检索结果-南通市图书馆

Effect of electromagnetic stirring on solidification structure of austenitic stainless steel in horizontal continuous casting

在线全文

学校读者我要写书评

暂无评论

China Foundry 2007年第3期4卷 198-201页

作者： ZHOU Shu-cai LI Hua-ji RAO Jin-song REN Zheng-de zhang jie-xin YANG Zhi-li School of Metallurgy and Material Engineering Chongqing University of science and technology Chongqing 400050 College of Mechanical Engineering Chongqing University Chongqing 400044 Steel Smelting Plant Chongqing Iron ＆ steel Co. Ltd. Chongqing 400081 China

An investigation on the influence of low frequency rotary electromagnetic stirring on solidification structure of austenitic stainless steel in horizontal continuous casting was experimentally conducted and carried out on an industrial trial basis. The results show that application of appropriate electromagnetic stirring parameters can obviously improve the macrostructure of austenitic stainless steel, in which both columnar and equiaxed grains can be greatly refined and shrinkage porosity or cavity zone along centerline can be remarkably decreased due to eliminating intracrystalline and enlarging equiaxed grains zone. The industrial trials verify that the electromagnetic stirring intensity of austenitic stainless steel should be higher than that of plain carbon steel. Electromagnetic stirring has somewhat affected the macrostructure of austenitic stainless steel even if the magnetic flux density of the electromagnetic stirring reaches 90 mT （amplitude reaches 141 mT ） in average at frequency f=3-4Hz, which provides a reference for the optimization of design and process parameters when applying the rotary electromagnetic stirrer.

关键词： horizontal continuous casting austenitic stainless steel electromagnetic stirring equiaxal grain center porosity

Safety and efficacy of intravenous esmolol before prospective electrocardio- gram-triggered high-pitch spiral acquisition for computed tomography coro- nary angiography

在线全文

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2014年第1期11卷 39-43页

作者： Jin-Da WANG Hua-Wei zhang Qian xin Jun-jie YANG Zhi-Jun SUN Hong-Bin LIU LianCHEN Luo-Shan DU Yun-Dai CHEN Department of Cardiology Chinese PLA General Hospital 28 Fuxing Road Beijing 100853 China

Background In order to acquire a high quality image with a low radiation dose, prospective electrocardiogram （ECG）-triggered computed tomography coronary angiography （CTCA） requires a stable heart rate （HR）〈 65 beats/min. Esmolol has the advantage of reduc-ing HR. The objective of this article is to assess the value of intravenous esmolol treatment before prospective ECG-tr/ggered high-pitch spiral acquisition for CTCA. Methods From March 2013 to June 2013, 313 patients underwent prospective ECG-triggered CTCA. Two hundred and thirty two of them received esmolol before angiography. We retrospectively analyzed clinical characteristics, esmolol dose, radiation exposure dose, and the change in HR and blood pressure in these 232 patients. Results A total of 232 patients with a HR 〉 65 beats/rain before CTCA examination received intravenous esmolol treatment （mean dose of 57.26±15.39 rag）, The mean initial HR （HR1）, slowest HR （HR2）, and the HR 30 min after HR2 （HR3） were 75.06± 5.59, 60.75 ±4.00, and 75.54 ± 5.96 beats/min, respectively （HR1 vs. HR2, P 〈 0.0001; HRI vs. HR3, P = 0.377）. The mean time from esmolol administration to HR2 was 24.25 ± 4.97 s and the mean effective radiation dose was 2.28 ± 0.02 mSv. Conclusions HR could be rapidly controlled at an optimum level with intravenous esmolol before prospective ECG-triggered high-pitch spiral acquisition for CTCA. Consequently, the patients received a very low radiation dose.

