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Negative effects of artiffcial nest boxes on birds:A review
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作者 Luchang Zhang Xingjian Ma +4 位作者 Zhiyu Chen Chunying Wang Zicheng Liu Xiang Li Xiaoying Xing 《Avian Research》 SCIE CSCD 2023年第2期257-266,共10页
Artificial nest boxes are placed to attract birds to nest and breed in a specific location,and they are widely used in avian ecology research and in the attraction of insectivorous birds.There is evidence that artific... Artificial nest boxes are placed to attract birds to nest and breed in a specific location,and they are widely used in avian ecology research and in the attraction of insectivorous birds.There is evidence that artificial nest boxes can adversely affect breeding fitness but no great focus has been placed on this issue by researchers.Therefore,we retrieved 321 research papers regarding artificial nest boxes published from 2003 to 2022 and used the'Biblioshiny'program to extract and integrate keywords;we then summarized the adverse effects of artificial nest boxes on avian breeding success.The studies highlighted many drawbacks and misuses in the designing and placement of nest boxes;furthermore,bird attraction was decreased by their inappropriate selection,thus reducing breeding success.Regarding nest box production,there were shortcomings in the construction material,color,smell,and structural design of the boxes used.Nest boxes were also placed at inappropriate densities,locations,orientations,heights,and managed incorrectly.Finally,we propose suggestions for more efficient and safer artificial nest boxes for future use in avian ecology research and bird conservation. 展开更多
关键词 Artificial nest box Avian breeding Management negative effect Nest box hanging Nest box location Nest box structure
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Collective Oriented Culture and Its Negative Impact upon Oral English Teaching
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作者 肖春艳 约翰.史密斯 《疯狂英语(教师版)》 2015年第3期76-77,81,共3页
As one of the most distinguished features of Chinese Culture,collective oriented culture is the deep structure of Chinese cultural psychology which has shaped Chinese character and influenced their behavior.As a resul... As one of the most distinguished features of Chinese Culture,collective oriented culture is the deep structure of Chinese cultural psychology which has shaped Chinese character and influenced their behavior.As a result of it,Chinese students suffer this negative effect from collective orientated culture when acquiring English,especially in oral English acquisition.TEFL teachers should be aware of cultural psychology and try their best to minimize its negative effect instead of neglecting or even enlarging it during oral English teaching. 展开更多
关键词 collective oriented culture negative effect oral English teaching
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Analysis of the negative effects of groundwater exploitation on geological environment in Asia
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作者 ZHANG Jian-kang WEN Xue-ru +2 位作者 GAO Yun YUE Chen YI Qing 《Journal of Groundwater Science and Engineering》 2015年第2期202-212,共11页
This paper summarizes the negative effects on geological environment caused by groundwater exploitation and its distribution. There are seven main types of the geological environment negative effects, which are genera... This paper summarizes the negative effects on geological environment caused by groundwater exploitation and its distribution. There are seven main types of the geological environment negative effects, which are generally as follows:(1) Constant decrease of groundwater level is mainly distributed in China(East Asia), India(South Asia), Tajikistan(Central Asia) and Saudi Arabia(West Asia);(2) land subsidence occurs mainly in eastern plains of East Asia and west Siberian Plain of North Asia;(3) seawater intrusion occurs mainly in China, Japan and South Korea in East Asia, Philippines and Indonesia in Southeast Asia, the Indian coastal areas in South Asia;(4) groundwater level decline caused by groundwater exploitation in oil fields;(5) mining collapse is mainly in 50° to 70° north latitude band;(6) the total area of karst collapse in China of East Asia is as much as 197.05 km^2; and(7) ground fracture is mainly distributed in the North China Plain, Fenwei Plain and the Yangtze River Delta. Asia can be divided into 6 zones in terms of the geological environment negative effect caused by groundwater exploitation. According to analysis, with the increasing intensity of human activities, geological environment issues become more and more serious, therefore it is vital to control the human activities within the scope of 5× 10~5 people/km^2 to 9.9× 10~5 people/km^2 for the effective control of the size of the affected area by geological environment problems. 展开更多
关键词 ASIA Groundwater development Geological environment negative effect and distributed regions Severity of geological environment problems
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Are Personal Exemptions Succeeded to Protect Low-Income Families in Egypt From the Negative Effects of COVID-19?
