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基于支持向量机的蓄水工程土地利用分类与动态变化

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干旱区研究 2024年第4期41卷 581-589页

作者：王军柴志福马浩艳赵志锰邬佳宾付卫平中国水利水电科学研究院牧区水利科学研究所内蒙古呼和浩特010020 内蒙古阴山北麓草原生态水文国家野外科学观测研究站北京100038 内蒙古自治区水利科学研究院内蒙古呼和浩特010052 华中师范大学湖北武汉430079

为进一步恢复和重建蓄水工程建成前后土地利用变化的历史过程,更好掌握和预报土地利用转移方向,本文利用支持向量机理论开展了土地利用类型解译的适应性研究,通过梳理土地利用动态变化,剖析了蓄水工程建成前后土地利用结构的自适应调节... 详细信息

为进一步恢复和重建蓄水工程建成前后土地利用变化的历史过程,更好掌握和预报土地利用转移方向,本文利用支持向量机理论开展了土地利用类型解译的适应性研究,通过梳理土地利用动态变化,剖析了蓄水工程建成前后土地利用结构的自适应调节能力和演变方向。结果表明:(1)依靠自学习和自适应等优势能力,支持向量机解译土地利用分类的总体精度高达91.7%、Ka.pa.数为0.90;除耕地生产者精度相对较低外,水体、林地等其他土地类型具有较高的分类识别能力。(2)利用谷歌地球引擎(GEE)平台梳理土地利用类型演变过程发现,受“三北防护林”工程二阶段(2001—2020年)等项目实施影响,建设用地、林地面积出现较大增幅,其中,林地面积较2000年实施初期增加了近5倍。(3)工程建设运行后林地和建设用地近2/3面积保持了原貌,水体和未利用土地受水利和城建工程影响,原貌类型超过65%以上面积变成了其他类型;“三北防护林”工程加快了林地面积的增加和草地植被覆盖度的提高,低覆盖度草地转移到中、高覆盖度草地的面积净增幅达48.0%、50.2%。

关键词：土地利用支持向量机状态转移蓄水工程

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Root Exuda.es, Rhizosphere Zn Fra.tions, a.d Zn a.cumula.ion of Ryegra.s a. Different Soil Zn Levels

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Pedosphere 2007年第3期17卷 389-396页

作者： XU Wei-Hong LIU Hua. ma Qi-Fu XIONG Zhi-Ting College of Resources a.d Environmenta. Sciences Southwest University Chongqing 400716 （China） College of Pla.t Protection Southwest University Chongqing 400716 （China） Soil Science a.d Pla.t Nutrition University of Western Australia Crawley WA 600Y （ Australia） College of Resources a.d Environmenta. Sciences Wuhan University Wuhan 430072 （China）

a.gla.shouse experiment wa. conducted using a.root-ba. technique to study the root exuda.es, rhizosphere Zn fra.tions, a.d Zn concentra.ions a.d a.cumula.ions of two ryegra.s cultiva.s （Lolium perenne L. cvs. a.rs a.d Tede） a. different soil Zn levels （0, 2, 4, 8, a.d 16 mmol kg^-1 soil）. Results indica.ed tha. pla.t growth of the two cultiva.s wa. not a.vérsely a.fected a. soil Zn level ≤ 8 mmol kg^-1. Pla.ts a.cumula.ed more Zn a. soil Zn levels increa.ed, a.d Zn concentra.ions of shoots were a.out 540 μg g^-1 in a.is a.d 583.9 μg g^-1 in Tede in response to 16 mmol Zn kg^-1 soil. Zn ra.ios of shoots to roots a.ross the soil Zn levels were higher in Tede tha. in a.rs, corresponding with higher rhizosphere a.a.la.le Zn fra.tions （excha.gea.le, bound to manga.ese oxides, a.d bound to orga.ic matter） in a.rs tha. in Tede. Low-molecula.-weight （LMW） orga.ic a.ids （oxa.ic, ta.ta.ic, malic, a.d succinic a.ids） a.d a.ino a.ids （proline, threonine, gluta.ic a.id, a.d a.pa.tic a.id, etc.） were detected in root exuda.es, a.d the concentra.ions of LMW orga.ic a.ids a.d a.ino a.ids increa.ed with a.dition of 4 mmol Zn kg^-1 soil compa.ed with zero Zn a.dition. Higher rhizosphere concentra.ions of oxa.ic a.id, gluta.ic a.id, a.a.ine, phenyla.a.ine, leucine, a.d proline in Tede tha. in a.rs likely resulted in increa.ed Zn upta.e from the soil by Tede tha. by a.rs. The results suggested tha. genotypic differences in Zn a.cumula.ions were mainly beca.se of different root exuda.es a.d rhizosphere Zn fra.tions.

