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Insect Science 2007年第6期14卷 497-502页

作者： feng gao XIANG-HUI LIU feng GE State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoology Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences Beijing China

Energy budgets of larval stages of the Chinese green lacewing, Chrysopa sinica （Tjeder）（Neuroptera： Chrysopidae） were determined under laboratory conditions at photoperiod of 14：10 L：D, 27 ± 1℃ and 75% ± 2% RH. The energy used as ingestion, assimilation, respiration, productivity and feces was constructed for each developmental stage. In addition, under these experimental conditions, the potential of C. sinica as a biological control agent was evaluated according to the ingestion by this predator and the energy content of cotton aphid, Aphis gossypii （Glover）（Homoptera： Aphididae）. The larval stage of C. sinica was able to consume 1281.4 1-day-old aphids, 1018.7 2-day-old aphids, 626.9 3-day-old aphids, 393.5 4-day-old aphids, 312.1 5-day-old aphids or 203.5 9-day-old aphids, respectively. No significant difference was detected between the estimated number of aphids consumed by the lacewings using energetic methods and the actual number of aphids consumed by the lacewings in this experiment. Our results showed that C. sinica is an important natural enemy of the cotton aphid, and energetic methods are very useful to quantify biological control efficacy of natural enemies.

关键词： Aphis gossypii biological control Chrysopa sinica ecological efficiency,energy budget predation

MULTI-AXLE VEHICLE STABILITY BASED ON WHOLE VEHICLE MODEL

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Chinese Journal of Mechanical Engineering 2007年第5期20卷 87-91页

作者： ZHU Xuebin gao feng Special Chassis Research Department Beijing Institute of Special Engineering Machinery Beijing 100076 China Department of Automobile Engineering Beihang University Beijing 100083 China

From the analysis of experiment data of the multi-axle vehicle chassis searching process, it is less accurate to predict multi-axle vehicle dynamic characteristic with simplified two-axle vehicle model. So it is important to find out a more effective modeling method in the study of multi-vehicle stability. In the development of heat transfer fluid（HTF） six-axle vehicle, a whole vehicle multi-body dynamic model is built through collaborate flowchart using Teamcenter Engineering, UG NX3 and ***. The modeling method of connected hydragas spring suspension is validated by running test results. Based on this whole vehicle model, a kinematical analysis of suspension is implemented to achieve optimized suspension geometry parameters according to the stable requirement. Then, different handling simulations are carried out with regard to various tire characteristics, driving con- figurations, and equipments. According to the evaluation of whole vehicle handling characteristic, some design rules are summarized to improve the stability of multi-axle vehicle.

关键词： Stability Multi-axle vehicle Whole vehicle model Connected hydragas spring

Effects of elevated CO2 and plant genotype on interactions among cotton, aphids and parasitoids

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Insect Science 2011年第4期18卷 451-461页

作者： Yu-Cheng Sun Li feng feng gao feng Ge State Key Laboratory of Integrated Management of Pest and Rodents Institute of Zoology Chinese Academy of Sciences Beijing Graduate University of Chinese Academy of Sciences Beijing Hunan Agricultural University Changsha China

Effects of CO2 level （ambient vs. elevated） on the interactions among three cotton （Gossypium hirsutum） genotypes, the cotton aphid （Aphis gossypii Glover）, and its hymenoptera parasitoid （Lysiphlebiajaponica Ashrnead） were quantified. It was hypothesized that aphid-parasitoid interactions in crop systems may be altered by elevated CO2, and that the degree of change is influenced by plant genotype. The cotton genotypes had high （M9101）, medium （HZ401） and low （ZMS13） gossypol contents, and the response to elevated CO2 was genotype-specific. Elevated C02 increased the ratio of total non-structural carbohydrates to nitrogen （TNC ： N） in the high-gossypol genotype and the mediumgossypol genotype. For all three genotypes, elevated CO2 had no effect on concentrations of gossypol and condensed tannins. A. gossypii fitness declined when aphids were reared on the high-gossypol genotype versus the low-gossypol genotype under elevated CO2. Furthermore, elevated CO2 decreased the developmental time of L. japonica associated with the high-gossypol genotype and the low-gossypol genotype, but did not affect parasitism or emergence rates. Our study suggests that the abundance of A. gossypii on cotton will not be directly affected by increases in atmospheric CO2. We speculate that A. gossypii may diminish in pest status in elevated COz and high-gossypol genotype environments because of reduced fitness to the high-gossypol genotype and shorter developmental time of L. japonica.