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作者 Mohamed Elshawarby 《Journal of Modern Accounting and Auditing》 2020年第10期460-466,共7页
This paper attempts to investigate the negative effects of the spread of COVID-19 on low-income families in Egypt.Coronavirus spread is measured by"Coronavirus cases"and"Coronavirus deaths"on a dai... This paper attempts to investigate the negative effects of the spread of COVID-19 on low-income families in Egypt.Coronavirus spread is measured by"Coronavirus cases"and"Coronavirus deaths"on a daily basis.Besides,it is measured by both"new Coronavirus cases"and"new deaths from Coronavirus",in relation to the population of Egypt.The Egyptian government is taking some measures to reduce the negative effects of COVID-19,including increasing personal exemptions by amending some provisions of the Egyptian Income Tax Law promulgated by Law No.91 of 2005 to protect low-income families.Of the negative effects of COVID-19,it is one of the most important tax policies to achieve social justice in distributing the tax burden,according to income levels,in a manner that achieves justice and equality.We find that Personal exemptions did not succeed in achieving tax justice by easing the tax burden on the low-income people in society. 展开更多
关键词 personal exemptions low-income families EGYPT the negative effects COVID-19
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Origin of Negative Imaginary Part of Effective Permittivity of Passive Materials
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作者 张凯伦 侯志灵 +2 位作者 孔令宝 房慧敏 战可涛 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第9期105-108,共4页
The anti-resonant phenomenon of effective electromagnetic parameters of metamaterials has aroused controversy due to negative imaginary permittivity or permeability. It is experimentally found that the negative imagin... The anti-resonant phenomenon of effective electromagnetic parameters of metamaterials has aroused controversy due to negative imaginary permittivity or permeability. It is experimentally found that the negative imaginary permittivity can occur for the natural passive materials near the Fabry Perot resonances. We reveal the nature of negative imaginary permittivity, which is correlated with the magnetoelectric coupling. The anti-resonance of permittivity is a non-inherent feature for passive materials, while it can be inherent for devices or metamaterials. Our finding validates that the negative imaginary part of effective permittivity does not contradict the second law of thermodynamics for metamaterials owing to the magnetoelectric coupling. 展开更多
关键词 Origin of negative Imaginary Part of Effective Permittivity of Passive Materials FPR
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The environmental negative effect for exploitation of the deep groundwater in mining area
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《Global Geology》 1998年第1期7-7,共1页
关键词 DEEP The environmental negative effect for exploitation of the deep groundwater in mining area
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The anodically polarized Mg surface products and accelerated hydrogen evolution 被引量:2
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作者 Jufeng Huang Guang-Ling Song +2 位作者 Yixing Zhu Dajiang Zheng Ziming Wang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第1期230-248,共19页
To clarify the anodic dissolution mechanism of Mg,the hydrogen evolution from pure Mg in acidic solutions under galvanostatic conditions were systematically measured.With increasing anodic current density,the cathodic... To clarify the anodic dissolution mechanism of Mg,the hydrogen evolution from pure Mg in acidic solutions under galvanostatic conditions were systematically measured.With increasing anodic current density,the cathodic hydrogen evolution rate decreased,and the anodic hydrogen evolution became faster while some surface area on the Mg was becoming dark under anodic polarization.Based on the surface analysis results and the generally accepted basic electrochemical equations,the evolution kinetics of hydrogen from Mg was deduced,and the most possible surface intermediate active species that could facilitate the anodic Mg dissolution and anodic hydrogen evolution were proposed.This paper further develops the model of incomplete film Mg^(+) dissolution,explains many reported experimental phenomena,and clarifies misunderstandings of current mechanism. 展开更多
关键词 MAGNESIUM CORROSION Hydrogen evolution negative difference effect
