检索结果-南通市图书馆

Effect of Vacuum Pressure on the Initiation and Propagation of Pitting Corrosion of 2205 Duplex Stainless Steel in Concentrated Seawater

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2022年第6期35卷 1023-1033页

作者： Yong Yang Xue-ling hou Mou-Cheng Li Institute of Materials School of Materials Science and EngineeringShanghai UniversityShanghai 200072China

Pitting initiation and stable propagation behaviors of 2205 duplex stainless steel were investigated in the hot concentrated seawater under vacuum pressures by potentiostatic polarization. Both applied potentials and vacuum pressures greatly influence the pitting corrosion. Higher potentials lead to much faster stable pitting initiation and growth rates in both static(101.3 kPa) and dynamic(28.4 kPa) solutions. The pressure reduction can also accelerate the pitting initiation rate. However, the boiling of solution can influence the pitting propagation mechanism. The dynamic actions of boiling bubbles are unfavorable to the pit propagation and result in the formation of relatively smooth pit bottom without secondary pits.

关键词： Duplex stainless steel Stable pitting Vacuum pressure Hot concentrated seawater Potentiostatic polarization

Crop Diversification in Coping with Extreme Weather Events in China

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2014年第4期13卷 677-686页

作者： HUANG Ji-kun JIANG Jing WANG Jin-xia hou ling-ling Center for Chinese Agricultural Policy Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences University of Chinese Academy of Sciences

Apart from the long-term effects of climate change, the frequency and severity of extreme weather events have been increasing. Given the risks posed by climate change, particularly the changes in extreme weather events, the question of how to adapt to these changes and mitigate their negative impacts has received great attention from policy makers. The overall goals of this study are to examine whether farmers adapt to extreme weather events through crop diversification and which factors influence farmers＇ decisions on crop diversification against extreme weather events in China. To limit the scope of this study, we focus on drought and flood events only. Based on a unique large-scale household survey in nine provinces, this study finds that farmers respond to extreme weather events by increasing crop diversification. Their decision to diversify crops is significantly influenced by their experiences of extreme weather events in the previous year. Such results are understandable because farmers＇ behaviors are normally based on their expectations. Moreover, household characteristics also affect farmers＇ decisions on crop diversification strategy, and their effects differ by farmers＇ age and gender. This paper concludes with several policy implications.

关键词： adaptation extreme weather event climate change crop diversification farmer

Does nature-based solution sustain grassland quality? Evidence from rotational grazing practice in China

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2023年第8期22卷 2567-2576页

作者： LI Dong-qing ZHANG Ming-xue Lü Xin-xin hou ling-ling Institute of Agricultural Economics and Development Chinese Academy of Agricultural SciencesBejing 100081P.R.China China Center for Agricultural Policy School of Advanced Agricultural SciencesPeking UniversityBeijing 100871P.R.China

Rotational grazing is considered as one of the nature-based solutions(NbS)to grassland protection by natural ***,its effects on improving grassland quality are still unclear when it is adopted by *** a householdlevel panel data from field survey in two main pastoral provinces of China,empirical results from fixed-effect model and instrumental approach show that rotational grazing practices have insignificant short-term effects on grassland quality,but have positive long-term *** addition,rotational grazing practices can improve grassland quality when villages invest public infrastructure or herders have private supporting measures for more efficiency livestock *** analysis shows that herders adopting rotational grazing have higher grazing intensity,higher supplementary intensity and more livestock-house-feeding days,which indicate herders can utilize more efficient livestock management without increasing pressure on natural *** also find that herders with pastoral income are more likely to adopt rotational grazing *** insightful findings offer policy implications on promoting grassroot NbS for ecosystem protection and resource utilization in developing pastoral countries.

关键词： grassroots nature-based solutions rotational grazing grassland quality pastoral region China

Nanoarchitectonics of MnO_(2)nanotubes as sea urchin-like aggregates for dielectric response and microwave absorption with a wide concentration domain

在线全文

学校读者我要写书评

暂无评论

Nano Research 2023年第2期16卷 2604-2610页

作者： Zhi-ling hou Kunrong Du Yiqin Zhang Song Bi Junying Zhang College of Mathematics and Physics&Beijing Key Laboratory of Environmentally Harmful Chemical Analysis Beijing University of Chemical TechnologyBeijing 100029China 501 Department Xi’an Research Institute of High-TechXi’an 710025China

