Macro-decision-making on Phase I Construction of the Three Gorges Project (TGP)

1AchievementsinCon structionofPhaseⅠTGPworks　TheTGPConstructionCommitteeun dertheStateCouncilapprovedthePre liminaryDesignReportoftheYangtzeThreeGorgesProjectonJuly 31 ,1 993.whenTGPenteredaphaseofprepara tionsforconstructionandphaseⅠworks.Bytheendof1 997,theprojecthadprogressedsmoothlyandthetaskforPhase 1workshadbeencompleted ,whichwashighlightedbytheriverclo sureoftheGrandChannel,providingfullpreparationforPhase 2construc tion .　ThededicatedaccessexpresswayandtheXilingYangtze…     

5-取代芳氧基-3-戊炔-2-醇的合成研究

研究了3－芳基丙炔基醚（硫醚）的加成反应，区域选择性，高产率获得一系列的5－芳氧基－3－戊炔－2－醇，反应的关键是使用了由炔与乙基溴化镁制备而成的端基炔格氏试剂。     

用于定容储存天然气的活性炭吸附剂的研制

用循环活化法制备了用于天然气定容储存的活性炭吸附剂。考察了活性炭的失重率、堆密度、比表面、孔径分布及灰分含量随活化次数的增加而变化的情况。提出了对于定容吸附储存,吸附剂比表面大小的比较应以单位体积吸附剂的比表面为基准。     

Strong convergence rate of a kind of Pickandstype estimator

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Accuracies of Global Land Cover Maps Checked against Fluxnet Sites

Global land cover data products are key sources of information in understanding the complex interactions between human activities and global change. They play a critical role in improving performances of ecosystem, hydrological and atmospheric models. Three freely available global land cover products developed in the United States are popularly used by the scientific community. These include two global maps developed separately by the United States Geological Survey （USGS） and the University of Maryland （UMD） with NOAA Advanced Very High Resolution Radiometer （ AVHRR ） data, and one developed by Boston University with the EOS Moderate Resolution Imaging Spectroradiometer （ MODIS） data. They are compared with known land cover types at 250 available Fluxnet sites around the world. The overall accuracies are 37%, 36% and 42%, respectively for the USGS, UMD and Boston global land cover maps, Some future global land cover mapping strategies are suggested.     

Origin of Gymnocypris przewalskii and phylogenetic history of Gymnocypris eckloni (Teleostei: Cyprinidae)

The origins and phylogenetic patterns were assessed for G. przewalskii and G. eckloni by analyzing the complete mtDNA cytochrome b gene sequence (1140bp). Phylogenetic analyses further supported that there were three mtDNA lineages (A-C) identified in G. przewalskii and G. eckloni, demonstrating that outer rakers of the first gill have little significance in the phylogeny of the Gymnocypris fishes. The network established showed that G . eckloni of the Yellow River specific haplotype Al was a founder and it radiated all haplotypes of G. przewalskii which suggested G . przewalskii might only originate from one of two maternals of G . eckloni from the Yellow River. Fs test and mismatch analysis showed at least two expansion events in the population of G. przewalskii about 0.2734 Ma and 0.0658 Ma, while G. eckloni from Qaidam Basin could have experienced severe bottleneck effect about 0.0693 Ma. The population expansion was detected in subclades Al and A21 with the most recent common ancestor (TMRCA) about 0. 2308±0.01 Ma and 0.1319±0. 015 Ma, respectively, which were within the geological age range of "Gonghe Movement" event that caused the separation of Lake Qinghai from the upper Yellow River. These results suggested the effect of the fish diversification by rapid uplift of the Qing-hai-Tibetan Plateau in the Late Pleistocene.     

The timing of graphic, phonological and semantic activation of high and low frequency Chinese characters: An ERP study

Two event-related potential (ERP) experiments were performed to compare the time course of graphic, semantic and phonological activation of high and low frequency Chinese characters. In Experiment 1, for high frequency materials, graphic priming produced smaller P200 and N400, while semantic priming produced smaller N400 only, but there were no homophonic priming compared to unrelated pairs. In Experiment 2, for low frequency materials, graphic priming produced a smaller P200 and N400, homophonic priming produced an increased P200 and smaller N400 and semantic priming produced a moderately reduced N400 compared to unrelated pairs. The results suggest that there are some differences of activating lexical information of high and low frequency Chinese characters. Graphic activation emerges first, regardless of frequency. For high frequency characters, semantic activation was found, but there is no phonological activation. Whereas for low frequency characters, phonological activation emerges before semantic activation.     

Cooling hot rolling steel strip using combined tactics

The coiling temperature control of a typical steel strip mill was investigated. Due to the high speed of a strip and complex circumstance, it is very hard to set up a cooling model with high accuracy. A simplified dynamic model was proposed, based on which a cooling control scheme with combined feedforward, feedback and adaptive algorithms was developed. Meanwhile, the genetic algorithms were used for the optimization of model parameters. Simulations with a model validated using actual plant data were conducted, and the results have confirmed the effectiveness of the proposed control methods. At last, a simulation system for coiling temperature control was developed. It can be used for new product trials and newcomer training.     

Thickness of compound layer in steel-aluminum solid to liquid bonding

The bonding of solid steel plate to liquid aluminum was studied using rapid solidification. The surface of solid steel plate was defatted, descaled, immersed (in K₂ZrF₆ flux aqueous solution) and stoved. In order to determine the thickness of Fe-Al compound layer at the interface of steel-aluminum solid to liquid bonding under rapid solidification, the interface of bonding plate was investigated by SEM (Scanning Electron Microscope) experiment. The relationship between bonding parameters (such as preheat temperature of steel plate, temperature of aluminum liquid and bonding time) and thickness of Fe-Al compound layer at the interface was established by artificial neural networks (ANN) perfectly. The maximum of relative error between the output and the desired output of the ANN is only 5.4%. From the bonding parameters for the largest interfacial shear strength of bonding plate (226℃ for preheat temperature of steel plate, 723℃ for temperature of aluminum liquid and 15.8 s for bonding time), the reasonable thickness of Fe-Al compound layer 10.8 μm was got.