Study on Skin Care Efficacy of the Active Ingredients in Camellia Japonica Flowers at High and Low Altitudes

The active ingredients of Camellia japonica flowers(CJF)at high and low altitudes,as well as their skin care efficacy were compared.The dried red CJF at high and low altitudes were ultrasonically extracted with 70%ethanol,and these extracts were concentrated and then diluted to a constant volume.The content of total flavonoids,total polyphenols and total proteins was tested and analyzed.In addition,DPPH free radical scavenging,inhibition of the formation of advanced glycation end products,and inhibitory activity against elastase was measured to compare their skin care efficacy in anti-oxidation,anti-glycation,anti-wrinkling and firming.The results showed that,based on the dry weight of CJF,the content of total flavonoids and total proteins of the CJF at high altitude was approximately 1.5 times of the CJF at low altitude,while the content of total polyphenols was approximately 2.4 times that of the CJF at low altitude.The skin care efficacy of CJF at high altitude was significantly better than that of the CJF at low altitude.This work could provide theoretical basis for the selection and application of Camellia japonica flowers in the field of cosmetics.

Initial Analysis on the Effect of High-low Altitude Jet Stream on Heavy Precipitation in Guangxi

By using the routine observation data,a heavy precipitation process which happened in Guangxi on May 27,2006 was analyzed.The results that this heavy precipitation occurred in the common coordination weather system which included the high-altitude trough,the shear line and the ground cold front.The ascent branch of subtropical longitude circle circulation and the polar front jet stream longitude circle circulation had the important role for the formation of rainstorm area.The coupling effect of southerly jet,low-altitude westerly jet and high-altitude westerly jet in the boundary layer was the important reason of rainstorm occurrence.

Low Altitude Satellite Constellation for Futuristic Aerial-Ground Communications

This paper discusses the significance and prospects of low altitude small satellite aerial vehicles to ensure smooth aerial-ground communications for next-generation broadband networks.To achieve the generic goals of fifthgeneration and beyondwireless networks,the existing aerial network architecture needs to be revisited.The detailed architecture of low altitude aerial networks and the challenges in resource management have been illustrated in this paper.Moreover,we have studied the coordination between promising communication technologies and low altitude aerial networks to provide robust network coverage.We talk about the techniques that can ensure userfriendly control and monitoring of the low altitude aerial networks to bring forth wireless broadband connectivity to a new dimension.In the end,we highlight the future research directions of aerial-ground communications in terms of access technologies,machine learning,compressed sensing,and quantum communications.

Regular Observation of De-Acclimatization and Randomized Controlled Research of Diagnostic Criteria of High Altitude De-Acclimatization Syndrome among Different Plateau Migrants Crowd after Their Return to the Plain

Objective: The objective of this study was to investigate the diagnostic methods of high altitude de-acclimatization syndrome and to formulate diagnostic criteria. Methods: This study was conducted using epidemiological surveys and a multi-center randomized controlled clinical trial. A total of 3011 subjects were studied, and the following indices were collected after their return to low altitude areas from the plateau: general health status, blood, urine and stool samples, myo-cardial enzyme levels, liver and kidney function, nerve function, sex hormone levels, microalbuminuria, electrocardiogram (ECG), echocardiography, pulmonary function, and hemorheological markers. These data were compared to those of randomized healthy subjects in the same age range who lived at the same altitude to determine the characteristics of high altitude de-acclimatization syndrome. Based on these characteristics, diagnostic criteria for high altitude de-acclimatization syndrome were formulated. Results: This study demonstrated that the incidence of high altitude de-acclimatization syndrome was 84.36%. Sixty percent of the cases were mild, 30% were medium, and 10% were severe. The incidence was higher among those who returned to a place of lower altitude, resided at a high altitude for a longer period of time, or engaged in heavy labor while at high altitude. Patients with high altitude de-acclimatization syndrome manifested hematological abnormalities and abnormal ventricular function, notably a right ventricular diastolic function, which recovered to baseline function after one to five years. Exposure to long-term hypoxia often caused obvious changes in cardiac morphology, i.e., left and right ventricular hypertrophy, particularly within the right ventricle. In addition, patients with high altitude de-acclimatization syndrome often presented with low blood pressure, low pulse pressure, and microalbuminuria. A few patients presented with occult blood in their feces. The diagnosis of high altitude de-acclimatization syndrome can be made if a patient who recently returns to the plain from the plateau complains of dizziness, weakness, sleepiness, chest tightness, edema, memory loss, and other symptoms and signs that do not alleviate under short-term rehabilitation or symptomatic treatment, and if organic diseases of the heart, lung, kidney, and other organs have been excluded. Conclusion: The diagnosis of high altitude de-acclimatization syndrome should be made after a comprehensive analysis of the patient’s clinical symptoms and signs.

