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Addressing the environmental risk of persistent organic pollutants in China

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Frontiers of Environmental Science & Engineering 2012年第1期6卷 2-16页

作者： bin WANG Jun HUANG Shubo deng Xiaoling YANG Gang YU POPs Research Center School of EnvironmentTsinghua UniversityBeijing 10084China

The Stockholm Convention on persistent organic pollutants （POPs） was adopted in 2001. This year is the 10th anniversary of the adoption of the Convention. Until now, 22 chemicals or chemical categories have been listed as POPs in the Stockholm Convention. The POPs Research Center was established in Tsinghua University in the same year when the Convention was adopted. In the last ten years, much work has been done by Chinese researchers to understand the environ- mental risk of POPs in China. This article aims to review the recent research progress of our POPs Research Center and some other Chinese researchers＇ studies in addressing the environmental risk of POPs, including the priority screening and inventory study of POPs, monitoring and modeling of POPs pollution and exposure, and environ- mental risk assessment and modeling of POPs. Although great advances in addressing the environmental risk of POPs have been made in recent years, we are still facing quite a few problems, such as data scarcity and uncertainty in environmental risk assessment of POPs. The study on the effect of POPs mixtures is in its infancy and currently POPs are usually assessed from legal perspective by risk assessment of single chemicals. These problems should be well addressed by further efforts. Further studies should also be taken in future to study environment risk of POPs by considering aspects of coupled dynamics between climate processes and POPs. Such sound scientific, riskbased information can support decision-making aiming to effectively minimize the risk level of POPs.

关键词： persistent organic pollutant (POPs) environ- mental risk assessment inventory environmental monitoring fugacity model emerging POPs

Assessment of tumor response to chemotherapy in patients with breast cancer using ^(18)F-FLT: a meta-analysis

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Chinese Journal of Cancer Research 2014年第5期26卷 517-524页

作者： Sheng-Ming deng Wei Zhang bin Zhang Yi-Wei Wu Department of Nuclear Medicine The First Affiliated Hospital of Soochow University School of Radiation Medicine and Protection Medical College of Soochow University Key Laboratory of Nuclear Medicine Ministry of HealthJiangsu Key Laboratory of Molecular Nuclear MedicineJiangsu Institute of Nuclear Medicine

Purpose： To determine the diagnostic performance of 3＇-deoxy-3＇-18F-fluorothymidine positron emission tomography/computed tomography（FLT PET/CT） and FLT PET for evaluating response to chemotherapy in patients with breast cancer.Methods： Databases such as Pub Med（MEDLINE included） and excerpta medica database（EMBASE）, were searched for relevant original articles. The included studies were assessed for methodological quality with quality assessment of diagnosis accuracy studies（QUADAS） score tool. Histopathological analysis and/or clinical and/or radiological follow-up for at least 6 months were used as the reference standard. The data were extracted by two reviewers independently to analyze the sensitivity, specificity, summary receiver operating characteristic（SROC） curve, area under the curve（AUC）, and heterogeneity.Results： The present study analyzed a total of 4 selected articles. The pool sensitivity was 0.773 [95% confidence interval（CI）： 0.594-0.900]. The pooled specificity was 0.685（95% CI： 0.479-0.849） on basis of FEM. The pooled LR^＋, LR^-, and DOR were 2.874（1.492-5.538）, 0.293（0.146-0.589）, and 14.891（3.238-68.475）, respectively. The AUC was 0.8636（±0.0655）, and the Q＊ index was 0.7942（±0.0636）.Conclusions： Our results indicate that 18^F-FLT PET/CT or PET is useful to predict chemotherapy response in breast cancer with reasonable sensitivity, specificity and DOR. However, future larger scale clinical trials will be needed to assess the regimen of 18^F-FLT PET/CT or PET in monitoring the response to chemotherapy in breast cancer patients.

关键词： Breast cancer 18 ^F-FLT PET chemotherapy meta-analysis

On Origin of Power-Law Distributions in Self-Organized Criticality from Random Walk Treatment

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Communications in Theoretical Physics 2008年第1期49卷 249-251页

作者： CAO Xiao-Feng deng Zong-Wei YANG Chun-bin Institute of Particle Physics Huazhong Normal University Wuhan 430079 China

The origin of power-law distributions in self-organized criticality is investigated by treating the variation of the number of active sites in the system as a stochastic process. An avalanche is then regarded as a first-return random walk process in a one-dimensional lattice. We assume that the variation of the number of active sites has three possibilities in each update： to increase by 1 with probability f1, to decrease by 1 with probability f2, or remain unchanged with probability 1 - f1 - f2. This mimics the dynamics in the system. Power-law distributions of the lifetime are found when the random walk is unbiased with equal probability to move in opposite directions. This shows that power-law distributions in self-organized criticality may be caused by the balance of competitive interactions.

