检索结果-南通市图书馆

DFT Study on the Germanium Ion Activated C–H Bond in Methane

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2018年第10期37卷 1533-1540页

作者： HOU Xiu-Fang fu Feng CHANG qing ZHANG wen-Lin Laboratory of Analytical Technology and Detection College of Chemistry and Chemical Engineering Yan ＇an University Yan ＇an 716000 China

Thermal reactions of methane with the main group metal cations Ge＋,GeO＋,GeOH＋ and OGeOH＋ were investigated by state-of-the-art quantum chemical *** GeO＋/CH_4,a H atom in CH_4 abstracted by the O atom in GeO＋ to form GeOH＋ and CH_3˙constitutes the channel *** barrier-free process,combined with a large exothermicity,suggested a fast and efficient reaction in agreement with the *** OGeOH＋ and CH_4,the intermediates and products of the most favorable path were below the reactant asymptote,and the reaction was easy to take place,while for Ge＋ and GeOH＋,the activation of C-H bond in methane was hard to happen under ambient *** results showed,in contrast to the inertness of Ge~＋ and Ge OH＋,the GeO＋ and OGeOH＋ can activate the H_3C-H *** NBO natural charge and molecular electrostatic potential were used to analyze the four main group metal germanium *** phenomenon suggested that ligands affect the electronic character and tune the chemical features of metal germanium center.

关键词： methane activation DFT ligand effect the germanium ion

Effect of Atmospheric Interfering Absorption on Measurement of BTX by DOAS

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2008年第3期21卷 202-210页

作者： fu-min Peng Pin-hua Xie Hai-yang Li Ying-hua Zhang Jun-de Wang wen-qing Liu Key Laboratory of Environmental Optical and Technology Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei 230031 China College of Chemistry and Chemical Engineering Anhui University Hefei 230039 China Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

It was reported on the elimination of interfering absorption of BTX. the absorption of O2 includes different absorption bands, which change differently when the partial pressure of oxygen is varied. These cause the nonlinear absorption of O2 and the observed band shape to vary with the column density of O2. The absorption ratios of molecular absorption in each of the Herzberg bands and dimer absorptions, as well as the contribution to the correction error of molecular absorption, are studied based on the characteristic of these absorption bands. The optimized way to eliminate the interfering absorption is obtained in the end and the effectiveness of using interpolation proposed by Volkamer et al. to remove O2 absorption is proved again. As to O2 and SO2, the effect of the thermal effect of characteristic spectra on the elimination error of their absorption is studied. Solutions to these problems are discussed and demonstrated together with methods to optimize the interpolation of spectra. As a sample application, differential optical absorption spectroscopy （DOAS） measurements of BTX are carried out. Results show a low detection limit and the good correlation with point instruments are achieved. All these prove the feasibility of using spectral interpolation to improve the accuracy of DOAS measurements of aromatic hydrocarbons for practical purposes.

关键词： Differential optical absorption spectroscopy BTX Herzberg band O2 dimer

HIGH RESOLUTION,REAL-TIME LINE-FIELD FOURIER-DOMAIN INTERFEROMETRY

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

Journal of Innovative Optical Health Sciences 2012年第2期5卷 41-48页

作者： qing XIAO LING fu Britton Chance Center for Biomedical Photonics Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology 1037 Luoyu Rd. Wuhan 430074P.R.China Key Laboratory of Biomedical Photonics of Ministry of Education Huazhong University of Science and Technology 1037 Luoyu Rd. Wuhan 430074P.R.China

To increase the application potential in manufacturing process,such as monitoring the processing performance,the profile measurement should be provided in real-time display and with high resolution *** propose a line-field Fourier-domain interferometric method(LFI),which combines the line-field microscope with spectral interferometer,for the surface cross-sectional profile measurement with no scan *** white light and objectives are employed to offer high axial and lateral resolution,*** our system setup,the measurement could be implemented in real-time display of 10 frame/s,and the resolutions of the LFI system in X;Y,and Z directions are~8μm,~3.2μm,and~1.4μm,*** a demonstration,the cross-sectional profiles of a microfluidic chip are *** graphics processing unit is also used to accelerate the reconstruction algorithm to achieve the real-time display of the cross-sectional profiles.