Designing highly reliable and practical microwave absorbers is one of the most important research directions in the microwave absorbing *** absorbents suffer from concentration-sensitivity and environmental-sensitivity dilemmas in practical ***,sea urchin-like aggregates of MnO_(2)nanotubes were synthesized by a simple hydrothermal method,which exhibit an outstanding impedance matching *** composites based on sea urchin-like aggregates of MnO_(2)nanotubes show excellent microwave absorption performance in a wide concentration domain from 20 wt.%to 70 wt.%,corresponding to electrical conductivities from 1.86×10^(−7)to 1.85×10^(−5)S/*** a wide concentration range of absorbent for excellent microwave absorption is mainly attributed to the beneficial impedance matching properties of sea urchin-like aggregates of hollow nanotubes.A competitive absorption bandwidth of 3.36 GHz is achieved at 1 mm thickness,which can be broadened to 13.4 GHz by structural *** work shows a new scheme for designing reliable and practical microwave absorbers benefit from the wide absorbent concentration domain.

关键词： MnO_(2)nanotubes sea urchin-like aggregates broadband microwave absorption wide filling range

The impact of migration on the food consumption and nutrition of left-behind family members: Evidence from a minority mountainous region of southwestern China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2019年第8期18卷 1780-1792页

作者： MIN Shi hou ling-ling Hermann Waibel HUANG Ji-kun MU Yue-ying China Center for Agricultural Policy School of Advanced Agricultural Sciences Peking University Beijing 100871 P.R.China Institute of Development and Agricultural Economics Leibniz University Hannover Hannover 30167 Germany College of Economics and Management China Agricultural University Beijing 100083 P.R.China

While migration is widely recognized as a valid option for improving farmers’ income, the welfare effects of migration on left-behind family members are ambiguous. This study examines the impacts of migration on left-behind family members’ food consumption and nutrient intake, particularly in remote rural areas in China. Based on household survey data collected from 611 smallholder rubber farmers in Xishuangbanna Dai Autonomous Prefecture of southwestern China, the empirical results suggest that the migration of family members contributes to improving household net income, whereas it negatively affects left-behind family members’ consumption of grain and pork. Migration also leads to a decrease in left-behind family members’ nutrient intake. Surprisingly, the economic returns of farmers’ migration not only do not foster the transformation of household food consumption from a staple food-dominated dietary structure to one including more meat and dairy products but also reduce left-behind family members’ nutrient intake. This study adds to the literature on the impact of farmers’ migration. The findings have important implications for better understanding the impacts of migration on farmers’ livelihood and human capital development in rural China.

关键词： migration food consumption nutrition left-behind

ECOLOGICAL DISTRIBUTION OF SOIL ANIMALS IN BROAD-LEAVED PINE FORESTS IN SOUTHERN SLOPE OF XIAO HINGGAN MOUNTAINS

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2000年第3期10卷 85-90页

作者： Wei-ling hou Hua Zhang College of Urban and Environment Sciences Northeast Normal University Changchun P. R. China Changchun Education College Changchun P. R. China

This paper studied the soil animals of four type forests of broad leaved pine forests in the southern slope of the Xiao Hinggan Mountains. The samples were extracted from four forest types in every first week of June, August, October, and every forest type was chosen out three plots. Since there are different soil animals in different depths, every plot was divided into four partitions with the same vertical distance: litter, 0－ 10 cm, 10－ 20 cm, 20－ 30 cm. Using hand sorting out large soil animals, Tullgren method (to middle and small soil animals) and Baermann method (to moist soil animals) to collect soil animals. Among the four type forests, insecta has the largest amount of groups of 54. Oribatida has the most number of individual, which is 1547, occupying 21.73 percent of total collectings. There are 81 groups of soil animals, totalling 7118 belonging to 8 Class 24 Order 57 Family, in which there are 54 groups of big sized soil animals totalling 2370, 41 groups of middle and small sized soil animals totalling 4808. Among all the soil animals,their dominant group is 3 ones, usual growp is 14 ones, and rare group is 64 ones. The results show that among the four type forests, the groups of soil animal in Tilia pine forest are much more than the others, with the highest variety index, and the individual number of the soil animals is also very large. The numbers of group and individual in Picea Abies Pine forest are both *** the four forest types, the soil animals in Tilia pine forest are most similar to Betula costata pine forest. There is so little similarity between the soil animals in Picea Abies pine forest and in the other three forest types.

