检索结果-南通市图书馆

维普期刊数据库博看期刊

Effect of squeeze casting process on microstructures and flow stress behavior of Al-17.5Si-4Cu-0.5Mg alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2017年第9期24卷 957-965页

作者： Yuan-ji Shi Lan-ji Liu Lei zhang Li-jun zhang Li Zheng Run-xia Li Bao-yi Yu School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870LiaoningChina

The effects of squeeze casting process on microstructure and flow stress behavior of Al-17.5Si-4Cu-0.5Mg alloy were investigated and the hot-compression tests of gravity casting and squeeze casting alloy were carried out at 350-500°C and *** results show that microstructures of Al-17.5Si-4Cu-0.5Mg alloys were obviously improved by squeeze *** to the decrease of coarse primary Si particles,softα-Al dendrite as well as the fine microstructures appeared,and the mechanical properties of squeeze casting alloys were ***,when the strain rate rises or the deformation temperature decreases,the flow stress increases and it was proved that the alloy is a positive strain rate sensitive *** was deduced that compared with the gravity casting alloy,squeeze casting alloy（solidified at 632 MPa）is more difficult to deform since the flow stress of squeeze casting alloy is higher than that of gravity casting alloy when the deformation temperature exceeds 400°*** stress behavior of Al-17.5Si-4Cu-0.5Mg alloy can be described by a hyperbolic sine form with Zener-Hollomon parameter,and the average hot deformation activation energy Q of gravity casting alloy and squeeze casting alloy is 278.97 and 308.77kJ/mol,respectively.

关键词： Squeeze casting Al-Si-Cu-Mg alloy Hot compression deformation Flow stress Constitutive equation

A female in vivo haploid-induction system via mutagenesis of egg cell-specific peptidases

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2023年第2期16卷 471-480页

作者： Xuecheng zhang Ce Shi Siling Li bo zhang Pan Luo Xiongbo Peng Peng Zhao Thomas Dresselhaus Meng-Xiang Sun State Key Laboratory of Hybrid Rice College of Life SciencesWuhan UniversityWuhan 430072China Hubei Hongshan Laboratory Wuhan 430070China Cell Biology and Plant Biochemistry University of RegensburgRegensburgGermany

Crop breeding schemes can be significantly accelerated by using(doubled)haploid *** vivo haploid induction has been applied in plant breeding for decades but is still not available for all crops and genotypes,and haploidization rates are generally very ***,methodological improvements to and new concepts for haploidization are ***,we report a novel system for the induction of haploid plants by mutating genes encoding egg cell-specific aspartic endopeptidases(ECSs).We show that after successful sperm–egg cell fusion,ECSs play a critical role to ensure male and female nucleus fusion after *** ecs1 ecs2 double mutant can induce haploids by both selfing and hybridization in Arabidopsis and ECS mutation is also capable of producing haploids in *** summary,our study develops a novel approach for maternal haploidization and provides new insights into the molecular basis of fertilization.

关键词： haploid induction egg cell maternal inducer semigamy fertilization

Sensory and immune genes identification and analysis in a widely used parasitoid wasp Trichogramma dendrolimi （Hymenoptera： Trichogrammatidae）

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2016年第3期23卷 417-429页

作者： Su-Fang zhang Xiang-bo Kong Hong-Bin Wang Gang Zhou Jin-Xiu Yu Fu Liu Zhen zhang Key Laboratory of Forest Protection Research Institute of Forest Ecology Environment and Protection Chinese Academy of ForestryBeijing China Hunan Academy of Forestry Changsha China

Trichogramma dendrolimi Matsumura （Hymenoptera： Trichogrammatidae） is one of the preponderant egg parasitoids of Dendrolimus spp., which are important defoliators of coniferous forests. This parasitoid wasp has been widely released to control pine caterpillar and other lepidopteran pests, but its control efficiency needs to be improved. Sensory systems are crucial for T dendrolimi to locate hosts, and immunity is probably involved after egg deposition in the host cavity; however, few reports have focused on the molecular mechanism of olfactory detection and survival of T. dendrolimi. It is necessary to identify these genes before further functional research is conducted. In this study, we assembled and analyzed the transcriptome of T. dendrolimi using next-generation sequencing technology. The sequencing and assembly resulted in 38 565 contigs with N50 of 3422 bp. Sequence comparison indicate that T dendrolimi sequences are very similar to those of another parasitoid Nasonia vitripennis. Then the olfactory, vision, and immune- related gene families were identified, and phylogenetic analyses were performed with these genes from T. dendrolimi and other model insect species. Furthermore, phylogenetic tree with odorant binding proteins of T. dendrolimi and their host Dendrolimus was constructed to determine whether convergent evolution exists. These genes can be valid targets for further gene function research. The present study may help us to understand host location and survival mechanisms of T dendrolimi and to use them more efficiently for pest control in the future.