Diagnostic criteria of high altitude de-acclimatization syndrome among plateau migrants after their return to the plain: a multi-center randomized controlled trial

Objective: The objective of this study was to investigate the diagnostic methods of high altitude de-acclimatization syndrome and to formulate diagnostic criteria.Methods: This study was conducted using epidemiological surveys and a multi-center randomized controlled clinical trial. A total of 3,011 subjects were studied, and the following indices were collected after their return to low altitude areas from the plateau: general health status, blood, urine and stool samples, myocardial enzyme levels, liver and kidney function, nerve function, sex hormone levels, microalbuminuria, electrocardiogram(ECG), echocardiography, pulmonary function, and hemorheological markers. These data were compared to those of randomized healthy subjects in the same age range who lived at the same altitude to determine the characteristics of high altitude deacclimatization syndrome. Based on these characteristics, diagnostic criteria for high altitude de-acclimatization syndrome were formulated.Results: This study demonstrated that the incidence of high altitude de-acclimatization syndrome was 84.36%. Sixty percent of the cases were mild, 30% were medium, and 10% were severe. The incidence was higher among those who returned to a place of lower altitude, resided at a high altitude for a longer period of time, or engaged in heavy labor while at high altitude. Patients with high altitude de-acclimatization syndrome manifested hematological abnormalities and abnormal ventricular function, notably a right ventricular diastolic function, which recovered to baseline function after one to five years. Exposure to long-term hypoxia often caused obvious changes in cardiac morphology, i.e., left and right ventricular hypertrophy, particularly within the right ventricle. In addition, patients with high altitude de-acclimatization syndrome often presented with low blood pressure, low pulse pressure, and microalbuminuria. A few patients presented with occult blood in their feces. The diagnosis of high altitude deacclimatization syndrome can be made if a patient who recently returns to the plain from the plateau complains of dizziness, weakness, sleepiness, chest tightness, edema, memory loss, and other symptoms and signs that do not alleviate under short-term rehabilitation or symptomatic treatment, and if organic diseases of the heart, lung, kidney, and other organs have been excluded.Conclusion: The diagnosis of high altitude de-acclimatization syndrome should be made after a comprehensive analysis of the patient's clinical symptoms and signs.

Discussion on Super High-temperature Weather and City Construction

With the method of structure analysis, this work analyzes the real data of the high-temperature weather of China in 2003 and those in history, and finds out that the structure character of the high-temperature weather process corresponds to the distribution of urban buildings. The result shows that excessive dense buildings could influence the atmosphere structure, which leads to the urban temperature increasing sharply. On the other hand, the structure analysis also reveals some problems on urban construction, and the corresponding countermeasure is an efficient method for high-temperature weather forecast.

HOI延迟对LEO卫星简化动力学POD的影响

通常使用无电离层(IF)线性组合(LC)消除低地球轨道(LEO)卫星简化动力学精密定轨(POD)一阶电离层延迟误差,忽略了高阶电离层(HOI)延迟误差。随着LEO卫星POD技术的发展,计算不同轨道高度的HOI延迟并探索其变化已成为进一步提高POD精度的重要手段。首先,使用国际参考电离层-2016(IRI-2016)和国际地磁参考场第13代(IGRF-13)模型,计算电离层穿刺点(IPP)位置和地磁场强度。其次,使用平滑星载GNSS数据计算电离层斜路径总电子含量(STEC)。然后,分别计算GOCE、GRACE-A和SWARM-A/B卫星的二阶和三阶电离层延迟。最后,评估了HOI延迟对LEO卫星重叠轨道分析、卫星激光测距(SLR)检核和精密科学轨道(PSO)比较结果的影响。实验结果表明:HOI延迟对LEO卫星简化动力学POD的影响大约在毫米至厘米的数量级上;HOI延迟对LEO卫星简化动力学POD外符合精度的影响分别达到0.92,0.22,0.21和0.18 mm;随着LEO卫星轨道高度的增加,HOI延迟对LEO卫星简化动力学POD的影响减小。

