Analysis of Meteorological Conditions of Freeze Damage to Citrus in Southern Shaanxi in the Winter of 2010 and Defensive Countermeasures

In order to take advantage of the climate resources more effectively ac- cording to the local circumstances and to plan and develop the citrus industry in Southern Shaanxi more reasonably. On the basis of the investigation of freeze dam- age to citrus occurring in Southern Shaanxi in the winter of 2010, the climatic back- ground for the formation of this freeze damage was analyzed. In combination with the freeze damage indicators during the overwintering period and the harmful accu- mulated cold during the cold wave, indexes for grading the freeze damage in southern Shaanxi were analyzed and verified, and the perspective of grading the freeze damage using the harmful accumulated cold during the cold wave was also presented. Through analyzing the extremely lowest temperature and the harmful ac- cumulated cold in the winter of 2010 and in history at 12 citrus growing counties （districts） in Ankang area and Hanzhong area, the reasons why the freeze damage to citrus during the overwintering period was severer in the west than in the east of Southern Shaanxi were discussed, and the results obtained were basically consistent with the actual situation observed from investigation. Finally, defensive countermea- sures against the freeze damage to citrus during the overwintering period were put forward from several aspects.

A Brief Analysis of the Forms and Features of Traditional Residential Dwellings in Southern Shaanxi in the Shaanxi Section of the“Silk Road”by Land

As one of the major types of traditional architecture in China,traditional residential dwellings have been characterized by a variety of complex forms under the influence of different regional cultures and historical background.This paper takes the opportunity to study the art and culture of traditional dwelling architecture along the Silk Road,focusing on the traditional dwellings in the southern Shaanxi region,the starting point of the Silk Road,through field research and literature research,to further elaborate and prove the regional form of traditional dwellings in the southern Shaanxi region and the causes of the formation of this north-south architectural form.Therefore,the authors summarize and analyze the architectural forms,mapping data and images and demonstrate through detailed examples of remaining dwellings in southern Shaanxi,in order to provide a theoretical basis for the preservation and inheritance of traditional dwellings in southern Shaanxi in the future.

The Development of Mountainous Rural Landscapes in Southern Shaanxi from the Perspective of Ecotourism

This study introduced the connotation of rural ecotourism,and analyzed the advantages of tourism resources development of mountainous rural landscapes in southern Shaanxi.On this basis,it expounded the existing problems of mountainous rural landscape development in southern Shaanxi,and concluded that its rural landscape resource tourism development was not enough,ecological awareness needed to be strengthened,and the characteristics of rural landscapes were not fully explored.Furthermore,the suggestions and measures for the protection and sustainable development of the ecological environment pattern and the inheritance and excavation of the characteristic culture of the rural landscape were proposed,with a view to providing a reference for the development and construction of rural landscape tourism in China.

Suitability and Construction of Self-Insulation Walls in the Hot Summer and Cold Winter Zone of Southern Shaanxi

In this paper, the suitability and construction technology of self-insulation walls were studied under the specific climatic conditions and regional resources of Hanzhong and Ankang in the hot summer and cold winter zone of Southern Shaanxi. Through the calculation of heat transfer coefficient and thermal inertia index, combined with the specifications of the shale hollow brick and aerated concrete block of Hanzhong and Ankang in southern Shaanxi, the thermal performance and suitable thickness of the external wall using self-insulation materials that meet the Design Standard for Energy Efficiency of Residential Buildings(DBJ61-65-2011) in Shaanxi Province were obtained. The results showed that the self-insulation wall had technical suitability in the hot summer and cold winter zone. The research results provide not only a theoretical basis for the external wall insulation design of urban residential buildings in the hot summer and cold winter zone of southern Shaanxi, but also a reference for designers to carry out energy-saving design of external walls of residential buildings in other similar climate zones.

