为研究人字闸门支枕垫块表面冲蚀分布规律,截取部分支枕垫块模型,进行模型简化,对比分析不同粒径、质量流量、上游水压对支枕垫块冲蚀分布的影响.结果表明,人字闸门枕垫块磨损快于支垫块磨损,较大粒径沙粒冲蚀区域主要在上游缝隙入口处,中等粒径沙粒冲蚀区域分布较为均匀,较小粒径沙粒冲蚀区域主要在下游缝隙出口处;沙粒粒径对支枕垫块磨损位置分布的影响较大,质量流量与上游压力对支枕垫块磨损位置分布的影响次之.

为解决弯曲航道桥梁通航宽度计算中桥墩紊流宽度计算精度不足的问题,依据实际弯曲航道串列桥墩及其水流条件,进行模型简化,采用DES中的SST k-ω模型,利用Fluent软件对弯曲航道桥区流场进行二维模拟.通过对比弯曲航道不同弯曲半径、桥墩直径,以及来流速度的流场研究桥墩紊流宽度的变化规律.仿真结果表明:弯曲航道凸岸侧桥墩紊流宽度大于凹岸侧桥墩紊流宽度,紊流宽度随着弯曲半径的增大而减小,随着桥墩直径及来流速度的增大而增大.进而拟合得出紊流宽度的计算公式.并通过工程实例验证了改进后的紊流宽度经验公式的准确性.

三维圆柱绕流的研究主要关注仿真精度,且单圆柱尾涡结构的分析较多,对于串列三圆柱绕流特征的研究较少.使用FLUENT软件对雷诺数为2.25×106在不同间距比下串列三圆柱的湍流模型进行三维模拟.运用Gambit软件对流场进行建模,并对圆柱临近水域网格进行加密,对串列三圆柱进行三维大涡模拟(LES);取间距比L/D(L为两圆柱间的距离,D为圆柱直径)为1.0、2.0和3.0,选取三维模拟中3个不同切面高度(距离水面0、2.25和4.40 m)研究速度场、压力场和涡量场的湍流特性.结果表明:三维模拟证实了表层的涡量变化显著,在连续圆柱后存在回流区域与间距比有强相关性;同时,3个不同切面的速度场变化较小,压力场变化甚微.

船舶自身的装卸设备会对驾驶台的瞭望视野产生阻挡,从而引发了瞭望不全,导致驾引人员对周围通航环境不能及时全面掌握常引起判断错误和疏忽,进而引发事故.针对这一问题提出一种面向盲区的船舶视觉辅助瞭望方法,并设计了辅助驾驶信息可视化系统的总体框架.首先重复采集图像信息,直到搜索到正焦状态的位置,并利用视频识别技术进行识别;最后通过单目测距算法,测量出与目标船舶的距离以把握周围船舶动态.随后通过实验进行测试,结果验证了本系统能有效消除视野盲区、具有较强的适用性.

The linearity was good for antimony and arsenic determination both by AFS and ICP-MS, with correlation coefficients rang from 9995 to 1.0000. National standard materials were adopted to test and verify the precision and accuracy of the two methods,and the test results acquired were in accordance with the standard values,which showed that the two methods had high accuracy,good precision and strong comparability. Both of the methods can be used to determine arsenic and antimony in surface water sam-ples effectively. The ICP-MS is more suitable for large scale samples and multi-elemental simultaneous a-nalysis,but its cost is relatively higher.

针对长锥管状零件,介绍了一种在无旋压设备的情况下,采用模具扩胀成形的方法,简单易行,制造成本低,可供中小企业参考使用.

This paper analyzes the status of University Computer Foundation course in independent college.Combining with the educational concept of computational thinking capacity building,it proposes the teaching mode of classification of teaching,individualized teaching,and teaching with practice.It advocates the evaluation of both practice and theory,to achieve student from "passive learning" to "active learning".And it explaines the actual methods and effects of applying the reform to reality.