关键词： power-law distribution sell'organized criticality random walk

Sensitivity of WRF simulated typhoon track and intensity over the South China Sea to horizontal and vertical resolutions

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Acta Oceanologica Sinica 2019年第7期38卷 74-83页

作者： Zhiyuan Wu Changbo Jiang bin deng Jie Chen Xiaojian Liu School of Hydraulic Engineering Changsha University of Science&TechnologyChangsha 410114China Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province Changsha 410114China School for Marine Science and Technology University of Massachusetts DartmouthNew BedfordMA 02744USA Key Laboratory of the Pearl River Estuarine Dynamics and Associated Process Regulation Ministry of Water ResourcesGuangzhou 510611China

To determine the grid resolutions of the WRF model in the typhoon simulation,some sensitivity analysis of horizontal and vertical resolutions in different conditions has been carried *** horizontal resolutions(5,10,20,30 km),nesting grids(15 and 5 km),different vertical resolutions(35-layers,28-layers,20-layers)and different top maximum pressures(1 000,2 000,3 500,5 000 Pa)had been used in the mesoscale numerical model WRF to simulate the Typhoon *** simulation results of typhoon track,wind speed and sea level pressure at different horizontal and vertical resolutions have been compared and *** horizontal and vertical resolutions of the model have limited effect on the simulation effect of the typhoon *** horizontal and vertical resolutions have obvious effects on typhoon strength(defined by wind speed)and intensity(defined by sea level pressure,SLP),especially for sea level *** typhoon intensity simulated by the high-resolution model is closer to the real situation and the nesting grids can improve computational accuracy and *** simulation results affected by vertical resolution using 35-layers is better than the simulation results using 20-layers and 28-layers *** comparison and analysis,the horizontal and vertical resolutions of WRF model are finally determined as follows:the two-way nesting grid of 15 and 5 km is comprehensively determined,and the vertical layers is 35-layers,the top maximum pressure is 2 000 Pa.

关键词： sensitivity analysis typhoon track and intensity horizontal and vertical resolutions Typhoon Kai-tak WRF

Effect of grain boundary segregation on aging resistance and mechanical properties of tetravalent element-doped 3Y-TZP ceramics for dental restoration

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International Journal of Smart and Nano Materials 2023年第2期14卷 170-188页

作者： bin deng Rongfang Zou Yang Huang Lu Feng Yanru Chen Department of Stomatology the First Medical CenterChinese PLA General HospitalBeijingChina Chinese PLA Medical School BeijingChina

In the humid oral environment,3Y-TZP ceramics always suffer from low-temperature degradation(LTD)for a long time,which results in the degradation of mechanical properties and catastrophic *** low-temperature degradation(LTD)and mechanical properties of low-cost tetravalent(Ge^(4+),Ti^(4+))element-doped 3Y-TZP were investigated by analysing grain boundary segregation in samples with deferent *** results show that GeO_(2) is superior to TiO_(2) in limiting LTD but results in lower flexural strength and fracture toughness when the content is≥1.5 mol%.This dilemma can be improved by adding only 0.1%-0.5 wt%Al_(2)O_(3),and the flexural strength and fracture toughness of 0.25 wt% Al_(2)O_(3) zirconia are then increased to 898 MPa and 4.68 MPa·m^(1/2) compared with 1Ge-3Y,*** work is expected to provide an effective reference for the development and application of budget dental materials.

关键词： 3Y-TZP low-temperature degradation grain boundary segregation mechanical properties GeO_(2)

Solution to the Fokker–Planck Equation with Piecewise-Constant Drift

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Chinese Physics Letters 2020年第6期37卷 1-4页

作者： bin Cheng Ya-Ming Chen Xiao-Gang deng College of Computer National University of Defense TechnologyChangsha 410073China College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China Chinese Academy of Military Science Beijing 100071China

We study the solution to the Fokker–Planck equation with piecewise-constant drift,taking the case with two jumps in the drift as an *** solution in Laplace space can be expressed in closed analytic form,and its inverse can be obtained conveniently using some numerical inversion *** results obtained by numerical inversion can be regarded as exact solutions,enabling us to demonstrate the validity of some numerical methods for solving the Fokker–Planck *** particular,we use the solved problem as a benchmark example for demonstrating the fifth-order convergence rate of the finite difference scheme proposed previously[Chen Y and deng X ***.E 100(2019)053303].

