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Parametric study on single shot peening by dimensional analysis method incorporated with finite element method

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Acta Mechanica Sinica 2012年第3期28卷 825-837页

作者： Xian-Qian Wu Xi Wang Yan-Peng wei hong-wei song Chen-Guang Huang Key Laboratory for Hydrodynamics and Ocean Engineering Institute of MechanicsChinese Academy of Sciences100190 BeijingChina

Shot peening is a widely used surface treatment method by generating compressive residual stress near the surface of metallic materials to increase fatigue life and re- sistance to corrosion fatigue, cracking, etc. Compressive re- sidual stress and dent profile are important factors to eval- uate the effectiveness of shot peening process. In this pa- per, the influence of dimensionless parameters on maximum compressive residual stress and maximum depth of the dent were investigated. Firstly, dimensionless relations of pro- cessing parameters that affect the maximum compressive residual stress and the maximum depth of the dent were de- duced by dimensional analysis method. Secondly, the in- fluence of each dimensionless parameter on dimensionless variables was investigated by the finite element method. Fur- thermore, related empirical formulas were given for each di- mensionless parameter based on the simulation results. Fi- nally, comparison was made and good agreement was found between the simulation results and the empirical formula, which shows that a useful approach is provided in this pa- per for analyzing the influence of each individual parameter.

关键词： Keywords Shot peening - Maximum compressive residualstress Maximum depth of the dent Dimensional analysismethod ~ Finite element method

Research on Effect of Four Natural Ultraviolet Light Absorbers on Photostabilization of Azadirachtin-A

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Agricultural Sciences in China 2006年第11期5卷 855-858页

作者： TAN wei-hong song Zhan-qian Institute of Chemical Industry of Forest Products/Key Laboratory on Forest Chemical Engineering Chinese Academy of Forestry Nanjing 210042 P.R.China

This study examined the photostabilization of Azadirachtin-A （Aza-A） when exposed to ultraviolet light in the presence of some natural absorbers. Aza-A extract solutions with and without natural UV light absorbers in methanol were applied onto the surface of glass slides. At particular intervals, the remaining concentration of Aza-A was analyzed by HPLC. Using first-order kinetic equation, the dissipation half-life values （DT^0） for the degradation of Aza-A under ultraviolet radiation were obtained. It indicated that the addition of ferulic acid, gallic acid, and rutin provided moderate degree of photostabilization of Aza-A and that addition of aloin provided the best photostabilization of Aza-A, among these UV absorbers studied. Photostabilization of Aza-A by different UV light absorbers appears to be due to the competitive energy absorption of UV photons by the absorbers molecules. The dissipation half-life values of Aza-A after irradiation under ultraviolet light suggested that the addition of aloin （in 1 ： 1 mol ratio） can provide better photostabilization of azadirachtin molecule.

关键词： ultraviolet light photostabilization Aza-A bioinsecticide

Dynamic Development of Aphelenchoides besseyi on Rice Plant by Artificial Inoculation in the Greenhouse

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Agricultural Sciences in China 2008年第8期7卷 970-976页

作者： LIU wei-hong LIN Mao-song LI hong-mei SUN Min-jie Plant Protection College Nanjing Agricultural University Nanjing 210095 P.R.China

A study was done on the relationship between Aphelenchoides besseyi and the symptoms of small grains and erect panicles. This is an important rice disease in Jiangsu Province, China. A. besseyi was extracted from small grains and erect panicles and cultured artificially, and then inoculated into bud and leaf sheaths of seedlings of two Oryza sativa cultivars, namely Zhendao 2 and Wuyunjing 7 in a greenhouse. The effect on rice growth, in particular the small grains and erect panicles, was revealed by the extent of the disease, seed expansion stages, nematode load, and nematode mortality. In contrast to healthy seedlings, the height, length, and the numbers of spikelets of unhealthy panicles of Zhendao 2 were decreased by 6.7, 16.4, and 13.5%, respectively. Before anthesis, nematodes were attracted to the leaf sheath and apical meristem, nematode load increased by 40%; after anthesis, nematodes occurred in spikelets principally and the number increased by 90.8%. The percentages of infected seeds and nematode load were highest in plump seeds and lowest in empty seeds. Nematode mortality on grain with normal endosperm was lower than seeds with abnormal endosperm. Results indicated that A. besseyi was the pathogen in rice with the symptoms of small grains and erect panicles. Wuyunjing 7 manifests only the small grains and erect panicles symptoms and not the symptoms of leaf white-tip. These symptoms of small grains and erect panicles are new symptom records for the disease caused by A. besseyi on rice.