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Dietary aflatoxin B1 induces abnormal deposition of melanin in the corium layer of the chicken shank possibly via promoting the expression of melanin synthesis-related genes
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作者 WANG Yong-li HUANG Chao +5 位作者 YU Yang CAI Ri-chun SU Yong-chun CHEN Zhi-wu ZHENG Mai-qing CUI Huan-xian 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第6期1847-1856,共10页
San-Huang chicken is a high-quality breed in China with yellow feather, claw and break. However, the abnormal phenomenon of the yellow shank turning into green shank of San-Huang chicken has been a concern, as it seri... San-Huang chicken is a high-quality breed in China with yellow feather, claw and break. However, the abnormal phenomenon of the yellow shank turning into green shank of San-Huang chicken has been a concern, as it seriously reduces the carcass quality and economic benefit of yellow-feathered broilers. In this study, the cause of this abnormal green skin in shank was systematically investigated. Physiological anatomy revealed that the abnormal skin in shank was primarily due to the deposition of melanin under the dermis. After analyzing multiple potential causes such as heredity(pedigree and genetic markers), environment(water quality monitoring) and feed composition(mycotoxin detection), excessive aflatoxin B1(AFB1) in feed was screened, accompanied with a higher L-dihydroxy-phenylalanine(L-DOPA)(P<0.05) and melanin content(P<0.01). So it was speculated that excessive AFB1 might be the main cause of abnormal green skin in shank. Subsequently, the further results showed that a high concentration of AFB1(>170 μg kg–1)indeed induced the abnormal green skin in shank compared to the normal AFB1 content(<10 μg kg–1), and the mRNA levels of TYR, TYRP1, MITE, MC1R and EDN3 genes related to melanin deposition would significantly up-regulate(P<0.01) and the content and activity of tyrosinase(TyR) significantly increased(P<0.05). At the same time, the content of L-DOPA and melanin deposition also increased significantly(P<0.01), which also confirmed the effect of excessive AFB1 on melanin deposition in skin of shank. Results of additional experiments revealed that the AFB1's negative effect on melanin deposition in skin of shank could last for a longer time. Taken together, the results of this study explained the occurrence and possible mechanisms of the abnormal AFB1-related green skin in shank of chickens. Excessive AFB1 in diets increased the L-DOPA content and melanin abnormal deposition in the chicken shank possibly via promoting TyR content and activity, and the expression of melanin synthesis-related genes. Furthermore, our findings once again raised the alarm of the danger of AFB1 in the broiler production. 展开更多
关键词 aflatoxin B1 melanin deposition skin color in shank CHICKEN negative effect
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Mechanistic insights into the active intermediates of 2,6-diaminopyridine dinitration
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作者 Junao Zhu Zhirong Yang +7 位作者 Yuanhan Chen Mingming Chen Zhen Liu Yueqiang Cao Jing Zhang Gang Qian Xinggui Zhou Xuezhi Duan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第4期160-168,共9页
Mechanistic understanding of the active intermediates of 2,6-diaminopyridine(DAP) dinitration in the concentrated nitric-sulfuric acid system is of crucial importance for the selectivity control of target product, i.e... Mechanistic understanding of the active intermediates of 2,6-diaminopyridine(DAP) dinitration in the concentrated nitric-sulfuric acid system is of crucial importance for the selectivity control of target product, i.e., 2,6-diamino-3,5-dinitropyridine(DADNP). The active intermediates determining the product selectivity are theoretically studied. The HSO_(4)^(-)-NO_(2)^(+) complex is proposed as the dominant active nitrating intermediate for the first time, which shows low energy barrier(i.e., 10.19 kcal·mol^(-1),1 kcal = 4.186 k J) for direct dinitration of DAP to DADNP. The formed water during the reaction results in not only the formation of less active SO_(4)^(2-)-NO_(2)^(+) complex, but also the occurance of DAP sulfonation(DAP-SO_(3)H intermediate)to facilitate the formation of mononitration byproduct. Meanwhile, the accompanied thermal effects cause the generation of undesirable pyridine-NHNO_(2) intermediate, which is difficult to be rearranged to yield DADNP, inhibiting the reaction and thus giving low DAP conversion. The insights reported here elucidates the importance of thermal effects elimination and water content control, confirmed experimentally in the batch-and micro-reaction systems. 展开更多