Carbon isotopes, sulfur isotopes, and trace elements of the dolomites from the Dengying Formation in Zhenba area, southern Shaanxi: Implications for shallow water redox conditions during the terminal Ediacaran

Carbon isotope, sulfur isotope, and trace element(including Rare Earth Elements, REE) analyses were conducted on the carbonates of the Dengying Formation at Lianghekou section in southern Shaanxi to reconstruct the terminal Ediacaran shallow-water environment on the northwestern margin of the Yangtze Platform. At Lianghekou section, samples in the middle 50-m of the Beiwan Member show characteristics of low ΣREE concentrations, no MREE-enriched REE distribution patterns, high Ce/Ce* values close to 1, and enriched redox-sensitive elements, whereas samples in the lower 30-m and upper 10-m show opposite characteristics of high ∑REE concentrations, MREE-enriched REE distribution patterns, low Ce/Ce* values around 0.6, and no redox-sensitive elements enriched, indicating that oxygenation did occur in the shallow water on the northwestern margin of the Yangtze Platform and redox conditions of the shallow water fluctuated from relatively oxygenated to anoxic and then back to oxygenated again. We propose that the anoxia appeared in middle of the Beiwan time may associate with the anoxic upwelled water. On one hand, abundant nutrients were brought in by this upwelling event, which stimulated the photosynthetic carbon fixation and increased the organic carbon burial under this anoxic condition, causing a peak of 3.6‰ in δ 13 C. On the other hand, because the anoxic upwelled water replaced the oxic shallow water, together with the increasing organic matter in the water column, bacterial sulfate reduction was enhanced and therefore quickly reduced the sulfate concentration, which eventually caused δ 34 S increasing to 50‰. However, as the upwelling gradually disappeared, δ 13 C and δ 34 SCAS values decreased as well in the late Beiwan time, indicating the shallow water went back to suboxic or oxic again.

Lower Cambrian phosphatized Punctatus from southern Shaanxi and their ontogeny sequence

Phosphatized and three-dimensionally preserved embryos and spherical fossils of metazoan recovered from the Kuanchuanpu Member, Dengying Formation in southern Shaanxi, China provide nice devel- opmental sequence for the studies of origination, taxonomy, phylogenic evolution and developmental biology of early animals. Ontogeny of these larva fossils has not been systemically studied mainly due to their poor preservation and limited identification. The Kuanchuanpu Member, predominated by phosphorites and cherts, yields phosphatized animal embryos, particularly those of Olivooides and Punctatus which have high resolution in fine structures and different ontogeny developmental stages. An ontogenetic sequence of the Punctatus is established mainly base on its developmental transitions from body part to oral one, which is perfectly consistent with the embryonic ontogeny sequence pro- posed by Bengtson and Yue (1997). Furthermore, a new genus Quadrapyrgites gen. nov is erected to receive a larva with tetraradial body plan.

Early Cambrian phosphatized blastula- and gastrula-stage animal fossils from southern Shaanxi

Marine invertebrate animal embryos and their early developmental products are of great significance to the study of taxonomy and phylogeny of early animals. A great number of phosphatized globular fossils were collected fromthe early Cambrian Kuanchuanpu Member (upper Dengying Formation), southern Shaanxi, and a nearly complete develo-pmental sequence—from a fertilized egg, via blastodisc formation, blastula development, blastodisc enlargement toward gastrulae, to tissue differentiation—can be discerned in this collection. This discovery provides unmatchable material for studies on the origin, taxonomy, radiation, and ontogeny of early metazoans.