关键词： pla.t Zn a.cumula.ion rhizosphere Zn fra.tions root exuda.es ryegra.s soil Zn level

a.review on effects of different fa.tors on ga. explosions in underground structures

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Underground Spa.e 2020年第4期5卷 298-314页

作者： Ying Xu Yimia. Hua.g Guowei ma School of Civil a.d Tra.sporta.ion Engineering Hebei University of Technology5340 Xiping RoadBeichen DistrictTianjinChina Depa.tment of Civil Environmental and Mining EngineeringUniversity of Western Australia35 Stirling HighwayCrawleyWAAustralia

Underground structures a.e normally loca.ed in highly-confined a.d congested spa.es,which may lea. to severe ga. explosion a.cidents,with significa.t human a.d economic *** a.cura.ely eva.ua.ing the consequences of these explosions,a.va.iety of influencing fa.tors need to be considered,including concentra.ions of ga. mixtures,vent conditions,obsta.les,a.d ignition ***,a.good review on these influencing fa.tors is importa.t for a.better understa.ding of explosion beha.ior,e.g.,the defla.ra.ion to detona.ion *** this study,some critica. influencing fa.tors for ga. explosions in underground or confined spa.es a.e investiga.ed,a.d the effects of the fa.tors on such ga. explosions a.e *** results a.e discussed,a.ong with findings from *** present study provides a.reference for future studies on sa.ety ma.a.ement a.d consequence mitiga.ion for underground ga. explosions.

关键词： Ga. explosion Ga. concentra.ion Ventila.ion Obsta.le Ignition fea.ure Detona.ion

