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| 1 | Change of Cultivated Land and Its Implications on Food Security in China显示文摘The population growth and demand for high living standard not only increase food demand but also cause more loss of the limited cultivated land resources.Cultivated land loss caused by disasters and the implementation of the “Conversion of Cropland to Forest or Grassland” project make this situation even worse in China.Thus,there is a problem to be solved imminently that to what extent the cultivated land can guarantee food security of China.Based on time-series data on food production and cultivated land area from 1989 to 2003 and other research results,this paper constructs quality index of cultivated land according to different land quality.Regression models are adopted to predicate changes of main factors from 2004 to 2030,which have great effect on cultivated land area or grain productivity,and verify accuracy with coefficient of determination(R2).Nine results were got according to three scenarios of decreasing rate of population growth rate and three cases of urban and rural built-up area per capita.There results show that China’s food supply can only be maintained at a low to middle level of 370-410kg per capita,that is,China has enough land productivity to meet primary demand of food independently.However,it cannot reach the safe target of 500kg per capita if there is no breakthrough in breeding or no remarkable improvement of irrigation works,when the grain self-sufficiency maintains no less than 80%.To breed productive crops and to improve land productivity by meliorating low quality cultivated land are appropriate measures to shrink the gap between food demand and supply.The results may offer helpful information for the formulation of policies on population growth,land use,protection of cultivated land. | YU Bohua LU Changhe | 2006 | Chinese Geographical Science2006，16，4： | 19 |
| 2 | Production potential and yield gaps of summer maize in the Beijing-Tianjin-Hebei Region显示文摘庄稼潜力生产率是科学地估价庄稼生产的一个关键索引并且打支持人口的能力。这研究第一与 40 年的气象学的数据用 WOFOST 模型在 Beijing-Tianjin-Hebei (BTH ) 区域模仿了潜力和夏天玉米的 waterlimited 产量,然后在县水平基于统计数据分析了在实际、潜在的收益之间的收益差距。潜力和在 BTH 区域的夏天玉米的水有限产量是 68548789 kg/hm2 和 64348741 kg/hm2,并且为整个区域的加权的一般水准分别地是 7861 kg/hm2 和 7185 kg/hm2。模仿的收益逐渐地特别地处于气候的条件与变化从东北减少到西南温度和降水。潜在的产量的年度变化比东北部分在中央、南部的部分是更高的。把产量比作潜力,水有限收益有变化(CV ) 的更高的系数,因为降水效果。夏天玉米的实际收益是 25378730 kg/hm2,地区性在 5582 点平均 kg/hm2,大约 70% 潜力让步,暗示这个区域有空间由改进庄稼管理和灌溉系统增加收益。 | WANG Tao LU Changhe YU Bohua | 2011 | Journal of Geographical Sciences2011，21，4： | 13 |
| 3 | Nano-enhanced biolubricant in sustainable manufacturing:From processability to mechanisms显示文摘To eliminate the negative effect of traditional metal-working fluids and achieve sustainable manufacturing,the usage of nano-enhanced biolubricant(NEBL)is widely researched in minimum quantify lubrication(MQL)machining.It's improved tool wear and surface integrity have been preliminarily verified by experimental studies.The previous review papers also concluded the major influencing factors of processability including nano-enhancer and lubricant types,NEBL concentration,micro droplet size,and so on.Nevertheless,the complex action of NEBL,from preparation,atomization,infiltration to heat transfer and anti-friction,is indistinct which limits preparation of process specifications and popularity in factories.Especially in the complex machining process,in-depth understanding is difficult and meaningful.To fll this gap,this paper concentrates on the comprehensive quantitative assessment of processability based on tribological,thermal,and machined surface quality aspects for NEBL application in turning,milling,and grinding.Then it attempts to answer mechanisms systematically considering multi-factor influence of molecular structure,physicochemical properties,concentration,and dispersion.Firstly,this paper reveals advanced lubrication and heat transfer mechanisms of NEBL by quantitative comparison with biolubricant-based MQL machining.Secondly,the distinctive filmformation,atomization,and infiltration mechanisms of NEBL,as distinguished from metal-working fluid,are clarified combining with its unique molecular structure and physical properties.Furtherly,the process optimization strategy is concluded based on the synergistic relationship analysis among process variables,physicochemical properties,machining mechanisms,and performance of NEBL.Finally,the future development directions are put forward aiming at current performance limitations of NEBL,which requires improvement on preparation and jet methods respects.This paper will help scientists deeply understand effective mechanism,formulate process specifications,and find future development trend of this technology. | Yanbin ZHANG Hao Nan LI Changhe LI Chuanzhen HUANG Hafiz Muhammad ALI Xuefeng XU Cong MAO Wenfeng DING Xin CUI Min YANG Tianbiao YU Muhammad JAMIL Munish Kumar GUPTA Dongzhou JIA Zafar SAID | 2022 | Friction2022，10，6： | 5 |