基于VSD模型的陕南城市群水资源脆弱性评价及影响因子研究

[目的]构建基于社会-经济-生态耦合作用下的陕南城市群水资源脆弱性模型,阐明水资源脆弱性状态,厘定影响因子,助力秦岭地区人水和谐。[方法]基于暴露度-敏感性-适应性(Vulnerability Scoping Diagram,VSD)对陕南城市群水资源脆弱性进行了评价,结合多元统计法,进一步识别了社会-经济-生态耦合作用下水资源脆弱性的影响因子。[结果]2011—2020年,陕南整体水资源脆弱性的变化趋势与商洛市最相似,除2011年极度脆弱外,基本保持在轻度脆弱状态,而汉中市和安康市的水资源脆弱性等级较高,水安全保障程度相对较低;陕南城市群水资源脆弱性的主控因子有生态环境用水量、人均水资源量、年降水量;优化生态环境用水量分配,加强对年降水量与人均水资源量监测,将成为陕南城市群降低水资源脆弱性新的工作重心。[结论]陕南城市群水资源系统安全性的提升与当地注重水生态文明建设以及与社会-经济协调发展有关。此外,构建的VSD模型适用于陕南城市群水资源脆弱性评价,可为缓解人-城-水矛盾提供理论指导。

基于PLUS-InVEST模型的陕南地区土地利用变化多情景模拟与碳储量评估

在PLUS模型中纳入POI驱动因子并利用LASSO回归进行驱动体系筛选与精度验证,设定自然发展、经济保护与生态保护3种情景,利用筛选后的驱动因子模拟2030年各情景下陕南地区的土地利用格局,利用InVEST模型分析2000—2020年陕南地区碳储量的时空分异特征,探讨不同发展情景下土地利用变化对陕南地区碳储量的影响。结果表明:(1)2000—2020年,陕南地区的建设用地面积由23648.49 hm^(2)增长到78000.21 hm^(2),侵占了耕地、林地和草地的生存空间,使其分别减少了39415.05 hm^(2),8787.51 hm^(2)与17476.56 hm^(2),2030年3种发展情景下的建设用地均保持扩张的趋势。(2)在PLUS模型中加入POI驱动因子且利用LASSO算法筛选驱动因子有效提升了模型的精度与运行效率,模型的Kappa系数和OA系数分别提高了2.53%和0.20%,更精准地模拟了建设用地的分布情况。(3)2000—2020年陕南地区碳储量总量呈下降趋势,由2.1887×10^(9)t下降至2.1775×10^(9)t。2030年经济保护情景与自然发展情景的碳储量总量均小于2020年,生态保护情景下的碳储量总量最高,达到了2.1830×10^(9)t。(4)生态保护情景更有利于陕南地区的可持续发展策略,以陕南地区平均碳密度分区分布为基础,可为陕南地区分区发展与区域碳收支平衡提供参考,对未来不同情景下土地利用对区域碳储量的影响和双碳背景下的国土空间规划具有借鉴意义。

蜀道陕南段传统聚落时空分布特征及影响因素

蜀道在中国古代交通史上具有重要地位,历史时期在政治、军事、经济、文化等方面发挥了突出作用。蜀道陕南段地理位置特殊、7条主线汇集,沿线传统聚落的形成和发展与线路密切相关。本文以历史地理学研究视角,结合文献研究、地图分析、统计分析及田野调查,梳理传统聚落的时空分布信息;对传统聚落历史职能进行类型分析,从具体线路和地理空间2个维度探究其分布特征。通过蜀道线路历史变迁及地理环境层面的归因分析,揭示了蜀道线路功能特点与历史演进及地形地貌、农业耕作条件等影响传统聚落时空分布的内在机制。

乡村振兴视域下生态环境治理的现实挑战与实践进路——以陕南农村为例

陕南农村生态环境治理以习近平生态文明思想为理论指导、以人民群众对优美生态环境需要为价值目标、以陕南农村生态环境发展实际为实践基础,加强对陕南农村生态环境治理的研究与实践,对全面推进乡村振兴有重要的现实意义和研究价值。党的十八大以来,陕南农村生态环境治理取得显著成效,但是还存在生态环境治理制度尚不完善,制度执行力有待提高;生态环境治理主体单一,多元共治责任有待落实;绿色生产方式有待创新等诸多现实挑战。为此,提出建立健全生态环境管理和监督制度,增强农村生态执法力度;充分发挥政府主导作用,推进农村多元主体协同共治;发展绿色循环产业,推动农业生产方式绿色转型等实践进路,以期为我国农村生态环境治理提供陕南经验。