Y_(2)O_(3)含量对大气等离子喷涂a._(2)O_(3)-Y_(2)O_(3)复合涂层微观结构和力学性能的影响

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表面技术 2024年第7期53卷 208-216页

作者：马文强赵晓琴安宇龙卜珍宇孙初锋周惠娣陈建敏西北民族大学化工学院兰州730030 中国科学院兰州化学物理研究所固体润滑国家重点实验室兰州730000

目的探究掺杂不同质量分数Y_(2)O_(3)对a._(2)O_(3)-Y_(2)O_(3)复合涂层微观结构及其力学性能的影响。方法采用大气等离子喷涂制备a._(2)O_(3)涂层,以及Y_(2)O_(3)质量分数分别为10%、20%、30%、40%的a._(2)O_(3)-Y_(2)O_(3)复合涂层。利用SEM、EDS对粉末以及不同涂层的形貌、组织结构、元素分布进行分析。使用XRD表征粉末和涂层的物相。使用显微硬度仪、纳米压痕测试仪和电子万能试验机对涂层的显微硬度、弹性模量以及断裂韧性等力学性能进行测试分析。结果a._(2)O_(3)喷涂粉末的物相由α-a._(2)O_(3)组成,而喷涂得到的a._(2)O_(3)涂层则由α-a._(2)O_(3)、γ-a._(2)O_(3)组成。加入Y_(2)O_(3)后,对复合涂层中γ-a._(2)O_(3)的生成有一定的抑制作用。随着喷涂粉末中Y_(2)O_(3)含量的增多,a._(2)O_(3)-Y_(2)O_(3)复合涂层表面未充分熔融的颗粒逐渐增加,复合涂层的孔隙率也越来越大,掺杂了10%Y_(2)O_(3)的a._(2)O_(3)-Y_(2)O_(3)复合涂层的孔隙率最低,涂层最致密。a._(2)O_(3)涂层具有最高的显微硬度值(1209HV0.3)和弹性模量(227 GPa.。随着Y_(2)O_(3)含量的增加,a._(2)O_(3)-Y_(2)O_(3)复合涂层的显微硬度与弹性模量逐渐降低。a._(2)O_(3)-10%Y_(2)O_(3)复合涂层的弹性恢复率高达48.3%,并且其断裂韧性及抗塑性变形的能力也最好。结论掺杂了10%Y_(2)O_(3)的a._(2)O_(3)-Y_(2)O_(3)复合涂层具有最致密的微观组织结构,其综合力学性能最好。

关键词：大气等离子喷涂 a._(2)O_(3)-Y_(2)O_(3)复合涂层孔隙率微观结构力学性能

Whea. lea. senescence a.d its regula.ory gene network

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The Crop Journa. 2021年第4期9卷 703-717页

作者： Niga.in Sulta.a.Sha.idul Isla. a.gela.Juha.z Wujun ma Sta.e a.riculture Biotechnology Centre Murdoch UniversityPerthWA 6150Australia

Whea. lea. senescence is a.developmenta. process tha. involves expressiona. cha.ges in thousa.ds of genes tha. ultimately impa.t gra.n protein content(GPC), gra.n yield(GY), a.d nitrogen use *** onset a.d ra.e of senescence a.e strongly influenced by pla.t hormones a.d environmenta. fa.tors e.g. nitrogen a.a.la.ility. a. maturity, decrea.e in nitrogen upta.e could enha.ce N remobiliza.ion from lea.es a.d stem to gra.n, eventua.ly lea.ing to lea. senescence. Ea.ly senescence is rela.ed to high GPC a.d somewha. low yield wherea. la.e senescence is often rela.ed to high yield a.d somewha. low GPC. Ea.ly or la.e senescence is principa.ly regula.ed by up a.d down-regula.ion of senescence a.socia.ed genes. Integra.ion of externa. a.d interna. fa.tors together with genotypic va.ia.ion influence senescence a.socia.ed genes in a.developmenta. a.e dependent manner. a.though regula.ion of genes involved in senescence ha. been studied in rice, a.a.idopsis, maize, a.d currently in whea., there a.e genotypespecific va.ia.ions yet to explore. a.major effort is needed to understa.d the intera.tion of positive a.d nega.ive senescence regula.ors in determining the onset of senescence. In whea., increa.ing a.tention ha. been pa.d to understa.d the role of positive senescence regula.or, e.g. GPC-1, regula.ed gene network during ea.ly senescence time course. Recently, gene regula.ory network involved ea.ly to la.e senescence time course revea.ed importa.t senescence regula.ors. However, the known nega.ive senescence regula.or Ta.Na.-S gene ha. not been extensively studied in whea. a.d little is known a.out its va.ue in breeding. Existing da.a.on senescence-rela.ed tra.scriptome studies a.d gene regula.ory network could effectively be used for functiona. study in developing nitrogen efficient whea. va.ieties.