关键词 2 6-Diaminopyridine Nitration mechanism Active intermediates Thermal effects negative water effects
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Two-dimensional tetragonal ZnB: A nodalline semimetal with good transport properties
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作者 赵永春 朱铭鑫 +1 位作者 李胜世 李萍 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期529-536,共8页
Nodal-line semimetals have become a research hot-spot due to their novel properties and great potential application in spin electronics. It is more challenging to find 2D nodal-line semimetals that can resist the spin... Nodal-line semimetals have become a research hot-spot due to their novel properties and great potential application in spin electronics. It is more challenging to find 2D nodal-line semimetals that can resist the spin–orbit coupling(SOC)effect. Here, we predict that 2D tetragonal Zn B is a nodal-line semimetal with great transport properties. There are two crossing bands centered on the S point at the Fermi surface without SOC, which are mainly composed of the pxy orbitals of Zn and B atoms and the pz orbitals of the B atom. Therefore, the system presents a nodal line centered on the S point in its Brillouin zone(BZ). And the nodal line is protected by the horizontal mirror symmetry M_(z). We further examine the robustness of a nodal line under biaxial strain by applying up to-4% in-plane compressive strain and 5% tensile strain on the Zn B monolayer, respectively. The transmission along the a direction is significantly stronger than that along the b direction in the conductive channel. The current in the a direction is as high as 26.63 μA at 0.8 V, and that in the b direction reaches 8.68 μA at 0.8 V. It is interesting that the transport characteristics of Zn B show the negative differential resistance(NDR) effect after 0.8 V along the a(b) direction. The results provide an ideal platform for research of fundamental physics of 2D nodal-line fermions and nanoscale spintronics, as well as the design of new quantum devices. 展开更多
关键词 nodal-line semimetals negative differential resistance(NDR)effect horizontal mirror symmetry
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Observation of stabilized negative capacitance effect in hafnium-based ferroic films
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作者 Leilei Qiao Ruiting Zhao +4 位作者 Cheng Song Yongjian Zhou Qian Wang Tian-Ling Ren Feng Pan 《Materials Futures》 2024年第1期1-9,共9页
A negative capacitance(NC)effect has been proposed as a critical pathway to overcome the‘Boltzmann tyranny’of electrons,achieve the steep slope operation of transistors and reduce the power dissipation of current se... A negative capacitance(NC)effect has been proposed as a critical pathway to overcome the‘Boltzmann tyranny’of electrons,achieve the steep slope operation of transistors and reduce the power dissipation of current semiconductor devices.In particular,the ferroic property in hafnium-based films with fluorite structure provides an opportunity for the application of the NC effect in electronic devices.However,to date,only a transient NC effect has been confirmed in hafnium-based ferroic materials,which is usually accompanied by hysteresis and is detrimental to low-power transistor operations.The stabilized NC effect enables hysteresis-free and low-power transistors but is difficult to observe and demonstrate in hafnium-based films.This difficulty is closely related to the polycrystalline and multi-phase structure of hafnium-based films fabricated by atomic layer deposition or chemical solution deposition.Here,we prepare epitaxial ferroelectric Hf_(0.5)Zr_(0.5)O_(2) and antiferroelectric ZrO_(2) films with single-phase structure and observe the capacitance enhancement effect of Hf_(0.5)Zr_(0.5)O_(2)/Al_(2)O_(3) and ZrO_(2)/Al_(2)O_(3) capacitors compared to that of the isolated Al_(2)O_(3) capacitor,verifying the stabilized NC effect.The capacitance of Hf_(0.5)Zr_(0.5)O_(2) and ZrO_(2) is evaluated as−17.41 and−27.64 pF,respectively.The observation of the stabilized NC effect in hafnium-based films sheds light on NC studies and paves the way for low-power transistors. 展开更多
关键词 negative capacitance effect fluorite structure hafnium-based ferroelectrics ANTIFERROELECTRIC
