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THE PRECISE AND NEW ANALYSIS FOR A MODE Ⅲ GROWING CRACK IN AN ELASTIC-PERFECTLY PLASTIC SOLID

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Applied Mathematics and Mechanics(English Edition) 1993年第4期14卷 345-352页

作者： Yi zhi-jian Bridge and Structural Engineering Department Chongqing Jiaotong InstituteChongqing

The near crack line field analysis method has been used to investigate into Mode III quasistatically propagating crack in an elastic-perfectly plastic *** significance of this paper is that the usual small scale yielding theory has been broken *** obtaining the general solutions of the stresses and the displacement rate of the near crack line plastic region,and by matching the general solutions with the precise elastic fields(not the usual elastic K-dominant fields)at the elastic-plastic boundary,the precise and new solutions of the stress and deformation fields,the size of the plastic region and the unit normal vector of the elastic-plastic boundary have been obtained near the crack *** solutions of this paper are sufficiently precise near the crack line region because the roughly qualitative assumptions of the small scale yielding theory have not been used and no other roughly qualitative assumptions have been taken,*** analysis of this paper shows that the assumingly'steady-state case'for stable crack growth,which has been discussed attentively in previous works,do not exist,and the plastic strains near the crack line do not have singularities,Two most important cases for stable crack growth have been discussed.

关键词： quasistatically propagating crack crack line elastic-plastic boundary precise solutions

α-Transience and α-Recurrence of Right Processes

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Acta Mathematica Sinica,English Series 2006年第5期22卷 1413-1424页

作者： Min zhi ZHAO jian Gang YING Department of Mathematics Zhejiang University Hangzhou 310027 P. R. China Institute of Mathematics Fudan University Shanghai 200433 P. R. China

In this article, we mainly discuss some potential theory in the framework of right Markov processes. We introduce the concept of α-excessive function, α-recurrence and α-transience for right processes with α ≤ 0,... 详细信息

关键词： α-transience α-recurrence Right process α-excessive function

Sub-chronic Toxicity of Defoamer Used in Seawater Desalination

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Biomedical and Environmental Sciences 2019年第5期32卷 334-344页

作者： DUAN Lian ZHANG Chong Hua gu Wen zhi Hong KONG jian ZHANG Shao Ping LI Yi Min LU Kai Institute for Environmental Health and Related Product Safety Chinese Center for Disease Control and PreventionBeijing 100020China The Centers for Disease Control and Prevention Harbin Harbin 150000HeilongjiangChina Chinese Center for Disease Control and Prevention Beijing 102206China

Objective To explore the possible long‐term health effects of the defoamer used in seawater desalination by sub‐chronic toxicity testing. Methods Blood analysis, internal organ assessment, and histopathological examination were carried out in rats exposed to low, medium, and high(0.5, 1.0, and 2.0 g/kg BW, respectively) doses of defoamer for 90 days through oral administration. Results The high dose group showed decreased blood alanine aminotransferase and aspartate aminotransferase(P < 0.05). All doses resulted in a significant increase in albumin and decrease in globulin(P < 0.05). The direct bilirubin and indirect bilirubin were decreased in the medium and high dose groups(P < 0.05). All dose groups showed significant induction of alkaline phosphatase(P < 0.05). Pathological examination revealed a case of liver mononuclear cell infiltration in the medium dose group and three cases of liver congestion, steatosis of hepatic cells around the central vein, and punctate necrosis with multiple focal mononuclear cell infiltration in male rats administered the high dose. The No Observed Adverse Effect Level was 0.5 g/kg BW in rats, with albumin and total bilirubin as health effect indices. Conclusion Long‐term defoamer exposure may cause liver injury but has no significant impact on renal function in rats. The effect on blood cells in female rats was more prominent than that in male rats.

关键词： Seawater desalination Defoamer Sub‐chronic toxicity

Effect of mechanical threshing on damage and vigor of maize seed threshed at different moisture contents

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Journal of Integrative Agriculture 2019年第7期18卷 1571-1578页

作者： gu Ri-liang HUANG Ran JIA guang-yao YUAN zhi-peng REN Li-sha LI Li WANG jian-hua Seed Science and Technology Research Center College of Agronomy and BiotechnologyChina Agricultural University/Beijing Key Laboratory of Crop Genetics and Breeding/Beijing Innovation Research Center on the Whole Process of Crop SeedsMinistry of Agriculture

Mechanical threshing used when preparing maize seeds for planting subjects seed to damage and reduces seed *** purpose of this study was to assess the effect of mechanical threshing on the quality of maize seed threshed at different moisture contents(MCs).Seeds of dent maize JK968 and flint maize DD2 were threshed at 12,15,18,21,and 24% *** damage degree was determined by iodine staining,and seed vigor was assessed by standard germination(SG),cold test germination(CTG),accelerated aging germination(AAG),seedling emergence rate,and seedling root and shoot *** results showed that the damage percentage increased,and the seed vigor parameters decreased with increasing seed MC during threshing in both *** obtaining high seed quality,indicated by at least 90,85,and 80% of SG,AAG,and CTG,respectively,JK 968 and DD2 should be threshed at MC lower than 15 and 18%,***,the damage mainly occurred in the apical part of seeds,irrespective of the threshing MC in both *** the embryo was damaged,seedling emergence rates were significantly reduced with great influence on shoot *** to the endosperm resulted in little effect on seedling *** maize DD2 was more tolerant to mechanical threshing than dent maize *** results provided technical reference for the production and processing of high vigor maize seeds.