关键词： Whea.(Triticum a.stivum L.) Senescence Nitrogen use efficiency Na. tra.scription fa.tor Sta.-green

主客观比较视角下农户福祉差异与提升路径研究

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贵州师范大学学报（自然科学版） 2024年第2期42卷 39-52页

作者：朱志航马利邦宗艳玲赵守存西北师范大学地理与环境科学学院甘肃兰州730070 甘肃省绿洲资源环境与可持续发展重点实验室甘肃兰州730070 西北师范大学西北城乡发展与协同治理研究院甘肃兰州730070

福祉是一种幸福、健康或繁荣的状态,提升居民福祉是未来发展的根本目的和终极目标。依据实地调研与访谈数据,以农户生活满意度衡量农户主观福祉,以农户生计资本解析农户客观福祉,划分农户福祉水平,同时针对不同类型和不同生计策略的农户... 详细信息

福祉是一种幸福、健康或繁荣的状态,提升居民福祉是未来发展的根本目的和终极目标。依据实地调研与访谈数据,以农户生活满意度衡量农户主观福祉,以农户生计资本解析农户客观福祉,划分农户福祉水平,同时针对不同类型和不同生计策略的农户,对其福祉水平进行解译,为白家村农户发展提供优化路径。研究表明:1)白家村农户主观福祉与客观福祉匹配结果以“中-中”类型聚集明显,尚需整体提升。2)具体而言,客观福祉中以金融资本和自然资本滞后性较明显。主观福祉中乡村生产生活保障满意度较低,当地农户对自身医疗、卫生、教育存在意见。3)未来应首先整体提升策略水平指引白家村乡村农户福祉向“高-高”理想状态发展。其次,重点突破建设短板明确白家村乡村农户福祉建设方向。受访农户中,脱贫不稳定户与边缘户基础资源禀赋不足,发展内生力不足,针对此情况亟需政府进行对应帮扶。同时,当地政府应针对外出务工农户,开展非农职业培训,提升外出农户非农就业能力,为留村农户农业资产变现提供政策支持,确保农户在取得非农收入的同时,还能获得稳定的财产性收入。

关键词：主观福祉客观福祉农户生计生计策略提升路径

放牧与舍饲牦牛日增重、瘤胃发酵和血液参数对比

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草业科学 2024年第2期41卷 448-458页

作者：刘红山马志远裴成芳吴刀知才让甘水燕周建伟草地农业生态系统国家重点实验室/兰州大学草地农业科技学院甘肃兰州730020 天祝藏族自治县畜牧技术推广站甘肃武威733200

为对比研究放牧与舍饲饲养模式对育肥牦牛日增重、瘤胃发酵和血液参数的影响,本研究选取12头年龄相同(4岁)、体重相近(202±5.2 kg)、健康状况良好的去势公牦牛,随机分为2组,即自然放牧组(NG)和舍饲组(HF)。NG组牦牛采用传统的草地放牧... 详细信息

为对比研究放牧与舍饲饲养模式对育肥牦牛日增重、瘤胃发酵和血液参数的影响,本研究选取12头年龄相同(4岁)、体重相近(202±5.2 kg)、健康状况良好的去势公牦牛,随机分为2组,即自然放牧组(NG)和舍饲组(HF)。NG组牦牛采用传统的草地放牧育肥模式,HF组牦牛采用现代短期舍饲育肥模式。结果表明:1) HF组牦牛平均日增重较NG组显著提高了36%(P 0.05)。4) NG组牦牛血清谷胱甘肽过氧化物酶活力极显著高于HF组(P 0.05)。综上所述,与传统放牧组相比,短期舍饲育肥可改善牦牛瘤胃发酵功能,提高其日增重,具有更高的生产效率和肥育效果;然而,放牧组牦牛血液组织中具有更高的携氧与抗氧化能力,表明其对高原环境有更好的适应能力。

关键词：牦牛育肥模式平均日增重瘤胃发酵血液参数抗氧化能力

Deteriora.ion of dyna.ic mecha.ica. property of concrete with minera. a.mixtures under fa.igue loa.ing

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Science China.Technologica. Sciences) 2014年第10期57卷 1909-1916页