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Anodic hydrogen evolution on Mg 被引量:4
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作者 Yang Li Zhiming Shi +1 位作者 Xingrui Chen Andrej Atrens 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2021年第6期2049-2062,共14页
We measured the anodic hydrogen evolution rates for various applied anodic current densities and estimated the corresponding cathodic hydrogen evolution rates.The estimated cathodic hydrogen evolution rates were less ... We measured the anodic hydrogen evolution rates for various applied anodic current densities and estimated the corresponding cathodic hydrogen evolution rates.The estimated cathodic hydrogen evolution rates were less than the measured anodic hydrogen evolution rates,contradicting the enhanced catalytic activity mechanism of Mg corrosion.In addition,this model was contradicted by the measured apparent Mg valence of 1.2±0.1.In contrast,the uni-positive Mg^(+)mechanism of Mg corrosion was supported by(i)the apparent Mg valence of 1.2±0.1,and(ii)the fact that the measured anodic hydrogen evolution rate increased with increasing weight loss rate. 展开更多
关键词 A magnesium B Galvanostatic POTENTIOSTATIC Weight loss Hydrogen evolution C negative difference effect
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PTC/NTC Behavior of PVDF Composites Filled with GF and CF 被引量:3
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作者 WANG Xin-lei ZHANG Guo LI Ji-xin LI Zhuo-shi LIU Zhan-fang LIU Xiu-qi 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2008年第5期648-652,共5页
Conductive polyvinylidene fluoride(PVDF)matrix composites filled with graphited fiber(GF)or carbon fiber(CF)were prepared by the melt-mixing method.The breakage and length distribution of the fibers in the polym... Conductive polyvinylidene fluoride(PVDF)matrix composites filled with graphited fiber(GF)or carbon fiber(CF)were prepared by the melt-mixing method.The breakage and length distribution of the fibers in the polymer matrix were studied by scanning electron microscope(SEM)and optical microscope(OM)observations,respectively. The differences in the positive temperature coefficient(PTC)effects of the composites were mainly attributed to inter-fiber contact ability.The elimination of the negative temperature coefficient(NTC)effect for CF/PVDF composite was because of an increase in the viscosity of the polymer matrix.With the same filler content,CF could be more effective,to eliminate the NTC effect when compared with GF.Addition of 2%CF(mass fraction)in the PVDF composite with 7%GF(mass fraction)could effectively eliminate the NTC phenomenon of the composite. 展开更多
关键词 Polyvinylidene fluoride Graphited fiber Carbon fiber Positive temperature coefficient effect negative temperature coefficient effect
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Resistivity-Temperature Behavior of CB-Filled HDPE Foaming Composites 被引量:4
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作者 LI Ji-xin ZHANG Guo +2 位作者 LI Zhuo-shi WANG Xin-lei LIU Xiu-qi 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2008年第2期215-219,共5页
High-density polyethylene/carbon black foaming conductive composites were prepared from acetylene black(ACEY) and super conductive carbon black(HG-1P) as conductive filler, low-density polyethylene(LDPE) as the ... High-density polyethylene/carbon black foaming conductive composites were prepared from acetylene black(ACEY) and super conductive carbon black(HG-1P) as conductive filler, low-density polyethylene(LDPE) as the second component, ethylene-vinyl acetate(EVA) and ethylene propylene rubber(EPR) as the third component, azobisformamide(AC) as foamer, and dicumyl peroxide(DCP) as cross-linker. The structure and resistivity-temperature behavior of high-density polyethylene(HDPE)/CB foaming conductive composites were investigated. Influences of carbon black, LDPE, EVA, EPR, AC, and DCP on the foaming performance and resistivity-temperature behavior of HDPE/CB foaming conductive composites were also studied. The results reveal that HDPE/CB foaming conductive composite exhibits better switching characteristic; ACET-filled HDPE foaming conductive composite displays better positive temperature coefficient(PYC) effect; whereas super conductive carbon black(HG-1P)-filled HDPE foaming conductive composite shows better negative temperature coefficient(NTC) effect. 展开更多
关键词 Resistivity-temperature behavior Carbon black High-density polyethylene Foam Positive temperaturecoefficient(PYC) effect negative temperature coefficient(NYC) effect
