Drought and Waterlogging Characteristics during the Growth Period of Summer Maize in Luxi Plain Areas

In summer maize growth period,the water supply and demand ratio is regarded as the evaluation index of drought and waterlogging for the summer maize in Liaocheng City. Using GIS,statistics,agrometeorology and other methods,we analyze the precipitation during the summer maize growth period in Luxi Plains from 1961 to 2011. Through the calculation of drought and waterlogging index,it indicates that the disasters of drought and waterlogging frequently occur during the summer maize growth period,mainly affected by the drought; the frequency of occurrence of drought accounts for 80. 4%,that is,it is very prone to serious drought phenomenon,seriously affecting the normal growth and development of summer maize during the seedling period. With global warming,the industrial and domestic water demand is increasing year by year,so it is extremely difficult to increase the water diversion to solve the problem of water shortage for the growth of summer maize. Finally we put forth the following recommendations:( i) Selecting drought-resistant varieties,and improving the water resource use efficiency;( ii)Promoting the water and fertilizer coupling,sprinkler irrigation,drip irrigation,micro-irrigation and other water-saving irrigation technologies,and improving the water use efficiency;( iii) Promoting the ditch,ridge and laminating cultivation technology,reducing the field evapotranspiration,keeping warming and conserving moisture,and saving water resources;( iv) Strengthening the construction of water conservancy facilities,so that it can be irrigated during drought and drained during waterlogging;( v) During dry season,timely organizing artificial rainfall operation,and increasing precipitation in arid areas to ease drought;( vi) Rationally exploiting the groundwater,and improving the underground water use efficiency.

Organic Geochemical Characteristics of Time-Series Settling Particles in Northern South China Sea and Their Implications

Organic carbon, total nitrogen, amino acids, sugars, and chlorophyll were determined in < 1 mm fractions of the samples collected by successive large aperture time-series sediment traps (Honjo-Mark Ⅵ ) in northern China China Sea during September 1987 to October1988. The ratio of C/N and the relative abundance of amino acids and sugars show that organicmatter in the settling particles from northem South China Sea is derived mainly from marineplantkon (especially phytoplankton). The organic carbon fluxes in our sediment traps are lowerthan those in other sediment traps. But the relative contents of Corg/total particulate matter aregenerally similar to those in the Panama Basin, Arabian Sea and Subarctic Pacific. It is suggested that monsoon-caused changes of physical and chemical conditions in the upper euphoticlayer would contro the fluxes of organic matter as well as its composition and transport innorthern South China Sea.

基于植被状态指数的中国干旱演变特征及遥相关驱动研究

干旱会引发植被绿度下降、农作物减产、生物栖息地破坏等诸多问题,对人类和自然环境均具有显著影响。以植被状态指数作为干旱指标,利用极点对称模态分解EPSMD方法对1999~2019年全国植被状态指数序列进行周期与趋势识别,采用网格化趋势检验法揭示网格化的干旱趋势特征,运用多变量小波相干方法探讨干旱与多种遥相关因素的内在关系。结果表明,1999~2019年基于植被状态指数的全国干旱大体呈减轻趋势,植被状态指数的线性倾向率为0.044/10a;不同分区的干旱变化特征各不相同,其中黄土高原区的干旱减轻趋势最为明显,植被状态指数线性倾向率为0.215/10a;网格尺度的植被状态指数趋势特征Z均值在春季、夏季、秋季、冬季分别为0.41、0.79、0.50、0.11,各季度旱情均呈减轻态势;遥相关因素组合PNA-ENSO对全国干旱的影响最为明显。未来可将PNA、ENSO作为干旱预警输入因子提高干旱预报精度。

不同青檀种质资源生长及光合特性比较分析

为了解不同地域青檀种质资源生长特性的差异,为进一步开展青檀优良品种选育提供科学依据,对不同种源地的青檀当年生实生苗的生长指标、光合特性(包括净光合速率、蒸腾速率、气孔导度、胞间CO_(2)浓度4个参数)和色素含量进行测定与分析。结果显示:1号(河北涞水野三坡)青檀无论在生长指标、光合特性、还是色素含量方面,均表现出优于其他地域条件下的相同指标,其在石家庄地区生长适应性最强。

滇南医学流派的形成溯源与特色初探

滇南医学流派始于庄礄入滇,成形于明清时期,追溯其源可发现早在青铜器时代,白族土著居民便掌握了简单外科工具的制造技术,用于治疗简单的外科疾病。在中央集权制度的时代背景下,随着大量移民入滇及官办医学的推行,中原医药文化与技术自秦朝之始不断涌入滇南地区,并与本地医药文化冲撞融合、兼容并蓄,历经千百年,形成了具有鲜明地域特征的"滇南医学"。如今的滇南医学流派容纳着云南地区的各新兴医学流派,融地域性、民族性、兼容性、实用性和时代性于一体,具有源远流长、学派纷呈、守正创新、兼容并蓄等学术特色。

