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Journal of Environmental Sciences 2013年第3期25卷 531-536页

作者： Jinze lv Lizhong Zhu Department of Environmental Science Zhejiang University Zhejiang Province Key Laboratory of Organic Pollution Process and Control

Central ventilation and air conditioner systems are widely utilized nowadays in public places for air exchange and temperature control,which significantly influences the transfer of pollutants between indoors and *** study the effect of central ventilation and air conditioner systems on the concentration and health risk from airborne pollutants,a spatial and temporal survey was carried out using polycyclic aromatic hydrocarbons （PAHs） as agent *** the period when the central ventilation system operated without air conditioning （AC-off period）,concentrations of 2-4 ring PAHs in the model supermarket were dominated by outdoor levels,due to the good linearity between indoor air and outdoor air （rp〉0.769,p〈0.05）,and the slopes （1.2-4.54） indicated that ventilating like the model supermarket increased the potential health risks from low molecular weight *** the period when the central ventilation and air conditioner systems were working simultaneously （AC-on period）,although the total levels of PAHs were increased,the concentrations and percentage of the particulate PAHs indoors declined *** BaP equivalency （BaPeq） concentration indicated that utilization of air conditioning reduced the health risks from PAHs in the model supermarket.

关键词： particulate gaseous PAHs health risk public place

Error- and loss-tolerant bundle fragment authentication for space DTNs

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Frontiers of Computer Science 2014年第6期8卷 1012-1023页

作者： Xixiang lv Hui LI The National Key Lab of Integrated Services Networks Xidian University Xi'an 710071 China

To ensure the authenticity and integrity of bundles, the in-transit PDUs of bundle protocol （BP） in space delay/disruption-tolerant networks （DTNs）, the bundle security protocol specification （IRTF RFC6257） suggested using a digital signature directly over each bundle. However, when bundle fragment services are needed, this mechanism suffers from heavy computational costs, bandwidth overheads and energy consumption. In this paper, we address the fragment authentication issue for BP by exploiting the combination of RS error correction and erasure codes with the help of batch transmission characteristic of DTNs. The RS error correction and erasure codes are adopted to allow the receivers to locate the false/injected fragments and reconstruct the only one signature shared by all fragments of a bundle, even if some other fragments are lost or routed to a different path. Getting only partial authentic fragments, a DTN node is able to detect and filter the false/injected fragments, and authenticate the origin of a bundle as well. Such an approach tolerates high delays, unexpected link disruption and the BP nature of routing fragments of the same bundle possibly via different paths. The performance analysis demonstrates that both of our schemes, which follow our generic idea based on RS codes, significantly reduce bandwidth overheads and computational costs as compared to the prior works.

关键词： space-based delay tolerant networks bundle authentication information security.

Measurements of convection electric field in the inner magnetosphere

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Science China(Technological Sciences) 2018年第12期61卷 1866-1871页

作者： lv Xin LIU WenLong School of Space and Environment Beihang University

In this paper, we study the characteristic of large-scale convection electric field in the inner magnetosphere, using magnetospheric multiscale(MMS) observations between L=5 and L=8 over the period from September 1, 2015 to October 31, 2016,covering almost all magnetic local time(MLT). Observations show that the DC convection electric field generally has small variations in this region. We investigate whether the convection electric field is correlated with geomagnetic indices and solar wind parameters. It is found that, among the studied parameters, solar wind electric field, z component of interplanetary magnetic field, AE and Kp indices show good correlations with the averaged convection electric field. The results in this paper provide valuable information for understanding the role of electric field on the dynamics of the inner magnetosphere.

关键词： convection electric field inner magnetosphere

A direct probabilistic approach to solve state equations for nonlinear systems under random excitation

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Acta Mechanica Sinica 2016年第5期32卷 941-958页

作者： Zheng lv Zhiping Qiu Institute of Solid Mechanics Beihang University

In this paper, a direct probabilistic approach（DPA） is presented to formulate and solve moment equations for nonlinear systems excited by environmental loads that can be either a stationary or nonstationary random *** proposed method has the advantage of obtaining the response＇s moments directly from the initial conditions and statistical characteristics of the corresponding external excitations. First, the response＇s moment equations are directly derived based on a DPA, which is completely independent of the It？/filtering approach since no specific assumptions regarding the correlation structure of excitation are *** solving them under Gaussian closure, the response＇s moments can be obtained. Subsequently, a multiscale algorithm for the numerical solution of moment equations is exploited to improve computational efficiency and avoid much wall-clock time. Finally, a comparison of the results with Monte Carlo（MC） simulation gives good ***, the advantage of the multiscale algorithm in terms of efficiency is also demonstrated by an engineering example.