关键词： Line-field Fourier-domain interferometry cross-sectional profile real-time

Cassava Me RS40 is required for the regulation of plant salt tolerance

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

Journal of Integrative Agriculture 2023年第5期22卷 1396-1411页

作者： MA Xiao-wen MA Qiu-xiang MA Mu-qing CHEN Yan-hang GU Jin-bao LI Yang HU qing LUO qing-wen wen Ming-fu ZHANG Peng LI Cong WANG Zhen-yu Institute of Nanfan&Seed Industry Guangdong Academy of SciencesGuangzhou 510316P.R.China National Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai 200032P.R.China Zhanjiang Research Center Institute of Nanfan&Seed IndustryGuangdong Academy of SciencesZhanjiang 524300P.R.China

Soil salinity affects the expression of serine/arginine-rich(SR) genes and isoforms by alternative splicing, which in turn regulates the adaptation of plants to *** previously identified the cassava spliceosomal component 35 like(SCL) and SR subfamilies, belonging to the SR protein family, which are extensively involved in responses to abiotic ***, the post-transcriptional regulatory mechanism of cassava arginine/serine-rich(RS) subfamily in response to salt stress remains to be *** the current study, we identified 37 genes of the RS subfamily from 11 plant species and systematically investigated the transcript levels of the RS40 and RS31 genes under diverse abiotic stress ***, an analysis of the conserved protein domains revealed that plant RS subfamily genes were likely to preserve their conserved molecular functions and played critical functional roles in responses to abiotic ***, we found that overexpression of MeRS40 in Arabidopsis enhanced salt tolerance by maintaining reactive oxygen species homeostasis and up-regulating the salt-responsive ***,overexpression of MeRS40 gene in cassava reduced salt tolerance due to the depression of its endogenous gene expression by negative autoregulation of its own ***, the MeRS40 protein interacted with MeU1-70Ks(MeU1-70Ka and MeU1-70Kb) in vivo and in vitro, ***, our findings highlight the critical role of cassava SR proteins in responses to salt stress in plants.

关键词： cassava alternative splicing serine/arginine-rich proteins salt stress

孤网模式下水电机组自适应最优PID控制器设计

在线全文

学校读者我要写书评

暂无评论

控制理论与应用 2025年第1期42卷 22-32页

作者：陈金保任刚徐龙胡文庆郑阳肖志怀武汉大学动力与机械学院湖北武汉430072 武汉大学水力机械过渡过程教育部重点实验室湖北武汉430072 中国长江电力股份有限公司溪洛渡水力发电厂云南永善657300

为确保孤网模式下频率稳定性,水电站通常采用参数较小的固定PID(F-PID)控制,导致调节速度慢,难以实现全工况最优控制.针对这一问题,设计了一种基于改进灰狼优化算法(IGWO)和反向传播神经网络(BPNN)的水轮机调节系统(HTRS)自适应变PID控... 详细信息

为确保孤网模式下频率稳定性,水电站通常采用参数较小的固定PID(F-PID)控制,导致调节速度慢,难以实现全工况最优控制.针对这一问题,设计了一种基于改进灰狼优化算法(IGWO)和反向传播神经网络(BPNN)的水轮机调节系统(HTRS)自适应变PID控制器(V-PID),以在全工况下获得最优调节效果.首先,搭建高精度的HTRS仿真平台,并按水头和导叶开度变化范围划分工况.然后基于Hopf分岔理论确定各工况下PID参数约束条件及最大值.进一步,采用基于PID参数最大值数据集、综合ITAE指标和非线性收敛因子的IGWO计算出各工况下最优PID参数,并以最优PID参数作为BPNN样本数据,通过训练得到自适应V-PID控制器神经网络模型.最后,以某实际水电站为例,验证了V-PID控制器效果.仿真试验表明:基于V-PID控制器的非线性HTRS模型可根据工况变化在线自动调整PID参数,以结构简单、易实现为前提,实现了孤网模式下水电机组全工况最优控制.

