Assessment of vegetation cover changes and the contributing factors in the Al-Ahsa Oasis using Normalized Difference Vegetation Index(NDVI)

The abandonment of date palm grove of the former Al-Ahsa Oasis in the eastern region of Saudi Arabia has resulted in the conversion of delicate agricultural area into urban area.The current state of the oasis is influenced by both expansion and degradation factors.Therefore,it is important to study the spatiotemporal variation of vegetation cover for the sustainable management of oasis resources.This study used Landsat satellite images in 1987,2002,and 2021 to monitor the spatiotemporal variation of vegetation cover in the Al-Ahsa Oasis,applied multi-temporal Normalized Difference Vegetation Index(NDVI)data spanning from 1987 to 2021 to assess environmental and spatiotemporal variations that have occurred in the Al-Ahsa Oasis,and investigated the factors influencing these variation.This study reveals that there is a significant improvement in the ecological environment of the oasis during 1987–2021,with increase of NDVI values being higher than 0.10.In 2021,the highest NDVI value is generally above 0.70,while the lowest value remains largely unchanged.However,there is a remarkable increase in NDVI values between 0.20 and 0.30.The area of low NDVI values(0.00–0.20)has remained almost stable,but the region with high NDVI values(above 0.70)expands during 1987–2021.Furthermore,this study finds that in 1987–2002,the increase of vegetation cover is most notable in the northern region of the study area,whereas from 2002 to 2021,the increase of vegetation cover is mainly concentrated in the northern and southern regions of the study area.From 1987 to 2021,NDVI values exhibit the most pronounced variation,with a significant increase in the“green”zone(characterized by NDVI values exceeding 0.40),indicating a substantial enhancement in the ecological environment of the oasis.The NDVI classification is validated through 50 ground validation points in the study area,demonstrating a mean accuracy of 92.00%in the detection of vegetation cover.In general,both the user’s and producer’s accuracies of NDVI classification are extremely high in 1987,2002,and 2021.Finally,this study suggests that environmental authorities should strengthen their overall forestry project arrangements to combat sand encroachment and enhance the ecological environment of the Al-Ahsa Oasis.

Spatial Protection and Development of Traditional Mountain Settlements from the Perspective of Self-organization : A Case Study of Anju Ancient Town in Tongliang District, Chongqing

Through literature research, field research and urban design analysis methods, based on the self-organization theory, the evolution characteristics of the settlement space of Anju Ancient Town with significant characteristics of traditional mountain settlements were analyzed, and then its internal and external influencing factors were summarized. Finally, appropriate protection and development strategies were proposed, such as reasonably planning functional zones, breaking through the single structure, and creating a good living cultural environment. The innovation of this study is that it integrates the self-organization theory into the cognition of traditional mountain settlement space, and discusses the connection between the mountain settlement space and the traditional regional context under the modern development concept, so as to seek the benign protection and reasonable development of traditional mountain settlement space.

老年及中青年ICU患者死亡率及OASIS评分的预测价值

目的探讨老年及中青年重症加强护理病房(ICU)患者死亡率及牛津急性疾病严重程度评分(OASIS)的预测价值。方法选取中国人民解放军联勤保障部队第904医院2019年1月—2020年2月收治的ICU患者100例为研究对象,回顾性分析100例患者的临床资料,根据预后情况分为好转组(71例)和死亡组(29例)。比较老年与中青年患者的死亡率,对比两组患者的性别、年龄、OASIS评分、住院时间、住ICU时间、机械通气情况、急性生理与慢性健康状况评分系统(APACHE)II评分、多器官功能障碍综合征(MODS)评分、创伤严重度评分(ISS)、糖尿病情况、心血管疾病情况。采取非条件Logistic逐步回归分析ICU患者预后的危险因素。结果老年患者死亡率明显高于中青年患者,比较差异有统计学意义(P<0.05);死亡组年龄≥65岁、OASIS评分>30分、住院时间≤7 d、住ICU时间>3 d、机械通气>3 d、APACHE II评分>25分、MODS评分>12分患者占比显著高于好转组,比较差异有统计学意义(P<0.05);Logistic回归性分析显示,年龄≥65岁、OASIS评分>30分、住院时间≤7 d、住ICU时间>3 d、机械通气>3 d、APACHE II评分>25分、MODS评分>12分是ICU患者预后的危险因素。结论老年ICU患者死亡率高于中青年,OASIS评分、住院时间、住ICU时间、机械通气、APACHE II评分、MODS评分是ICU患者预后不良的影响因素。

