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Meso-mechanical model of concrete under a penetration load

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Defence Technology（防务技术） 2019年第6期15卷 936-948页

作者： cheng wu Wenbin Li Xiaojun Shen Ministerial Key Laboratory of ZNDY Nanjing University of Science and TechnologyNanjing210094China Beijing Special Electrical and Mechanical Research Institute Beijing100012China

The influence of concrete components on projectile penetration is *** study the relationship between the equivalent mechanical properties and components of concrete under a penetration load,concrete is simplified as a two-phase composite of coarse aggregate and mortar,and a meso-mechanical model is established,including the equivalent equation of state model,the equivalent confining pressure strength model and the equivalent dynamic tensile strength model,considering shear stress,large deformation and pore *** of the mechanical properties of mortar,concrete and limestone were conducted;the results show that the equivalent mechanical properties of concrete calculated by the meso-mechanical model are consistent with the test results,and the equivalent mechanical properties of concrete with different volume fractions of coarse aggregate are ***-scale and macro-scale numerical simulations of a projectile penetrating into concrete are carried out,the penetration depths obtained by meso-scale and macro-scale numerical simulations are consistent for different volume fractions of coarse aggregate and different velocities of the projectile,which verifies the rationality of the meso-mechanical model.

关键词： Meso-mechanical Inclusion model Concrete Penetration Projectile

Dominance property based tabu search for single machine scheduling problems with family setups

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Journal of Systems Engineering and Electronics 2009年第6期20卷 1233-1238页

作者： Jin Feng Song Shiji wu cheng Dept. of Automation Tsinghua Univ. Beijing 100084 P. R. China

The problem of minimizing the maximum lateness on a single machine with family setups is *** solve the problem, dominance property is studied and then introduced into the tabu search（TS） *** the dominance property, most unpromising neighbors can be excluded from the neighborhood, which makes the search process always focus on the most promising areas of the solution *** proposed algorithms are tested both on the randomly generated problems and on the real-life *** results show that the proposed TS algorithm outperforms the best existing algorithm and can solve the real-life problems in about 1.3 on average.

关键词： single machine family setups tabu search dominance property.

Infinitesimal dividing modeling method for dual suppliers inventory model with random lead times

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Journal of Systems Engineering and Electronics 2009年第3期20卷 527-536页

作者： Ji Pengcheng Song Shiji wu cheng Dept. of Automation Tsinghua Univ. Beijing 100084 P. R. China

As one of the basic inventory cost models, the （Q, τ）inventory cost model of dual suppliers with random procurement lead time is mostly formulated by using the concepts of ＂effective lead time＂ and ＂lead time demand＂, which may lead to an imprecise inventory cost. Through the real-time statistic of the inventory quantities, this paper considers the precise （Q, τ） inventory cost model of dual supplier procurement by using an infinitesimal dividing method. The traditional modeling method of the inventory cost for dual supplier procurement includes complex procedures. To reduce the complexity effectively, the presented method investigates the statistics properties in real-time of the inventory quantities with the application of the infinitesimal dividing method. It is proved that the optimal holding and shortage costs of dual supplier procurement are less than those of single supplier procurement respectively. With the assumption that both suppliers have the same distribution of lead times, the convexity of the cost function per unit time is proved. So the optimal solution can be easily obtained by applying the classical convex optimization methods. The numerical examples are given to verify the main conclusions.

关键词： inventory precise model random lead times dual supplier infinitesimal dividing method optimiza- tion.

