城市地下空间的资源属性与开发特性分析

从自然资源、经济资源及自身开发利用特性角度,全面分析城市地下空间的资源属性和开发特性。研究认为:城市地下空间资源是一种可耗竭的自然资源,具有自然资源一般特性,也具有区别与地上空间资源的特性;城市地下空间资源属于经济资源,能够成为独立的产权客体;城市地下空间开发具有开发成本高、开发不可逆及竖向分层特性,合理科学的规划对地下空间开发非常重要。据此提出:城市地下空间开发是经济、社会和技术共同发展的结果,需要根据城市地下空间资源属性和开发特性,制定以资源优化利用为目的的城市地下空间开发利用策略。

致密油地质特征及开发特性研究

为了满足日益增长的能源需求,世界各国不断寻找新类型的能源作为补给。随着勘探开发技术的不断革新,美国的致密油勘探开发取得了巨大成功,由此致密油吸引了越来越多石油公司的关注。在调研大量国内外致密油相关文献的基础上,对致密油的定义和油藏特征进行了分析,重点介绍致密油地质特征。对近年来出现的连续型油气聚集理论与技术、纳米级孔喉系统的观测、各类资源评价技术等与致密油有关的先进理论和技术进行了分析总结。致密油的生产特性决定了其生产状态曲线和生产高峰取决于钻井数量和质量,最终将受到油田面积钻井规划总量的限制。我国要在借鉴国外最新致密油勘探技术及生产管理政策的基础上,结合国内实际情况,进行致密油的勘探开发。

关于产品特性及其开发的研究

通过对产品属性的分析，讨论了产品特性与顾客购买动机的关系，论述了产品特性对于产品竞争力的重要意义；提出了开发产品特性的思路。

浅谈中学化学课程资源的开发策略

新课程标准下的化学课程资源的开发与利用,使化学课程由狭变广、由静转动。化学课程资源不再只限于教材,而是教材、教师、学生、学校、社会的有机整合。本文拟从化学课程资源的界定、化学课程资源开发的特性、化学课程资源开发的策略方面进行一些探讨。

贵州黔东南地区侗族传统食品——虾酱的研究与开发

虾酱是贵州省黔东南自治州侗民族传统腌制食品,集甜、酸、辣、香、咸为一体,味道鲜美。通过对虾酱的微生物种类及化学成分测定分析,阐述了风味物质的形成机理及营养成分特点,探讨了虾酱的贮藏特性及开发利用价值。

浅议农村化学乡土课程资源的开发策略

农村地区尽管教育条件薄弱，但却蕴藏着丰富的乡土资源。化学教师应结合学科特点，努力寻找乡土知识与化学教学的结合点，挖掘农村化学教学中学生最需要的化学乡土知识，积极争取政策支持，转变角色，勇于开发、善于开发，并有效引导学生应用于化学学习中，提高学生对化学学习的浓厚兴趣和热爱家乡的情感。

Distribution, Development and Utilization of Bioactive Components Resources of Russian Melilotus officinalis

To confirm the content and distribution of bioactive components in roots, stems, leaves and grains of Russian Me/i/otus officina/is ＇Sligen 1 ＂, an experiment involving bioactive components detection and field planting was conducted. Kjeldahl method and high performance gas chromatography were used to detect the protein. The automatic amino acid analyzer was used to detect amino acid. Gas chromatography-mass spectrometry （GC-MS） and molecular distillation apparatus were used to confirm the fatty acid content. Gravimetric method was used to detect saponin and alkaloid contents. High performance liquid chromatography was used to detect the coumarin content. The polyphenol content was determined by forint reagent colorimetric method. Anthracene copper-sulfuric acid colorimetry was used to detect the polysaccharide, and aluminum nitrate-sodium nitrite-sodium hydroxide col- orimetric method was used to confirm flavone. The results showed that protein and amino acid were mainly distributed in leaves and seeds. The fatty acid was mainly distributed in seeds. The saponin was mainly distributed in roots and leave. The polyphenol was mainly distributed in roots, stems and leaves. The alkaloid was mainly distributed in stems, leaves and seeds. Seeds mainly contained coumarin. M. officinalis had little polysaccharide and flavone. The total production of bioactive in- gredients was 3 016.3 kg/hm2. The output of crude protein, amino acids and fatty acids was 1 400.6, 1 246.8, 112.2, respectively. The yields of effective components saponins, alkaloids, polyphenols and coumarin were 97.0, 77.9, 41.7, 40.1 kg/hm2, respectively. After separation, extraction and purification, those components can be used as the natural ingredients to develop medicine, food, chemical and other biotechnological products.