关键词： equation. piecewise conveniently

Does labor off-farm employment inevitably lead to land rent out?Evidence from China

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Journal of Mountain Science 2019年第3期16卷 689-700页

作者： deng Xin XU Ding-de ZENG Miao QI Yan-bin College of Economics Sichuan Agricultural University Sichuan Center for Rural Development Research College of ManagementSichuan Agricultural University School of Economics Sichuan University

The focus of land economics is on how to decrease the misallocation of resources to achieve an optimal allocation of resources. Both the theories of new economics of labor migration(NELM) and the conclusions of empirical studies reveal that land resources will inevitably be reallocated(e.g., rented out) if the resources of family labor are reallocated(e.g., off-farm employment). However, this study reveals that off-farm employment does not inevitably lead to land rent out. More precisely, this study uses survey data on 8031 peasant households from 27 provinces in China and explores the relationship between off-farm employment and land rent out by describing spatial features and through empirical analysis(e.g., IV-Probit model and IV-Tobit model). The results show the following: 1) There is an indirect relationship between off-farm employment and land rent out regarding spatial area aggregation, i.e., regions with a higher ratio of off-farm employment also have a lower area of land rent out. 2) Off-farm employment is significantly positively correlated with the behavior of land rent out, but its square is significantly negatively correlated with the behavior, i.e., there is an inverted U-shaped relationship between off-farm employment and the behavior of land rent out, with the turning point being 55.55% offfarm employment. 3) Off-farm employment is significantly positively correlated with the area of land rent out, but its square is significantly negatively correlated with the area, i.e., there is an inverted Ushaped relationship between off-farm employment and the area of land rent out, with the turning point being 56.22% off-farm employment. This study helps explain why China has a high ratio of off-farm employment but a lower rate of land rent out.

关键词： Rural labor Off-farm employment Land rent out Rent out area China

EFFECTS OF NONPARALLELISM ON THE BOUNDARY LAYER STABILITY

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Journal of Hydrodynamics 2002年第4期14卷 81-87页

作者： Tang deng bin College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics

The nonparallel effects on the stability of the boundary layer flow was investigated using the Parabolie Stability Equations (PSE). In order to improve the accuracy of the calculation which is very important for the investigation of stability, higher order expansions in orthogonal functions in normal direction and the effective algebraic mapping to deal with the problem of infinite region were used and the way to collocate the boundary point based on its characteristics was adopted. With the effective control of step size in the marching procedure, the special condition was satisfied, and the stability of calculation was assured. From the curves of the neutral stability, the growth rate, the amplitude variation and disturbed velocity profile, the effects of the nonparallelism were given accurately and analyzed detailedly. It is found that the nonparallelism of the flow amplifies the amplitude and growth rate of disturbances, especially for three-dimensional disturbances, even can change the sign of flow stability from stability to instability for some cases. Computed results are in good agreement with the classical experimental results.

关键词： nonparallelism boundary layer stability chebyshev polynomials pressure gradient parabolic stability equations

The Protective Role of Procyanidins and Lycopene Against Mercuric Chloride Renal Damage in Rats

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Biomedical and Environmental Sciences 2011年第5期24卷 550-559页

作者： YANG HaiBo XU ZhaoFa LIU Wei deng Yu XU bin Department of Environmental Health School of Public Health China Medical University Shenyang 110001 Liaoning China

Objective This study aims to investigate the protection of procyanidins and lycopene from the renal damage induced by mercuric *** Rats were treated with either procyanidins or lycopene 2h before HgCl 2 subcutaneously injection,once daily treatment for 2 successive *** In comparison with HgCl 2 group,markers of renal function such as blood urea nitrogen in serum and urinary protein were decreased to （18.45±11.63） mmol/L and （15.93±9.36） mmol/L,（4.54±0.78） g/（g Cr） and （4.40±1.12） g/（g Cr）.N‐acetyl‐beta‐D‐glucosaminidase,lactate dehydrogenase,alkaline phosphatase in urine were depressed to （125.49±11.68） U/（g Cr）,（103.73±21.79） U/（g Cr）,（101.99±12.28） U/（g Cr）,and （113.19±23.74） U/（g Cr）,（71.14±21.80） U/（g Cr）,（73.64±21.51） U/（g Cr） in procyanidins and lycopene *** of oxidative stress,for example,Glutathion was reduced to （45.58±9.89） μmol/（g pro） and （45.33±5.90） μmol/（g pro）,and antioxidant enzymes such as superoxide dismutase,glutathione‐peroxidase were enhanced to （43.07±10.97） U/（mg pro） and （39.94±6.04） U/（mg pro）,（83.85±18.48） U/（mg pro）,and （85.62±12.68） U/（mg pro）.Malondialdehyde was lowered to （0.95±0.12）（μmol/g pro） and （1.03±0.12） μmol/（g pro） in procyanidins and lycopene *** generation was decreased by 27.63% and 16.40% and apoptosis was also decreased in procyanidins and lycopene groups *** changes were much better as *** Procyanidins and Lycopene play some protective role against mercury kidney damage.

关键词： Mercuric chloride Procyanidins Lycopene Renal damage Protection