220 research outputs found
东山在闽台旧石器时代文化交流中的地位
依据东山岛发现的306件石制品、东山海域发现的170件哺乳动物化石和“东山人”化石以及台湾海峡第四纪沉积物特征,结合分析台湾第四纪哺乳动物化石、旧石器和人类化石,从古生物、古人类、古文化、海平面变化诸方面阐述东山在闽台旧石器时代文化交流中的地位,认为漳州是古人类、哺乳动物迁徙台湾的出发地,东山是桥头堡,“东山陆桥”是连接大陆与台湾的纽带
The metabolic profilings study of serum and spinal cord from acute spinal cord injury rats ^1H NMR spectroscopy
目的:采用-1H NMR核磁共振代谢组学的方法研究急性脊髓损伤模型大鼠的代谢组学特征及生物标志物,探讨核磁共振代谢组学应用于脊髓损伤研究的可行性。方法:取8周龄清洁级雄性SD大鼠20只,体重(200±10)g,按照随机数字法分为假手术组和模型组,每组10只,模型组采用改良的Allens法制作急性脊髓不完全损伤模型,假手术组不损伤脊髓,术后第1、5、7天采用BBB运动功能评分法进行行为学观察,术后第7天收集脊髓组织作病理学观察,核磁共振代谢组学对两组大鼠血清和脊髓样本进行代谢组学分析。结果:BBB评分显示假手术组术后后肢运动无明显改变,各时间点差异无统计学意义,模型组大鼠术后双下肢呈迟缓性瘫痪,BBB运动评分较低,各时间点差异存在统计学意义,两组运动功能评分在各时间点的差异均有统计学意义;病理切片显示假手术脊髓结构正常,神经分布均匀,模型组脊髓组织结构紊乱,神经元数目减少,存在炎性细胞浸润和空腔坏死组织。代谢组学分析表明,血清中极低密度脂蛋白(VLDL)、低密度脂蛋白(LDL)、谷氨酰胺(glutamine)、柠檬酸(citrate)、二甲基甘氨酸(DMG)等物质和脊髓中谷胱甘肽(glutathione)、3-羟基丁酸(3-OH-butyrate)、N-乙酰天冬氨酸(NAA)、磷酸胆碱(GPC)、谷氨酸(glutamate)、抗坏血酸(ascorbate)等物质浓度有明显变化(P〈0.05)。结论 :通过对假手术组和模型组大鼠血清和脊髓样本进行代谢组学检测和分析得到了两组样本的差异性代谢物质,有助于解释急性脊髓损伤后血清和脊髓组织中的特异性小分子物质的变化规律,为后期针对性地研究这些代谢标记物在急性脊髓损伤中的作用提供研究基础。Objective: To establish the rat model of acute spinal cord injury,followed by aprimary study on this model with 1H NMR based on metabonomics and to explore the metabonomics and biomarkers of spinal cord injury rat.Methods: Twenty eight-week-old adult male SD rats of clean grade,with body weight of (200±10) g,were divided into sham operation group and model group in accordance with the law of random numbers,and every group had 10 rats. The rats of sham operation group were operated without damaging the spinal cord,and rats of model group were made an animal model of spinal cord incomplete injury according to the modified Allen's method. According to BBB score to observate the motor function of rats on the 1th,5th,and 7th days after surgery. Postoperative spinal cord tissue was collected in order to pathologic observation at the 7th day,and the metabolic profilings of serum and spinal cord from spinal cord injury rats were studied by 1H NMR spectroscopy.Results: The hindlimb motion of rats did not obviously change in sham operation group,there was no significant difference at each time point;and rats of model group occurred flaccid paralysis of both lower extremities,there was a significant difference at each time; there was significant differences between two groups at each time. Pathological results showed the spinal cord structure was normal with uniform innervation in shame group,while in model group,the spinal cord structure was mussy,and the neurons were decreased,with inflammatory cells and necrotic tissue. Analysis of metabonomics showed that concentration of very low density fat protein (VLDL),low density fat protein (LDL),glutamine,citric acid,dimethylglycine (DMG) in the serum and glutathione,3-OH-butyrate,N-Acetyl-L-aspartic acid (NAA),glycerophosphocholine (GPC),glutamic acid,and ascorbate in spinal cord had significant changes(P〈0.05).Conclusion: There are significant differences in metabolic profile from serum and spinal cord sample between model group and sha浙江省自然基金(编号:LY15H270003);浙江省中医药科技计划项目(编号:2015ZZ017
Application of Hierarchical Modeling and Analysis Method in C4ISR System