Multi-UAV Collaborative Mission Planning Method for Self-Organized Sensor Data Acquisition

In recent years,sensor technology has been widely used in the defense and control of sensitive areas in cities,or in various scenarios such as early warning of forest fires,monitoring of forest pests and diseases,and protection of endangered animals.Deploying sensors to collect data and then utilizing unmanned aerial vehicle(UAV)to collect the data stored in the sensors has replaced traditional manual data collection as the dominant method.The current strategies for efficient data collection in above scenarios are still imperfect,and the low quality of the collected data and the excessive energy consumed by UAV flights are still the main problems faced in data collection.With regards this,this paper proposes a multi-UAV mission planning method for self-organized sensor data acquisition by comprehensively utilizing the techniques of self-organized sensor clustering,multi-UAV mission area allocation,and sub-area data acquisition scheme optimization.The improvedα-hop clustering method utilizes the average transmission distance to reduce the size of the collection sensors,and the K-Dimensional method is used to form a multi-UAV cooperative workspace,and then,the genetic algorithm is used to trade-off the speed with the age of information(AoI)of the collected information and the energy consumption to form the multi-UAV data collection operation scheme.The combined optimization scheme in paper improves the performance by 95.56%and 58.21%,respectively,compared to the traditional baseline model.In order to verify the excellent generalization and applicability of the proposed method in real scenarios,the simulation test is conducted by introducing the digital elevation model data of the real terrain,and the results show that the relative error values of the proposed method and the performance test of the actual flight of the UAV are within the error interval of±10%.Then,the advantages and disadvantages of the present method with the existing mainstream schemes are tested,and the results show that the present method has a huge advantage in terms of space and time complexity,and at the same time,the accuracy for data extraction is relatively improved by 10.46%and 12.71%.Finally,by eliminating the clustering process and the subtask assignment process,the AoI performance decreases by 3.46×and 4.45×,and the energy performance decreases by 3.52×and 4.47×.This paper presents a comprehensive and detailed proactive optimization of the existing challenges faced in the field of data acquisition by means of a series of combinatorial optimizations.

OASIS超声波果蔬清洁器

OASIS是一种超声波清洁器,用于清洗家庭中的水果和蔬菜。为了提高人们对用超声波清洗食品的认识,它的设计便于新手使用和管理。它提出了一个优化的容量,可以为一个4人家庭清洗3-4天的食品杂货,同时保持有效的清洁能力。上部容器可以与下部容器分离,便于填充和用水冲洗。清洗后,潮湿的食品杂货可以放在盖子上自然干燥。干燥过程中收集的水被设计成通过盖子上的两个小孔流入内部,让剩余的水流入内部。

基于Oasis Montaj平台的航空物探数据处理软件系统

在深入研究Oasis Montaj平台特点的基础上,对已有的处理功能进行移植、优化,并开发了新的功能,集成为航空物探数据处理软件系统。这里就系统的整体架构、主要功能及其实现方法进行了详细介绍。通过大量的数据处理证明了该系统具有集成度高、实用性强、运行效率高、稳定性强、易操作、容错性强等诸多优势,能极大地提高数据处理的效率和质量。

OASIS程序的开发与应用

全面描述了对来自法国原子能委员会 (简称CEA)的快堆系统安全分析程序OASIS的引进和开发工作 ,并在此基础上介绍了该程序在中国实验快堆 (ChinaExperimentalFastReactor,简称CEFR)初步安全分析报告中对主给水管道断裂事故的分析计算。

Sustainable Development of Agriculture in Northwestern Ecologically Fragile Desert Oasis——A case study of Guazhou County of Gansu Province

Guazhou County of Gansu Province is a typical ecological fragile area lying in the transition area of desert and oasis.The development of its agricultural economy is highly dependent on natural resources and environment.Contradiction of resources characterized agriculture and the fragile ecological environment has become one of the main barriers to log the impact of local agriculture to achieve sustainable development.Aiming at fragile ecological environment and limiting factors of agricultural sustainable development,thoughts and countermeasures of realizing agricultural sustainable development have been proposed.