A kind of PCI data acquisition card is designed and realized, which can provide 2 high-speed high-precision analog signal convert channels, a CAN communication interface and a RS485 serial COM interface.

ox9 is the first member of Sox gene family which has intron fragments after the discovery of SRY gene.About 671 Sox9 gene sequences are recorded in the Genebank,which are widely distributed in many species from mammals and bird to coelenterate.Sox9 is a multifunctional gene which takes part in sex determination,chondrogenesis,formation of nervous system and pancreas.Furthermore,this gene can also play roles in oncogenesis.This paper reviews the research progress of the structure,function and evolution of Sox9,to provide references for further study on Sox9 gene.

To establish the two-dimensional electrophoresis(2-DE) proteomic analysis method of Mycoplasma bovis,we used M.bovis Hubei isolate as the experimental material to explore optimum conditions of 2-DE such as sample preparation,immobilized pH gradients,sample volume and staining.On 13 cm IPG strip(pH 4-7) for 400 μg M.bovis proteins extacted by 2D-Clean-up kit,we obtained 2-DE of high resolution and repeatability.The 2-DE could show the most protein spots that we were interested in,then these protein spots were analyzed using the software Image Master 2D Platinum version 6.0.The results revealed that more than 800 spots were detected,and the match rate of protein spots was 80.95%.20 proteins of high repeatability selected randomly were analyzed using mass spectrometry,and the peptide mass fingerprints of 19 proteins were successfully obtained with appraisal rate of 95%.Compared mass spectrum identification results with self-built M.bovis protein library,12 different proteins of matching rate higher than 82(P0.05) were obtained and they were mostly enzymes.In conclusion,this technology platform could be effectively used in the M.bovis proteomics investigation.

The oilfield water injection corrosion inhibitor was synthesized by reacting different long-chain fatty acids with tetraethylenepentamine, and the optimal synthetic conditions were obtained using orthogonal experiment method. Static coupon weight loss method was adopted to evaluate the inhibitor performance and the effects of the temperature and concentration on the performance were studied. The results showed that the corrosion inhibitor had good performance at the conditions of concentration as 800 mg/L and relatively low temperature.

Monitoring the rainfall runoff in the downstream trunk of combined sewer network in Beijing old district was selected to analyze the variation of the water quality which blended the runoff and the sanitary sewage,providing data for controlling the pollution in combined sewer network.The results showed that the pollution has got a high degree in Beijing's combined sewer network.The rainfall intensity,collection process in sewers,pollution characteristics of the surface runoff and the wash-off processes of the in-sewer pollution stocks can affect the non-point source pollution process in combined sewer network.

Sox9 gene can take part in many physiological activities of gene regulations.Its most important role is involved in sex determination.The molecular mechanisms of sex determination and differentiation regulated by Sox9 gene in different species are reviewed,which is expected to provide reference materials for further study on sex determination and differentiation of Sox9 gene.

Mycoplasma bovis is the causative agent of M.bovis-associated disease(MbAD).While the mechanisms by which M.bovis adherent host cells is remain unclear,our recent study provided that M.bovis express variable surface lipop proteins(Vsps) is facilitated it invasion and dissemination in the infected host and speculated that there are other adhesion-related factors in existence of M.bovis.We cloned and expressed a novel gene of M.bovis,designate P18,which express a profibrinolysin binding protein according to the domain sequence analysis binding test.The P18 gene express a 67 ku recombinant protein.The recombinant P18 protein were detected by SDS-PAGE and confirmed by western blot with positive serum.There fore,we conjectured that P18 protein is one of M.bovis adhesion-related factors.

A new film sensor using PVDF film as sensing element was developed to measure the contact stress,which overcame two weaknesses as follows:when calculating blank holder force by hydraulic pressure,the accuracy of transmission link was reduced;when researching the blank holder force,the difference of contact stresses caused by different contact areas were ignored.The fineblanking process of H62 sheet with thickness of 0.65 mm was testet by the developed stress sensor.The results show that the existing of contact stress is performed in the two waves with exponential decay after the peak,the contact stress rises as the result of the increase in metal flow resistance caused by the V-shaped tooth being pressed into sheet.