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Safety Analysis of Riding at Intersection Entrance Using Video Recognition Technology 被引量:1
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作者 Xingjian Xue Linjuan Ge +3 位作者 Longxin Zeng Weiran Li Rui Song Neal N.Xiong 《Computers, Materials & Continua》 SCIE EI 2022年第9期5135-5148,共14页
To study riding safety at intersection entrance,video recognition technology is used to build vehicle-bicycle conflict models based on the Bayesian method.It is analyzed the relationship among the width of nonmotorize... To study riding safety at intersection entrance,video recognition technology is used to build vehicle-bicycle conflict models based on the Bayesian method.It is analyzed the relationship among the width of nonmotorized lanes at the entrance lane of the intersection,the vehicle-bicycle soft isolation form of the entrance lane of intersection,the traffic volume of right-turning motor vehicles and straight-going non-motor vehicles,the speed of right-turning motor vehicles,and straight-going non-motor vehicles,and the conflict between right-turning motor vehicles and straight-going nonmotor vehicles.Due to the traditional statistical methods,to overcome the discreteness of vehicle-bicycle conflict data and the differences of influencing factors,the Bayesian random effect Poisson-log-normal model and random effect negative binomial regression model are established.The results show that the random effect Poisson-log-normal model is better than the negative binomial distribution of random effects;The width of non-motorized lanes,the form of vehicle-bicycle soft isolation,the traffic volume of right-turning motor vehicles,and the coefficients of straight traffic volume obey a normal distribution.Among them,the type of vehicle-bicycle soft isolation facilities and the vehicle-bicycle traffic volumes are significantly positively correlated with the number of vehicle-bicycle conflicts.The width of non-motorized lanes is significantly negatively correlated with the number of vehicle-bicycle conflicts.Peak periods and flat periods,the average speed of right-turning motor vehicles,and the average speed of straight-going non-motor vehicles have no significant influence on the number of vehicle-bicycle conflicts. 展开更多
关键词 Video recognition technology vehicle-bicycle conflict intersection entrance random effect poisson-log-normal model random effect negative binomial regression model
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EFFECT OF WEAK INTERACTIONS ON PHENOL ADSORPTION FROM AQUEOUS SOLUTIONS BY AMINATED POLYMERIC ADSORBENTS
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作者 Wei-ming Zhang Jin-long Chen +3 位作者 Ai-min Li Bing-cai Pan Qun Chen Ming-yang He and Quan-xing Zhang a State Key Laboratory of Pollution Control and Resources Reuse,School of the Environment,Nanjing University,Nanjing 210093,China b Research Center for Engineering Technology of Organic Poison Control and Resources Reuse in Jiangsu Province,Nanjing 210038,China c Department of Chemical Engineering,Jiangsu Polytechnic University,Changzhou 213016,China 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2006年第1期61-66,共6页
Adsorption behaviors of phenol from aqueous solutions have been investigated in batch systems at 303 K and 318 K respectively, using hypercrosslinked polymeric adsorbent (CHA111), aminated hypercrosslinked polymeric... Adsorption behaviors of phenol from aqueous solutions have been investigated in batch systems at 303 K and 318 K respectively, using hypercrosslinked polymeric adsorbent (CHA111), aminated hypercrosslinked polymeric adsorbents (NDA101, NDA103, NDA105) and weakly basic polymeric adsorbent (D301) with a view to studying the effect of hydrogen bonding and Van der Waals interactions between adsorbate and the adsorbent. All adsorption isotherms can be well fitted by Langmuir and Freundlich equations. Compared with D301 driven by hydrogen bonding interaction only and CHA111 driven by Van der Waals interaction only, phenol adsorption on aminated adsorbents driven by both hydrogen bonding and Van der Waals interactions were apparently different, i.e., negative effect for NDA105, positive effect for NDA101 and synergistic effect for NDA103. In this synergistic action, some weak interactions would contribute more or less to the adsorption than they work individually. 展开更多
关键词 Polymeric adsorbent PHENOL Adsorption behaviours negative effect Positive effect Synergistic effect.