乡村振兴背景下脱贫山区乡村韧性演变及影响因素--以陕南秦巴山区为例

探究乡村振兴背景下乡村韧性动态演变及影响因素,对于脱贫山区推进乡村全面振兴与实现乡村可持续发展具有重要意义。陕南秦巴山区受脆弱生态环境以及薄弱经济基础的双重胁迫,脱贫乡村发展与农户生计仍面临不确定性风险。以陕南秦巴山区28个县区为例,将乡村韧性分解为经济、社会、生态以及制度四个维度,构建乡村韧性指标体系并对其进行量化,运用GIS技术和地理探测器探究乡村韧性的时空演变及影响因素。结果显示:(1)陕南秦巴山区2010—2021年乡村韧性整体呈先下降后上升的趋势。社会韧性与经济韧性变化较小,制度韧性逐年上升,生态韧性逐年下降。(2)近10年土地资源利用、文化教育等是乡村韧性分异的主导因子,且制约因子由生态维度转向社会维度,乡村基础教育与农业生产效率影响程度不断加深,土地利用与人口结构的作用不断减弱。(3)依据研究区乡村振兴背景下面临的现实问题,针对各县区乡村韧性提升的短板和关键影响因子,从产业、人才、组织、文化、生态五大振兴出发提出了脱贫山区韧性提升的建设路径及对策。乡村产业振兴方面应打造新兴产业集群,提升农业现代化水平;乡村人才振兴方面应开展农户就业扶持活动,政策吸引人才返乡下乡;乡村文化振兴方面应推进教育新型基础设施建设,建立农民群众文化需求反馈机制;乡村生态振兴方面应优化农业生产结构和区域布局,盘活耕地资源促进绿色生产;乡村组织振兴方面应探索多元组织协作,全面建立健全村务监督委员会,为未来脱贫山区韧性建设提供了参考依据。

X射线衍射和TIMA研究陕南镇巴地区富锂黏土岩的矿物组成及锂的赋存状态

黏土岩型锂矿作为可利用锂资源的重要组成部分,由于其分布广、储量大而备受关注。陕西镇巴地区晚二叠世吴家坪组新发现黏土岩型锂矿(资源),Li_(2)O最高含量可达0.39%,达到了黏土锂矿的工业指标(0.2%),具有一定的开发利用价值。为了查明陕南镇巴地区富锂黏土岩中黏土矿物种类、含量及富锂黏土岩中锂的赋存状态,本文选取陕西镇巴地区富锂黏土岩,通过偏光显微镜鉴定初步查明黏土岩的矿物组成,利用X射线衍射(XRD)、全自动综合矿物分析系统(TIMA)分析技术定量查明富锂黏土岩中黏土矿物及主要元素含量。结果表明:该黏土岩主要由高岭石、铝绿泥石、伊利石、锂绿泥石等黏土矿物以及赤铁矿组成,含少量绿泥石、金红石等矿物。TIMA分析表明样品中锂绿泥石最高含量为8.94%,对应锂含量为0.12%(Li_(2)O含量为0.26%),略低于该样品全岩Li_(2)O含量(0.31%)。锂绿泥石呈丝缕状,不规则粒状,嵌布于一水软铝石、伊利石、铝绿泥石之间。综合研究认为镇巴地区富锂黏土岩中锂主要赋存于锂绿泥石中,其他矿物的锂含量很低。锂绿泥石、伊利石、高岭石等层状结构硅酸岩矿物具有很好的吸附性,锂以Li^(+)形式吸附于黏土矿物中。