| 4 | Multistage analysis method for detection of effective herb prescription from clinical data显示文摘为特定的疾病条件或特别的耐心的组决定有效繁体中文药(TCM ) 治疗是因为复杂个性化的表明,在真实世界的病人和在临床的背景规定的个性化的联合治疗要求调查的一个困难的问题。在这研究,集成倾向大小写匹配的一个多级式的分析方法,复杂网络分析,和植物给了丰富分析被建议为特别疾病识别有效植物药方(例如,失眠) 。首先,匹配的倾向大小写被使用匹配临床的盒子。然后,核心网络抽取和植物集合丰富被联合检测核心有效植物药方。基于有效性的相互的信息被用来检测强壮的 herbsymptom 关系。这个方法在一个 TCM 临床的数据集合上被使用, 955 个病人从设计得好的观察研究收集了。结果与更高的有效性率揭示了那组植物药方(76.9% 对 42.8% 为匹配的样品;94.2% 对 84.9% 为所有样品) 与原版相比,药方被发现。有症状表明的特别的耐心的组也被识别帮助调查有效植物药方的指示。 | Kuo Yang Runshun Zhang Liyun He Yubing Li Wenwen Liu Changhe Yu Yanhong Zhang Xinlong Li Yan Liu Weiming Xu Xuezhong Zhou Baoyan Liu | 2018 | Frontiers of Medicine2018，12，2： | 5 |
| 5 | Impacts of Sloping Land Conversion Program on the vegetation in loess hilly and gully area of northern Shaanxi显示文摘Aiming at alleviating the serious soil erosion, the Chinese government initiated the Sloping Land Conversion Program (SLCP) in 1999. Now, after 8 years of project implementation, the ecological recovery effects of the SLCP have become the hot issue of academic circle. This paper, taking the loess hill and gully area of northern Shaanxi as an example, presents a methodology for assessing the vegetation restoration effect of SLCP with normalized difference vegetation index (NDVI). The key components include calculation of the Growing Season NDVI (GSNDVI), and estimation of the NVDI change induced by climate and SLCP, respectively. Based on the method, the NDVI change between 2000 and 2006 was obtained using the GSNDVI that excluded the noise from snow and ice. After the part of total NDVI change caused by climate variation was estimated using empiric formulae, we obtained the part induced by human factors, i.e. the SLCP. The human induced part of NDVI change was considered as an approximation indicating the effect of the SLCP on the vegetation. Finally, we analyzed the NDVI change characters of the whole study area, different slope lands and different land use types by spatial statistics method. Results show that the vegetation condition is significantly improved by the SLCP, particularly land types that directly involved in the SLCP, such as steeply slope farmlands, degraded grasslands, etc. | Ma Junfei Lu Changhe Yu Bohua | 2009 | Ecological Economy2009，5，2： | 3 |
| 6 | The SLCP-driven land use changes and farmers' responses in the loess hilly and gully region:a case study for Ansai County显示文摘Taking Ansai County located in loess hilly and gully area as a case,this study analyzes the land use changes driven by the SLCP(Slope Land Conversion Program)and the farmers'responses by household survey and participatory rapid appraisal(PRA).It is found that the SLCP aroused various changes in land use,agricultural production,rural incomes,etc.In the period of 1999-2005,the farmland and grasslands were reduced by 26,809 ha and 17,571 ha respectively,while forestland increased by 38,203 ha;greenhouse vegetable and orchard got a quick development,with the area enlarged by about 7 times and nearly doubled respectively.The SLCP reduced the area of crops particularly those that normally grown on slope lands,e.g.the sowing area of winter wheat dropped from 19.39% of the total cropping area in 1999 to 0.98%in 2005.Draught animals,pigs and sheep have a decline in the number because the remained land and the ban on grazing on natural grasslands can not provide sufficient feed forage.Thanks to the financial subsidy,farmers increased land inputs and thus outputs.To achieve long-term sustain-able development and improve rural income,the government should continuously support farmers to improve the land management,to adopt alternative land use systems,and to increase inputs on soil conservation.Vegetable and fruit production are two promise land use systems,and should be further developed. | Wang Qian Lu Changhe Yu Bohua Ma Junfei | 2009 | Ecological Economy2009，5，4： | 1 |
| 7 | Somatic em bryogenesis and plant regeneration from litichi protoplasts iso lation from embryogenic suspensions显示文摘 | Changhe Yu Zhenguang Chen Liuxin Lu | 2000 | Plant Cell Tissue and Organ Cuhure2000，61，： | 1 |