Oasis HLB固相萃取-超快速液相-三重四极杆质谱法测定花生和花生油中黄曲霉毒素B1、B2、G1、G2

目的建立了Oasis HLB固相萃取-超快速液相-三重四极杆质谱法测定花生和花生油中黄曲霉毒素B1、B2、G1、G2的方法。方法样品用甲醇-水（V甲醇∶V水=20∶80）提取,离心后过Oasis HLB柱萃取净化,超快速液相进行梯度洗脱,质谱用电喷雾离子源（ESI）,经过正离子MRM模式,外标法定量。结果黄曲霉毒素（AFT）B1、B2、G1、G2的最低检出限分别为：0.05、0.05、0.10、0.20μg/kg,平均加标回收率在89.3%-98.7%之间,精密度（RSD）在2.6%-5.3%之间。结论本法利用Oasis HLB固相萃取柱良好的性能和质谱仪采用弯曲180度的碰撞池技术大大减少了样品中的杂质干扰,精密度和准确度高,方法操作简便,结果可靠。

Assessment of Ecosystem Services Value in Hotan Oasis, Xingjiang

[Objective] The study aimed to assess the ecosystem services value in Hotan Oasis, Xingjiang. [Method] The visual interpretation method was adopted to process TM/ETM＋ images based on field investigation in Hotan Oasis. These inter- pretation data, along with two periods of land use data, were reclassified to farm- land, forest, grassland and so on. Then, the ecosystem services value was calculat- ed and analyzed. [Result] Analysis indicated that the ecosystem services value had been increased by 30.44x108 Yuan （16.51%） in the study area during 1980-2010, which can be explained by the increase of glacier and snowfield distributed in the south mountain with the increase of annual precipitation. At the same time, the con- tribution rate of grassland to ecosystem services value had been decreased as a result of degradation of grassland and occupation from farmland. For the whole basin, the increase of ecosystem services value came from the upper reaches, while the ecosystem services value had been reduced in the middle and lower reaches. In the middle reaches, the reduction came mainly from wetland （-1.83x10s Yuan）, waters （-1.68x10s Yuan）, forest （-0.86x108 Yuan） and grassland （-0.80x108 Yuan）. But in the lower reaches, the ecosystem services values of waters, grassland and forest were -0.61 x108 Yuan, -0.24x108 Yuan, and -0.07x10s Yuan, respectively. [Conclusion] If some effective policies, such as the implementation of returning farm- land to forest and ceasing from farming to grazing, would be taken, the ecosystem degradation can be constrained and reversed in the northwest arid region.

Comprehensive Evaluation of Environmental Effects from Land Change in Hotan Oasis,Xinjiang

[Objective] This study aimed to evaluate the environmental effects coming from land changes in Hotan oasis during 1980-2010. [Method] Based on the Driving Force-State-Response model, expert weight method and entropy method were used to determine weight, and then the composite indexes of environmental effects （CIE for short） were calculated. [Result] During the period from 1980 to 2010, CIE had presented a rising trend whether expert weight method or entropy method in the study area, while the CIE presents downtrend basically in lower reaches. [Conclu- sion] It was the arable land expansion in middle reaches that led to serious land degradation in lower reaches, and may endanger ecosystem safety in Hotan River green corridor. Therefore, it is suggested that the agricultural land use should be restructured, such as reducing the sown areas of some crops with large amount of water consumption. Meanwhile, the effective measures should be taken to distribute water resources and utilize them reasonably. In addition, the oasis-desert ecotone, as well as the groundwater resources, should be also protected.

Effects of Different Irrigation Amounts on Wheat Growth in Arid Oasis Area

[Objective] The study was conducted to analyze the effects of different irrigation amount on the growth of wheat in arid oasis area and determine effective use measures and reasonable irrigation indices of water in farmland under arid oasis environment,so as to provide reference for the development and management of water-saving technology.[Method] Spring wheat in different growth periods was irrigated for four times.The leaf area index,dry matter content,1 000-grain weight of wheat in different growth peri...