关键词： Esmolol Electrocardiogram Coronary angiography Heart rate

在线全文

学校读者我要写书评

暂无评论

工程机械零件离散复杂曲面求交算法

长安大学学报（自然科学版） 2007年第5期27卷 116-119页

作者：张接信吴坚长安大学工程机械学院陕西西安710064

针对离散多样化的工程机械复杂零件,为快速准确地描述其曲面特征,提出了一种隐式曲面之间的求交方法。将其中的一个隐式曲面离散成许多三角面片,判断每个三角面片是否与另一个隐式曲面相交,求出交线,所有交线构成了隐式曲面之间的交线;... 详细信息

针对离散多样化的工程机械复杂零件,为快速准确地描述其曲面特征,提出了一种隐式曲面之间的求交方法。将其中的一个隐式曲面离散成许多三角面片,判断每个三角面片是否与另一个隐式曲面相交,求出交线,所有交线构成了隐式曲面之间的交线;进一步给出了一种交点的精确计算方法,使所得交线更加准确。试验结果表明:该方法迅速准确地描述了复杂曲面的特征性能,简单实用,为复杂曲面的五轴联动加工提供了可靠的加工中心刀位轨迹。

关键词：机械工程零件离散复杂曲面隐式曲面相交边界

Protective effects of soybean phospholipid liposome on glutamate-induced nerve cell injury in vitro

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2007年第10期2卷 587-590页

作者： Jian ying Xiao xin zhang Yu jie Liu Department of Biochemistry Liaoning Medical UniversityJinzhou 121001Liaoning ProvinceChina

It has been previously reported that soybean phosphatide could reduce the cerebral ischemia damage obviously. Whether soybean phospholipid liposome （SPL） can protect cerebral cortical neurons cultured in vitro from glutamate （Glu）-induced neurotoxicity, particularly nerve cell membrane damage has not been fully investigated. OBJECTIVE： To study the protective effects of SPL on Glu-induced neurotoxicity of neurons in culture, and to discuss the possible mechanisms of neuroprotection. DESIGN： Randomized controlled trial. SETTING： Department of Biochemistry, Liaoning Medical University. MATERIALS： Twelve Spragne-Dawley rats, of either gender, aged 0 to 1 day, were involved in this study. Drugs and reagents： poly-L-lysine and L-glutamate were purchased from Sigma company （USA）. METHODS： The study was carried out in the Department of Biochemistry of Jinzhou Medical University from November 2004 to June 2005. Glu （ 1 X 10^- 4 mol/L ） was added to cortical neurons in injury group for 3 hours, while different concentrations of SPL （0.2, 0.4, 0.8, 1.6 g/L） were added at the same time in the SPL groups. Neurons in the normal control group were untouched. MAIN OUTCOME MEASURES： According to the instruction of reagent kit, lactate dehydrogenase（LDH） activity and nitric oxide（NO） content in the supernatant fluid of the culture medium were assayed, and the activity of nitric oxide synthase （NOS） and superoxide dismutase（SOD）, malonaldehyde （MDA） content in the neurocytes were also determined. RESULTS： ①Activities of LDH and NOS, as well as NO content in the supernatant fluid of injury group were significantly higher than those of normal control group （P 〈 0.01）. Activities of LDH and NO S, and NO content in the supernatant fluid of SPL groups were significantly lower than those of injury group （P 〈 0.01）. ②MDA content of the SPL groups was significantly lower than that of injury group （P 〈 0.01）; SOD activity of neurons in the injury group was significantly lower than that in the

关键词： soybean phospholipid liposome glutamate nerve cell culture cerebral ischemia

Transcriptional regulation of secondary metabolism and autophagy genes in response to DNA replication stress in Setosphaeria turcica

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2023年第4期22卷 1068-1081页

作者： MENG Ya-nan zhang xin-jie ZENG Fan-li ZHAI Wei-bo LI Pan HU Jing-jing XIAO Sheng-lin HAO Zhi-min CAO Zhi-yan CHEN Chuan DONG Jin-gao State Key Laboratory of North China Crop Improvement and Regulation Hebei Agricultural UniversityBaoding 071001P.R.China College of Life Sciences Hebei Agricultural UniversityBaoding 071001P.R.China Key Laboratory of Microbial Diversity Research and Application of Hebei Province School of Life SciencesHebei UniversityBaoding 071001P.R.China Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology Hebei Agricultural UniversityBaoding 071001P.R.China College of Plant Protection Hebei Agricultural UniversityBaoding 071001P.R.China