| 8 | Quantifying production potentials of winter wheat in the North China Plain 显示文摘 | Wu Dingrong Yu Qiang Lu Changhe et 81 | 2006 | European Journal of Agronomy2006，24，： | 1 |
| 9 | Factors affecting Agrobacterium-mediated transformation and regeneration of sweet orange and citrange显示文摘 | Changhe Yu Shu Huang Chuxian Chen | 2002 | Plant Cell Tissue Organ Culture2002，71，： | 1 |
| 10 | Tribological Mechanism of Graphene and Ionic Liquid Mixed Fluid on Grinding Interface under Nanofluid Minimum Quantity Lubrication显示文摘Graphene has superhigh thermal conductivity up to 5000 W/(m·K),extremely thin thickness,superhigh mechanical strength and nano-lamellar structure with low interlayer shear strength,making it possess great potential in mini-mum quantity lubrication(MQL)grinding.Meanwhile,ionic liquids(ILs)have higher thermal conductivity and better thermal stability than vegetable oils,which are frequently used as MQL grinding fluids.And ILs have extremely low vapor pressure,thereby avoiding film boiling in grinding.These excellent properties make ILs also have immense potential in MQL grinding.However,the grinding performance of graphene and ionic liquid mixed fluid under nano-fluid minimum quantity lubrication(NMQL),and its tribological mechanism on abrasive grain/workpiece grinding interface,are still unclear.This research firstly evaluates the grinding performance of graphene and ionic liquid mixed nanofluids(graphene/IL nanofluids)under NMQL experimentally.The evaluation shows that graphene/IL nanofluids can further strengthen both the cooling and lubricating performances compared with MQL grinding using ILs only.The specific grinding energy and grinding force ratio can be reduced by over 40%at grinding depth of 10μm.Work-piece machined surface roughness can be decreased by over 10%,and grinding temperature can be lowered over 50℃at grinding depth of 30μm.Aiming at the unclear tribological mechanism of graphene/IL nanofluids,molecular dynamics simulations for abrasive grain/workpiece grinding interface are performed to explore the formation mechanism of physical adsorption film.The simulations show that the grinding interface is in a boundary lubrication state.IL molecules absorb in groove-like fractures on grain wear flat face to form boundary lubrication film,and graphene nanosheets can enter into the grinding interface to further decrease the contact area between abrasive grain and workpiece.Compared with MQL grinding,the average tangential grinding force of graphene/IL nanofluids can decrease up to 10.8%.The interlayer shear effect and low interlayer shear strength of graphene nanosheets are the principal causes of enhanced lubricating performance on the grinding interface.EDS and XPS analyses are further carried out to explore the formation mechanism of chemical reaction film.The analyses show that IL base fluid happens chemical reactions with workpiece material,producing FeF_(2),CrF_(3),and BN.The fresh machined surface of workpiece is oxidized by air,producing NiO,Cr_(2)O_(3) and Fe_(2)O_(3).The chemical reaction film is constituted by fluorides,nitrides and oxides together.The combined action of physical adsorption film and chemical reaction film make graphene/IL nano-fluids obtain excellent grinding performance. | Dexiang Wang Yu Zhang Qiliang Zhao Jingliang Jiang Guoliang Liu Changhe Li | 2023 | Chinese Journal of Mechanical Engineering2023，36，4： | 0 |
| 11 | Circular Dammann gratings for enhanced control of the ring profile of perfect optical vortices显示文摘Perfect optical vortices(POVs)provide a solution to address the challenge induced by strong dependence of classical optical vortices on their carried topological charges.However,traditional POVs are all shaped into bright rings with a single main lobe along the radial direction.Here we propose a method for enhanced control on the ring profile(the radial intensity profile of circular rings)of POVs based on modulated circular sine/cosine radial functions,which is realized by a circular Dammann grating embedded with a spiral phase.Specifically,a type of'absolute'dark POVs surrounded by two bright lobe rings in each side is presented,which provides a perfect annular potential well along those dark impulse rings for trapping low-index particles,cells,or quantum gases.In addition,several POVs with different ring profiles,including conventional POVs with bright rings,the dark POVs mentioned above,and also POVs with tunable ring profiles,are demonstrated.This work opens up new possibilities to controllably tune the ring profile of perfect vortices,and this type of generalized POVs will enrich the content of singular optics and expand the application scope of perfect vortices in a range of areas including optical manipulation,both quantum and classical optical communications,enhanced optical imaging,and also novel structured pumping lasers. | JUNJIE YU CHAOFENG MIAO JUN WU CHANGHE ZHOU | 2020 | Photonics Research2020，8，5： | 0 |