关键词： dent maize flint maize germination threshing vigor

Spatial patterns and storage composition of woody debris in a natural secondary forest dominated by Pinus tabulaeformis on Loess Plateau, China

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Journal of Mountain Science 2017年第9期14卷 1839-1851页

作者： gu Li GONG zhi-wen LI Wei-zhong College of Forestry Northwest A&F University Yangling 712100 China College of Economics &Management Northwest A&F University Yangling 712100 China

Woody debris(WD) is an important par of natural Pinus tabulaeformis mixed stands, and i affects the forest ecosystem stability and developmen The WD spatial patterns are especially importan structural characteristics that can provide insights into forest dynamics. In this paper, the WD storage WD spatial patterns and WD associations among the main species were examined in the natural secondary forest on Loess Plateau in northwest China. Data were collected in a 1 ha(100 m × 100 m) permanent plot and all the trees with a diameter at breast height o more than 3 cm were measured and stem-mapped Ripley's K functions from the spatial-point-pattern analysis method were used to analyze the spatia distribution and associations. The results showed tha(1) The total storage of WD was 10.73 t/ha, fallen wood was the main source of WD, and the majority diameters were greater than 20 cm, and in intermediate levels of decay;(2) The overall spatia pattern was closely related to the spatial scale, which exhibited an aggregated pattern on a small scale, and a random pattern on a large scale. The spatia patterns of coarse woody debris also gradually transitioned from an aggregated pattern in fine scales to a random pattern in broader spatial scales, which matched the overall spatial pattern. The spatial intensity was gradually decreased with the increasing diameters, and increased with the decomposition classes;(3) The WD of Pinus tabulaeformis species was negatively associated with Betula platyphylla and Populus davidiana on a small scale but positively associated with these species on a large scale. The spatial pattern and interspecies relations were the results of long-term interactions between the natural secondary forest community and the surrounding natural environment. These findings would provide a scientific basis for the sustainable management and protection of natural secondary forest ecosystems on Loess Plateau.

关键词： Spatial pattern Spatial association Storage Woody debris Natural secondary forest Loess Plateau

Grain yield,nitrogen use efficiency and physiological performance of indica/japonica hybrid rice in response to various nitrogen rates

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Journal of Integrative Agriculture 2023年第1期22卷 63-79页

作者： ZHOU Qun YUAN Rui ZHANG Wei-yang gu Jun-fei LIU Li-jun ZHANG Hao WANG zhi-qin YANG jian-chang jiangsu Key Laboratory of Crop Genetics and Physiology/jiangsu Key Laboratory of Crop Cultivation and Physiology/jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops College of AgricultureYangzhou UniversityYangzhou 225009P.R.China

Utilizing the heterosis of indica/japonica hybrid rice(IJHR)is an effective way to further increase rice grain *** application of nitrogen(N)fertilizer plays a very important role in using the heterosis of IJHR to achieve its great yield ***,the responses of the grain yield and N utilization of IJHR to N application rates and the underlying physiological mechanism remain *** purpose of this study was to clarify these *** rice cultivars currently used in rice production,an IJHR cultivar Yongyou 2640(YY2640),a japonica cultivar Lianjing 7(LJ-7)and an indica cultivar Yangdao 6(YD-6),were grown in the field with six N rates(0,100,200,300,400,and 500 kg ha^(-1))in 2018 and *** results showed that with the increase in N application rates,the grain yield of each test cultivar increased at first and then decreased,and the highest grain yield was at the N rate of 400 kg ha^(-1)for YY2640,with a grain yield of 13.4 t ha^(-1),and at 300 kg ha^(-1)for LJ-7 and YD-6,with grain yields of 9.4–10.6 t ha^(-1).The grain yield and N use efficiency(NUE)of YY2640 were higher than those of LJ-7 or YD-6 at the same N rate,especially at the higher N *** compared with LJ-7 or YD-6,YY2640 exhibited better physiological traits,including greater root oxidation activity and leaf photosynthetic rate,higher cytokinin content in the roots and leaves,and more remobilization of assimilates from the stem to the grain during grain *** results suggest that IJHR could attain both higher grain yield and higher NUE than inbred rice at either low or high N application *** shoot and root traits of the IJHR contribute to its higher grain yield and NUE,and a higher content of cytokinins in the IJHR plants plays a vital role in their responses to N application rates and also benefits other physiological processes.