The fungal pathogen Setosphaeria turcica causes northern corn leaf blight(NCLB),which leads to considerable crop *** turcica elaborates a specialized infection structures called appressorium for maize ***,we demonstrated that the *** triggers an S-phase checkpoint and ATR(Ataxia Telangiectasia and Rad3 related)-dependent self-protective response to DNA genotoxic insults during maize ***,how the regulatory mechanism works was still largely ***,we report a genome wide transcriptional profile analysis during appressorium formation in the present of DNA replication *** performed RNA-Seq analysis to identify *** genes responsive to DNA replication *** the current work,we found that appressorium-mediated maize infection by *** is significantly blocked by S-phase checkpoint.A large serial of secondary metabolite and melanin biosynthesis genes were blocked in appressorium formation of *** during the replication *** secondary metabolite biosynthesis genes including alcohol dehydrogenase GroES-like domain,multicopper oxidase,ABCtransporter families,cytochrome P450 and FAD-containing monooxygenase were related to plant pathogen *** addition,we demonstrated that autophagy in *** is up-regulated by ATR as a defense response to *** identified StATG3,StATG4,StATG5,StATG7 and StATG16 genes for autophagy were induced by ATR-mediated S-phase *** therefore propose that in response to genotoxic stress,*** utilizes ATR-dependent pathway to turn off transcription of genes governing appressorium-mediated infection,and meanwhile inducing transcription of autophagy genes likely as a mechanism of self-protection,aside from the more conservative responses in eukaryotes.

关键词： Setosphaeria turcica appressorium secondary metabolite autophagy DNA replication stress

在线全文

学校读者我要写书评

暂无评论

从《礼记·大学》篇论王闿运的天子之学

湖南大学学报（社会科学版） 2021年第3期35卷 24-31页

作者：张鑫洁湖南大学岳麓书院湖南长沙410082

《礼记·大学》为“天子之学”,是王闿运对《礼记·大学》篇下的结论。天子之学,以修身为本。王闿运在《礼记·大学》篇中对天子修身之学的阐释,围绕修身定义、修身之法、修身目的展开。“修身”即“明明德止于至善”,只有“止于至善”... 详细信息

《礼记·大学》为“天子之学”,是王闿运对《礼记·大学》篇下的结论。天子之学,以修身为本。王闿运在《礼记·大学》篇中对天子修身之学的阐释,围绕修身定义、修身之法、修身目的展开。“修身”即“明明德止于至善”,只有“止于至善”的“明明德”,方可称为“修身”。修身始于格物,是以经世为基本认知的修身之法。天子重修身,目的在于经世之用。求贤化民与散财聚民,是天子“亲民”之治的关键。王闿运的天子之学,是在尊重天子性情差异的基础上,以经世致用为目的,政学一体的修身之学。

关键词：王闿运天子之学修身

在线全文

学校读者我要写书评

暂无评论

高速公路交通流信息时序分析

筑路机械与施工机械化 2006年第8期23卷 58-60页

作者：张接信长安大学工程机械学院陕西西安710064

在高速公路的营运过程中,新技术的不断推广与应用,特别是智能交通系统(ITS)的普遍应用与系统结合,使得交通信息系统越来越庞杂,交通状态更加难以把握,信息处理面临新的挑战。就高速公路的营运过程中如何判别交通状态,何时出现拥堵问题,... 详细信息

在高速公路的营运过程中,新技术的不断推广与应用,特别是智能交通系统(ITS)的普遍应用与系统结合,使得交通信息系统越来越庞杂,交通状态更加难以把握,信息处理面临新的挑战。就高速公路的营运过程中如何判别交通状态,何时出现拥堵问题,运用时序分析法从理论上给予分析研究,给出高速公路交通流信息系统处理的理论研究应用方向。