关键词： immunity OBP opsin parasitoid sensory transcriptome

Synoptic mode of Antarctic summer sea ice superimposed on interannual and decadal variability

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2021年第2期12卷 147-161页

作者： YU Le-Jiang ZHONG Shi-Yuan SUI Cui-Juan zhang Zhao-Ru SUN bo MNR Key Laboratory for Polar Science Polar Research Institute of ChinaShanghai200136China Department of Geography Environment and Spatial SciencesMichigan State UniversityEast Lansing48824USA National Marine Environmental Forecasting Center Beijing10008JChina School of Oceanography Shanghai Jiao Tong UniversityShanghai200240China

In contrast to decreased Arctic sea ice extent,Antarctic sea ice extent shows a somewhat increased *** is a large interannual variability of Antarctic sea ice,especially in the Pacific sector of the Southern *** change and variability of Antarctic sea ice in synoptic timescales in the recent decades remain *** identify synoptic modes of variability of Antarctic summer sea ice by applying the Self Organizing Map(SOM)technique to daily sea ice concentration data for the period 1979–*** 40%of the variability is characterized by opposite changes between sea ice cover in the Bellingshausen,Amundsen and western Ross Seas and in the rest of the Antarctic seas,and another 30%by meridional asymmetry in the Weddell,Amundsen,and Ross *** of these spatial patterns may be explained by the dynamics and thermodynamic processes associated with anomalous atmospheric circulations related to the Southern Annular Mode(SAM)with a structure of strong zonal *** interannual variability of the sea ice modes appears to have little connection to SAM,and only a weak relation to *** annual frequencies of SOM node occurrences also show a great decadal *** 9 appears mainly prior to 1990;while node 1 occurs mainly after *** decadal variability of nodes 1 and 9 is associated with the asymmetrical SAM,which results from two wavetrains excited over northern Australia and the southeastern Indian *** results further highlight the importance of understanding the role of southern mid-to-high latitude atmospheric intrinsic variability in predicting Antarctic summer sea ice variations from synoptic to decadal timescales.

关键词： Antarctic sea ice Sea ice variability Southern annular mode Amundsen sea low Self organizing map

Primitive neuroectodermal tumors of the abdominal wall and vulva in children: Report of two cases and review of the literature

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2019年第21期7卷 3671-3682页

作者： Qiong-Qian Xu Wen-Wen Xing Gang Chen yi-Wu Dang yi-Ge Luo Peng Chen Song-Wu Liang Jia-bo Chen Department of Pediatric Surgery the First Affiliated Hospital of Guangxi Medical UniversityNanning 530021Guangxi Zhuang Autonomous RegionChina Department of Pathology the First Affiliated Hospital of Guangxi Medical UniversityNanning 530021Guangxi Zhuang Autonomous RegionChina

BACKGROUND Primitive neuroectodermal tumors are rare,highly malignant small round cell tumors belonging to the Ewing sarcoma *** purpose of this article is to present clinical manifestation,histology,treatment,and prognosis of two primitive neuroectodermal tumors(PNETs)in extremely rare anatomic locations,the abdominal wall and *** SUMMARY Case 1 was a 66-month-old girl with lesions on the abdominal wall;tumor size was about 3.4 cm×6.1 cm×2 *** patient underwent radical resection of the *** the operation,an alternating vincristine,doxorubicin,and cyclophosphamide/ifosfamide and etoposide(IE)regimen was given for eight cycles,and the patient survived for 66 mo without *** 2 was a 40-month-old girl,with a vulvar lesion;tumor size was about 3.3 cm×5 cm×2.5 *** tumor was partially resected by *** family left treatment after two cycles of vincristine,pirarubicin,and cyclophosphamide/IE chemotherapy,and the patient died at home six months after *** PNET is a rare,fast-growing,highly malignant tumor that requires histologic and molecular analyses for exact diagnosis,and multimodal treatment is required to achieve a good prognosis.

关键词： Primitive neuroectodermal tumor Therapy Prognosis Case report

An air-stable single-crystal layered oxide cathode based on multifunctional structural modulation for high-energy-density sodium-ion batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第12期67卷 4242-4250页

作者： yi-Feng Liu Hai-Yan Hu Jia-Yang Li Hongrui Wang yi Zhao Jingqiang Wang Yuan-bo Wu Yan-Jiang Li Guang-Yu zhang Qing-Qun Sun Yan-Fang Zhu Rui-Ren Tang Xiong-Wei Wu Jia-Zhao Wang Shi-Xue Dou Shu-Lei Chou Yao Xiao Institute for Carbon Neutralization College of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325035China Wenzhou Key Laboratory of Sodium-Ion Batteries Wenzhou University Technology Innovation Institute for Carbon NeutralizationWenzhou 325035China College of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China School of Chemistry and Materials Science Hunan Agricultural UniversityChangsha 410128China Institute of Energy Materials Science University of Shanghai for Science and TechnologyShanghai 200093China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjin 300071China

