgSO4·7H2O 0.2g/L,FeSO4·7H2O 0.4g/L,CaCl20.015g/L,ZnSO4·7H2O0.004g/L,乙醇2%(v/v),接种量10%(v/v),种龄2d,初始pH 5.82,培养时间5.94d,培养温度30℃.

Using high fructose syrup (HFS)and corn steep liquor (CSL),the fermentation medium of bacterial cellulose (BC)was optimized by Plackett-Burman design (PB),uniform design (UD),artificial neural network (ANN)and genetic algorithm (GA)successively.The optimal culture parameters were:HFS 40 g/L,CSL 23.88 g/L,(NH4)2SO43 g/L,Na2HPO4·12H2O 4.66 g/L,citric acid 1 g/L,acetic acid 0.5 g/L,MgSO4·7H2O 0.2 g/L,FeSO4·7H2O 0.4 g/L,CaCl2 0.015 g/L,ZnSO4·7H2O 0. 004 g/L,ethanol 2% (v/v),inoculum size 10% (v/v),inoculum age 2 d,initial pH 5.82,culture peri-od 5.94 d at 30℃.

通过孟加拉红培养基计数试验,测定了9种传统糯米酒曲的微生物含量,结果表明9种酒曲的微生物含量相差很大。经酒曲液化、糖化能力试验,结果表明1~9号酒曲中2号、4号和6号酒曲的液化力与糖化力较强,它们的液化力分别为1.7g/(g·h)、1.4g/(g·h)和1.2g/(g·h),糖化力分别为591mg/(g·h)、438mg/(g·h)和411mg/(g·h)。经酿酒产酒精能力试验,结果表明1号、2号、4号、5号酒曲产酒精能力较强,它们发酵的酒精度分别为11.8%(v/v)、8.5%(v/v)、8.4%(v/v)和8.2%(v/v)。通过对不同酒曲液化力、糖化力和产酒精能力的筛选实验,为酿造优良品质的糯米酒打下了基础。

By spreading plate technique, yeasts and molds of the nine selected starters were enumerated on rose Bengal chloramphenicol agar plate, and the results showed that microbiological load of each wine starter was quite different. Wine starter No.2, No.4 and No.6 were selected from the nine traditional wine starters for their higher ability to liquefy and saccharify starch. The ability of liquefaction for wine starter No.2, No.4 and No.6 was 1.7g/(g·h), 1.4 g/(g·h) and 1.2g/(g·h), respectively. The ability of saccharification for wine starter No.2, No.4 and No.6 was 591mg/(g·h), 438mg/(g·h) and 411mg/(g·h), respectively. Starter No.1, No.2, No.4 and No.5 were selected from the nine traditional wine starters as their higher ability to produce alcohol. The alcohol level for wine starter No.1, No.2, No.4 and No.5 was 11.8%(v/v), 8.5%(v/v), 8.4%(v/v) and 8.2%(v/v), respectively. By screening experiment of ability of liquefaction, ability of saccharification and ability to produ

图 G 的导出森林 k-划分是指其顶点集 V（G）的一个 k-划分（V1，V2，…，Vk），使得对于每个 i（1≤i≤k），导出子图 G[Vi]是一个森林。图 G 的点荫度是使得图 G 有导出森林 k-划分的最小的正整数 k，记为 va（G）。主要证明了如果图 G 能够嵌入到欧拉示性数非负的曲面上，则当图 G 满足三类条件时，可以得到 va（G）≤2。

An induced forest k-partition of a graph G is a k-partition (V1 ,V2 ,…,Vk)of the vertex set V(G)such that, for each i with 1≤i≤k,the induced subgraph G[Vi ]is a forest.The vertex arboricity of a graph G is the minimum positive integer k such that G has an induced forest k-partition,denoted by va(G).Let G be a simple graph embedded in a surface of nonnegative Euler characteristic,and if G satisfies three kinds of conditions,then va(G)≤2.

针对电动汽车入网特性具有较强空间随机性及时间随机性的问题，基于蒙特卡洛随机模拟法，随机抽取了调度区域内不同类型电动汽车的日行驶里程及充放电起始时间节点，提出了 V2G 系统实时功率容量预测模型。以上海地区为例，预测了一天24时段 V2G 系统实时功率容量，结合相关政策及统计数据分析并验证了 V2G 技术的可行性。总结了我国 V2G 技术的发展趋势。

In order to solve the problems of randomness in both time and space which exist in the process of accessing the power grid for electric vehicles, based on Monte Carlo stochastic modeling method, we select randomly daily mileages and charging and discharging starting time of different types of electric vehicles, and propose a real-time power capacity forecast model in the V2G system. Taking the city of Shanghai as an example, we predict the real-time power capacity of V2G system in the 24 h one day, and validate feasibility of V2G technology with related policies and statistics analysis. Finally the development trends of V2G technology in China are summarized.