检索结果-南通市图书馆

Crystal Structure and Thermochemical Properties of 2-Pyrazine Carboxylate Lithium Monohydrate [Li（pyza）（H2O）]n（S）（pyza=2-Pyrazine Carboxylate）

引用

Chemical Research in Chinese Universities 2015年第2期31卷 253-260页

作者： XU Dan di Youying kong Yuxia DOU Jianmin College of Chemistry and Chemical Engineering Liaocheng University Liaocheng 252059 P. R. China

A 2-pyrazine carboxylate lithium monohydrate [Li（pyza）（H2O）]n was synthesized in a mixed solution of redistilled water and anhydrous ethanol. X-Ray crystallography was applied to characterizing its crystal structure. Low temperature molar heat capacities were measured in a temperature range of from 78 K to 400 K with a precision automatic adiabatic calorimeter. Two polynomial equations of experimental molar heat capacity as a function of temperature were obtained by the least-squares method. The smoothed molar heat capacities and thermodynamic functions of the compound were calculated based on the fitted polynomial equations. In accordance with Hess＇s law, a reasonable thermochemical cycle was designed based on the preparation reaction of the target compound. The standard molar enthalpies of dissolution for the reactants and products of the designed thermochemical reaction were measured by an isoperibol solution-reaction calorimeter, and the enthalpy change of the reaction was obtained, i.e., △rHm^ Ф→=-（30.084±0.329） kJ/mol. The standard molar enthalpy of the formation of the target compound was determined as △fHm^ Ф→,{[Li（pyza）（H2O）n（S）} =-（260.844±1.178） kJ/mol based on the enthalpy change of the reaction and standard molar enthalpies of the formation of other reactants and products. In addition, UV-Vis spectroscopy and the data of the refractive indexes were used to confirm whether the designed Hess thermochemieal cycle was reasonable and reliable.

关键词： 2-Pyrazine carboxylate lithium monohydrate Crystal structure Low temperature heat capacity Enthalpy of the dissolution Standard molar enthalpy of formation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Anti-proliferation effects of Twist gene silencing in gastric cancer SGC7901 cells

引用

World Journal of Gastroenterology 2015年第10期21卷 2926-2936页

作者： Hui Zhang Jian Gong di kong Hong-Yi Liu Department of Oncology Surgery Tianjin Nankai Hospital

AIM:To study the role of Twist gene in gastric cancer by gene silencing,including the potential of induction of apoptosis,cell cycle arrest,and proliferation inhibition in human malignant gastric SGC7901 ***:The expression level of Twist in gastric cancer samples was measured by *** effects of Twist gene silencing were detected at both m RNA and protein levels by RT-PCR and Western *** also evaluated the cell proliferation and apoptosis by CCK-8 assay and flow *** determined the activity of caspase-3 and caspase-9 with a caspase activity assay *** cycle distribution was analyzed by flow *** migration and invasion ability was evaluated by wound scratch assay and Boyden chamber ***:Twist protein was highly expressed in gastric cancer *** gene silencing significantly induced apoptosis,cell cycle arrest at G0/G1 phase,proliferation inhibition,and reduced the ability of migration and invasion in human gastric cancer SGC7901 ***,both caspase-3 and caspase-9 were ***:The Twist gene could serve as a potential molecular target for gene therapy of gastric cancer with targeted small interfering RNA.

关键词： Twist si RNA SGC7901 Apoptosis Invasion

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Upreguiation of human telomerase reverse transcriptase mRNA expression by in vitro transfection of hepatitis B virus X gene into human hepatocarcinoma and cholangiocarcinoma cells

引用

World Journal of Gastroenterology 2005年第36期11卷 5627-5632页

作者： Zhen-Liang Qu Sheng-Quan Zou Nai-Qiang Cui Xian-Zhong Wu Ming-Fang Qin di kong Zhen-Li Zhou Department of surgery Tianjin Nankai Hospital Tianjin 300100 China Department of Surgery Tongji Hospital Wuhan430030 Hubei Province China