陕南千枚岩地区护坡基材优化及抗侵蚀性能

为了进一步探究适宜于陕南千枚岩地区的边坡生态防护基材,以陕南当地废弃的千枚岩碎石为主要基材,添加秸秆、硅酸盐水泥、有机肥、草炭土和保水剂,组成护坡基材。设计正交试验,选取陕南地区的乡土草本植物高羊茅作为试验草种进行盆栽种植。运用综合评分法和极差分析法分析护坡基材的最佳配比和各因素对高羊茅生长影响的重要性程度,最后用室内模拟降雨侵蚀试验来验证基材的强度。结果表明,在陕南地区,适合高羊茅生长的最优基材配比为秸秆含量4%、水泥含量4%、有机肥含量5%、草炭土含量8%、保水剂含量0.25%。根据极差结果分析可知,各因素对高羊茅生长因素的影响从大到小依次为水泥、秸秆、草炭土、保水剂、有机肥。室内模拟降雨侵蚀试验表明,本研究的护坡基材具有较好的抗侵蚀能力,实用性较强。

陕南地区数字经济发展水平测度及推进路径

准确测度我国陕南地区数字经济发展水平,对于陕南地区数字经济实现持续、稳健、高质量发展具有重要意义。参照国家统计局颁布的《数字经济及其核心产业统计分类(2021)》,从发展环境、数字产业化、产业数字化三个维度构建数字经济发展水平评价指标体系,利用熵权法对2015—2019年陕南地区各地级市的数字经济发展情况进行测算和评价。结果表明:陕南地区数字经济发展水平逐年稳定上升,其中数字产业化和产业数字化指数的上升是其核心驱动力,而发展环境指数的下降减缓了发展速度;各地级市的数字经济发展水平存在显著差异,呈现出汉中领先、安康次之、商洛最末的发展格局;安康和商洛的发展水平相对落后,但其发展速度较汉中更快,具有较大潜力;各地级市在数字人才培养和数字支出方面整体呈下滑趋势,数字服务业成为陕南地区的重点发展领域。据此提出陕南地区数字经济发展的对策建议:优化数字经济发展环境,夯实数字化产业基础,推进产业数字化全面转型。

Influence Factors of Farmers' Willingness to Poverty Alleviation Relocation in South Shaanxi Province

In southern Shaanxi,far from the core areas of politics and economy,the conditions are inconvenient and farmers have been threatened by geology,floods for many years,resulting in a large population of poor people.The relocation of poverty alleviation project in southern Shaanxi is helpful for improving living standards of people in disaster-stricken areas.Based on the field survey,this paper analyzed 274 valid questionnaires and established a Logistic Regression Analysis Model.The result shows that the health status of head of household,road type before relocation,annual loss of disasters,and changes in the family income after relocation have a greater influence on the relocation willingness of farmers,while the educational level of householder,the distance from the original place of residence to the town and market,the condition of household electricity before relocation and other factors have a little influence on the relocation willingness of farmers.

客省庄文化出土玉石器研究——以康家遗址出土玉石器分析为主

分布于关中―陕南地区的客省庄文化,历来以其朴素单一的陶器组合和以村落级别的聚落规模为考古学文化特征。但诸多遗址中玉石器的发现,反映出客省庄文化朴素的文化面貌中蕴含复杂的内涵。玉石器作为新石器时代上层社会间交流频繁的遗物,是研究考古学文化性质的重要方面。本文以目前正在整理的临潼康家遗址出土玉石器为主要分析对象,并结合其他遗址出土的玉石器,尝试从玉石器所体现的礼仪层面,探讨客省庄文化的社会结构以及其与周边同期考古学文化的交流动态。