A Multi-model Approach for Soft Sensor Development Based on Feature Extraction Using Weighted Kernel Fisher Criterion

Multi-model approach can significantly improve the prediction performance of soft sensors in the process with multiple operational conditions.However,traditional clustering algorithms may result in overlapping phenomenon in subclasses,so that edge classes and outliers cannot be effectively dealt with and the modeling result is not satisfactory.In order to solve these problems,a new feature extraction method based on weighted kernel Fisher criterion is presented to improve the clustering accuracy,in which feature mapping is adopted to bring the edge classes and outliers closer to other normal subclasses.Furthermore,the classified data are used to develop a multiple model based on support vector machine.The proposed method is applied to a bisphenol A production process for prediction of the quality index.The simulation results demonstrate its ability in improving the data classification and the prediction performance of the soft sensor.

Regional earth system modeling：review and future directions

The authors review recent advances in the development of coupled Regional Earth System Models （RESMs）,a field that is still in its early stages.To date,coupled regional atmosphere-ocean-sea ice,atmosphere-aerosol and atmosphere-biosphere models have been developed,but they have been applied onlyto limited regional settings.Much more work is thus needed to assess their transferability to a wide range of settings.Future challenges in regional climate modeling are identified,including the development of fully coupled RESMs encompassing not only atmosphere,ocean,cryosphere,biosphere,chemosphere,but also the human component in a fully interactive way.

包头市九原区休闲观光农业发展模式探讨

休闲观光农业是以生态休闲旅游为主体,把传统的农业生产和新兴的农业科技应用与游客参加农事体验活动等融为一体,是种新型的农业产业,是推进城乡一体化发展的重要载体。包头市九原区人文自然资源丰富,区域特色鲜明,发展休闲观光农业客观优势较好,近几年来发展成效明显。文章重点探讨了休闲观光农业的基本特性和开发原则以及包头市九原区休闲观光农业的发展模式。

Development of control strategy of variable speed limits for improving traffic operations at freeway bottlenecks

A control strategy of variable speed limits(VSL)was developed to reduce the travel time at freeway recurrent bottleneck areas.The proposed control strategy particularly focused on preventing the capacity drop and increasing the discharge flow.A cell transmission model(CTM)was developed to evaluate the effects of the proposed VSL control strategy on the traffic operations.The results show that the total travel time is reduced by 25.5% and the delay is reduced by 56.1%.The average travel speed is increased by 34.3% and the queue length is reduced by 31.0%.The traffic operation is improved by the proposed VSL control strategy.The way to use the proposed VSL control strategy in different types of freeway bottlenecks was also discussed by considering different traffic flow characteristics.It is concluded that the VSL control strategy is effective for merge bottlenecks but is less effective for diverge bottlenecks.

合作是关键

十二个合作者,四个时区,两个国家,一个网络。此篇文章讲述的是3Com公司利用网络为它的因特网产品开发新的网络包装的故事。在3Com公司去年年末准备推出第一套所谓网络应用软件Audrey的时候,公司就已开始通过网络对此产品进行包装设计了。在包装发行公司Santa Clara的协作下。

Relationship of atmospheric boundary layer depth with thermodynamic processes at the land surface in arid regions of China