Infection by Mycoplasma bovis (M. bovis) can induce diseases, such as pneumonia and otitis media in young calves and mastitis and arthritis in older animals. Here, we report the finished and annotated genome sequence of M. bovis strain Hubei-1, a strain isolated in 2008 that caused calf pneumonia on a Chinese farm. The genome of M. bovis strain Hubei-1 contains a single circular chromosome of 953,114 bp with a 29.37% GC content. We identified 803 open reading frames (ORFs) that occupy 89.5% of the genome. While 34 ORFs were Hubei-1 specific, 662 ORFs had orthologs in the M. bovis type strain PG45 genome. Genome analysis validated lateral gene transfer between M. bovis and the Mycoplasma mycoides subspecies mycoides, while phylogenetic analysis found that the closest M. bovis neighbor is Mycoplasma agalactiae. Glycerol may be the main carbon and energy source of M. bovis, and most of the biosynthesis pathways were incomplete. We report that 47 lipoproteins, 12 extracellular proteins and 18 transmembrane proteins are phase-variable and may help M. bovis escape the immune response. Besides lipoproteins and phase-variable proteins, genomic analysis found two possible pathogenicity islands, which consist of four genes and 11 genes each, and several other virulence factors including hemolysin, lipoate protein ligase, dihydrolipoamide dehydrogenase, extracellular cysteine protease and 5'-nucleotidase.

By single factor and orthogonal experiment the optimum corn cob pretreated technology was confirmed,and provided carbon sources for ethanol fermentation of S.cerevisiaee.In this paper,dilute sulfuric acid combined with high temperature and pressure,high temperature and pressure,dilute sulfuric acid combined with microwave and dilute sulfuric acid combined with ultrasonic pretreated corn cob.The results showed that 1% of dilute sulfuric acid and the corn cob in the case of 10:1 at 121℃ high-temperature processing 3 hours was the best treatment solution,and the reducing sugar concentration was up to 36.38mg/ml.

Objective:To evaluate the kinetic models of Absidia coerulea producing low molecular chitosan(LMC) in Batch fermentation.Method:Absidia coerulea was cultured in 10L fermentor,and then the data of cell growth,product formation and substrate consumption were analyzed.Based on the Logistic and Luedeking-Piret equations,the mathematic models of cell growth,LMC production and substrate consumption were developed to describe the Absidia coerulea fermentation process.The parameters of the models were fitted by 1stOpt software using non-linear fitting techniques.Result:The mathematic models and the parameters of cell growth,LMC production and substrate consumption were made and the fitting degree was 0.994,0.986 and 0.992 respectively.Conclusion:The results showed the production of LMC was growth-associated and the process of Absidia coerulea fermentation was well reflected by the mathematic models of cell growth,LMC production and substrate consumption.

<正>小模数内齿轮精密冲压工艺及多工位级进模具设计中的技术难点,包括工位设计、排样图设计、步距精度计算、模具结构设计及关键零件设计等关键技术。笔者公司采用固定凸模式精密冲裁连续模,保证了条料准确定位和送料顺畅,实现了冲裁过程的自动化。

The damage mechanism and intensity of Anti-Radar Missile(ARM) to the surface-to-air missile guidance radar were analyzed,and the relevant mathematical models and calculation methods were put forward.The function and structure of the surface-to-air missile guidance radar were analyzed,and the damage mechanism of fragmentation warheads was deduced out.Then,the damage effect model was established based on fragment damage process.The systematic equivalent target thickness expression was built up taking comprehensive consideration of ultimate strength and shear stress.The guidance radar critical part damage model was established based on fuzzy theory,and the damage probability of guidance radar was calculated out.The models have fine hierarchy and are convenient for computer implementation.The study will establish a basis for research on the operational efficiency of anti-radar missiles.