陕南地区茶叶农药残留状况调查与分析

为了解陕南地区茶叶农药残留现状,在陕南地区采集了160份茶叶样品,采用QuEChERS-气相色谱-串联质谱法检测了50种农药残留,依据《食品安全国家标准食品中农药最大残留限量》(GB 2763—2021)进行判定。结果表明,160份陕南地区茶叶样品中,共检出农药残留72份,检出率为45.0%,超标样品2份,超标率为1.25%。共检出26种农药,以拟除虫菊酯类农药和有机杂环类农药为主,检出率最高的是氯氟氰菊酯。检出禁用农药3种,分别是六六六、滴滴涕、三氯杀螨醇,检出禁止在茶叶上使用的农药4种,分别是水胺硫磷、氰戊菊酯、氧乐果、乐果。检出的禁限用农药中,水胺硫磷和氧乐果超标。红茶农药残留检出率高于绿茶,且具有统计学差异,不同包装类型和不同等级茶叶农药残留检出率均不存在统计学差异。总体而言,陕南地区茶叶农药残留检出率较高,农药混合使用现象普遍,但农药残留水平不高,仅有个别样品超标,总体合格率较高,部分茶叶存在被禁限用农药污染的可能,应加强禁限用农药的管理,提升当地茶叶质量安全。

核桃优良品种‘清香’在陕北南部的生长性状研究

为引进选育适应性强、商品质量较高的核桃主导品种,在渭北黄土高原,持续17年将‘清香’核桃与香玲、辽核1号、辽核2号、陕核5号4个早实品种的特性与商品性,进行综合试验研究。结果表明:清香核桃属晚实品种中的早果品种,树势健壮,其适应性、抗病性较强、丰产性及坚果商品特性明显优于香玲等早实品种,尤其在无灌溉条件下表现更为突出,可作为当地核桃产业的主导品种,对该区域核桃品种化、栽培省力化、果品商品化及产业化发展与巩固脱贫成效具有积极的创新意义。

陕南中低海拔山区植物物种多样性与海拔及坡向的关系

为了研究陕南中低海拔山区植物物种多样性与坡向、海拔之间的关系,在研究区内设置并选取了具有代表性的样方91处,统计分析了每150 m海拔区间内乔木层、灌木层、草本层物种多样性及其关系。结果表明:(1)研究区内共有维管束植物129科、312属、460种;阴坡乔木、灌木、草本植物的物种数均多于阳坡;相同坡向内草本植物的科、属、种数量最多,灌木次之,乔木最少。(2)除草本植物的H、D值外,其他层次物种多样性指数的变异系数阴坡均大于阳坡;阳坡海拔1250 m以上草本植物物种数逐渐降低,优势种逐渐显现;在阴坡,海拔500—650 m处草本植物物种数最多,而海拔1400—1550 m灌木的个体数量最多。(3)回归分析中,多样性指数与海拔之间大多能呈现较好的拟合效果。阴、阳坡向内乔木层的多样性指数均先降低再升高,海拔950 m以上,阴坡乔木层的H、M值大于阳坡,差异显著(P<0.05);而D、J值差异不显著。阴坡灌木层的H、J、M值在海拔800 m处呈现单峰格局;阳坡灌木层的H、M值在研究区域内单调升高,而J值与海拔之间没有很好的拟合效果。在研究区内,阳坡草本层的H、J、M值随海拔升高呈现先增加再降低趋势,而阴坡草本层各指数与海拔之间没有很好的拟合效果。(4)不同层次间相关性检验中,阳坡乔木层H值与灌木层的H、D、M为显著负相关(0.01<P≤0.05),乔木层的J值与灌木层的J值、灌木层的J值与草本层的J值为显著正相关(0.01<P≤0.05);阴坡灌木的多样性指数与草本层各指数(D值除外)多呈显著或极显著正相关;其他相关性均达不到显著水平。(5)阳坡的种间共同出现率的峰值位于海拔800—950 m、950—1100 m的两个区间内,最低值在海拔1100—1250 m、1250—1400 m两个区间内。阴坡的峰值海拔比阳坡峰值海拔高100—400 m,而最低值所处的海拔区间与阳坡相同。