关键词： Xiao Hinggan Mountains soil animal , ecological distribution

Molecular dynamics and principal components of potassium binding with human telomeric intra-molecular G-quadruplex

在线全文

学校读者我要写书评

暂无评论

Protein & Cell 2015年第6期6卷 423-433页

作者： Zhiguo Wang Ruping Chen ling hou Jianfeng Li Jun-Ping Liu Institute of Aging Research School of Medicine Hangzhou Normal University Hangzhou 311121 China School of Medicine Shandong University Jinan 250100 China Department of Immunology Central Eastern Clinical School Monash University Melbourne VIC 3004 Australia Center for Cancer Research Monash Institute of Medical Research Clayton VIC 3168 Australia

Telomere assumes intra-molecular G-quadruplex that is a significant drug target for inhibiting telomerase main- tenance of telomeres in cancer. Metal cations have been recognized as playing important roles in stabilizing G-quadruplex, but their binding processes to human telomeric G-quadruplex remain uncharacterized. To in- vestigate the detailed binding procedures, molecular dynamics simulations were conducted on the hybrid [3 ＋ 1] form-one human telomeric intra-molecular G-quadruplex. We show here that the binding of a potas- sium ion to a G-tetrad core is mediated by two alternative pathways. Principal component analysis illustrated the dominant concerted motions of G-quadruplex occurred at the loop domains. MM-PBSA calculations revealed that binding was energetically favorable and driven by the electrostatic interactions. The lower binding site was found more constructive favorable for binding. Our data provide useful information on a potassium-mediated stable structure of human telomeric intra-molecular G-quadruplex, implicating in ion disorder associated conformationa｜ changes and targeted drug design.

关键词： G-quadruplex potassium ion moleculardynamics principal component analysis MM-PBSA

Tunable Multiple Morphological Transformation of Supramolecular Hyperbranched Polymers Based on an A_(2)B_(6)-type POSS Monomer

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2021年第12期39卷 1562-1571页

作者： Lin-Feng Fan Cui-ling hou Xing Wang Li-Tang Yan 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 State Key Laboratory of Chemical Engineering Department of Chemical EngineeringTsinghua UniversityBeijing 100049China Department of Biomedical Engineering Southern University of Science and TechnologyShenzhen 518055China

The growing dema nds of supramolecular hyperbranched polymers integrati ng non covale nt in teraction and unique topological structure merits had received considerable interest in the fabrication of novel materials for advaneed ***,we prepared A2B6-type POSS-containing supramolecular hyperbranched polymers with multiple morphologies including lamellar-like,branched,hollow,core-shell and porous spherical structures through regulating self-assembling monomer concentrations and solvent *** incorporation of appropriate emulative guest molecules would further trigger morphological transformations(such as vesicles and spherical micelles)by synergistic effects of unique POSS aggregation ability,supramolecular complexations and hydrophilic-hydrophobic ***,this facile and universal strategy may enable a modular nanofabrication of supramolecular hyperbranched polymers with diversiform topological structure and sophisticated multifunctionality for their potential applications.

关键词： POSS Host-guest interaction A2B6-type monomer Supramolecular polymer Morphological transformation

Effects of Na_(2)CO_(3)on reduction mechanism and kinetics of iron during deep reduction of ilmenite concentrate

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2023年第3期30卷 419-428页

作者： Xiao-dong Lv You-ling hou Yun-tao Xin Wei Lv Xue-wei Lv Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing 400044China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina

High-quality upgraded titanium slag obtained through semi-molten reduction with the addition of Na_(2)CO_(3)is important for the fluidizing chlorination process to produce TiO_(2)*** key is the effect of Na_(2)CO_(3)on the reduction behavior of ***,the effects of Na_(2)CO_(3)on reduction mechanism and kinetics of iron during deep reduction of ilmenite concentrate were *** results indicated that the metallization ratio of the reduced sample increased with increasing temperature,time,and dose of Na_(2)CO_(3).The addition of Na_(2)CO_(3)significantly accelerated the reduction of iron in the ilmenite concentrate and promoted the growth of iron ***,the addition of Na_(2)CO_(3)produced sodium iron titanates;thus,the metallization ratio of the sample decreased with an increase in the temperature and time when the temperature was above 1200℃and the time was more than 30 *** the doses of Na_(2)CO_(3)were 0,3,and 6 wt.%,the reduction of iron was controlled by the interfacial chemical reaction,both the interfacial chemical reaction and diffusion,and diffusion,respectively,and the apparent activation energies were 134.91,64.89,and 120.82 kJ/mol,respectively.

关键词： Ilmenite concentrate Sodium carbonate Metallization ratio Reduction mechanism Kinetics