关键词： Aphis gossypii cotton genotype elevated CO2 gossypol Lysiphlebiajaponica tritrophic interaction

Immunological and virological characteristics of human immunodeficiency virus type i superinfection： implications in vaccine design

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Frontiers of Medicine 2017年第4期11卷 480-489页

作者： Yang gao Wen Tian Xiaoxu Han feng gao Key Laboratory of AIDS Immunology of Nattonal Health and Famdy Plannmg Commtsston Department of Laboratory Medicme The First Affiliated Hospital China Medical University Shenyang 110001 China National Engineering Laboratory for AIDS Vaccine School of Life Sciences Jilin University Changehun 130012 China Department of Medicine Duke University Medical Center Durham NC 27710 USA

Superinfection is frequently detected among individuals infected by human immunodeficiency virus type I （HIV-1）. Superinfection occurs at similar frequencies at acute and chronic infection stages but less frequently than primary infection. This observation indicates that the immune responses elicited by natural HIV-1 infection may play a role in curb of superinfection; however, these responses are not sufficiently strong to completely prevent superinfection. Thus, a successful HIV-1 vaccine likely needs to induce more potent and broader immune responses than those elicited by primary infection. On the other hand, potent and broad neutralization responses are more often detected after superinfection than during monoinfection. This suggests that broadly neutralizing antibodies are more likely induced by sequential immunization of multiple different immunogens than with only one form of envelope glycoprotein immunogens. Understanding why the protection from superinfection by immunity induced by primary infection is insufficient and if superinfection can lead to cross-reactive immune responses will be highly informative for HIV-1 vaccine design.

关键词： human immunodeficiency virus type I superinfection incidence immtme response

Optimized multiuser detection algorithm for uplink SCMA system

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The Journal of China Universities of Posts and Telecommunications 2017年第1期24卷 11-17页

作者： Tan Yuxi gao Zehua Guo Siyan gao feng School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

Sparse code multiple access （SCMA） is a competitive nonorthogonal access scheme for the next mobile communication. As a multiuser sharing system, SCMA adopts message passing algorithm （MPA） for decoding scheme in receiver, but its iterative method leads to high computational complexity. Therefore, a serial message passing algorithm based on variable node （VMPA） is proposed in this paper. Making some subtle alterations to message update in original MPA, VMPA can greatly reduce overall computing complexity of decoding scheme. Furthermore, considering that serial structure may increase decoding delay, a novel grouping scheme based sparse matrix is applied to VMPA. Simulation results verify that the new algorithm, termed as grouping VMPA （G-VMPA）, can achieve a better tradeoff between bit error rate （BER） and computing complexity than MPA.

关键词： SCMA MPA computational complexity

A time-series modeling method based on the boosting gradient-descent theory

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Science China(Technological Sciences) 2011年第5期54卷 1325-1337页

作者： gao YunLong PAN JinYan JI GuoLi gao feng Department of Automation Xiamen University Xiamen 361005 China SKLMS Laboratory Xi 'an Jiaotong University Xi 'an 710049 China College of Information Engineering Jimei University Xiamen 361021 China

The forecasting of time-series data plays an important role in various domains. It is of significance in theory and application to improve prediction accuracy of the time-series data. With the progress in the study of time-series, time-series forecasting model becomes more complicated, and consequently great concern has been drawn to the techniques in designing the forecasting model. A modeling method which is easy to use by engineers and may generate good results is in urgent need. In this paper, a gradient-boost AR ensemble learning algorithm (AREL) is put forward. The effectiveness of AREL is assessed by theoretical analyses, and it is demonstrated that this method can build a strong predictive model by assembling a set of AR models. In order to avoid fitting exactly any single training example, an insensitive loss function is introduced in the AREL algorithm, and accordingly the influence of random noise is reduced. To further enhance the capability of AREL algorithm for non-stationary time-series, improve the robustness of algorithm, discourage overfitting, and reduce sensitivity of algorithm to parameter settings, a weighted kNN prediction method based on AREL algorithm is presented. The results of numerical testing on real data demonstrate that the proposed modeling method and prediction method are effective.