Studies of Soil Physical Property on Different Abandoned Lands in the Minqin Oasis,Downstream of the Shiyang River

The vast area of farmland was abandoned at downstream of the Shiyang River because of decreased water recourse. To ensure the ecological safety of Minqin Oasis and to provide management basis for the abandoned land, soil physical properties were observed and studied. The authors analyzed land with abandonment time of 1 year, 2 years, 3 years, 4 years, 5 years, 8 years, 15 years, 24 years and 31 years. Samples were took at the 0-40 cm layer of soil to measure the bulk density, porosity and grain composition of soil in the different abandoned lands. Results showed that the tendency of clay content was decreasing, conversely, the fine sand increased at the layer of 0-10 cm of different abandoned lands.The changes of grain content reached a peak at the fourth year after the land was abandoned, then varied slightly. The variation of grain content of abandoned land was obvious with the extension of the abandonment year. The soil bulk density decreased and porosity increased with the extension of the abandonment year. The difference of porosity and soil bulk density at the range of 0-40 cm of different abandoned land decreased after the land abandoned for 3 years. The quality of soil was decreased, while the soil permeability was improved. The soil physical properties changed obviously in 3 to 4 years after abandonment, so it is the key time for land management.

OASIS内置式虹膜扩张器在小瞳孔白内障超声乳化术中的应用

目的:观察OASIS内置式虹膜扩张器在小瞳孔白内障超声乳化术中的应用效果。方法:选择2016-01/2017-10在我院接受治疗的小瞳孔白内障患者44例,随机分为对照组(22例31眼)和观察组(22例30眼),对照组采用劈核器和晶状体调位钩手动撕开扩张瞳孔行常规白内障超声乳化手术治疗,观察组在术中植入OASIS内置式虹膜扩张器扩大瞳孔行常规白内障超声乳化手术治疗,对两组患者手术前后最佳矫正视力(BCVA)、角膜内皮细胞计数、瞳孔直径及眼压变化情况进行对比分析,评价OASIS内置式虹膜扩张器的应用效果。结果:术后1mo,两组患者BCVA较术前均显著改善,且观察组患者BCVA(0. 09±0. 04)显著优于对照组(0. 20±0. 03),差异均有统计学意义(P<0. 05)。术后1mo,两组患者角膜内皮细胞计数均较术前明显减少,但观察组患者角膜内皮细胞计数(2455. 77±52. 98个/mm^2)显著高于对照组(2298. 94±49. 12个/mm^2),差异均有统计学意义(P<0. 05)。术后1mo,两组患者瞳孔直径较术前均有所扩大(P<0. 05),且观察组患者瞳孔直径(3. 52±1. 14mm)大于对照组(3. 15±1. 02mm);术后6mo,两组患者瞳孔直径较术后1mo均显著扩大(P<0. 05),但两组间比较,差异无统计学意义(P>0. 05)。术后1mo,两组患者眼压较术前均有所降低(P<0. 05),且观察组眼压(13. 40±1. 73mmHg)低于对照组(13. 93±1. 98mmHg);术后6mo,两组患者眼压均低于术后1mo(P<0. 05),但两组间比较差异无统计学意义(P>0. 05)。结论:OASIS内置式虹膜扩张器用于小瞳孔白内障超声乳化术中可提高术后最佳矫正视力、降低眼压、扩张瞳孔直径,应用效果较好。

用Oasis^(TM)固相柱研究检测腐败生物组织中的吗啡

目的建立一种适合大批量腐败生物检材的标准化分析测定方法。方法应用新型亲水亲酯的OasisTM固相柱,并使用Zymark全自动固相萃取仪,对腐败生物组织中的吗啡进行检测。结果与传统的C18固相柱相比较,OasisTM固相柱具有选择范围广、吸附能力强的特点,其方法操作简单、快速、重现性好及回收率高。结论该方法可应用于案件的检测工作。