Wave Propagation Simulation Using the CIP Method of Characteristic Equations

We apply the CIP(Cubic Interpolated Profile)scheme to the numerical sim-ulation of the acoustic wave propagation based on characteristic equations.The CIP scheme is based on a concept that both the wavefield and its spatial deriv ative propa-gate along the same characteristic curves derived from a hyperbolic differential equa-tion.We describe the derivation of the characteristic equations for the acoustic waves from the basic equations by means of the directional splitting and the diagonaliza-tion of the coffcient matrix,and establish geophysical boundary conditions.Since the CIP scheme calculates both the wavefield and its spatial derivatives,it is easy to realize the boundary conditions theretically.We also show some numerical simula-tion examples and the CIP can simulate acoustic w ave propagation with high stability and less numerical dispersion.The method of characteristics with the CIP scheme is a very powerful technique to deal w ith the wave propagation in complex geophysical problems.

Characteristics and Causes of the Spatial Evolution of Urban Villages:A Case Study of Shenzhen Special Economic Zone

Studies on the renovation and governance of urban villages have become the interest of human geography since the 1990s.However up to now,there is little literature focusing on the development patterns and dynamic mechanism of the spatial evolution of urban villages based on the theoretical system of urban spatial structure,and there are few scholars doing analyses on the relationship between urban villages and general urban areas in terms of spatial development.In this paper,Shenzhen,the most representative city of China in terms of urban village development,is taken as a case for exploring the characteristics and modes of the spatial evolution of urban villages.With census data of urban village construction in 1999 and 2004 in terms of built-up area,floor area,and construction intensity,the spatial and temporal evolution of the 91 administrative urban villages in the original Shenzhen Special Economic Zone have been analyzed in comparison with that of Shenzhen's general urban areas.It is indicated that the spatial evolution of urban villages matches with the general rules of the spatial development of general urban areas in three aspects.First,land expansion is the most remarkable mode of spatial evolution in the early stage of development;second,in the period of rapid development,there is the obvious tendency of "distance-decay" in terms of construction intensity accompanied by some anomalous fluctuations at certain points;third,renewal and redevelopment are carried out gradually in the mature stage of development.However,because of historical and institutional restrictions,the spatial evolution of urban villages shows its unique characteristics in the aspects of original spatial distribution and spatial expansion mode in the period of rapid development,etc.The outcomes of this study would help not only enrich the theoretical study on the evolution mode of urban spatial structure,but also strengthen the administration over urban villages,in particular with the suggestions that the spatial evolution of urban villages as a type of urban space should not be the same as that of general urban areas and its unique characteristics should not be ignored;specific rules should be set up to guide the rational spatial evolution of urban villages according to the economic development of the city,as well as the housing demands of various kinds of residents.

塔里木盆地顺北4号走滑断裂带变形特征及有利区评价

顺北4号走滑断裂带位于塔里木盆地顺托果勒低隆起,向北延伸至沙雅隆起,具有埋藏深,平面分段、纵向分层、多期活动、结构复杂等特征。通过对顺北4号走滑断裂带高品质三维地震资料解释,开展了断裂带分层、分段、分期、活动性和有利区评价。结果表明,顺北4号走滑断裂带在古生界具有4层结构,大致以中奥陶统顶界面为界,其上发育雁列式断层,其下发育高陡走滑断层;走滑断裂带具有明显的分段特征,按走向可分为北段、中段和南段,整体具有南压北张的特征;走滑断裂带在古生界先后经历了加里东运动中期Ⅰ幕、加里东运动中期Ⅲ幕、加里东运动晚期和海西运动期4期活动;通过对影响顺北地区油气富集成藏的主控因素通源性、储集体规模和晚期调整性的叠加,对顺北4号走滑断裂带进行有利区评价,得到多个有利区,并在实钻中得到验证。

高速冲击下轨道车运动特性分析

针对轨道车高速冲击下复杂的运行状态及车体失稳等问题,采用现代控制理论状态空间轨迹的方法,构建车体撞击力与倾覆力的数学模型。使用Matlab语言编写程序,求解轨道车在高速冲击下的运动状态,得到车体在不同工况下运动状态的变化规律。结果表明,车体最大点头角与冲击速度和车体长高比相关,点头角随冲击速度增加而增加,随长高比的增加而减小;弯道半径影响摇头角的大小;侧击角度影响车体极限失稳状态,其影响随速度变化,速度越大允许值越小;运行冲击坡度降低,车体运动状态的稳定性降低,最大失稳极限速度降低;运行冲击坡度提升,车体运动状态的稳定性增大,最大失稳极限速度增大。

