The Evolution Characteristics of Spatial Layout of Ancient Chinese Capitals: A Case Study of Sui,Tang and Northern Song Dynasties With Important Changes in the Historical Development of Feudal Society

Imperial city and outer city are the most important differentiation of the spatial structure of ancient Chinese capitals.The relationship between city and Guo changed from the original spatial structure mode of "respecting the west" and "sitting in the west and facing the east" to the spatial structure mode of "sitting in the north and facing the south" and the three outer cities in the east,south and west surrounding the imperial city after the Wei,Jin,Southern and Northern Dynasties,and gradually changed from the original "multi palace" system to the "single palace" system.Finally,a "heavy city" capital spatial structure with the outer city around the imperial city and the imperial city around the palace city,and the central axis of the chessboard format was formed.During the Tang and Song Dynasties,it was a period of great change in the history of feudal society in China.Through the investigation of the evolution characteristics of the spatial form of capital cities in the Tang and Song Dynasties,the track of the transformation of social ideology,political system,economic structure and many other fields in the Tang and Song Dynasties was made clear.     

Atmospheric humidity and genotype are key determinants of the diurnal stomatal conductance pattern

Great understanding of the genotypic difference in diurnal stomatal conductance (g_s) pattern and the key determinants of the pattern is important for saving water by adopting cultivars appropriately. Fifteen wheat genotypes were studied under different soil conditions and various meteorological conditions with pot cultivation in rain shelter for two years. Genotype and air humidity were found to be key determinants of diurnal g_s pattern. All genotypes under low relative humidity (LRH) and most genotypes under high relative humidity (HRH) displayed a gradual decline pattern from morning through the afternoon. Under moderate relative humidity (MRH), all genotypes present a single-peak curve pattern, but they differed in peak time, which may lead to unreliable g_s comparison between genotypes and get ostensible contrasting materials. The stomatal conductance was significantly different among genotypes under LRH and the increased g_s magnitude is also significantly different when it was compared between LRH and HRH. The present results provide new thinking for selecting and adopting appropriate cultivars with specific stomata traits for the area with various meteorological conditions.     

中国古典园林与戏曲舞台空间布景的共通性

优秀的传统文化是一个民族劳动人民智慧的结晶。随着全球经济一体化的发展，中国传统文化受到西方文化的猛烈冲击，因此以中国古典园林和戏曲艺术的研究为代表的优秀传统文化的研究对中国现代文化发展有着深远意义。笔者通过查阅国内现有的关于古典园林和戏曲舞台空间布景的研究，发现该领域的研究并不丰富。通过对二者空间布局的层次、置陈布势的常用手法和艺术性进行共通性研究，希望对古典园林和戏曲保护提供参考和指导。     

Occurrence of Incisional Complications After Closure of Equine Ventral Midline Celiotomies With 2 Polyglycolic Acid in Simple Interrupted Suture Pattern

The aim of this retrospective study was to describe the use of simple interrupted suture pattern for the closure of the abdomen after ventral midline celiotomy in horses and to evaluate the prevalence of resulting incisional complications. Seventy horses undergoing abdominal surgery (2006–2015) and surviving at least 30 days were included in the study. Closure technique of the abdominal wall was performed on three layers. Linea alba was closed with a simple interrupted pattern using number two coated braided absorbable polyglycolic acid suture. Follow-up information was recovered at the 90th day postoperatively. Incisional complications considered included drainage, infection, dehiscence, and herniation. The complications observed in the present study using simple interrupted suture pattern were 4.29% (3 of 70), lower than reported in literature with different suture pattern. Simple interrupted suture pattern could be a valid option for the closure of linea alba after ventral midline celiotomy in horses.     