关键词：高速公路交通信息交通流拥堵

The effect of oxidative stress in myocardial cell injury in mice exposed to chronic intermittent hypoxia

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2010年第1期123卷 74-78页

作者： LIU Jian-nan zhang jie-xin LU gan QIU Yan YANG Di YIN Guo-yong zhang Xi-long Department of Respiratory Diseases. Key Laboratory of Human Functional Genomics of JiangsuProvince Nanjing Medical University Nanjing Jiangsu 210024China Department of Pathology Department of Cardiology Department ofRespiratory Diseases

Background Obstructive sleep apnea syndrome （OSAS） is an important risk factor for cardiovascular diseases. Chronic intermittent hypoxia （CIH） is considered to be one of the most important causes of cardiovascular diseases in OSA patients. This repeated hypoxia and reoxygenation cycle is similar to hypoxia-reperfusion injury, which initiates oxidative stress. In this study, we observed cardiocytes injury induced by CIH and the effect of N-acetylcysteine （NAC）. Methods Thirty ICR mice were randomly assigned to 3 groups： control, CIH and NAC （CIH＋NAC） groups. Malondialdehyde （MDA） and superoxide dismutase （SOD） of cardiocyte homogenates were measured. Serum lipids were measured by an instrument method. Serum cardiac troponin I （cTnl） was detected by enzyme-linked immunosorbent assays （ELISA）. Myocardium pathological sections were observed. Results （1） The SOD activity and MDA concentration of cardiocyte homogenates in the CIH group were significantly higher than in other groups （P 〈0.005）. The MDA concentration of the NAC group was lower than that of the control group （P 〈0.01）. （2） The serum cTnl concentration of the CIH and NAC groups was significantly higher than that of the control group （P 〈0.01）. （3） Serum triglyceride levels in the NAC group were lower than in the other groups （P 〈0.01）, while there were no significant differences in low density lipoprotein and high density lipoprotein among the three groups. （4） The degeneration of myocardium, transverse striation blurred, and fabric effusion were observed in tissue sections in the CIH and NAC groups. However, normal tissue was found in the control group. Conclusion The oxidative stress induced by CIH can injure cardiocytes and the injury effect can be partially inhibited by NAC.

关键词： obstructive sleep apnea syndrome chronic intermittent hypoxia oxidative stress N-acetylcysteine

在线全文

学校读者我要写书评

暂无评论

拟态构造的Web服务器异构性量化方法

软件学报 2020年第2期31卷 564-577页

作者：张杰鑫庞建民张铮数学工程与先进计算国家重点实验室河南郑州450001

拟态构造的Web服务器是一种基于拟态防御原理的新型Web安全防御系统,其利用异构性、动态性、冗余性等特性阻断或扰乱网络攻击,以实现系统安全风险可控.在分析拟态防御技术原理的基础上,论证异构性如何提高拟态构造的Web服务器的安全性,... 详细信息

拟态构造的Web服务器是一种基于拟态防御原理的新型Web安全防御系统,其利用异构性、动态性、冗余性等特性阻断或扰乱网络攻击,以实现系统安全风险可控.在分析拟态防御技术原理的基础上,论证异构性如何提高拟态构造的Web服务器的安全性,并指出对异构性进行量化的重要性.在借鉴生物多样性的量化方法基础上,将拟态构造的Web服务器的异构性定义为其执行体集的复杂性与差异性,提出了一种适用于量化异构性的量化方法,通过该方法分析了影响拟态构造的Web服务器异构性的因素.在理论上为拟态防御量化评估提供了一种新方法,工程实践上为选择冗余度、构件和执行体提供了指导.实验结果表明,该方法比香浓维纳指数和辛普森指数更适合于量化拟态构造的Web服务器的异构性.

关键词：网络空间安全拟态防御 Web服务器异构性量化方法