C4ISR系统是一个规模庞大、层次分明的离散动态系统,文章提出了一种面向C4ISR系统的UML和Petri网结合的建模分析方法。该方法采用从上到下的层次分析方法,用扩展的UML模型对系统组织结构和系统的静态特征进行描述,用扩展的Petri网模型描述和分析系统动态特性,通过相应的规则将Petri网模型转化成状态图和序列图。新方法可以对系统要求进行验证,同时还可以编程实现。最后通过该方法,对一个C4ISR系统进行了建模分析。C4ISR system is a discrete dynamic system with large scale and clearly hierarchy,this paper presents the modeling and analysis method combining UML with Petri net for C4ISR system.This approach adopts a hierarchical analytical method with top-down techniques,describes the whole systemic structure and static property through extended UML model,shows systemic dynamic characteristic using extended Petri net then transforms to the correspondence state diagram and sequence diagram.New methods verify system requirement and easily realize its code.At last the approach is illustrated by its application to C4ISR system.国家“十五”计划基金资助项目(40405010101C
垃圾焚烧炉氧量调整试验
随着我国城镇化建设的稳步推进,各类生活垃圾的产生量也在快速增加。垃圾焚烧发电技术具有无害化和资源化等特点,是我国城市生活垃圾处理的重要发展方向。焚烧炉内氧量的调整直接影响垃圾的着火、燃烧及燃尽情况,以余热锅炉省煤器出口的实测氧量为依据,分别分析炉内氧量的变化对余热锅炉主蒸汽参数、垃圾燃尽情况和污染物排放等的影响,为垃圾焚烧电厂科学调节炉内氧量,实现焚烧炉的高效、环保和安全运行提供重要的技术支撑
Effect of Calcination Temperature on the Structure and Catalytic Performance of K_2WO_4/Al_2O_3 Catalysts for Methanethiol Synthesis
通讯联系人. 电话/传真: (0592)2182368; 电子信箱: [email protected][中文文摘]研究了焙烧温度对溶胶-凝胶法制备的甲硫醇催化剂K2WO4/Al2O3的表面结构和催化性能的影响.表征结果显示,K2WO4在Al2O3上分散得较好,在450和550oC焙烧的催化剂颗粒大小均匀,无明显团聚现象.随着焙烧温度的升高,催化剂的比表面积减小,表面钨物种与Al2O3的相互作用减弱,与碱物种的相互作用增强,酸碱强度降低.K2WO4/Al2O3表面不含质子酸.催化剂活性与其比表面积及表面的共轭酸碱对密切相关.评价结果表明,在550oC焙烧而制得的催化剂活性最高.[英文文摘]The effect of calcination temperature on the surface morphology and catalytic performance of the K2WO4/Al2O3 catalyst prepared by the sol-gel method for the synthesis of methanethiol from methanol and hydrogen sulfide was investigated.Physicochemical characterization results of the catalyst showed that the K2WO4 is well dispersed on Al2O3,and the catalyst possesses uniform particle size after calcination at 450 or 550 oC.With increasing the calcination temperature,the specific surface area decreases,the interaction of W species with Al2O3 was weakened, but strengthened with basic species, leading to the decrease of surface acidity and basicity. No Brönsted acid was found on the catalyst surface. The catalytic activity of the catalyst is closely related with the specific surface area and the presence of conjugate
acid-base pairs on the surface. Activity assay results show that the catalyst calcined at 550 oC exhibits the highest activity for the reaction.重庆紫光化工股份有限公司的经费资
焙烧温度对甲硫醇催化剂K_2WO_4/Al_2O_3结构和性能的影响
研究了焙烧温度对溶胶-凝胶法制备的甲硫醇催化剂K2WO4/Al2O3的表面结构和催化性能的影响.表征结果显示,K2WO4在Al2O3上分散得较好,在450和550oC焙烧的催化剂颗粒大小均匀,无明显团聚现象.随着焙烧温度的升高,催化剂的比表面积减小,表面钨物种与Al2O3的相互作用减弱,与碱物种的相互作用增强,酸碱强度降低.K2WO4/Al2O3表面不含质子酸.催化剂活性与其比表面积及表面的共轭酸碱对密切相关.评价结果表明,在550oC焙烧而制得的催化剂活性最高
低温胁迫对长苞铁杉幼苗的生理影响
经模拟低温(-12、-8、-4、0、4℃)胁迫处理后,长苞铁杉幼苗叶片和根系相关生理指标均发生明显变化.随着温度降低,叶片光合色素含量增加,但反映光合活性强弱的Chla/Chlb降低;叶片中渗透调节物质脯氨酸和可溶性糖含量增加,呈极显著正相关(r=0.804,p<0.01),根系中可溶性糖含量的减少说明根对低温胁迫的渗透调节更依赖于脯氨酸的累积.幼苗在-4℃及更低温度胁迫下受到严重的冻害使SOD活性持续下降,叶片中POD活性与SOD活性变化呈极显著负相关(r=-0.908,p<0.01),但根系中POD活性与SOD活性没有相关性,说明长苞铁杉幼苗对抗外界胁迫机理的复杂性.叶片MDA含量比根系低可能与叶片中Car能缓解1O2对细胞的伤害有关
船舶压舱水引入外来藻类的危害及监测
船舶压舱水是外来海洋生物入侵的主要媒介之一,是造成有害赤潮藻类世界范围的传播蔓延的重要原因。有害藻类的引入对当地的生态系统和经济已造成严重和深远的影响,是植物检疫的盲区。本文论述了压舱水引入外来藻类尤其是有害藻造成危害的问题和检疫技术。以引起有关部门的重视,解决压舱水藻类检测和检疫处理问题
鼻咽癌筛查成本效果的初步分析
目的:评价鼻咽癌新筛查方案的成本和效果。方法:在鼻咽癌高发区中山市进行鼻咽癌筛查,统计癌检出率、早诊率、人均筛查成本、发现早期病例平均费用和早期发现成本系数等指标。结果:共筛查16 712人,确诊鼻咽癌25例,检出率149.59/10万,早诊率76.0%,治疗率100.0%。筛查成本41.56元/人,发现病例费用27 779.82元,发现早期病例费用36 552.40元,按我国人均GDP计算,早期发现成本系数(EDCI)为1.71,按中山市人均GDP计算,EDCI为0.65。结论:相对常见恶性肿瘤鼻咽癌筛查成本较高,但在高发区筛查可以显著提高早诊率,并降低治疗费用
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