Oasis^(TM)小柱用于腐败生物组织中吗啡检测的研究

应用新型亲水亲酯的OasisTM固相柱 ,并使用Zymark全自动固相萃取仪 ,检测了腐败生物组织中的吗啡。与传统的C1 8固相柱相比 ,OasisTM固相柱具有选择范围广、吸附能力强的特点 ,其方法操作简单、快速、重现性好及回收率高。所建立的方法适合大批量腐败生物检材的标准化分析测定 ,并已成功应用于一些案例的检测工作 。

Quantitative Analysis of Land Use Landscape Pattern in Shihezi Desert Oasis

Based on the land use status map of Shihezi City,the land use landscape map of Shihezi City was made with the support of GIS then many landscape indices were selected to quantitatively analyze the landscape pattern characteristics of Shihezi Oasis from three aspects of landscape diversity index,landscape space configuration index and plaque characteristics index. The results showed that the main plaque types of the landscape in Shihezi reclamation area are arable land and water areas,which totally account for 58% of the total area; farmland,gardens,woodland,urban sites,industrial and mining land use were embedded in this oasis landscape in the form of mosaics,and their fractal index was high due to the strong impact of human activities; arable land and mining land distribution was scattered,but marshes and other uncultivated land were relatively concentrated. The dominance degree of the landscape was low because there was no advantageous type in this landscape and all patches distributed equably which was easily to be disturbed so that the whole landscape was unstable. Comprehensively speaking,the landscape in Shihezi region was rather complicate,and its diversity index,fragmentation degree and heterogeneity were high.

Studies of Soil Physical Properties and Community Characteristics of Different Abandoned Lands in the Minqin Oasis,Downstream of the Shiyang River

[Objective] The aim was to explore physical properties and community characteristics of abandoned lands in different years in Minqin Oasis, downstream of the Shiyang River, [Method] The evolution of environment and plant community characteristics in different abandoned lands were analyzed after abandonment for 1, 2, 3, 4, 5, 8, 15, 24 and 31 years, and the plant community characteristics, water content, bulk density, porosity and mechanical composition of soil in the different a- bandoned lands were also researched in the Minqin Oasis, downstream of the Shiyang River. [Result] Plant of 32 species spread over 14 family live through fifty years appeared in abandoned lands in the study area. Shrubs was 6 species, herbs was 26 species among them, which were 18.75%, 81.25% respectively. The goose- foot family （6 species）, the composite family（4 species）,the grass family（4 species）, caltrop family（3 species） were 53.13% among them. Within the range of 0-40 cm of different abandoned Land, the soil moisture content showed a trend of first increase and then decrease with the increase of soil depth changes in soil bulk density and porosity of less obvious. In the range of 0-40 cm soil depth, the largest proportion of fine sand, followed by silt and clay and the smallest proportion of coarse sand in every plot, but the proportion of the each silt size varies little with the years aban- doned. [Conclusion] The research provides references for vegetation reconstruction and eco-environment construction in abandoned lands in downstream of Shiyang River.

Oasis Montaj精准调入位图的方法

Oasis Montaj是数据处理和成图软件,实际应用中常需要导入位图进行综合分析。在Oasis Montaj中,通过对位图进行注册的方法,将位图导入到DATA类图层中,可随成图比例尺进行任意变换,达到精准调入位图的目的。文章介绍了几种获取图像变换参数和对位图进行注册的方法,对Oasis Montaj平台在平面图、三维图精准调入位图的应用效果进行了展示。

Influential Factors of Water Productivity of Maize in Oasis of Arid Areas——A Case Study of Linze County

[Objective] The aim was to research influential factors of water productivity of maize in oasis in arid areas. [Method] In middle reach of Heihe River in Linze County of Zhangye City, maize, a major crop in irrigated area in the oasis, was studied and nine influential factors were chosen through grey relation analysis. [Result] According to grey relation analysis, top five factors influencing water produc- tivity of maize during 1995-2009 were as follows： applied quantity of chemical fertil- izers〉labour input〉seeds〉mulch amount〉pesticide amount, which indicated that controllable factors, instead of uncontrollable ones, dominate in influence of water productivity of maize in oasis in arid areas. [Conclusion] With water resource limited, investment of controllable factors in high-efficient agricultural production should be the major strategy to improve water productivity of maize in oasis of arid areas.