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Galvanostatic anodic polarisation of WE43
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作者 Zhiming Shi Jimmy Xueshan Jia Andrej Atrens 《Journal of Magnesium and Alloys》 SCIE EI CAS 2014年第3期197-202,共6页
The Mg corrosion mechanism was explored using galvanostatic polarisation curves,hydrogen evolution and weight loss.The data(a)were consistent with the existence of the uni-positive Mg+ion,(b)indicated that some hydrog... The Mg corrosion mechanism was explored using galvanostatic polarisation curves,hydrogen evolution and weight loss.The data(a)were consistent with the existence of the uni-positive Mg+ion,(b)indicated that some hydrogen dissolved in the WE43 metal,and(c)indicated that self corrosion was more important than the applied current density in causing weight loss. 展开更多
关键词 MAGNESIUM GALVANOSTATIC Polarisation SEM Weight loss Hydrogen adsorption negative difference effect
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Review of Groundwater Protection and Management in China
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作者 刘丹 张爱平 《Journal of Southwest Jiaotong University(English Edition)》 2008年第3期266-274,共9页
This review begins with an introduction of groundwater resources in China and their distribution characteristic,followed by an elaboration of the exploitation and utilization of groundwater and the negative environmen... This review begins with an introduction of groundwater resources in China and their distribution characteristic,followed by an elaboration of the exploitation and utilization of groundwater and the negative environmental effects from groundwater overexploitation, and a description of the existing groundwater protection and management measures. At last, the existing problems in groundwater protection and management, with some suggestions, are presented. 展开更多
关键词 GROUNDWATER negative environmental effect UTILIZATION PROTECTION MANAGEMENT
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Conductive Behaviors of Carbon Nanofibers Reinforced Epoxy Composites
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作者 梅启林 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2008年第1期139-142,共4页
By means of ultrasonic dispersion, carbon nanofibers reinforced epoxy resin composite was prepared in the lab, the electrical conductivity of composite with different carbon nanofibers loadings were studied, also the ... By means of ultrasonic dispersion, carbon nanofibers reinforced epoxy resin composite was prepared in the lab, the electrical conductivity of composite with different carbon nanofibers loadings were studied, also the voltage-current relationship, resistance-temperature properties and mechano-electric effect were investigated. Results show that the resistivity of composite decreases in geometric progression with the increasing of carbon nanofibers, and the threshold ranges between 0.1 wt%-0.2 wt%. The voltage-current relationship is in good conformity with the Ohm's law, both positive temperature coefficient and negative temperature coefficient can be found at elevated temperature. In the course of stretching, the electrical resistance of the composites increases with the stress steadily and changes sharply near the breaking point, which is of importance for the safety monitor and structure health diagnosis. 展开更多
关键词 carbon nanofibers positive temperature coefficient negative temperature coefficient mechano-electric effect
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Tunneling field effect transistors based on in-plane and vertical layered phosphorus heterostructures
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作者 冯申艳 张巧璇 +2 位作者 杨洁 雷鸣 屈贺如歌 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第9期421-427,共7页
Tunneling field effect transistors(TFETs) based on two-dimensional materials are promising contenders to the traditional metal oxide semiconductor field effect transistor, mainly due to potential applications in low... Tunneling field effect transistors(TFETs) based on two-dimensional materials are promising contenders to the traditional metal oxide semiconductor field effect transistor, mainly due to potential applications in low power devices. Here,we investigate the TFETs based on two different integration types: in-plane and vertical heterostructures composed of two kinds of layered phosphorous(β-P and δ-P) by ab initio quantum transport simulations. NDR effects have been observed in both in-plane and vertical heterostructures, and the effects become significant with the highest peak-to-valley ratio(PVR)when the intrinsic region length is near zero. Compared with the in-plane TFET based on β-P and δ-P, better performance with a higher on/off current ratio of - 10-6 and a steeper subthreshold swing(SS) of - 23 mV/dec is achieved in the vertical TFET. Such differences in the NDR effects, on/off current ratio and SS are attributed to the distinct interaction nature of theβ-P and δ-P layers in the in-plane and vertical heterostructures. 展开更多
关键词 tunneling field effect transistors negative differential resistance effect on/off current ratio subthreshold swing
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