亚精胺对雷司令葡萄生理特性和果实品质的影响

【目的】探讨亚精胺(Spd)对葡萄生理特性和果实品质的影响。【方法】以雷司令葡萄为试材,通过不同浓度(0.3、0.6、0.9、1.2 mmol/L)亚精胺(Spd)处理,以喷施清水(CK)为对照,于开花期、坐果期、果实膨大期、转色期进行全树喷施。【结果】不同浓度Spd处理均可改善叶片的生理特性和果实品质,但随着处理浓度的升高,雷司令葡萄叶片生理特性及品质的变化趋势不同。其中,经T_(3)处理后,叶片叶绿素a含量、果实单粒质量、果实大小、可溶性固形物质量分数、VC、固酸比、单宁含量均得到显著提升,分别较CK增加32.00%、91.10%、99.68%、17.43%、102.86%、44.64%、64.29%;T_(2)处理下丙二醛(MDA)含量最低,且与CK呈显著性差异,较CK降低66.67%;T_(4)处理下叶片叶绿素b、SOD、POD、CAT活性最高,分别较CK增加59.62%、9.38%、387.55%、89.70%;T_(1)处理下总酚含量最高,较CK增加17.50%。经过主成分分析,喷施Spd浓度为0.9 mmol/L对提高雷司令葡萄生理活性和果实品质效果最佳。【结论】喷施Spd浓度为0.9 mmol/L可以减少雷司令葡萄叶绿素的降解和丙二醛(MDA)的积累,提高抗氧化酶活性,增加果实大小,提高可溶性固形物质量分数和VC含量,从而改善果实品质。

摆线轮磨齿机回转台系统动态特性分析

为提高摆线轮磨齿机的加工精度以及传动过程的稳定性,对其回转台的性能进行分析。建立转台传动系统的动力学模型,结合转台的实际参数,计算连接轴的扭转刚度和阻尼系数。通过Newmark-β法对建立的动力学模型进行求解,得出传动系统在传动过程中的稳定性和传动精度,并搭建实验台进行验证。实验结果表明:回转台传动系统具有良好的动态响应,可以获得很高的定位精度和重复定位精度。

产业融合视角下体育特色小镇建设的价值、理念与发展策略研究

体育特色小镇伴随着体育产业转型升级、乡村振兴与全民健身国家战略的实施而产生,体育特色小镇加速相关产业的集聚发展和产业链态的延伸,促进城乡体育服务均等化,推动城乡体育产业的协调发展。体育特色小镇作为体育产业跨界融合的新载体,需要秉承科学的发展理念,以新理念、新机制、新模式打造宜居、宜业、宜游的多元发展空间平台,实现产、城、人、文的有机结合与协调发展。

中国式现代化新道路的制度文化阐析

中国特色社会主义制度文化贯穿于中国式现代化新道路的全过程,关乎着中国特色社会主义事业的成效,影响着中国式现代化新道路的走向。中国式现代化新道路不仅是经济腾飞、人口增长、绿色发展之路,也是中国特色社会主义制度文化拓新之路。在中国现代化的伟大进程中,中国特色社会主义制度文化发挥了不可替代的重要作用,中国特色社会主义制度的架构、执行、完善、创新等都与中国特色社会主义制度文化的功效不可分割,中国特色社会主义制度文化是中国现代化活力奔涌的重要源泉。中国式现代化新道路充分彰显了中国特色社会主义制度文化的独特魅力,中国特色社会主义制度文化俨然成为中国式现代化新道路的重要精神标识。

2003—2022年南通市海门区病毒性肝炎流行特征及趋势分析

目的:分析2003—2022年南通市海门区病毒性肝炎流行特征及趋势,为科学防控病毒性肝炎提供依据。方法:从海门区疫情年报和疾病监测信息报告管理系统收集2003—2022年病毒性肝炎数据,进行流行病学分析。结果:2003—2022年海门区累计报告病毒性肝炎5742例,年平均发病率为28.66/10万,总发病率呈显著下降趋势(χ^(2)=15.996,P<0.01)。甲型肝炎、乙型肝炎、未分型肝炎发病率呈下降趋势,春季为甲型肝炎、戊型肝炎的发病高峰。丙型肝炎、戊型肝炎发病率随年龄增长呈上升趋势。结论:建议提高医疗机构病毒性肝炎诊断能力,加强监测工作,对重点人群开展甲型肝炎、乙型肝炎和戊型肝炎疫苗的接种工作,做到早发现、早诊断、早治疗,扩大治疗覆盖面,从而控制病毒性肝炎的流行。

基于时域有限差分的金属光子晶体波导定向辐射特性研究

为剖析在光子晶体中引入微腔和线缺陷有效控制光波的传输特性.利用时域有限差分方法研究金属光子晶体波导的透过谱和场分布,并通过改变波导出射端界面上柱子的大小位置等实现定向辐射.比较Ag和Al金属介质的光子晶体波导的定向辐射效果.结果表明,当固定晶格常数后,光子晶体的半径r=0.2a时,通过改变表面层可提高定向辐射.当金属介质是Ag,半径为0.12a时,得到的波导模最大.

