AN ALGORITHM TO IDENTIFY ALL PATHS IN SCHEDULING NETWORKS

The purpose of this paper is to present an algorithm that identifies every path in scheduling networks. The algorithm finds the answer by simulating the way we solve the problem by hand. The result is a list, in sequential order, of all activities involved in each path, the algorithm is divided into forward and backward passes that are repeated until all paths have been identified. Backward passes determine the existence of paths, while forward passes determine the activities involved in the paths. The algorithm has been successfully tested with 31 construction networks, and has been implemented in simulation programs used for construction scheduling and probabilistic analyses.     

腐植酸产业低碳化技术解决途径探讨

<正>随着全球人口和经济规模不断增长,环境污染问题越发严重。近百年来,大气中二氧化碳(CO2)浓度的不断升高,导致全球正在经历一场以地球变暖为特征的显著气候变化。以低消     

Effects of Public Investments on Urban Land Values

The study reported in this paper was an attempt to develop a model for identifying and assessing the impact of alternative development policies on urban land values. The statistical analysis carried out suggests that the most important factor determining the values of urban land is accessibility to the central urban functions. Age of existing structures and zoning regulations are secondary factors. Since future development of central urban functions can be projected with the help of existing models and since accessibility of places (particularly by means of public transportation) and zoning regulations can be influenced by public authorities, indirect public actions considerably influence urban land values.     

我所知道的槇文彦

自二战结束后半个多世纪以来,日本由于战后重建的需要和经济快速发展而提供的可能,产生了大规模的建设过程,也涌现了大批有高度成就的建筑师。在文化方面,日本既保持了原来本土的遗产,又在隋唐以来受中国文化的滋养和明治维新以后受西方列强的影响。特别是二战以后,西方的影响更是在加速扩展。这在建筑方面就表现得尤为清楚。在这50多年来,战前盛极一时的复古风、"帝冠式"逐渐式微。但民族主义     

双非贵金属催化nC_5异构化反应条件探索

考察正戊烷异构化应用双非贵金属丝光沸石催化剂的反应条件,实验在反应温度270～320℃,空速0.2～2.5h~(-1),氢油摩尔比2.0～6.0,反应压力1.4～4.0MPa的范围内进行。首先分析单因素对正戊烷异构化反应的影响,然后应用正交法获取了正戊烷异构化最佳反应条件和结果,即在反应温度300℃,反应压力3.0MPa,空速1.0h~(-1),氢油摩尔比4.0条件下,达到反应转化率0.6754,选择性0.9750;≥C_5异构烷产率0.6382;≥C_5液体收率0.9650。在100mL实验装置上连续进行1000h催化剂活性稳定性试验,证明双非贵金属丝光沸石异构化催化剂性能稳定。     

How many protein‐coding genes are there in the Saccharomyces cerevisiae genome?

We have compared the results of estimations of the total number of protein-coding genes in the Saccharomyces cerevisiae genome, which have been obtained by many laboratories since the yeast genome sequence was published in 1996. We propose that there are 5300-5400 genes in the genome. This makes the first estimation of the number of intronless ORFs longer than 100 codons, based on the features of the set of genes with phenotypes known in 1997 to be correct. This estimation assumed that the set of the first 2300 genes with known phenotypes was representative for the whole set of protein-coding genes in the genome. The same method used in this paper for the approximation of the total number of protein-coding sequences among more than 40 000 ORFs longer than 20 codons gives a result that is only slightly higher. This suggests that there are still some non-coding ORFs in the databases and a few dozen small ORFs, not yet annotated, which probably code for proteins.     

大型注水系统的运行优化

提出了油田大型注水系统优化运行的２类问题，１类是在注水单耗水于规定值的情况下，确定注水系统各注水站水泵运行台数，使注水系统中各注水站实际水量和分配注水量误差平方和最小；另１类是在注水系统各配水间配注误差不超过值的条件下，使注水系统总的能耗达到最小。