关键词： time-series forecasting boosting ensemble learning overfitting

Critical-Current Degeneration Dependence on Axial Strain of Bi-based Superconducting Multi-filamentary Composite Tapes

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Chinese Physics Letters 2014年第4期31卷 155-158页

作者： gao Pei-feng WANG Xing-Zhe Key Laboratory of Mechanics on Western Disaster and Environment (Ministry of Education) and College of Civil Engineering and Mechanics Lanzhou University Lanzhou 730000

Superconducting materials are always severely restricted in practical engineering applications due to their carrying- current degradation under mechanical loads. Based on Ekin＇s exponential model and Weibull＇s distribution func- tion, we propose an empirical degradation model for describing the mechanical deformation influence on the critical-current of Bi-based superconducting multi-filamentary composite tapes under axial loading. The critical currents of superconducting tapes depending on the axial strain are investigated analytically. It is shown that the predictions by the developed degradation model agree with the experimental data, in the processes of axial mechanical loading and unloading on the samples. The effect of the critical tension and compression damage strains on the normalized critical currents is also discussed.

关键词： Tapes Critical-Current mechanical

A novel six-legged walking machine tool for in-situ operations

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Frontiers of Mechanical Engineering 2020年第3期15卷 351-364页

作者： Jimu LIU Yuan TIAN feng gao State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

The manufacture and maintenance of large parts in ships,trains,aircrafts,and so on create an increasing demand for mobile machine tools to perform in-situ ***,few mobile robots can accommodate the complex environment of industrial plants while performing machining *** study proposes a novel six-legged walking machine tool consisting of a legged mobile robot and a portable parallel kinematic machine *** kinematic model of the entire system is presented,and the workspace of different components,including a leg,the body,and the head,is analyzed.A hierarchical motion planning scheme is proposed to take advantage of the large workspace of the legged mobile platform and the high precision of the parallel machine *** repeatability of the head motion,body motion,and walking distance is evaluated through experiments,which is 0.11,1.0,and 3.4 mm,***,an application scenario is shown in which the walking machine tool steps successfully over a 250 mmhigh obstacle and drills a hole in an aluminum *** experiments prove the rationality of the hierarchical motion planning scheme and demonstrate the extensive potential of the walking machine tool for in-situ operations on large parts.

关键词： legged robot parallel mechanism mobile machine tool in-situ machining

Creep rate sensitivities of materials by a depth-sensing indentation technique

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Journal of University of Science and Technology Beijing 2006年第4期13卷 308-312页

作者： Yang gao Shengping Wen feng Pan Laboratory of Advanced Materials Department of Materials Science and Engineering Tsinghua University Beijing 100084 China

The strain rate sensitivity to creep of single crystal Cu（110）, metal tantalum, and 128°Y-X LiNbO3 piezoelectric single crystal were measured at room temperature by MTS Nanoindenter XP. Among the three kinds of materials studied, Cu showed the highest degree of resistance to creep-induced deformation, which is followed by Ta, while the LiNbO3 single crystal deformed more readily than the others. The values of the steady-state strain rate sensitivities determined by the indentation methods are in the range of 0.002-0.006, 0.02-0.06 and 0.02-0.03 for Cu, Ta, and LiNbO3, respectively. The mechanisms for the indentation-induced creeping behavior and the factors that influenced the creeping are discussed.

关键词： indentation creep strain rate sensitivity copper tantalum LiNbO3 piezoelectric single crystal

Green synthesis of metal/C and metal oxide/C films by using natural membrane as support

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Frontiers of Materials Science 2014年第2期8卷 150-156页

作者： Cheng-Zhen WEI Hai-feng MA feng gao Department of Materials Science and Engineering Nanjing University Nanjing 210093 China State Key Laboratory of Coordination Chemistry Coordination Chemistry Institute Nanjing National Laboratory of Microstructures Nanjing University Nanjing 210093 China

A protocol aiming at making use of the huge amount of naturally existing wastes such as defoliation, pericarp and egg shell for nanostructured composite materials was proposed. In this study, a green synthetic route using naturally existing membrane as support was developed for the synthesis of nanostructured and porous metalor metal oxide-carbon composite films. Different metallic ions （Co2＋, Ni2＋, Fe3＋, Mn2＋ or Cu2＋） can be easily adsorbed onto egg membranes and the followed calcination process results in the formation of Co/C, Ni/C, Fe304/C, MnO/C or CulCu2OICuOIC composite films. The electrochemical studies demonstrate that such composite films would have potential applications in energy fields. This method would provide a general green concept for chemical synthesis and be beneficial to the global sustainable future.

关键词： green synthesis metal metal oxide composite electrochemistry