| 12 | Achieving macroscale superlubricity with ultra-short running-in period by using polyethylene glycol-tannic acid complex green lubricant显示文摘Superlubricating materials can greatly reduce the energy consumed and economic losses by unnecessary friction.However,a long pre-running-in period is indispensable for achieving superlubricity;this leads to severe wear on the surface of friction pairs and has become one of the important factors in the wear of superlubricating materials.In this study,a polyethylene glycol-tannic acid complex green liquid lubricant(PEG10000-TA)was designed to achieve macroscale superlubricity with an ultrashort running-in period of 9 s under a contact pressure of up to 410 MPa,and the wear rate was only 1.19×10^(–8)mm^(3)·N^(−1)·m^(−1).This is the shortest running-in time required to achieve superlubricity in Si_(3)N_(4)/glass(SiO_(2)).The results show that the strong hydrogen bonds between PEG and TA molecules can significantly reduce the time required for the tribochemical reaction,allowing the lubricating material to reach the state of superlubrication rapidly.Furthermore,the strong hydrogen bond can share a large load while fixing free water molecules in the contact zone to reduce shear interaction.These findings will help advance the use of liquid superlubricity technology in industrial and biomedical. | Changhe DU Tongtong YU Zishuai WU Liqiang ZHANG Ruilin SHEN Xiaojuan LI Min FENG Yange FENG Daoai WANG | 2023 | Friction2023，11，5： | 0 |
| 13 | Erratum to:Nano-enhanced biolubricant in sustainable manufacturing:From processability to mechanisms显示文摘 | Yanbin ZHANG Hao Nan LI Changhe LI Chuanzhen HUANG Hafiz Muhammad ALI Xuefeng XU Cong MAO Wenfeng DING Xin CUI Min YANG Tianbiao YU Muhammad JAMIL Munish Kumar GUPTA Dongzhou JIA Zafar SAID | 2023 | Friction2023，11，5： | 0 |
| 14 | Tribological mechanism of carbon group nanofluids on grinding interface under minimum quantity lubrication based on molecular dynamic simulation显示文摘Carbon group nanofluids can further improve the friction-reducing and anti-wear properties of minimum quantity lubrication(MQL).However,the formation mechanism of lubrication films generated by carbon group nanofluids on MQL grinding interfaces is not fully revealed due to lack of sufficient evidence.Here,molecular dynamic simulations for the abrasive grain/workpiece interface were conducted under nanofluid MQL,MQL,and dry grinding conditions.Three kinds of carbon group nanoparticles,i.e.,nanodiamond(ND),carbon nanotube(CNT),and graphene nanosheet(GN),were taken as representative specimens.The[BMIM]BF4 ionic liquid was used as base fluid.The materials used as workpiece and abrasive grain were the single-crystal Ni–Fe–Cr series of Ni-based alloy and single-crystal cubic boron nitride(CBN),respectively.Tangential grinding force was used to evaluate the lubrication performance under the grinding conditions.The abrasive grain/workpiece contact states under the different grinding conditions were compared to reveal the formation mechanism of the lubrication film.Investigations showed the formation of a boundary lubrication film on the abrasive grain/workpiece interface under the MQL condition,with the ionic liquid molecules absorbing in the groove-like fractures on the grain wear’s flat face.The boundary lubrication film underwent a friction-reducing effect by reducing the abrasive grain/workpiece contact area.Under the nanofluid MQL condition,the carbon group nanoparticles further enhanced the tribological performance of the MQL technique that had benefited from their corresponding tribological behaviors on the abrasive grain/workpiece interface.The behaviors involved the rolling effect of ND,the rolling and sliding effects of CNT,and the interlayer shear effect of GN.Compared with the findings under the MQL condition,the tangential grinding forces could be further reduced by 8.5%,12.0%,and 14.1%under the diamond,CNT,and graphene nanofluid MQL conditions,respectively. | Dexiang WANG Yu ZHANG Qiliang ZHAO Jingliang JIANG Guoliang LIU Changhe LI | 2023 | Frontiers of Mechanical Engineering2023，18，1： | 0 |
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