AIM： To study the changes of human telomerase reverse transcriptase （hTERT） mRNA expression in human hepatocarcinoma cell lines （HepG2） and cholangiocarcinoma cell lines （QBC939） after HBx gene transfection and to illustrate the significance of transcriptional regulation of hTERT gene by HBx gene in the carcinogenesis. METHODS： HepG2 and QBC939 cell lines were cultured and co-transfected with eukaryotic expression vector containing the HBx coding region and cloning vector containing enhanced green fluorescent protein （EGFP） coding sequence using lipid-mediated gene transduction technique. Thirty-six hours after transfection, EGFP expression in cells was used as the indicator of successful transfection. Flow cytometry was performed to determine the transfection efficiency. Cells were harvested and total RNA was extracted using TRIzol reagent. The expression of hTERT mRNA in HepG2 and QBC939 cell lines was assayed by reverse transcriptionpolymerase chain reaction. The expression of HBx protein in both cell lines was detected by immunocytochemical staining and Western blotting. RESULTS： Flow cytometry showed that the transfection efficiency was 46.4% in HepG2 cells and 29.6% in QBC939 cells for both HBx gene expression vector and blank vector. The expression of hTERT mRNA was meaningfully increased in HepG2 and QBC939 cell lines when transfected with HBx gene expression vector compared to those transfected with OPTI-MEM medium and blank vector. Immunocytochemical staining and Western blotting revealed HBx protein expression in HepG2 and QBC939 cells only when transfected with HBx gene. CONCLUSION： HBx gene transfection can upregulate the transcriptional expression of hTERT mRNA. The transactivation of hTERT gene by HBx gene is a newfound mechanism for pathogenesis of hepatocarcinomas and cholangiocarcinomas after HBV infection. 2005 The WJG Press and Elsevier Inc. All rights reserved

关键词： Hepatocholangiocarcinoma Human telomerasereverse transcriptase Gene expression Hepatitis B virus X protein

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Parameter uncertainty modeling of safety instrumented systems

引用

Petroleum Science 2021年第6期18卷 1813-1828页

作者： Bao-Ping Cai Wen-Chao Li Yong-Hong Liu Yan-Ping Zhang Yi Zhao Xiang-di kong Zeng-Kai Liu Ren-Jie Ji Qiang Feng College of Mechanical and Electronic Engineering China University of PetroleumQingdao266580ShandongChina School of Reliability and Systems Engineering Beihang UniversityBeijing100191China

In this study,a novel safety integrity level(SIL)determination methodology of safety instrumented systems(SISs)with parameter uncertainty is proposed by combining multistage dynamic Bayesian networks(DBNs)and Monte Carlo simulation.A multistage DBN model for SIL determination with multiple redundant cells is *** models of function inspection test interval and function inspection test stages are alternately connected to form the multistage *** redundant cells can have different M out of N voting system *** automatic modeling of conditional probability between nodes is *** SIL determination of SISs with parameter uncertainty is constructed by using the multistage DBNs and Monte Carlo simulation.A high-pressure SIS in the export of oil wellplatform is adopted to demonstrate the application of the proposed *** SIL and availability of the SIS and its subsystems are *** influence of single subsystem on the SIL and availability of the SIS is *** influence of single redundant element on the SIL and availability of the subsystem is analyzed.A user-friendly SIL determination software with parameter uncertainty is developed on MATLAB graphical user interface.

关键词： Safety integrity level Dynamic Bayesian network Monte Carlo Parameter uncertainty

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimized segmented regression models for the transition period of intervention effects

引用

Global Health Research and Policy 2023年第1期8卷 240-252页

作者： Xiangliang Zhang Kunpeng Wu Yan Pan Rong Yin Yi Zhang di kong Qi Wang Wen Chen Department of Medical Statistics School of Public HealthSun Yat-sen UniversityGuangzhouChina Center for Migrant Health Policy Sun Yat-sen UniversityGuangzhouChina