关键词： Aphelenchoides besseyi small grains and erect panicles nematode distribution seed expansion nematodemortality

What is the destiny of a threatened fish, Ptychobarbus chungtienensis, now that non-native weatherfishes have been introduced into Bita Lake, Shangri-La？

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Zoological Research 2016年第5期37卷 275-280页

作者： Wan-Sheng JIANG Tao QIN wei-Ying WANG Ya-Peng ZHAO Shu-Sen SHU wei-hong song Xiao-Yong CHEN Jun-Xing YANG State Key Laboratory of Genetic Resources and Evolution Kunming Institute of Zoology Chinese Academy of Sciences Kunming Yunnan 650223 China Southeast Asia Biodiversity Research Institute Chinese Academy of Sciences Yezin Nay Pyi Taw 05282 Myanmar POWERCHINA Kunming Engineering Corporation Limited Kunming Yunnan 650051 China Management Division of Yunnan Bitahai Nature Reserve Shangri-La Yunnan 674400 China

Biological invasion is a pervasive negative force of global change, especially in its effects on sensitive freshwater ecosystems. Even protected areas are usually not immune. Ptychobarbus chungtienensis is a threatened freshwater fish now almost confined to Bita Lake, in the Shangri-La region of Yunnan province, China. Its existence is threatened by the introduction of non-native weatherfishes （Misgumus anguillicaudatus and Paramisgurnus dabryanus） by an unusual method known as ＇prayer animal release＇ Periodic surveys revealed the ratio of invasive weatherfishes to P. chungtienensis has been increasing since the former species was first recorded from the lake in August, 2009. Ptychobarbus chungtienensis shows low genetic diversity in the relict Lake Bita population. Weatherfishes, however, have highly successful survival strategies. The degree of dietary overlap between the species is alarming and perhaps critical if food is found to be a limiting factor.

关键词： Biological invasion Threatened fish Prayer animal release Genetic diversity Dietary

Understanding Rotational Mode Specificity in the O（3P）+CHD3→OH+CD3 Reaction by Simple Reactant Alignment Pictures

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Chinese Journal of Chemical Physics 2019年第1期32卷 46-52,I0001页

作者： Rui Liu hong-wei song Ming-hui Yang Key Laboratory of Magnetic Resonance in Biological Systems National Center for Magnetic Resonance in Wuhan State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan 430071 China

The mode specificity plays an important role in understanding the fundamental reaction dynamics. This work reports a theoretical study of the rotational mode specificity of the reactant CHD3(JK) in the prototypical hydrocarbon oxidation reaction O(3P)+CHD3→OH+CD3. The time-dependent quantum wave packet method combined with a seven-dimensional reduced model is employed to calculate the reaction probability on an accurate potential energy surface. The obtained reaction probability depends on the values of both K and Ktot with PKtot=K=0>PKtot=K=J>PKtot=J,K=0=PKtot=0,K=J. This observation can be well rationalized by the reactant alignment pictures. Rotational excitations of CHD3 up to the angular momentum quantum number J=4 have a very weak enhancement effect on the reaction except for the state (J=4, K=0). In addition, the rotationally excited states of CHD3 with K=0 promote the reaction more than those with K=J. The quantum dynamics calculations indicate that the K=0 enhancements are mainly caused by the contributions from the components with K=Ktot=0. The components correspond to the tumbling rotation of CHD3, which enlarges the range of the reactive initial attack angles.

关键词： Polyatomic reaction Rotational excitation Time-dependent wave packet

A New Many-Body Expansion Scheme for Atomic Clusters:Application to Nitrogen Clusters

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Chinese Journal of Chemical Physics 2021年第6期34卷 717-727,I0002页

作者： wei Yan Yong-fa Zhu wei-yu Xie hong-wei song Chao-yang Zhang Ming-hui Yang State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and MathematicsInnovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China University of Chinese Academy of Sciences Beijing 100049China Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430071China

Although the many-body expansion(MBE)approach is widely applied to estimate the energy of large systems containing weak interactions,it is inapplicable to calculating the energies of covalent or metal *** this work,we propose an interaction manybody expansion(IMBE)to calculate the energy of atomic clusters containing covalent *** this approach,the energy of a system is expressed as the sum of the energy of atoms and the interaction energy between the atom and its surrounding *** IMBE method is first applied to calculate the energies of nitrogen clusters,in which the interatomic interactions are truncated to four-body *** results show that the IMBE approach could significantly reduce the energy error for nitrogen clusters compared with the traditional MBE *** weak size and structure dependence of the IMBE error with respect to DFT calculations indicates the IMBE method has good potential application in estimating energy of large covalent systems.

关键词： Many-body expansion Covalent bond Nitrogen cluster

Spontaneous viral clearance after 6-21 years of hepatitis B and C viruses coinfection in high HBV endemic area

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World Journal of Gastroenterology 2003年第9期9卷 2012-2016页

作者： Chun-Lei Fan Lai wei Dong Jiang hong-song Chen Yan Gao Ruo-Bing Li Yu Wang Institute of Hepatology,People’s Hospital,Peking University,Beijing 100044,China Institute of Hepatology People's Hospital Peking University Beijing 100044 China.