P2-type layered oxide,Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2),has drawn particular interest as a promising cathode material for sodium-ion batteries(SIBs)due to its fast sodium-ion transport channels with low migration ***,some catastrophic flaws,such as air instability,complicated multiphase evolution,and irreversible anionic redox,limit its electrochemical performance and hinder its ***,an air-stable single-crystal P2-type Na_(2/3)Ni_(1/3)Mn_(1/3)Ti_(1/3)O_(2)is proposed based on the multifunctional structural modulation of Ti substitution that could alleviate the issues for practical *** a result,the cathode with high energy density shows excellent air stability and highly reversible phase transitions(P2–OP4),and delivers faster kinetics and stable anion redox ***,a thorough investigation of the relationship between structure,function,and properties is demonstrated,emphasizing formation processes,electrochemical behavior,structural evolution,and air ***,this study provides the direction of multifunctional structural modulation for the development of high-performance sodium-based layered cathode materials for practical applications.

关键词： sodium layered oxide cathodes single crystal multifunctional structural modulation controllable multiphase transition anionic redox chemistry

A highly selective and instantaneous upconversion fluorescent nanoprobe for ascorbic acid detection in biological samples

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2017年第10期28卷 1983-1986页

作者： Yuanyuan Chen Tingting zhang Xiaonan Gao Wei Pan Na Li bo Tang College of Chemistry Chemical Engineering and Materials Science Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong Key Laboratory of Molecular and Nano Probes Ministry of Education Institute of Moleeular and Nano Science Shandong Normal University Ji'nan 250014 China

Ascorbic acid（AA） serves as a key coenzyme in many metabolic pathways. Enough daily AA supplements from different dietary sources are the only way for human to maintain their AA levels in *** of AA content in different foods guides to build healthy diet, which is of great biomedical significance. Hence, developing a highly selective and instantaneous fluorescent nanoprobe for the detection of AA in biological samples is highly needed. Here we present a novel turn-on fluorescent nanoprobe using lanthanide-doped upconversion nanoparticles（UCNPs） and cobalt oxyhydroxide（Co OOH） nanoflakes for monitoring AA in fruit samples. In this nanosystem, the UCNPs can be adsorbed onto the Co OOH nanoflakes, leading to a remarkable fluorescence decrease through Fo？rster resonance energy transfer. Furthermore, the AA could trigger the disassembly of the Co OOH to liberate the upconverted fluorescence. The UCNPs-based nanoprobe can provide an effective platform for highly selective and rapid detection of AA in biological samples.

关键词： Cobalt oxyhydroxide nanoflakes Upconversion nanoparticles Ascorbic acid Fluorescent nanoprobe Biological samples

Sulfuric acid leaching kinetics of South African chromite

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2015年第3期22卷 233-240页

作者： Qing Zhao Cheng-jun Liu Pei-yang Shi bo zhang Mao-fa Jiang Qing-song zhang Ron Zevenhoven Henrik Saxén Key Laboratory for Ecological Metallurgy of Multimetallic Ores (Ministry of Education) Northeastern University Thermal and Flow Engineering Laboratory bo Akademi University

The sulfuric acid leaching kinetics of South African chromite was investigated. The negative influence of a solid product layer constituted of a silicon-rich phase and chromium-rich sulfate was eliminated by crushing the chromite and by selecting proper leaching con- ditions. The dimensionless change in specific surface area and the conversion rate of the chromite were observed to exhibit a proportional re- lationship. A modified shrinking particle model was developed to account for the change in reactive surface area, and the model was fitted to experimental data. The resulting model was observed to describe experimental findings very well. Kinetics analysis revealed that the leach- ing process is controlled by a chemical reaction under the employed experimental conditions and the activation energy of the reaction is 48 ***-1.

关键词： chromite ore treatment sulfuric acid leaching kinetics physical models

Effects of nanoparticles on fluorescence enhancement of the complexes of dsDNA and SYBR GreenⅠ

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2012年第4期23卷 247-251页

作者： CHEN Jiajia zhang Chen ZHAO Binyu MI Lijuan zhang yi HU Jun Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China Graduate School of the Chinese Academy of Sciences Beijing 100039China

Fluorescence enhancement in a DNA-dye system is favorable for sensitive and accurate DNA detection/ sensing *** this paper,we report that the fluorescence of the double-stranded DNA(dsDNA) and SYBR GreenⅠ(SG) system(dsDNA-SG) can be effectively enhanced by negatively charged magnetic iron oxide (Fe_2O_3@DMSA) and gold nanoparticles in suitable concentrations,but positively charged nanoparticles quench the *** of the Fe_2O_3@DMSA on the fluorescence intensities are investigated with dsDNA-SG of different lengths or *** results show that nanoparticles perform similarly in enhancing fluorescence intensity for several kinds of ***,the dsDNA concentration determines the fluorescence *** shows that fluorescence intensity of lower concentration dsDNA is enhanced remarkably in *** finding may be useful in sensitive biomolecular detection.

关键词：双链DNA 金纳米粒子 Green 荧光增强 SYBR 复合物 FE203 荧光强度