Background The interrupted time series(ITS)design is a widely used approach to examine the effects of ***,the classic segmented regression(CSR)method,the most popular statistical technique for analyzing ITS data,may not be adequate when there is a transitional period between the pre-and post-intervention *** To address this issue and better capture the distribution patterns of intervention effects during the transition period,we propose using different cumulative distribution functions in the CSR model and developing corresponding optimized segmented regression(OSR)*** study illustrates the application of OSR models to estimate the long-term impact of a national free delivery service policy intervention in *** Regardless of the choice of transition length(L)and distribution patterns of intervention effects,the OSR models outperformed the CSR model in terms of mean square error(MSE),indicating the existence of a transition period and the validity of our model’s ***,the estimates of long-term impacts using OSR models are sensitive to the selection of L,highlighting the importance of reasonable parameter *** propose a data-driven approach to select the transition period length to address this *** Overall,our OSR models provide a powerful tool for modeling intervention effects during the transition period,with a superior model fit and more accurate estimates of long-term *** study highlights the importance of appropriate statistical methods for analyzing ITS data and provides a useful framework for future research.

关键词： Segmented regression Transition period Intervention evaluation Cumulative distribution functions distribution patterns

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Mining cost analysis and cost control based on the sensitivity factor analysis

引用

Journal of Modern Accounting and Auditing 2007年第11期3卷 44-49页

作者： ZHAO Shun-di kong Yu-sheng LU Min School of Business Administration Jiangsu University Jiangsu 212013 China

This paper systematically generalizes relevant theories and methods regarding mining cost control and constitutes the model for the mining cost analysis. It also comes up with the sensitivity factor analysis to conduct mining cost control. The theories and methods have been experimented with Jiangsu Chuanshan Mining Joint-Stock Company Ltd. Case studies have been undertaken on mining cost of the company and the most sensitive factor which affects mining cost has been found accordingly. Finally the paper concludes that the focus concerning the cost control of the company should be directed at output and material costs.

关键词： mining cost cost analysis cost control

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

NO2双通道光谱成像定量监测技术研究

引用

仪器仪表学报 2022年第4期43卷 155-162页

作者：吴靖张朋朋黄峰孔迪福州大学机械工程及自动化学院福州350108

二氧化氮(NO)是危害环境和人类健康的主要污染气体之一,需要对其排放进行监测以实现更好的治理。现有成像监测方法具有大范围实时的优点,但存在重建背景准确性和适用性不足的问题。本文提出了一种利用双通道光谱图像对气体浓度进行定量... 详细信息

二氧化氮(NO)是危害环境和人类健康的主要污染气体之一,需要对其排放进行监测以实现更好的治理。现有成像监测方法具有大范围实时的优点,但存在重建背景准确性和适用性不足的问题。本文提出了一种利用双通道光谱图像对气体浓度进行定量监测的方法,通过405和470 nm双通道光谱图像反演NO浓度,开展了以下理论与实验研究:进行了理论推导,得到气体柱浓度与双通道光强比之间的关系式;分析了双通道曝光时间对标定公式的影响,比较了采集的双通道光强比值与理论值,两者相差0.26%;采集了北纬26.08°不同气象条件的太阳散射辐射光谱,给出了不同太阳天顶角下的双通道光强比经验值;对探测相机系统性能进行了分析,探测限为19.6×10m^(-6);浓度标定与反演实验给出了标定函数,反演了扩散中的气体浓度二维分布图,验证了双通道光谱成像方法定量检测气体浓度的可靠性。

关键词：双通道成像监测 NO 气体太阳天顶角探测限

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

某型航空发动机进气压力畸变试验研究

引用

航空发动机 2014年第3期40卷 60-65页

作者：孔迪中航工业沈阳发动机设计研究所沈阳110015

针对飞机在大攻角飞行时易引起进气道和发动机进口流场畸变的情况,对某型发动机的综合抗进气压力畸变能力进行了整机试验研究。试验采用插板式畸变模拟器研究发动机综合抗总压畸变能力,获得了各规定风扇换算转速下发动机临界畸变指数,... 详细信息

针对飞机在大攻角飞行时易引起进气道和发动机进口流场畸变的情况,对某型发动机的综合抗进气压力畸变能力进行了整机试验研究。试验采用插板式畸变模拟器研究发动机综合抗总压畸变能力,获得了各规定风扇换算转速下发动机临界畸变指数,完成了畸变条件下遭遇加速试验,发动机过渡态工作正常。结果表明:该试验方案可行、数据可靠、结果有效,该型发动机满足飞机/发动机相容性试验要求。

