检索结果-南通市图书馆

Effects of photoperiod and temperature on diapause induction in Conogethes punctiferalis （Lepidoptera： Pyralidae）

Insect Science 2014年第5期21卷 556-563页

作者： li-rong xu Xinzhi Ni Zhen-Ying Wang Kang-Lai He The State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant Protection Chinese Academy of Agricultural Sciences China USDA-ARS Crop Genetics and Breeding Research Unit University of Georgia-Tifton Campus Tifton GeorgiaUSA

The yellow peach moth, Conogethes punctiferalis （Guenee）, a multivoltine species that overwinters as diapausing larvae, is one of the most serious insect pests on maize in China. Effect of photoperiod and temperature on larval diapause was examined under empirical laboratory conditions. Short-day treatments caused larval diapause at 25℃, and the critical photoperiod was between 12 and 13 h （or 12 h 51 min） light per day. No sensitive instar was identified for diapause induction under alternated short- （L ： D 11 ： 13 h） and long-day （L ： D 14 ： 10 h） treatments at different larval stages. However, accumulative treatment of three instars and 10 d under short-day treatment was required for the induction of 50% larval diapause. All larvae entered diapause at 20℃, whereas less than 3% did so at 30℃, irrespective of the long- or short-day treatment. Furthermore, under the short-day treatment, more than 90% of larvae went into diapause with temperatures ≤ 25℃, but less than 17% did so at 28℃. In contrast, under the long-day treatment, less than 19% of larvae went into diapause with temperatures ≥23 ℃. The forward shift （5℃） of critical temperature under the long-day regime demonstrated the compensatory effect of temperature and photoperiod on diapause induction. In conclusion, C. punctiferalis had a temperature-dependent type Ⅰ photoperiodic diapause response; there was no sensitive instar for diapause determination, but the photoperiodic accumulation time countermeasures both of the short-day cycles and the number ofinstars exposed, and the photoperiodic diapause response, was a temperature-compensated phenomenon.

关键词： Conogethes punctiferalis diapause induction photoperiod sensitive larval instar temperature dependence yellow peach moth

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

Prediction and Analysis on Oxidation of H13 Hot Work Steel

引用

Journal of Iron and Steel Research International 2006年第1期13卷 44-49页

作者： MIN Yong-an WU Xiao-chun WANG rong li lin xu Luo-ping School of Materials Science and Engineering Shanghai University Shanghai 200072 China

The understanding of oxidation behaviors on H13 steel was helpful to improve the service life and performance of hot work moulds and dies. Thermal-Calc Software was performed to calculate the oxidation phases on H13 steel along with different partial oxygen pressures in the interesting temperature range of 500-700 ℃. In this range H13 steel samples were treated respectively in different atmosphere including flowing water vapor （0.2 MPa）, normal pressure air （0.1 MPa） and low pressure air （0. 001 MPa）. The different oxidation films were detected with optical microscopy and X-ray diffraction. The microstructures and phase constitutions of the films formed in low pressure air were similar to those of the films formed in water vapor, and obviously different to those of the films formed in normal pressure air. The oxidation mechanisms of H13 steel in different atmosphere were also discussed.

关键词： oxidatiom hot work steel surface treatment die casting

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

Retention Mechanism of Phenolic Compounds in Subcritical Water Chromatography

引用

Chemical Research in Chinese Universities 2015年第1期31卷 103-106页

作者： WUYichao DENG Xiuqing MAO Yinchun ZHANG Yan liU Jiaqin rong li xu Zhihong School of Physics and Chemistry Xihua University Chengdu 610039 P. R. China

The transfer enthalpies and entropies of hydroxyl and nitryl in different mobile phase systems were compared by van＇t Hoff curve. Results suggest that the presence of acetonitrile and methanol in the mobile phase may decrease the interaction of solute and stationary phase with respect to subcritical water, thereby reducing the contribution of enthalpy to the retention. Retention mechanisms of phenolic compound appear to be more similar in subcritical water and water/methanol systems on the PRP-1 column. Hydrogen bond in subcritical water system plays a very important role in the retention of the phenols.

