A Transport Protocol and Its Formal Description for Local Networks

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Investigation and Research on Auto-Aiming of Self-Propelled Gun

1IntroductionWhenself-propelledgunmovesontofiringsite,itsplatformmayslopetowardgroundplane.Atthisplace,whelltheplatformparalleltogroundplane,llorizontalangleofself-propelledgullshootingis;andillclinatiollis7'.Whellplatformillclilletowardgroundplane,howtodeterminethehorizolltalanglealldelevatiollmadebybarreltoplatfornlisabasicproblemt'.hiclllustbesolvedforauto-ainlofself-propelledgun.Asaresultofresearch.mathematicalmodelissetupallddetailedsolutiollisprovided.2BasicModelandSolutionwhenplatfor…     

A Multiple Intelligence Man-Machine System for Production Management through Hierarchical Cooperation in Mining District

1IntroductionThekeylinksintheproductioninminingdistrictarecoalmininganddrivillg,whichareaffectedbynaturalconditions(suchasgeologicalcondition,occurrenceofcoalseam),technologicalconditions(suchasequipmentsformining),rawmaterialsprovided,marketsforcoal,man-madeandsocialfactors.Thekeysintheproductionmanagementarecompilingproductionplanandoperatingschedule.Becausetherearethedynamicandthestochasticbehaviourintheproductionresultingfi.omthevaritiesofthenatualconditionsandtheexternalsllrroundingsthata…     

Evaluating the Tourism Resources' Development by AHP

1IntroductionAseveryoneknobes,tollrisnlistheworldwidefavoriterecreatiollalactivitiesillnloderllsociety.TOurisnlproducesalotofjobopportunitiesandstaterevPllue.IllmodernChina,thereareplentyofscellicsports,historicalsitesandundevelopedPotentialtourismresources.Hoal'tomostutilizetheseexistingandUlldevelopedPotentialtourislllresollrceadvalltageoustotilenationalandregionaleconomyisamostimportantstrategicproblemtotheleadersofregionalornationaltourismdepartment,governmentofChina.Thedevelopmentofto…     

A relevant in vitro rat model for the evaluation of blood-brain barrier translocation of nanoparticles

Poly(MePEG₂₀₀₀cyanoacrylate-co-hexadecylcyanoacrylate) (PEG-PHDCA) nanoparticles have demonstrated their capacity to reach the rat central nervous system after intravenous injection. For insight into the transport of colloidal systems across the blood-brain barrier (BBB), we developed a relevant in vitro rat BBB model consisting of a coculture of rat brain endothelial cells (RBECs) and rat astrocytes. The RBECs used in our model displayed and retained structural characteristics of brain endothelial cells, such as expression of P-glycoprotein, occludin and ZO-1, and immunofluorescence studies showed the specific localization of occludin and ZO1. The high values of transendothelial electrical resistance and low permeability coefficients of marker molecules demonstrated the functionality of this model. The comparative passage of polyhexadecylcyanoacrylate and PEG-PHDCA nanoparticles through this model was investigated, showing a higher passage of PEGylated nanoparticles, presumably by endocytosis. This result was confirmed by confocal microscopy. Thanks to a good in vitro/in vivo correlation, this rat BBB model will help in understanding the mechanisms of nanoparticle translocation and in designing new types of colloidal carriers as brain delivery systems.Received 4 March 2005; accepted 14 April 2005     

Copper and zinc dismetabolism in the mouse brain upon chronic cuprizone treatment

Recent reports describe successful treatment using copper chelation therapy in neurodegenerative animal models. However, the success claimed for chelation therapy in neurodegenerative diseases is still rather controversial. To acquire new information on copper metabolism/homeostasis, we utilized cuprizone, a very sensitive and selective copper-chelating agent with well-known neurotoxic properties, as a relevant chemical model in mice. Upon cuprizone treatment, mice developed a pronounced astrocytosis, with brain oedema and spongiosis characterised by vacuolisations of the neuropil predominantly in the white matter. In addition, cuprizone treatment severely altered copper and zinc homeostasis in the central nervous system (CNS) as well as in all other tissues examined, with increasing metal ion concentrations particularly in the CNS. Concomitant with this increase in the Cu and Zn concentration in the brain, metallothionein-I and -II were also highly immunoreactive in astrocyte, consistent with the astrocytosis and demyelination observed in our and other laboratories.Received 23 February 2005; received after revision 3 May 2005; accepted 13 May 2005     

均相湍流动力学

本书汇集了均相湍流动力学相关的最新理论、计算和实验结果,内容涉及各向异性流动、波主导的流动和可压缩湍流的流动,还包括旋转、分层、剪切、激波和声波等的相互作用,对于每一种情况,均用计算和实验结果来说明,包括线性理论和非线性理论的结果。这些成果对宇航工程、天体物理学和地球科学是相当有用的。     

珠穆朗玛峰东绒布冰芯1800 AD以来的火山活动记录

通过元素Bi的含量, 研究了珠穆朗玛峰东绒布冰芯记录的1800 AD以来的9次强火山活动的信号. 结果表明, 东绒布冰芯中Bi含量的变化对关键区域的强火山活动有很好的记录, 这为山地冰芯定年提供了很好的标志层, 并为开展更长时间序列的山地冰芯火山记录研究提供了基础.     

早期海绵的四辐射对称性

目前学术界对最古老后生动物门类的分支序列及系统演化仍没有共识,但大多数学者都深信海绵动物是最早分支的后生动物.现生海绵部分属种有似辐射对称、少部分有顺轴旋系对称,因此,海绵被认为是在真后生动物发育特征,如有明确的轴性对称出现之前演化的动物.其他早期后生动物门类有两侧对称、四辐射对称(刺胞动物门)、二辐射对称(栉水母门)或是没有对称轴性(扁盘动物门).本研究报道了来自华南寒武系荷塘组具有四辐射对称结构的海绵化石,并且从已报道的柱状海绵化石中鉴别出前人所忽略的四辐射对称结构.本研究指出四辐射对称是海绵的原始特征,并且推测最早的海绵始祖应该是由基因控制、外形规整、细胞结构交织而成的个体.     

Jaws and teeth of the earliest bony fishes

Extant jawed vertebrates, or gnathostomes, fall into two major monophyletic groups, namely chondrichthyans (cartilaginous fishes) and osteichthyans (bony fishes and tetrapods). Fossil representatives of the osteichthyan crown group are known from the latest Silurian period, 418 million years (Myr) ago, to the present. By contrast, stem chondrichthyans and stem osteichthyans are still largely unknown. Two extinct Palaeozoic groups, the acanthodians and placoderms, may fall into these stem groups or the common stem group of gnathostomes, but their relationships and monophyletic status are both debated. Here we report unambiguous evidence for osteichthyan characters in jaw bones referred to the late Silurian (423-416-Myr-old) fishes Andreolepis hedei and Lophosteus superbus, long known from isolated bone fragments, scales and teeth, and whose affinities to, or within, osteichthyans have been debated. The bones are a characteristic osteichthyan maxillary and dentary, but the organization of the tooth-like denticles they bear differs from the large, conical teeth of crown-group osteichthyans, indicating that they can be assigned to the stem group. Andreolepis and Lophosteus are thus not only the oldest but also the most phylogenetically basal securely identified osteichthyans known so far.