高技术统计的系统思考

高技术产业发展状况已成为一国综合国力的发展标志 ,因此高技术产业统计工作十分重要。我们认为高技术不等于高新技术 ,从统计意义上必须将高技术与新技术分开。高技术产业界定方法应采用定性和定量判断 ,本文试把高技术领域作为一个系统 ,提出了高技术统计的“动态循环淘汰论。”

贫困家庭教育投资能力的分析逻辑——基于可行能力理论的视角

在国家义务教育保障体系下,民族贫困地区依旧普遍存在着辍学、失学现象。对滇西特困地区的实地调研发现,贫困家庭无力为子女进行教育投资是导致辍学、失学现象的主要原因。在理论层面建构贫困家庭教育投资能力的逻辑框架,将有利于透视贫困地区辍学、失学现象,助力实践层问题的解决。基于可行能力理论的视角,围绕资本和权利及两者的互动关系建构关于贫困家庭教育投资能力的逻辑框架,进而提出该领域分析的核心思想——"动态循环",有助于贫困家庭教育投资困境的缓解。

A Dynamic Modeling For Cyclic Total Reflux Batch Distillation

Cyclic total reflux(CTR) batch distillation is a promising mode of the process but lacking of appropriate modeling for the period of filling the reflux drum.A new dynamic modeling method for the simulation of CTR batch distillation is proposed in this work,in which the changes in column holdup and liquid flow rate during the filling of the drum,and the consequent change in valid number of theoretical plates are considered.The effect of drum holdup on operation time is investigated and the optimal drum holdup is obtained from the simulation.The dynamic modeling is compared to the conventional modeling without consideration of change in liquid flow rate. The experimental result shows that the present modeling is more reliable and more accurate,especially for the column with large liquid holdup.

Bottleneck Prediction Method Based on Improved Adaptive Network-based Fuzzy Inference System (ANFIS) in Semiconductor Manufacturing System

Semiconductor manufacturing (SM) system is one of the most complicated hybrid processes involved continuously variable dynamical systems and discrete event dynamical systems. The optimization and scheduling of semiconductor fabrication has long been a hot research direction in automation. Bottleneck is the key factor to a SM system, which seriously influences the throughput rate, cycle time, time-delivery rate, etc. Efficient prediction for the bottleneck of a SM system provides the best support for the consequent scheduling. Because categorical data (product types, releasing strategies) and numerical data (work in process, processing time, utilization rate, buffer length, etc.) have significant effect on bottleneck, an improved adaptive network-based fuzzy inference system (ANFIS) was adopted in this study to predict bottleneck since conventional neural network-based methods accommodate only numerical inputs. In this improved ANFIS, the contribution of categorical inputs to firing strength is reflected through a transformation matrix. In order to tackle high-dimensional inputs, reduce the number of fuzzy rules and obtain high prediction accuracy, a fuzzy c-means method combining binary tree linear division method was applied to identify the initial structure of fuzzy inference system. According to the experimental results, the main-bottleneck and sub-bottleneck of SM system can be predicted accurately with the proposed method.

A dynamic model for railway freight overbooking

In order to apply overbooking idea in Chinese railway freight industry to improve revenue, a Markov decision process(dynamic programming) model for railway freight reservation was formulated and the overbooking limit level was proposed as a control policy. However, computing the dynamic programming treatment needs six nested loops and this will be burdensome for real-world problems. To break through the calculation limit, the properties of value function were analyzed and the overbooking protection level was proposed to reduce the calculating quantity. The simulation experiments show that the overbooking protection level for the lower-fare class is higher than that for the higher-fare class, so the overbooking strategy is nested by fare class. Besides, by analyzing the influence on the overbooking strategy of freight arrival probability and cancellation probability, the proposed approach is efficient and also has a good application prospect in reality. Also, compared with the existing reservation(FCFS), the overbooking strategy performs better in the fields of vacancy reduction and revenue improvement.

Dynamic test on waste heat recovery system with organic Rankine cycle

Dynamic performance is important to the controlling and monitoring of the organic Rankine cycle(ORC) system so to avoid the occurrence of unwanted conditions. A small scale waste heat recovery system with organic Rankine cycle was constructed and the dynamic behavior was presented. In the dynamic test, the pump was stopped and then started. In addition, there was a step change of the flue gas volume flow rate and the converter frequency of multistage pump, respectively. The results indicate that the working fluid flow rate has the shortest response time, followed by the expander inlet pressure and the expander inlet temperature.The operation frequency of pump is a key parameter for the ORC system. Due to a step change of pump frequency(39.49-35.24 Hz),the expander efficiency and thermal efficiency drop by 16% and 21% within 2 min, respectively. Besides, the saturated mixture can lead to an increase of the expander rotation speed.