关键词： Direct probabilistic approach Nonlinear dynamic system Nonstationary random process Response’s moments Multiscale algorithm

Efficacy,safety and treatment satisfaction of transition to a regimen of insulin degludec/aspart:A pilot study

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World Journal of Diabetes 2025年第1期16卷 65-73页

作者： Na Yang Lu lv Shu-Meng Han Li-Yun He Zi-Yi Li Yu-Cheng Yang Fan Ping Ling-Ling Xu Wei Li Hua-Bing Zhang Yu-Xiu Li Department of Endocrinology Key Laboratory of Endocrinology of National Health CommissionPeking Union Medical College HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100730China Department of Allergy Beijing Key Laboratory of Precision Medicine for Diagnosis and Treatment of Allergic DiseasesNational Clinical Research Center for Dermatologic and Immunologic DiseasesPeking Union Medical College HospitalChinese Academy of Medical SciencesPeking Union Medical CollegeBeijing 100730China

BACKGROUND There is a lack of clinical evidence on the efficacy and safety of transitioning from a thrice-daily pre-mixed insulin or basal-prandial regimen to insulin degludec/aspart(IDegAsp)therapy,with insufficient data from the Chinese *** To demonstrate the efficacy,safety,and treatment satisfaction associated with the transition to IDegAsp in type 2 diabetes mellitus(T2DM).METHODS In this 12-week open-label,non-randomized,single-center,pilot study,patients with T2DM receiving thrice-daily insulin or intensive insulin treatment were transitioned to twice-daily injections of insulin *** doses,hemoglobin A1c(HbA1c)levels,fasting blood glucose(FBG),hypoglycemic events,a Diabetes Treatment Satisfaction Questionnaire,and other parameters were assessed at baseline and *** This study included 21 participants.A marked enhancement was observed in the FBG level(P=0.02),daily total insulin dose(P=0.03),and overall diabetes treatment satisfaction(P<0.01)in the participants who switched to *** was a decrease in HbA1c levels(7.6±1.1 vs 7.4±0.9,P=0.31)and the frequency of hypoglycemic events of those who switched to IDegAsp decreased,however,there was no statistically significant *** The present findings suggest that treatment with IDegAsp enhances clinical outcomes,particularly FBG levels,daily cumulative insulin dose,and overall satisfaction with diabetes treatment.

关键词： Insulin degludec/aspart Type 2 diabetes management Basal-bolus insulin therapy Pre-mixed insulin Diabetes treatment satisfaction questionnaire

High-order discontinuous Galerkin method for applications to multicomponent and chemically reacting flows

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Acta Mechanica Sinica 2017年第3期33卷 486-499页

作者： Yu lv Matthias Ihme Department of Mechanical Engineering Stanford University

This article focuses on the development of a discontinuous Galerkin (DG) method for simulations of multicomponent and chemically reacting flows. Compared to aerodynamic flow applications, in which DG methods have been successfully employed, DG simulations of chemically reacting flows introduce challenges that arise from flow unsteadiness, combustion, heat release, compressibility effects, shocks, and variations in thermodynamic properties. To address these challenges, algorithms are developed, including an entropy-bounded DG method, an entropy-residual shock indicator, and a new formulation of artificial viscosity. The performance and capabilities of the resulting DG method are demonstrated in several relevant applications, including shock/bubble interaction, turbulent combustion, and detonation. It is concluded that the developed DG method shows promising performance in application to multicomponent reacting flows. The paper concludes with a discussion of further research needs to enable the application of DG methods to more complex reacting flows.

关键词： Discontinuous Galerkin method High-order schemes Reacting flows Multicomponent flows

Fractures interaction and propagation mechanism of multi-cluster fracturing on laminated shale oil reservoir

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Petroleum Science 2024年第4期21卷 2600-2613页

作者： Jia-Xin lv Bing Hou Department of Petroleum Engineering China University of Petroleum(Beijing)at KaramayKaramay834000XinjiangChina Key Laboratory of Petroleum Engineering Ministry of EducationChina University of Petroleum(Beijing)Beijing102249China State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China

The continental shale reservoirs of Jurassic Lianggaoshan Formation in Sichuan Basin contain thin lamina,which is characterized by strong plasticity and developed longitudinal shell limestone *** improve the production efficiency of reservoirs by multi-cluster fracturing,it is necessary to consider the unbalanced propagation of hydraulic fractures and the penetration effect of *** paper constructed a numerical model of multi-fracture propagation and penetration based on the finite element coupling cohesive zone method;considering the construction cluster spacing,pump rate,lamina strength and other parameters studied the influencing factors of multi-cluster fracture interaction propagation;combined with AE energy data and fracture mode reconstruction method,quantitatively characterized the comprehensive impact of the strength of thin interlayer rock interfaces on the initiation and propagation of fractures that penetrate layers,and accurately predicted the propagation pattern of hydraulic fractures through laminated shale oil *** results revealed that in the process of multi-cluster fracturing,the proportion of shear damage is low,and mainly occurs in bedding fractures activated by outer *** the cluster spacing enhances the fracture system's penetration ability,though it lowers the activation efficiency of *** high plasticity of the limestone interlayer may impact the vertical propagation distance of the main *** the interface strength is beneficial to the reconstruction of the fracture height,but the interface communication effect is *** selection of layers with moderate lamina strength for fracturing stimulation,increasing the pump rate during fracturing and setting the cluster spacing reasonably are beneficial to improve the effect of reservoir stimulation.