Accreting CO material onto ONe white dwarfs towards accretion-induced collapse

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Research in Astronomy and Astrophysics 2018年第3期18卷 121-128页

作者： cheng-Yuan wu Bo Wang Yunnan Observatories Chinese Academy of Sciences Kunming 650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650216 China University of Chinese Academy of Sciences Beijing 100049 China Center for Astronomical Mega-Science Chinese Academy of Sciences Beijing 100012 China

The final outcomes of accreting ONe white dwarfs（ONe WDs） have been studied for several decades,but there are still some issues that are not resolved. Recently,some studies suggested that the deflagration of oxygen would occur for accreting ONe WDs with Chandrasekhar masses. In this paper,we aim to investigate whether ONe WDs can experience accretion-induced collapse（AIC） or explosions when their masses approach the Chandrasekhar limit. Employing the stellar evolution code Modules for Experiments in Stellar Astrophysics（MESA）,we simulate the longterm evolution of ONe WDs with accreting CO material. The ONe WDs undergo weak multicycle carbon flashes during the mass-accretion process,leading to mass increase of the WDs. We found that different initial WD masses and mass-accretion rates influence the evolution of central density and temperature. However,the central temperature cannot reach the explosive oxygen ignition temperature due to neutrino cooling. This work implies that the final outcome of accreting ONe WDs is electroncapture induced collapse rather than thermonuclear explosion.

关键词： stars evolution - binaries close - supernovae general - white dwarfs

Study on risk analysis of supply chain enterprises

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Journal of Systems Engineering and Electronics 2006年第4期17卷 781-787页

作者： wu Xiaohui Zhong Xiaobing Song Shiji wu cheng Dept of Automation Tsinghua Univ. Beijing 100084 P. R. China Dept. of Economics Harbin Inst. of Technology Harbin 150001 P. R. China

The sources of supply chain enterprise risk from different aspects including material flow, information flow, cash flow and partner relationship is analyzed. Measures for risk reduction have also been summarized from the aspects of risk sharing, information sharing, change of inventory control mode, and supply chain flexibility. Finally, problems in current research on supply chain risk management are pointed out and a discussion on future research trend is presented.

关键词： supply chain risk management risk analysis information sharing.

Layer-wise domain correction for unsupervised domain adaptation

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Frontiers of Information Technology & Electronic Engineering 2018年第1期19卷 91-103页

作者： Shuang LI Shi-ji SONG cheng wu Automation Department Tsinghua University

Deep neural networks have been successfully applied to numerous machine learning tasks because of their impressive feature abstraction ***,conventional deep networks assume that the training and test data are sampled from the same distribution,and this assumption is often violated in real-world *** address the domain shift or data bias problems,we introduce layer-wise domain correction(LDC),a new unsupervised domain adaptation algorithm which adapts an existing deep network through additive correction layers spaced throughout the *** the additive layers,the representations of source and target domains can be perfectly *** corrections that are trained via maximum mean discrepancy,adapt to the target domain while increasing the representational capacity of the *** requires no target labels,achieves state-of-the-art performance across several adaptation benchmarks,and requires significantly less training time than existing adaptation methods.

关键词： Unsupervised domain adaptation Maximum mean discrepancy Residual network Deep learning

Facile Fabrication of Hyperbranched Polyacetal Quaternary Ammonium with pH-Responsive Curcumin Release for Synergistic Antibacterial Activity

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Chinese Journal of Polymer Science 2023年第4期41卷 564-573,I0008页

作者： Xing Wang Ya-Qiang Wang De-cheng wu Beijing National Laboratory for Molecular Sciences State Key Laboratory of Polymer Physics&ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China Department of Biomedical Engineering Southern University of Science and TechnologyShenzhen518055China

In the current global crisis of antibiotic resistance,persuit of an effective multi-pathway collaborative approach to enhance antibacterial activity is urgently ***,a kind of hyperbranched polyacetal quaternary ammonium(Hyper-ace-QA)with efficiently antibacterial function were synthesized by a succession of efficient click *** high molecular weights can be obtained just after UV irradiation for 3 h,and the grafting ratio can be easily adjusted through controlling solvent system,molar ratio,and *** studies indicated that Hyper-ace-QA had good biocompatibility and can be used as a potential antibacterial *** importantly,after in situ encapsulation of bioactive curcumin drugs into the hyperbranched intramolecular cavities,the acid-liable acetal linkers within the hyperbranched backbone made the loading antibacterial drugs rapidly release with pH-or bacterial-responsive behaviors since many bacteria can produce acids at the infection site by the combined actions of immune response and bacterial ***,the integration of quaternary ammonium characteristics and pH-triggered curcumin release could facilitate the antibacterial activity against gram-positive Staphylococcus *** work represents a synergistic strategy on offering important guidance to rational design of multifunctional antimicrobial vehicles,which would be promising therapeutic alternatives for first aid treatment of wound infection in critical situations.