To a Question about Forecasting Number of Micromammalia （Rodentia）

In the present study, the data for population dynamics of micromammalia in Dnipropetrovs＇k Region in 1957-1999 and Dnipro-Orel＇s Natural Reserve at 1991-2009 are adduced. With the purpose to drawing up of the long-term forecast at number are analyzed long-term lines of number on background kind＇s fine micromammals of dominant group. The analysis of long standing rows of number small mammals and comparison data with Wolf number were demonstration, which indicate that dynamic of number phone species （and dominant in particular） carry a cyclic character and contact with 11-year cycles of sun activity. Consequently, it was clearing up hidden periodical in dynamic of number mouse rodents. By that observation was dependence from cycles of sun activity. Probably, that in 2012 year, before peak of sun activity in 2013, next high increase about the number of small mammals for maxima （＂outbreak＂ mass reproduction is a peak ＂big wave＂） will take place.

Application of coal mine dynamic safety management and occupational health and safety management system

A method system was put forward based on the occupational health and safety management system to develop the dynamic safety management of coal mine. It aimed at the problems in the mining safety management and was put in practice in Lingxin coal mine of Ningxia Coal Industry Group Co., Ltd.. And good effect was obtained in safety work. It developed the mining dynamic safety management based on the building of occupational health and safety management system of mining enterprise and its main contents are as follows： timely identification and dynamic control of accident risk, persistent improvement of safety management performance according to the ＂PDCA＂ circle.

Functional polymer materials based on dynamic covalent chemistry

In the past two decades,dynamic covalent chemistry has been greatly developed,which is mainly reflected in two aspects:1.new dynamic covalent bonds(DCBs)are continuously discovered;2.various DCBs have been introduced into polymer materials for different functions.These functional polymer materials have brought new opportunities for sustainable development.In this review,we provide an overview of various functions endowed by DCBs in polymer materials,including self-healing,chemical recycling,and shape controlling.Particularly,we pay much attention to the three-dimensional(3D)shape reconfiguration/programming,surface patterning,and reversible actuation.In addition,we also give the current issues,challenges,and opportunities on DCBs-containing materials and point out its developing directions in the future.

Robust metal–organic framework with multiple traps for trace Xe/Kr separation

Direct separation of Xe and Kr from air or used nuclear fuel(UNF)off-gas by means of porous adsorbents is of industrial importance but is a very challenging task.In this work,we show a robust metal-organic framework(MOF),namely ECUT-60,which renders not only high chemical stability,but also unique structure with multiple traps.This leads to the ultrahigh Xe adsorption capacity,exceeding most reported porous materials.Impressively,this MOF also enables high selectivity of Xe over Kr,CO2,O2,and N2,leading to the high-performance separation for trace quantitites of Xe/Kr from a simulated UNF reprocessing off-gas.The separation capability has been demonstrated by using dynamic breakthrough experiments,giving the record Xe uptake up to 70.4 mmol/kg and the production of 19.7 mmol/kg pure Xe.Consequently,ECUT-60 has promising potential in direct production of Xe from UNF off-gas or air.The separation mechanism,as unveiled by theoretical calculation,is attributed to the multiple traps in ECUT-60 that affords rigid restrict for Xe atom via van der Waals force.

Effects of electroacupuncture pretreatment on motor function and cerebral blood flow in MCAO model rats

Objective:To observe the effects of electroacupuncture(EA)pretreatment on motor function,cerebral blood flow,cerebral infarction volume,and vascular endothelial growth factor(VEGF)level in middle cerebral artery occlusion(MCAO)model rats.Methods:Twenty-four male Sprague-Dawley rats were randomly divided into a normal group,a model group,and an EA group,with eight rats in each group.The middle cerebral artery ischemia-reperfusion model was established by the suture-occluded method in the model group and the EA group,while not in the normal group.The EA group was pretreated with EA at bilateral Fengchi(GB20)before model preparation,once a day for 30 min each time for a total of 7 d.The changes in the CatWalk gait parameters,modified Bederson neurological deficit score,cerebral blood flow,cerebral infarction volume after ischemia,and VEGF level in the brain tissue of rats in each group were observed.Results:Compared with the normal group,the modified Bederson neurological deficit score in the model group and the EA group increased after modeling(P<0.05),and the CatWalk gait parameters(one-leg stance duration,gait cadence,and gait cycle)were all changed(P<0.05).Compared with the model group,the modified Bederson neurological deficit score in the EA group decreased(P<0.05),and the CatWalk gait parameters improved(P<0.05).Immediately after ischemia,the cerebral blood flow in the normal group was greater than that in the model group and the EA group(P<0.05);after reperfusion,the cerebral blood flow in the EA group was greater than that in the model group(P<0.05).Compared with the normal group,the cerebral infarction volume in the model group and the EA group increased(P<0.05).Compared with the model group,the cerebral infarction volume in the EA group decreased(P<0.05).The expression level of VEGF-positive cells in the rat brain tissue in the model group was higher than that in the normal group(P<0.05),and was higher in the EA group than in the model group(P<0.05).Conclusion:EA pretreatment improves the limb motor function in MCAO model rats,alleviates the symptoms of neurological deficits,promotes the recovery of cerebral blood flow,reduces the cerebral infarction area after MCAO modeling,and increases the VEGF expression in the brain tissue.