关键词： indica/japonica hybrid rice grain yield nitrogen use efficiency cytokinins non-structural carbohydrate root activity

Quantitative division of succession and spatial patterns among different stand developmental stages in Changbai Mountains

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Journal of Mountain Science 2019年第9期16卷 2063-2078页

作者： GONG zhi-wen KANG Xin-gang gu Li College of Economics and Management Research Center of Resource Economics and Environment Management Northwest A8J7 University Yangling 712100 China College of Forestry Northwest A&F University Yang ling 712100 China College of Forestry Beijing Forestry University Beijing 100083 China

Broadleaf-Korean pine forests exhibit high species richness and distinctive species composition, which are currently becoming more dominant among natural forests in Changbai Mountains of northeastern China. Understanding the ecological process of restored vegetation is quite important for ecosystem reconstruction. Distinguishing stand development stages and analyzing the dynamic spatial patterns could provide insights into significant community coexistence mechanisms. In the present study, eight permanent study areas were established according to the substituting space for time method in Changbai Mountains of north-eastern China. The optimal division method was used to quantify the successional series into different stand development stages, and the point pattern analysis method(L(r) function) was used to analyse the dynamic changes in spatial patterns and interspecific associations. Our results suggested that:(1) The stand development process was divided into five stages: the first three stages were poplar-birch secondary forests in different stages of recovery, the fourth stage was thespruce-fir mixed forest, and the last stage was the primary broadleaf-Korean pine forest;(2) The spatial pattern showed an aggregated distribution at a small scale and changed to a random distribution as the scale increased in poplar-birch secondary forests, but the spatial pattern appeared to be randomly distributed in spruce-fir mixed forest and broadleafKorean pine forest;(3) The interspecific associations between pioneer species and climax species changed from negative to positive among the different stand stages, and environmental resources were shared among these species. Interspecific differences in shade tolerance among the tree species were key determinants of forest dynamics and structure. Our study is vital to the understanding of the forest development;thus, the spatial change features should receive greater attention when forest management is being planned and restoratio

关键词： Dynamic spatial patterns Interspecific association Optimal division method Stand developmental stages Space for time substitution

Synthesis and analysis of new humidity-controlling composite materials

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International Journal of Minerals,Metallurgy and Materials 2017年第5期24卷 594-602页

作者： jian-li Shang zhi-fang Zong Hao Zhang College of Materials and Mineral Resources Xi’an University of Architecture and TechnologyXi’an 710055China

Gypsum is a traditional building material. To improve the humidity-controlling properties of gypsum, we prepared a new type of humidity-controlling composite using the sol-gel method. Methods to determine the maximum equilibrium moisture content and speed of adsorption/desorption were subsequently applied to analyze the performance of the samples. The appearance and structural properties of the samples were characterized by scanning electronic microscopy (SEM). The experimental results show that the humidity-controlling gel with added LiCl exhibits high moisture storage and that the equilibrium maximum moisture content is 5.652 g/g at a 75.29% relative humidity (RH). A mass ratio of LiCl/sol = 0.15 is demonstrated to be appropriate for the preparation of the new humidity-controlling composites. A coarse network with tiny pores is observed on the surface of the new humidity-controlling composites, and this pore network provides sufficient space for moisture adsorption.

关键词： composite materials gypsum humidity control sol-gel processing adsorption desorption

Context-Based Moving Object Trajectory Uncertainty Reduction and Ranking in Road Network

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Journal of Computer Science & Technology 2016年第1期31卷 167-184页

作者： jian Dai zhi-Ming Ding Jia-Jie Xu School of Computer Science Beijing University of Technology Beijing 100124 China University of Chinese Academy of Sciences Beijing 100049 China Institute of Software Chinese Academy of Sciences Beijing 100190 China School of Computer Science and Technology Soochow University Suzhou 215000 China

To support a large amount of GPS data generated from various moving objects, the back-end servers usually store low-sampling-rate trajectories. Therefore, no precise position information can be obtained directly from the back-end servers and uncertainty is an inherent characteristic of the spatio-temporal data. How to deal with the uncertainty thus becomes a basic and challenging problem. A lot of researches have been rigidly conducted on the uncertainty of a moving object itself and isolated from the context where it is derived. However, we discover that the uncertainty of moving objects can be efficiently reduced and effectively ranked using the context-aware information. In this paper, we focus on context- aware information and propose an integrated framework, Context-Based Uncertainty Reduction and Ranking （CURR）, to reduce and rank the uncertainty of trajectories. Specifically, given two consecutive samplings, we aim to infer and rank the possible trajectories in accordance with the information extracted from context. Since some context-aware information can be used to reduce the uncertainty while some context-aware information can be used to rank the uncertainty, to leverage them accordingly, CURR naturally consists of two stages： reduction stage and ranking stage which complement each other. We also implement a prototype system to validate the effectiveness of our solution. Extensive experiments are conducted and the evaluation results demonstrate the efficiency and high accuracy of CURR.

关键词： moving object trajectory uncertainty reduction road network context-aware information