The atmospheric boundary layer （ABL） is an important physical characteristic of the Earth＇s atmosphere. Compared with the typical ABL, the ABL in arid regions has distinct features and is formed by particular mechanisms. In this paper, the depth of the diurnal and nocturnal ABLs and their related thermodynamic features of land surface processes, including net radiation, the ground-air temperature difference and sensible heat flux, under typical summer and winter conditions are discussed on the basis of comprehensive observations of the ABL and thermodynamic processes at the land surface carried out in the extreme arid zone of Dunhuang. The relationships of the ABL depth in the development and maintenance stages with these thermodynamic features are also investigated. The results show that the depth of the ABL is closely correlated with the thermodynamic features in both development and maintenance stages and more energy is consumed in the development stage. Further analysis indicates that wind velocity also affects ABL development, especially the development of a stable boundary layer in winter. Taken together, the analysis results indicate that extremely strong thermodynamic processes at the land surface are the main driving factor for the formation of a deep ABL in an arid region.

Development and application of a neural network based coating weight control system for a hot-dip galvanizing line

The hot-dip galvanizing line(HDGL) is a typical order-driven discrete-event process in steelmaking. It has some complicated dynamic characteristics such as a large time-varying delay, strong nonlinearity, and unmeasured disturbance, all of which lead to the difficulty of an online coating weight controller design. We propose a novel neural network based control system to solve these problems. The proposed method has been successfully applied to a real production line at Va Lin LY Steel Co., Loudi, China. The industrial application results show the effectiveness and efficiency of the proposed method, including significant reductions in the variance of the coating weight and the transition time.

Raman micro-spectrometry as a technique for investigating heterogeneous reactions on individual atmospheric particles

Investigating the heterogeneous reaction on individual atmospheric particles is important because it approximates actual atmospheric conditions and can aid in reducing artifacts in elucidating real mechanisms and processes,and determining real kinetic parameters of the atmosphere relevance.This study developed a Raman microspectrometry method to investigate heterogeneous reactions on individual particles.The method was applied to the reaction of NO2 with individual CaCO3 particles.It was demonstrated that Raman microspectrometry can obtain information on both chemical composition and microscopic morphology at the same time,as well as information on chemical characteristics,such as the phase,which is useful for studying reaction processes.Raman spectra of individual particles deposited on a substrate showed no interference by morphological resonance,which is helpful for obtaining high-quality spectra.Moreover,Raman microspectrometry was compared with other methods for investigating heterogeneous reactions on individual particles and was found to have several advantageous characteristics.

Study and development of high peak power short pulse Nd:YAG laser for peening applications

Because short pulse Nd:YAG laser of nanosecond pulse-width and high peak power has a unique capability to improve the mechanical properties of metal parts,a study on the development of high peak power short pulse from Nd:YAG laser along with its peening application has been performed.The design scheme of laser and the characteristic of laser beam transmission are presented and discussed.A pulse energy of 25 J with 15 ns pulse-width and a maximum peak power of 1660 k W laser system which use one oscillation and eight amplifiers has been achieved.Laser beam has a max divergence angle of 0.03 mrad,a pulse-to-pulse pulse-width stability of±0.1 ns,and the pulse-to-pulse energy stability factors of less than±2.8%.A low value of divergence means an easier modification of a nearly hat-top laser beam intensity profile and an easier transmission of laser beam.To evaluate the performance of the laser system,several metal materials are processed.Laser peening quality and efficiency are analyzed by using an optical microscope,a transmission electron microscope,and an X-ray diffraction device.The processing results show that the performance of this laser system is excellent.

Analysis of two models for metal hot-electron power generation

Hot electron emission means that electrons move over potential barriers to come out of the metal when the metal is being heated.Obviously,voltage will generate between electrons and the metal.Based on this,the model of metal hot-electron power generation is built.Free electron model of Sommerfeld is used to describe the movement of electrons in metal.According to the different width of potential barriers,two models are built.One assumes that electrons move from one metal to another mainly by moving over the potential barrier as the barrier is wide enough.The other assumes that the potential barrier is so narrow that electrons mainly move through the potential barrier by tunnel effect.The first model is analyzed and proved strictly,including the building of model,the calculation of open-circuit voltage and the drawing of volt-ampere characteristic curve.The second model is analysed simply.This paper shows that power generation by metal hot-electron is possible based on the theory and can provide reference for researching in power generation of metal hot-electron.