关键词： Subcritical water chromatography Phenols Retention mechanism Hydrogen bond

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

Numerical simulation of fracturing and imbibition in shale oil horizontal wells

引用

Petroleum Science 2023年第5期20卷 2981-3001页

作者： rong-li xu Tian-Kui Guo Xiao-Jia xue Wen-Bin Chen Zhan-Qing Qu Ming Chen Zun-Peng Hu National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongPR China School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongPR China Oil and Gas Technology Research Institute Changqing Oilfield Company Petrochina Company LimitedXi'an710000ShaanxiPR China

The shale oil reservoir is characterized by tight lithology and ultra-low permeability,and its efficient exploitation requires the technology of multi-stage and multi-cluster hydraulic fracturing in horizontal wells and shut-in *** multi-stage and multi-cluster hydraulic fracturing,a complex fracture network is formed,and a large volume of frac fluid is stored within the fracture *** shut-in,imbibition and exchange between oil and water occurs under the action of the capillary force and osmotic pressure,and the formation pressure builds up in the shale *** basis of the characteristics of shale oil reservoir,we establish a model of imbibition during fracturing injection and shut-in by coupling oilewater two-phase flow and saline ion diffusion in the hydraulic fractures(HFs)network,natural fractures(NFs)and matrix system under the action of capillary force and osmotic *** DFN method and the multiple continuum method are introduced to characterize fluid flow between the HF and the NF and that between the NF and the matrix respectively,which avoids the problem of a large amount of computation of seepage within the complex ***,the discrete fracture network(DFN)model and the multiple continuum model are solved with the finite element method,and it is verified in flow field,saturation field and concentration field that the models are accurate and *** propose the imbibition exchange volume for quantitative evaluation of the imbibition degree and a method of calculating the imbibition exchange *** of oil and water flow in the fracturing and shut-in stages is performed based on these *** is found that imbibition in the shale reservoir is driven by mechanisms of pressure difference,capillary force and osmotic *** osmotic pressure and capillary force only cause an increase in the imbibition rate and a reduction in the imbibition equilibrium time and do not lead to variation in the peak of i

关键词： Shale oil Hydraulic fracturing Imbibition exchange volume Oilewater two-phase flow Shut-in time

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

Pricing General Exchange Option on Jump-diffusion Model

引用

Journal of Systems Science and Information 2008年第2期6卷 189-194页

作者： rong li Yun xu College of Mathematics and Systems Science Xinjiang University Urumqi 830046 China （Received January 26 2008）

The problem of general exchange option pricing on jump-diffusion model is presented, we use the methods of the change of numeraire and martingale measure, and get the analytic solution of above option.

关键词： option pricing exchange option jump-diffusion process martingale method

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

应用积分图的织物瑕疵检测快速算法

引用

纺织学报 2016年第11期37卷 141-147页

作者：董蓉李勃徐晨南通大学电子信息学院江苏南通226019 南京大学电子科学与工程学院江苏南京210093

为解决现有基于图像处理的织物瑕疵检测算法实时性较差、正确率偏低等问题,提出一种包含学习和检测2个阶段的瑕疵检测算法。通过对无瑕疵模板图像的梯度能量特征及其分布特性的学习,自适应获得检测阶段所需的参数。一方面利用积分图原... 详细信息

为解决现有基于图像处理的织物瑕疵检测算法实时性较差、正确率偏低等问题,提出一种包含学习和检测2个阶段的瑕疵检测算法。通过对无瑕疵模板图像的梯度能量特征及其分布特性的学习,自适应获得检测阶段所需的参数。一方面利用积分图原理将任意大小的图像块内的求和运算化简为三次加法运算,快速提取织物图像的梯度能量特征,实现织物瑕疵的实时检测,另一方面利用核函数拟合特征参数分布,结合均值漂移法求解分布峰值获得自适应的瑕疵判定阈值参数,实现织物瑕疵的准确分割。通过实验将本文算法与现有基于局部二值模式特征、小波特征、规则带特征等算法进行对比,针对包含3种纹理6类瑕疵的织物图像数据集的测试结果显示,本文算法平均处理时间为56 ms,正确率为97%。

关键词：织物瑕疵检测积分图特征提取核函数均值漂移

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

Effect of Sb_2O_3-doped on optical absorption of ZnO thin film

引用

Optoelectronics Letters 2006年第1期2卷 51-54页

作者： CHANG Chun-rong li Zi-quan xu Yun-yun Institute of Material Science and Technology Nonjing University of Aeronautics and Astronautics Nonjing 210016 China

Sb2O3 doped ZnO thin film was prepared by RF magnetron sputtering *** influence of Sb2O3 on the structure and the optical absorption of ZnO thin film was studied by XPS,XRD apparatuses and UV-Vis *** results show that doped Sb2O3 has affected atomic and electronic structures,growth modes of crystal grains and optical absorption of *** element Sb exists in many forms in the film including transpositional atoms and compounds such as Sb2O3,Zn7Sb2O 14 *** crystal grains grow in mixing *** lattice relaxation and the content of second phases increase when more Sb is *** UVA absorption of doped ZnO thin film increases *** ultraviolet absorption peak narrows,absorption intensity increases,the absorption margin becomes steep and moves to shorter wavelength of about 5 nm,and the visible absorption increases in some sort.