村庄空心化背景下的农村居民点空间布局重构研究

农村居民点空间布局重构对于指导区域农村居民点整理规划、实现土地可持续发展具有重要意义。笔者以黑龙江省明水县明水镇为研究区,通过计算研究区空心化程度、农村居民点整理的重要性指数、迫切性指数、整理时序指数,对农村居民点的整理时序进行划分,提出农村居民点的整理迁移方案。研究结果表明:研究区各村屯农村居民点空心化现象明显,向阳村张奎英屯空心化率最高;在空心化趋势预测结果中,规划近期城北村空心化增强趋势变化最明显,规划中期互助村空心化增强趋势变化最明显,规划远期向阳村空心化增强趋势变化最明显;在农村居民点整理时序上,保留农居点占总数的35.29%,近期整理农居点占总数的9.8%,中期整理农居点占总数的23.53%,远期整理农居点占总数的31.37%。最后提出合理的整理迁移方案,研究成果为指导县域农村居民点整理规划提供参考和科学依据。     

江西省新型农业社会化服务体系的特点与运行模式

实地调研江西省新型农业社会化服务体系建设现状，对江西省目前的新型农业社会化服务体系的特点与运行模式进行分析，针对当地在服务体系构建过程中出现的问题，提出新时期的发展建议。     

Influences of sand cover on erosion processes of loess slopes based on rainfall simulation experiments

Aeolian-fluvial interplay erosion regions are subject to intense soil erosion and are of particular concern in loess areas of northwestern China.Understanding the composition,distribution,and transport processes of eroded sediments in these regions is of considerable scientific significance for controlling soil erosion.In this study,based on laboratory rainfall simulation experiments,we analyzed rainfall-induced erosion processes on sand-covered loess slopes(SS)with different sand cover patterns(including length and thickness)and uncovered loess slopes(LS)to investigate the influences of sand cover on erosion processes of loess slopes in case regions of aeolian-fluvial erosion.The grain-size curves of eroded sediments were fitted using the Weibull function.Compositions of eroded sediments under different sand cover patterns and rainfall intensities were analyzed to explore sediment transport modes of SS.The influences of sand cover amount and pattern on erosion processes of loess slopes were also discussed.The results show that sand cover on loess slopes influences the proportion of loess erosion and that the compositions of eroded sediments vary between SS and LS.Sand cover on loess slopes transforms silt erosion into sand erosion by reducing splash erosion and changing the rainfall-induced erosion processes.The percentage of eroded sand from SS in the early stage of runoff and sediment generation is always higher than that in the late stage.Sand cover on loess slopes aggravates loess erosion,not only by adding sand as additional eroded sediments but also by increasing the amount of eroded loess,compared with the loess slopes without sand cover.The influence of sand cover pattern on runoff yield and the amount of eroded sediments is larger than that of sand cover amount.Furthermore,given the same sand cover pattern,a thicker sand cover could increase sand erosion while a thinner sand cover could aggravate loess erosion.This difference explains the existence of intense erosion on slopes that are thinly covered with sand in regions where aeolian erosion and fluvial erosion interact.     