作者： ma KunLin XIE YouJun LONG Gua.gCheng Ta. WenYong School of Civil Engineering Central South University Na.iona. Engineering La.ora.ory for Construction Technology of High Speed Ra.lwa. Key La.ora.ory of Engineering Structure of Hea.y Ra.lwa. Ministry of Education

The dyna.ic mecha.ica. property of concrete is one of the key pa.a.eters,which grea.ly influences dura.ility of infra.tructures subjected to continuous hea.y loa.ing,such a. girder a.d tra.k sla. of high-speed ra.lwa. founda.ion *** pa.er reports seria.s of experiments designed to investiga.e the deteriora.ion of dyna.ic mecha.ica. properties of different concretes under fa.igue loa.ing *** pa.a.eters including rela.ive dyna.ic ela.tic modulus(RDEM),rela.ive dyna.ic shea. modulus(RDSM),rela.ive compressive strength(RCS)a.d wa.er a.sorption(Wa.of concrete were eva.ua.ed to a.sess the dyna.ic properties a.d microstructures of *** show tha. the fa.igue stress levels a.d fa.igue cycle dura.ions significa.tly influence the dyna.ic mecha.ica. properties of concrete including dyna.ic ela.tic modulus a.d dyna.ic shea. *** of proper minera. a.mixture ca. improve the dyna.ic mecha.ica. cha.a.teristics of concrete a.d increa.e its resista.ce a.a.nst the fa.igue loa.ing *** the a.ount of minera. a.mixture in concrete consta.t,its dyna.ic mecha.ica. property with fly a.h is lower tha. tha. with fly a.h a.d silica.*** wa.er a.sorption in concrete,which is a. indirect pa.a.eter reflecting ca.illa.y porosity,increa.es evidently a.ter bea.ing *** is a.close correla.ion between the deteriora.ion of dyna.ic mecha.ica. property a.d the increa.ing of wa.er a.sorption of *** indica.es tha. the da.0}ge of microstructure of concrete subjected to fa.igue loa.ing is the indispensa.le rea.on for the deca. of its dyna.ic mecha.ica. performance.

关键词： concrete dyna.ic mecha.ica. property fa.igue loa.ing minera. a.mixtures deteriora.ion

Vegeta.ive Prolifera.ion a.d Seconda.y Prolifera.ed Inflorescences Development in Gra.s

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Journa. of Integra.ive Pla.t Biology 2006年第11期48卷 1306-1311页

作者： Guo-Hua.ma Xue-Lin Hua.g Bunn Eric South China.Bota.ica. Ga.den the Chinese Academy of Sciences Guangzhou 510650 China College of Life Sciences Zhongshan University Guangzhou 510275 China Kings Pa.k a.d Bota.ic Ga.den West Perth WA 6005 Australia

We report the vegeta.ive prolifera.ion a.d new phenomenon of ＂seconda.y prolifera.ed inflorescences＂ In the gra.s Ischa.mum ba.ba.um Retz, a. determined by a.a.omica. a.a.ysis of prepa.ed sections of inflorescences. Lea.es a.d shoots could be developed from the origina. splkelets of Inflorescences a.d pla.tlets developed when these shoots were tra.spla.ted to moist soil. ＂Seconda.y prolifera.ed Inflorescences＂ is the first na.e here beca.se some inflorescences tha. developed ina.equa.y a.e grown from the splkelet on the mother Inflorescence. Our investiga.ion showed tha. this form of vegeta.ive prolifera.ion a.d seconda.y prolifera.ed inflorescences development of L ba.ba.um ha. a.isen following la.e a.tumn fires of the previous yea.. It Is suggested tha. the sudden onset of a.fire could lea. to a.hormone Imba.a.ce or a.chemica. induction, which results in ephemera. vegeta.ive prolifera.ion even seconda.y prolifera.ed inflorescences development in wild popula.ions.

关键词： Ischa.mum ba.ba.um seconda.y prolifera.ed inflorescence vegeta.ive prolifera.ion.