关键词： ZnO 薄膜光学吸收 RF磁电管电子散射

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

Computed tomography perfusion study of hemodynamic changes and portal hyperperfusion in a rabbit model of small-for-size liver

引用

Hepatobiliary & Pancreatic Diseases International 2012年第1期11卷 74-80页

作者： Zhi-Guo Zhuang,Jian-rong xu,li-Jun Qian,Qiang Xia and Jia-Chang Chi Department of Radiology,and Center of Transplantation,Renji Hospital,Shanghai Jiaotong University School of Medicine,Shanghai 200127,China [a] Department of Radiology Shanghai Jiaotong University School of Medicine Shanghai 200127 Shanghai China [b] Center of Transplantation Renji Hospital Shanghai Jiaotong University School of Medicine Shanghai 200127 Shanghai China

BACKGROUND:Portal hyperperfusion in the small-for-size (SFS) liver can threaten survival of ***,it is important to understand the hemodynamic changes in the SFS ***:Twenty rabbits were divided into two groups:a control group and a modulation *** control group underwent an extended *** modulation group underwent the same procedure plus splenectomy to reduce portal blood *** perfusion examinations were performed on all rabbits before and after *** parameter values,especially portal vein perfusion (PVP),were ***:PVP in the modulation group was lower than in the control group after operation (P=0.002).In the control group,postoperative PVP increased by 193.7±55.1% compared with preoperative PVP.A weak correlation was found between the increased percentage of PVP and resected liver-to-body weight ratio (RLBWR) (r=0.465,P=0.033).In the modulation group,postoperative PVP increased by 101.4±32.5%.No correlation was found between the increased percentage of PVP and RLBWR (r=0.167,P=0.644).Correlations were found between PVP and serum alanine aminotransferase,aspartate aminotransferase,and total bilirubin after surgery (Pliver in rabbits by the CT technique.

关键词： computed tomography perfusion portal vein perfusion hemodynamics hepatectomy small-for-size liver

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

Aquaporin-4-IgG-seropositive neuromyelitis optica spectrum disorders:progress of experimental models based on disease pathogenesis

引用

Neural Regeneration Research 2025年第2期20卷 354-365页

作者： li xu Huiming xu Changyong Tang Department of Neurology The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong ProvinceChina

Neuromyelitis optica spectrum disorders are neuroinflammatory demyelinating disorders that lead to permanent visual loss and motor *** date,no effective treatment exists as the exact causative mechanism remains ***,experimental models of neuromyelitis optica spectrum disorders are essential for exploring its pathogenesis and in screening for therapeutic *** most patients with neuromyelitis optica spectrum disorders are seropositive for IgG autoantibodies against aquaporin-4,which is highly expressed on the membrane of astrocyte endfeet,most current experimental models are based on aquaporin-4-IgG that initially targets *** experimental models have successfully simulated many pathological features of neuromyelitis optica spectrum disorders,such as aquaporin-4 loss,astrocytopathy,granulocyte and macrophage infiltration,complement activation,demyelination,and neuronal loss;however,they do not fully capture the pathological process of human neuromyelitis optica spectrum *** this review,we summarize the currently known pathogenic mechanisms and the development of associated experimental models in vitro,ex vivo,and in vivo for neuromyelitis optica spectrum disorders,suggest potential pathogenic mechanisms for further investigation,and provide guidance on experimental model *** addition,this review summarizes the latest information on pathologies and therapies for neuromyelitis optica spectrum disorders based on experimental models of aquaporin-4-IgG-seropositive neuromyelitis optica spectrum disorders,offering further therapeutic targets and a theoretical basis for clinical trials.

关键词： aquaporin-4 experimental model neuromyelitis optica spectrum disorder pathogenesis

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

TET2基因突变在髓系肿瘤中的研究进展

引用

中国医学科学院学报 2016年第5期38卷 583-588页

作者：李荣许明江杨逢春周圆中国医学科学院北京协和医学院血液学研究所&血液病医院实验血液学国家重点实验室天津300020

TET2为TET家族成员之一,是一个与造血系统发育密切相关的肿瘤抑制基因。近年研究发现,TET2通过将DNA上的5-甲基胞嘧啶(5-mc)氧化为5-羟甲基胞嘧啶(5-hmc),参与DNA的去甲基化过程。体细胞中TET2基因异常会导致骨髓生成异常及恶性髓系疾... 详细信息

TET2为TET家族成员之一,是一个与造血系统发育密切相关的肿瘤抑制基因。近年研究发现,TET2通过将DNA上的5-甲基胞嘧啶(5-mc)氧化为5-羟甲基胞嘧啶(5-hmc),参与DNA的去甲基化过程。体细胞中TET2基因异常会导致骨髓生成异常及恶性髓系疾病的发生。本文将就TET2的结构与功能,TET2基因突变与不同类型髓系肿瘤的关系进行综述。

关键词： TET2 突变髓系肿瘤

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：