关键词： Laminated shale Multi-cluster fracturing Cross-layer Cohesive zone model Acoustic emission technique

A fast forward computational method for nuclear measurement using volumetric detection constraints

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Nuclear Science and Techniques 2024年第2期35卷 47-63页

作者： Qiong Zhang Lin-lv Lin University of Electronic Science and Technology of China Chengdu 610000China

Owing to the complex lithology of unconventional reservoirs,field interpreters usually need to provide a basis for interpretation using logging simulation *** the various detection tools that use nuclear sources,the detector response can reflect various types of information of the *** Monte Carlo method is one of the primary methods used to obtain nuclear detection responses in complex ***,this requires a computational process with extensive random sampling,consumes considerable resources,and does not provide real-time response ***,a novel fast forward computational method(FFCM)for nuclear measurement that uses volumetric detection constraints to rapidly calculate the detector response in various complex environments is ***,the data library required for the FFCM is built by collecting the detection volume,detector counts,and flux sensitivity functions through a Monte Carlo ***,based on perturbation theory and the Rytov approximation,a model for the detector response is derived using the flux sensitivity function method and a one-group diffusion *** environmental perturbation is constrained to optimize the model according to the tool structure and the impact of the formation and borehole within the effective detection ***,the method is applied to a neutron porosity tool for *** various complex simulation environments,the maximum relative error between the calculated porosity results of Monte Carlo and FFCM was 6.80%,with a rootmean-square error of 0.62 *** field well applications,the formation porosity model obtained using FFCM was in good agreement with the model obtained by interpreters,which demonstrates the validity and accuracy of the proposed method.

关键词： Nuclear measurement Fast forward computation Volumetric constraints

N掺杂TiO_(2)-Fe_(2)O_(3)/C光催化剂的制备及其光催化降解性研究

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化工新型材料 2025年第2期53卷 210-214页

作者：李洁张佳陈连喜吕博武昌工学院食品与健康研究所武汉430065 湖北工业大学生命科学与健康工程学院武汉430068 武汉理工大学化学化工与生命科学学院武汉430070

为寻找一种简便且具有良好孔结构的光催化剂合成路径,提升并拓宽其光催化应用范围,通过将N掺杂的双金属Ti-Fe MOFs在500℃的空气气氛中直接热解制备N掺杂TiO_(2)-Fe_(2)O_(3)/C纳米结构。获得的产物显示出独特的树枝状结构,且具有较大... 详细信息

为寻找一种简便且具有良好孔结构的光催化剂合成路径,提升并拓宽其光催化应用范围,通过将N掺杂的双金属Ti-Fe MOFs在500℃的空气气氛中直接热解制备N掺杂TiO_(2)-Fe_(2)O_(3)/C纳米结构。获得的产物显示出独特的树枝状结构,且具有较大比表面积和良好的介孔结构。同时,红外光谱(FT-IR)和X射线光电子能谱(XPS)结果证实,在空气条件下煅烧后,衍生物仍保留了N和C成分。此外,将制备的N掺杂树枝状双金属结构多孔材料作为光催化剂用于降解亚甲基蓝(MB)染料。结果表明:N掺杂TiO_(2)-Fe_(2)O_(3)/C比N掺杂非Fe参与的TiO_(2)/C和非N非Fe掺杂TiO_(2)/C具有更好的光催化性能,且N掺杂TiO_(2)-Fe_(2)O_(3)/C对MB染料的有效降解率达到81%。

关键词： Ti基-MOFs Fe基-MOFs TiO_(2)-Fe_(2)O_(3)/C N掺杂光催化

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清代木兰围场八旗驻防与各民族交往交流交融

河北民族师范学院学报 2025年第1期45卷 1-6页

作者：艾虹吕晓青河北民族师范学院历史文化学院河北承德067000

木兰围场是清代肄武绥藩的重地,木兰围场初设时由扎萨克蒙古管领,康熙四十五年(1706)始设八旗驻防官兵看护。乾嘉时期,清廷实施严格的封禁政策,形成以驻防八旗官兵为主、地方州县与扎萨克蒙古协同看围制度。道光以降,清帝鲜少北巡,木兰... 详细信息

木兰围场是清代肄武绥藩的重地,木兰围场初设时由扎萨克蒙古管领,康熙四十五年(1706)始设八旗驻防官兵看护。乾嘉时期,清廷实施严格的封禁政策,形成以驻防八旗官兵为主、地方州县与扎萨克蒙古协同看围制度。道光以降,清帝鲜少北巡,木兰秋狝制度衰落,加之热河八旗生计问题严峻,清廷对木兰围场进行招佃放垦,以济兵食,驻防八旗官兵看护围场的职能因之衰落,但客观上加深了域内各民族间的交往交流交融。

关键词：清代木兰围场八旗驻防北部边疆民族交往交流交融