关键词：进气压力畸变总压畸变畸变指数航空发动机风扇压气机

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

经肝动脉栓塞化疗联合微波刀治疗中晚期肝癌的临床疗效分析

引用

中国肿瘤临床 2011年第20期38卷 1283-1286页

作者：段巨涛孔棣柴友龙天津市南开医院第四外科天津市300100

目的:探讨联合应用经肝动脉化疗栓塞联合微波刀治疗中晚期肝癌的临床应用价值。方法:收集经病理、AFP和(或)影像学证实的不能手术切除的中晚期肝癌患者63例,按治疗方法随机分为经肝动脉化疗栓塞治疗组和经肝动脉化疗栓塞联合微波刀治疗... 详细信息

目的:探讨联合应用经肝动脉化疗栓塞联合微波刀治疗中晚期肝癌的临床应用价值。方法:收集经病理、AFP和(或)影像学证实的不能手术切除的中晚期肝癌患者63例,按治疗方法随机分为经肝动脉化疗栓塞治疗组和经肝动脉化疗栓塞联合微波刀治疗组,经肝动脉化疗栓塞治疗组31例,联合治疗组32例。结果:经肝动脉化疗栓塞治疗组与联合治疗组治疗后患者AFP定量平均下降率分别为52.2%(12/23)和80.0%(20/25),两组间差异有统计学意义(P<0.05);经肝动脉化疗栓塞治疗组的完全坏死率为12.9%(4/31);而联合治疗组的完全坏死率为34.4%(11/32),经统计学分析两组有明显统计学意义。经肝动脉化疗栓塞治疗组在1个疗程治疗结束6个月后复查影像学发现肝癌复发率为32.3%(10/31);联合治疗组肝癌复发率为9.4%(3/32),两者间差异有显著意义(P<0.05)。经肝动脉化疗栓塞治疗后患者1年的生存率为64.5%(18/31),而经联合治疗后患者1年生存率为87.5%(28/32),两组间差异有统计学意义(P<0.05)。结论:经肝动脉化疗栓塞联合微波消融治疗可显著提高中晚期肝癌患者的生存率,延长患者生存期。

关键词：原发性肝癌经肝动脉化疗栓塞术微波消融术

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

聚合物基压力敏感涂料近真空稳态特性研究及优化

引用

仪器仪表学报 2022年第7期43卷 123-130页

作者：吴靖陈远哲郭禹泽孔迪黄峰福州大学机械工程及自动化学院福州350108

压力敏感涂料(PSP)作为一种分子级的氧传感器,已广泛应用于飞行器气动力的高分辨率全场测量。为了将PSP应用于近真空环境飞行器气动特性的分析和研究,需要研究和制备在低压下压力灵敏度足够高的PSP,以实现近真空环境下的微小压力测量。... 详细信息

压力敏感涂料(PSP)作为一种分子级的氧传感器,已广泛应用于飞行器气动力的高分辨率全场测量。为了将PSP应用于近真空环境飞行器气动特性的分析和研究,需要研究和制备在低压下压力灵敏度足够高的PSP,以实现近真空环境下的微小压力测量。采用具有高氧透过性的高分子聚合物PTMSP为基层、以PdTFPP和PtTFPP为不同发光分子的两种PSP,即PdTFPP/PTMSP和PtTFPP/PTMSP,在近真空环境下开展稳态校准特性研究。实验结果表明,PdTFPP/PTMSP的压力灵敏度显著高于PtTFPP/PTMSP,而温度敏感度和光稳定性与PtTFPP/PTMSP相当,更适合用于近真空环境下测量微小压力的变化。进一步对PdTFPP/PTMSP开展特性优化研究,发现PdTFPP/PTMSP的压力灵敏度随发光分子和聚合物浓度的增加而先上升后下降,并且在发光分子和聚合物浓度分别为1.2和8 mg/mL时达到最高值68.65%/kPa。使用甲苯作为溶剂的PdTFPP/PTMSP配方压力灵敏度明显高于二氯甲烷和丙酮为溶剂时的配方,且温度敏感性和光稳定性最佳。

关键词：压力敏感涂料聚合物基近真空环境稳态校准压力灵敏度

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：