不同质地土壤夏玉米生育后期光合特性比较研究

在4种质地不同的土壤和2种施肥水平下,研究了玉米的光合特性。结果表明,黏壤土、壤土、砂质壤土和壤质黏土玉米生育后期光合速率(Pn)差异达显著或极显著水平,玉米生育后期各处理的光合参数的日变化存在明显差异,不同质地土壤玉米Pn、Ls 表现为黏壤土>壤土>壤质黏土>砂质壤土,Ci 表现为砂质壤土>壤质黏土>壤土>黏壤土,Gs 表现为质地黏重的土壤大于轻质土壤。蜡熟期各处理的Pn、Gs、Ls 明显小于乳熟期。施肥使各种质地土壤玉米Pn、Gs 和Ls 明显提高,Ci 降低,尤其砂壤玉米变化更为明显。不同处理玉米的叶面积动态和产量差异显著。

黄芩苷和黄芩素的大鼠在体肠吸收特性

目的研究黄芩苷和黄芩素的肠吸收特性。方法采用大鼠在体肠吸收模型,以高效液相色谱法测定循环液中药物的浓度。结果不结扎胆管时,黄芩苷和黄芩素的吸收速率常数分别为(-0·0047±0·0134)h-1和(0·4960±0·0512)h-1;结扎胆管时,黄芩苷和黄芩素的吸收速率常数分别为(0·0239±0·0262)h-1和(0·2106±0·0735)h-1;结扎胆管,在单独以黄芩苷或黄芩素进行在体肠循环时,循环液中分别出现了随时间增加的黄芩素和黄芩苷;结扎胆管尾静脉注射黄芩素时,循环液中出现了黄芩苷。结论黄芩素比黄芩苷更适于口服给药;胆汁不但可以分泌黄芩苷,而且可以促进黄芩素的吸收;黄芩苷在肠内经过菌群代谢为黄芩素而被吸收,被吸收的或静脉注射的黄芩素可在体内还原为黄芩苷,并再被小肠分泌排出。

煤显微组分热解过程中含硫气体逸出特性

在TG-151热天平上利用在线质谱仪考察了兖州煤及其显微组分热解过程中含硫气体的逸出特征,并根据不同含硫气体的逸出规律对兖州煤镜质组和惰质组中硫的存在形态进行了分析.结果表明:镜质组在480℃左右有较强的H2S和COS逸出,惰质组较低,而惰质组在600℃有较强的H2S和COS逸出,镜质组则基本没有,说明镜质组中有机硫含量较高而惰质组中黄铁矿硫含量较高.镜质组和惰质组不同的SO2逸出说明镜质组含有较高的脂肪硫和芳香硫,极少的黄铁矿硫,而惰质组则含有较少脂肪硫和芳香硫,很高的黄铁矿硫.镜质组比惰质组有较高的C4H4S和C8H6S逸出,说明镜质组中的噻吩环和苯并环有较多的以弱的桥键与煤主体结构相连,而惰质组中的噻吩环和苯并环多与缩合芳香体系缩聚在一起,热稳定性较高,难以断裂分解.各种含硫气体不同的逸出强度和分布反映了镜质组和惰质组中硫存在形态和含量的差异而导致的镜质组和惰质组在热解过程中硫的不同变迁规律.

四川烟草大田生长期害虫种类及主要害虫发生规律研究

初步查明四川烟草大田生长期有害虫75种,分属昆虫纲7目25科70种,软体动物门腹足纲1目3科5种。并观察研究了烟蚜(Myzus persicae Sulzer)、烟蛀茎蛾(Phthorimaea helopa Lower)、烟草夜蛾(Heliothis assulea Guenee)、小地老虎(Agrotis ypsilon Rottemberg)、东方蝼蛄(Gryllotalpa orentalis Burmeistr)等重要害虫的发生特点。

杂草稻密度对栽培稻生长发育和产量的影响

以杂草稻wr04-12和栽培稻辽粳294为材料,在大田条件下研究了杂草稻密度对栽培稻生长发育和产量的影响。结果表明:随着杂草稻密度的逐渐增加,栽培稻分蘖数、叶面积指数、叶绿素含量和干物质积累均有不同程度的减少,最终导致栽培稻产量显著降低。从对产量构成因素的影响来看,水稻有效穗数受杂草稻密度的影响最大,穗粒数和结实率受到的影响次之,千粒重受到的影响最小。因此,水稻有效穗数减少和干物质生产能力降低是杂草稻竞争造成栽培稻减产的主要原因。