AIM: To investigate the clinical and virological course of coinfection by hepatitis B virus (HBV) and hepatitis C virus (HCV) in ***: We enrolled 40 patients with chronic HBV and HCV coinfection (Group BC), 16 patients with chronic HBV infection (Group B) and 31 patients with chronic HCV infection (Group C). They infected HBV and/or HCV during 1982 to *** of all the 87 patients were collected in 1994 and 2002respectively. We detected biochemical and virologic markers and serum HBV DNA and HCV RNA levels of all the patients. Btype ultrasound detection was performed in some ***: In Group BC, 67.5% of the patients cleared HBsAg,and 92.5% of the patients cleared HBeAg. The clearance rate of HBV DNA was 87.5%. There was no significant difference of HBV clearance between Group BC and Group B. In Group BC, 85.7% of males and 47.4% of females cleared HBV, and males were easier to clear HBV (x2=6.686, P=0.010). Such a tendency was also found in Group B. The clearance rate of HCV RNA in Group BC was 87.5%, significantly higher than that in Group C (x2=22.963, P＜0.001). Less than 40% of the patients in all groups had elevated liver enzyme values. The highest value of alanine aminotransferase (ALT) was 218 u/L (normal range for ALT is 0-40 u/L). In most patients the ultrasonogram presentations changed ***: The clinical manifestations of patients with HBV/HCV coinfection are mild and occult. High clearance rate of HBV and easy to clear HBV in male patients are the characteristics of HBV infection in adults in China. HBV can inhibit HCV replication, but no evidence has been found in our data that HCV suppresses HBV replication.

关键词：乙型肝炎病毒丙型肝炎病毒同时感染临床研究病理学中国

Domain generalization with semi-supervised learning for people-centric activity recognition

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Science China(Information Sciences) 2025年第1期68卷 171-188页

作者： Jing LIU wei ZHU Di LI Xing HU Liang song Academy for Engineering & Technology Fudan University Shanghai East-bund Research Institute on Networking Systems of AI School of Optoelectronic Information and Computer Engineering University of Shanghai for Science & Technology

People-centric activity recognition is one of the most critical technologies in a wide range of real-world applications,including intelligent transportation systems, healthcare services, and brain-computer interfaces. Large-scale data collection and annotation make the application of machine learning algorithms prohibitively expensive when adapting to new tasks. One way of circumventing this limitation is to train the model in a semi-supervised learning manner that utilizes a percentage of unlabeled data to reduce the labeling burden in prediction tasks. Despite their appeal, these models often assume that labeled and unlabeled data come from similar distributions, which leads to the domain shift problem caused by the presence of distribution gaps. To address these limitations, we propose herein a novel method for people-centric activity recognition,called domain generalization with semi-supervised learning(DGSSL), that effectively enhances the representation learning and domain alignment capabilities of a model. We first design a new autoregressive discriminator for adversarial training between unlabeled and labeled source domains, extracting domain-specific features to reduce the distribution gaps. Second, we introduce two reconstruction tasks to capture the task-specific features to avoid losing information related to representation learning while maintaining task-specific consistency. Finally, benefiting from the collaborative optimization of these two tasks, the model can accurately predict both the domain and category labels of the source domains for the classification task. We conduct extensive experiments on three real-world sensing datasets. The experimental results show that DGSSL surpasses the three state-of-the-art methods with better performance and generalization.

关键词： activity recognition deep learning domain generalization semi-supervised learning adversarial training

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Precise gradient separation of nanoparticles using reduced graphene oxide-polyoxomolybdate membranes

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Science China Chemistry 2025年第1期68卷 209-216页

作者： Yixin Yang Wanlei Zhao Ruoxuan Zheng hongqiang Li wei Chen Yu-Fei song State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Quzhou Institute for Innovation in Resource Chemical Engineering

The purification and size sieving of nanoparticles （NPs） represents a significant scientific ***,the r GO-polyoxometalates (POMs=PMo12,Mo132and Mo368) membranes were fabricated successfully via a simple and scalable POMsassisted in-situ photoreduction *** the mass ratio of r GO to PMo12was 1:30,the resultant r GO-PMo12membranes with highly ordered and uniform nanochannels of 1.0 nm can be obtained,which showed an accurate carbon quantum dots（CQDs） separation with a cut-off size approximately 1.0 *** increase of the size of the interlayered POMs from PMo12（1.0 nm）,{Mo132}（2.9 nm） to{Mo368}（3.8 nm）,the resultant r GO-PMo12,r GO-Mo132and r GO-Mo368exhibited precise gradient separation of CQDs and Au nanoparticles by size exclusion *** results pave a promising way to construct new twodimensional （2D） membranes for highly efficient size-selective separation.

关键词： reduced graphene oxide polyoxometalates membranes gradient separation nanoparticles