关键词： Hyperbranched polymer Acetal Quaternary ammonium pH-Responsive Antibacterial activity

p38γ regulates UV-induced checkpoint signaling and repair of UV-induced DNA damage

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Protein & Cell 2010年第6期1卷 573-583页

作者： Chia-cheng wu Xiaohua wu Jiahuai Han Peiqing Sun Department of Immunology and Microbial Science The Scripps Research Institute10550 N.Torrey Pines Road.La JollaCA 92037USA Department of Molecular and Experimental Medicine The Scripps Research Institute10550 N.Torrey Pines Road.La JollaCA 92037USA Key Laboratory of Ministry of Education for Cell Biology and Tumor Cell Engineering School of Life SciencesXiamen UniversityXiamen 361005China Dempartment of Molecular Biology The Scripps Research Institute10550 N.Torrey Pines Road.La JollaCA 92037USA

In eukaryotic cells,DNA damage triggers activation of checkpoint signaling pathways that coordinate cell cycle arrest and repair of damaged *** DNA damage responses serve to maintain genome stability and prevent accumulation of genetic mutations and development of *** p38 MAPK was previously implicated in cellular responses to several types of DNA ***,the role of each of the four p38 isoforms and the mechanism for their involvement in DNA damage responses remained poorly *** this study,we demonstrate that p38γ,but not the other p38 isoforms,contributes to the survival of UV-treated *** of p38γsensitizes cells to UV exposure,accompanied by prolonged S phase cell cycle arrest and increased rate of *** investigation reveal that p38γis essential for the optimal activation of the checkpoint signaling caused by UV,and for the efficient repair of UVinduced DNA *** findings have established a novel role of p38γin UV-induced DNA damage responses,and suggested that p38γcontributes to the ability of cells to cope with UV exposure by regulating the checkpoint signaling pathways and the repair of damaged DNA.

关键词： p38γ DNA damage UV DNA repair checkpoint signaling

Controlled Cross-linking Strategy for Formation of Hydrogels,Microgels and Nanogels

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Chinese Journal of Polymer Science 2018年第1期36卷 8-17页

作者： Qing-Chen Cao Xing Wang De-cheng wu Beijing National Laboratory for Molecular Sciences State Key Laboratory of Polymer Physics&ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Hydrogels are a kind of unique cross-linking polymeric materials with three-dimensional networks. Various efforts have been devoted to manipulate the formation of functional hydrogels in situ and enrich the production of hydrogels, microgels and nanogels with improved modulation capacity. However, these methods always fail to tune the gel properties because of the difficulty in achieving the precise control of cross-linking extents once the gel formation is initiated. Therefore, the preparation of tailor-made hydrogels remains a great challenge. Herein, we summarize a controlled cross-linking strategy towards not only fabrication of hydrogels at nano-, micro-and macro-scales, but also achievement of controlled assembly of nanoparticles into multifunctional materials in macroscopic and microscopic scales. The strategy is conducted by controllably activating and terminating the disulfide reshuffling reactions of disulfide-linked core/shell materials with selective core/shell separation using system p H or UV triggers. So it provides a facile approach to producing hydrogels, hydrogel particles and nanoparticle aggregates with tunable structures and properties, opening up the design possibility, flexibility and complexity of hydrogels, microgels/nanogels and nanoparticle aggregates from nanoscopic components to macroscopic objects.

关键词： Thiol-disulfide exchange Controlled cross-linking Hybrid hydrogels Hydrogel particles Biodegradation