关键词：水电机组改进灰狼优化算法自适应控制 Hopf分岔神经网络 PID控制器

Treatment of simulated wastewater containing Reactive Red 195 by zero-valent iron/activated carbon combined with microwave discharge electrodeless lamp/sodium hypochlorite

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2010年第4期22卷 512-518页

作者： Jie fu Zhen Xu qing-Shan Li Song Chen Shu-qing An qing-fu Zeng Hai-Liang Zhu State Key Laboratory of Pharmaceutical Biotechnology School of Life Sciences Nanjing University Nanjing 210093 China. Engineering Research Center for Clean Production of Textile Dyeing and Printing of Ministry of Education Wuhan University of Scienee & Engineering Wuhan 430073 China Pharmacy Department Shanghai Hospital of Skin Diseases and Sexually Transmitted Diseases Shanghai 200443 China

A comparative study of treatment of simulated wastewater containing Reactive Red 195 using zero-valent iron/activated carbon （ZVI/AC）, microwave discharge electrodeless lamp/sodium hypochlorite （MDEL/NaCIO） and the combination of ZVI/AC- MDEL/NaCIO was conducted. The preliminary results showed the two steps method of ZVI/AC-MDEL/NaCIO had much higher degradation efficiency than both single steps. The final color removal percentage was nearly up to 100% and the chemical oxygen demand reduction percentage was up to approximately 82%. The effects of operational parameters, including initial pH value of simulated wastewater, ZVI/AC ratio and particle size of ZVI were also investigated. In addition, from the discussion of synergistic effect between ZVI/AC and MEDL/NaCIO, we found that in the ZVI/AC-MEDL/NaCIO process, ZVI/AC could break the azo bond firstly and then MEDLfNaCIO degraded the aromatic amine products effectively. Reversing the order would reduce the degradation efficiency.

关键词： activated carbon microwave discharge electrodeless lamp Reactive Red 195 sodium hypochlorite zero-valent iron.

大五人格特征及情绪对2型糖尿病患者自我管理行为的预测作用

在线全文

学校读者我要写书评

暂无评论

中华健康管理学杂志 2025年第2期19卷 99-105页

作者：付文徐珏姜彩霞刘仕俊裘欣杭州市疾病预防控制中心（杭州市卫生监督所），杭州　310017

目的:分析大五人格特征及情绪对2型糖尿病患者自我管理行为的预测作用。方法:本研究为横断面研究。2016—2020年于杭州市开展慢性病患者自我管理社区干预工作，以全市69个社区卫生服务中心招募的2型糖尿病患者为研究对象，本研究数据来... 详细信息

目的:分析大五人格特征及情绪对2型糖尿病患者自我管理行为的预测作用。方法:本研究为横断面研究。2016—2020年于杭州市开展慢性病患者自我管理社区干预工作，以全市69个社区卫生服务中心招募的2型糖尿病患者为研究对象，本研究数据来源于社区干预中获取的基线资料。采用中国大五人格问卷（CBF-PI-15）、2型糖尿病自我管理行为量表（2-DSCS）、焦虑自评量表（SAS）及抑郁自评量表（SDS）进行问卷评估，并对餐后2 h血糖、糖化血红蛋白（HbA 1c）、总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）等生化指标进行检测。采用Spearman相关性分析探讨人格、相关生化指标与自我管理行为的相关性。采用分层回归分析方法，在校正人口学特征及患病情况相关因素后，评估大五人格及情绪对自我管理行为的预测作用。结果:纳入研究的839例患者中，女性518例（61.75%），男性321例（38.25%），年龄为（66.92±8.67）岁，病程为（8.87±6.91）年。不同病程、文化程度、治疗方式及不同程度焦虑、抑郁情绪的糖尿病患者自我管理行为得分存在差异（ t/F=6.172、3.340、4.699、16.007、27.127，均 P<0.05）。神经质人格与自我管理行为多维度呈负性相关（ r=-0.130~-0.073），尽责性、宜人性人格与自我管理行为多维度呈正相关（ r=0.072~0.215）。饮食控制评分与HbA 1c、LDL-C呈负相关（ r=-0.106、-0.077），规律锻炼评分与餐后2 h血糖、HbA 1c、TG、TC、HDL-C、LDL-C呈负相关（ r=-0.115~-0.071），2-DSCS总分与HbA 1c、TG、TC呈负相关（ r=-0.104~-0.071）。病程超过15年、注射胰岛素、服药+注射胰岛素的患者2-DSCS总分较高（ β=0.085、0.146、0.118，均 P<0.05），HbA 1c、SDS标准分高的患者2-DSCS总分较低（ β=-0.151、-0.328，均 P<0.05），宜人性评分高的患者2-DSCS总分较高（ β=0.143， P<0.05）。结论:大五人格特征中的神经质、尽责性、宜人性人格及焦虑、抑郁情绪均与自我管理行为存在相关性，其中宜人性人格对自我管理行为存在正性预测作用，而抑郁情绪则存在负性预测作用。