东北棕壤长期不同施肥处理轮作大豆氮素吸收和土壤硝态氮特征

【目的】在玉米–玉米–大豆轮作体系下,基于棕壤肥料长期定位试验,研究不同施肥处理对东北地区大豆生物量、产量、各部位吸氮量及收获期土壤0―100 cm硝态氮累积的影响,为该地区合理施肥提供理论依据和科学指导。【方法】棕壤肥料长期定位田间试验始于1979年,包括不施肥(CK)、单施氮肥(N)、氮磷钾肥配施(NPK)、低量厩肥(M1)及其与化肥配施(M1N和M1NPK)、高量厩肥(M2)及其与化肥配施(M2N和M2NPK)9个处理。厩肥为猪厩肥,1992年后大豆季不施猪厩肥,仅在玉米季相关处理中施用。39年后,调查分析了大豆生物量、产量、氮素吸收利用及大豆收获期0―100 cm土壤硝态氮累积特征。【结果】高量、低量厩肥配施化肥处理大豆生物量、产量、总吸氮量及各部位吸氮量均显著高于单施氮肥和不施肥处理,其中,M1NPK处理大豆生物量、产量和总吸氮量最高,分别为9107、2979和314.2 k g/h m^2,较其他处理分别提高了6.1%~133.6%、23.9%~232.5%和11.7%~359.4%。施肥提高了大豆氮收获指数,但氮素生理效率降低。NPK和M1NPK处理的氮素收获指数最高,均为63.5%,而氮素生理效率较CK分别降低了30.6%和28.1%。大豆收获期各处理土壤硝态氮累积量随土层深度的增加而降低。与播前相比,大豆收获期单施氮肥处理的0―100 cm土层硝态氮积累量显著增加,NPK处理变化不显著,M1、M1N和M1NPK处理显著降低。低量厩肥配施化肥处理收获期0―100 cm土壤硝态氮积累量远低于高量厩肥配施化肥处理,较播前平均降低了79.2%。所有处理中,土壤硝态氮积累量以M1NPK处理最低,比其他处理平均降低了58.2%。【结论】在东北棕壤地区玉米–玉米–大豆轮作体系下,玉米季低量厩肥(13.5 t/hm^2)与氮磷钾化肥配合施用时,大豆季仅施氮磷钾化肥既可提高大豆生物量、产量,促进氮素吸收,同时还可降低大豆收获期土壤硝态氮累积量,降低环境风险,是该轮作体系较为合理的施肥方式。     

中国农耕区土壤有机质含量及其与酸碱度和容重关系

对我国农耕区土壤有机质区域变化及其与酸碱度和容重关系进行系统分析，为耕地地力提升和改善土壤结构提供支撑。基于国家级耕地长期定位监测点913个，统计分析全国及7大区域（东北NE、华北NC、西北NW、长江中游MYR、长三角YRD、华南SC、西南SW）耕层土壤有机质含量、酸碱度及容重变化特征。结果表明，全国农耕区耕层土壤有机质含量平均值为22.4~24.8 g/kg。其中有机质含量中等偏低的监测点位占比达72.5%。不同区域耕层土壤有机质含量差异显著（p<0.05），MYR耕层土壤有机质含量显著高于其他6个区域。全国农耕区耕层土壤pH和容重平均分别为（6.90±1.20），（1.30±0.15） g/cm³。不同土壤利用方式对土壤有机质、酸碱度及容重产生影响。水田耕层土壤有机质含量显著高于旱地，旱地耕层土壤pH和容重则显著高于水田。亚当斯方程和指数函数分别推荐拟合土壤容重对有机质含量响应关系（R²=0.09，RMSE=0.17，n=759），以及土壤pH对土壤有机质含量响应（R²=0.16，RMSE=1.24，n=886）。全国农耕区耕层土壤有机质含量总体中等偏低，呈现出东南向西北依次降低趋势。土壤pH及容重与土壤有机质呈现显著的负相关关系。亚当斯模型及指数方程能较好地拟合土壤容重及pH对有机质的响应关系，可用于非线性插值法补充土壤容重及pH缺失值。     

不同苦荞品种花和籽粒空间分布特征及差异分析

以8个苦荞品种为试验材料,研究不同苦荞品种花和籽粒在植株不同部位的分布特征及差异。结果表明,不同苦荞品种花和籽粒总数存在显著差异,其中川荞2号总花数、总籽粒数最高,分别为3 046.6和1 367.8,而川荞1号最少,分别为1 017.6和487.2,品种间总花数和总籽粒数变异系数分别为34.8%、29.0%。不同苦荞品种花和籽粒空间分布呈现相同趋势,均主要分布于分枝上,分别占整株的76.3%和74.2%以上,且均显著高于主茎,分别高68.7%~87.0%和65.2%~84.5%。生产上可通过调控分枝的有效籽粒数来提高苦荞产量。