关键词：糖尿病,2型自我管理行为人格焦虑抑郁

融合先验信息的民航发动机自适应气路故障诊断方法

在线全文

学校读者我要写书评

暂无评论

航空学报 2025年第4期46卷 150-161页

作者：郭庆刘晓阳樊俊峰付宇左洪福中国民航大学航空工程学院天津300300 中国南方航空股份有限公司工程技术分公司动力装置部广州510890 南京航空航天大学民航学院南京210016

针对民用航空发动机传感器数量不足、难以实现有效故障诊断的问题,提出了融合先验信息的自适应气路分析模型(AGPAM-PI),提升了发动机故障诊断的准确性与效率。AGPAM-PI结合发动机指印图的先验信息和非线性气路故障诊断方法,首先通过指... 详细信息

针对民用航空发动机传感器数量不足、难以实现有效故障诊断的问题,提出了融合先验信息的自适应气路分析模型(AGPAM-PI),提升了发动机故障诊断的准确性与效率。AGPAM-PI结合发动机指印图的先验信息和非线性气路故障诊断方法,首先通过指印图对故障信息进行有效补充,对故障因子求解范围约束限定,然后再利用非线性气路分析模型进行故障诊断。以一台在实际运营过程中发生故障的CFM56-7B发动机数据进行验证,结果表明模型对该发动机的故障进行了准确的定位并通过发动机故障诊断规则分析了发动机故障模式,证明了模型的有效性。相比传统的气路故障诊断方法,先验故障信息的引入增强了单元体故障的识别能力,提高了诊断精度。

关键词：民航发动机故障诊断部件级建模信息融合非线性气路分析

Causes of maize density loss in farmers’ fields in Northeast China

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

Journal of Integrative Agriculture 2019年第8期18卷 1680-1689页

作者： ZHAO Ying-jie XING Sen ZHANG qing-song ZHANG fu-suo MA wen-qi Key Laboratory of Plant-Soil Interactions Ministry of Education Beijing 100193 P.R.China College of Resources and Environmental Sciences China Agricultural University Beijing 100193 P.R.China College of Resources and Environmental Science Hebei Agricultural University Baoding 071001 P.R.China

Increasing plant density is an effective and important way to reduce maize yield gaps in Northeast China. However, the fact is that a significant plant density gap exists between optimum plant density and actual plant density in farmers’ *** quantify the density gap between planned planting density and final harvest plant density(HPD), we studied 60 farmers’ fields on three types of soil for three crop seasons from 2015 to 2017 by measuring their plant-plant distance, actual seedlings density(ASD), final HPD and yield. We also explored the potential causes of density loss by digging the places where the seedlings were missing for two consecutive years in 2016–2017. Results show that the three-year average HPD in farmers’ fields was 59 699 plants ha^–1, which was significantly lower than the planned density, including both the machine setting density(MSD;67 962 plants ha^–1) and theoretical plant density(TPD;67 467 plants ha^–1). No significant difference was found in HPD between years and soil types. However, for MSD and TPD, the average value in 2015 was significantly higher than that in 2016 and 2017. No significant difference between soil types was observed. furthermore,the results from 2016 till 2017 indicated that a lack of seeds in the soil, a failure to germinate due to low-quality seeds,and a lack of seedlings breaking out of the soil due to environmental problems explained approximately 60.88, 10.33 and 28.80% of density loss, respectively. According to our survey, 63% of farmers did not know their own TPD and HPD, and 54% of farmers did not know the density loss. Therefore, we argue that farmers’ limited knowledge of density and density loss is an urgent problem that needs to be solved in maize production. These observations will be useful for determining best management practices for maize production and for providing helpful suggestions for machine improvement.

关键词： plant density maize production density loss density gap farmers’ fields