高海拔潮气量双环PID控制系统研究

为解决高海拔地区气压降低导致急救呼吸机潮气量控制精度下降的问题,提出了双环PID潮气量控制系统。该系统采用气压补偿型PID控制器调整风机转速,并辅以积分分离式PID控制器,以实现对气流速度的精确控制。在实际海拔4370 m、大气压59 kPa的环境中,系统性能测试表明,相较于单环PID控制,双环控制系统在高海拔条件下表现出快速响应和无超调的卓越性能。平均气流速度输出误差为3.19%,最大误差为4.1%,优于现有临床设备的准确性。这一技术突破不仅提供了高海拔急救呼吸机潮气量控制的有效解决方案,也为特殊环境下的通气控制技术发展贡献了重要参考。

低空经济高质量发展的法治保障研究

在中国式现代化的背景下,低空经济实现高质量发展是必然要求,而法治现代化则是其内在逻辑。就法治基础而言,应确立发展与安全并重的法治目标,采取积极风险防范主义的法治理念,建立软硬法混合模式的法治结构,适用多元协同治理的法治进路。就体系框架而言,低空经济战略立法是顶层设计,低空空域管理立法是关键因素,低空飞行监管立法是核心内容,低空经济促进立法是重要支撑。就规范构造而言,应重点建立健全低空空域开放共享制度、低空经济管理监督制度和低空飞行器监管制度。低空经济法治建设应注重内在功能协调,着重处理好军航与民航之间的关系、中央立法与地方立法之间的关系、创制新法与清理旧法之间的关系和立法与执法之间的关系。

低海拔汉族生源大学生高原习服过程追踪调查研究

目的:追踪调查初入高原的低海拔汉族大学生高原习服相关生理指标并探究其变化规律。方法:于2023年3月9日至9月21日追踪记录西藏大学2022年春季入学的107名汉族大学生的生理指标,并以同年入学的149名世居高原藏族学生,以及2023年秋季入学的74名汉族学生为对照。结果:初入高原低海拔汉族大学生的血氧饱和度,心率显著高于世居高原藏族大学生,而血红蛋白浓度无显著差异;血红蛋白浓度、血氧饱和度和心率在进入高原后分别呈现上升、下降及上升趋势且在两个月后均出现转折点。结论:初入高原低海拔汉族大学生的血红蛋白浓度、血氧饱和度和心率均呈现趋于习服的一致性变化趋势且具相关性。研究结果提示移居高原人群在进入高原低氧环境约两个月后出现习服。

急进短期高原暴露对中青年男性不同系统的影响

目的观察健康中青年男性急进短期高原暴露(fast-advancing short-term high altitude exposure,FSHAE)前后机体的肝功能、血细胞、肺功能等主要相关指标的变化,并探讨FSHAE对肝脏、血细胞、肺功能的影响及可能机制。方法共纳入健康中青年志愿者男性48名,在进驻高原前1d(海拔100m)、FSHAE 15d(海拔3000m)采集研究对象的生理指标并检测肝功能、血细胞、肺功能相关指标。比较FSHAE前后各系统相关参数的差异。结果与进驻高原前比较,中青年男性FSHAE15d后生理参数指标:心率明显增快、呼吸频率增加、收缩压升高、平均动脉压升高、血氧饱和度下降、舒张压升高,差异均有统计学意义(P<0.05);肝功能指标:天冬氨酸转氨酶、丙氨酸转氨酶均升高、谷氨酰转肽酶、碱性磷酸酶、总胆汁酸均升高,总蛋白下降,差异均有统计学意义(P<0.05);血细胞相关指标:红细胞计数、红细胞压积、平均红细胞体积、平均血红蛋白量、平均血红蛋白浓度、血红蛋白均升高,血小板计数降低,差异均有统计学意义(P<0.01),虽然白细胞计数升高,但差异无统计学意义(P>0.05);肺功能相关指标:用力肺活量下降,差异有统计学意义(P<0.05);第1秒钟用力呼气容积下降、一秒用力呼气率升高,但差异均无统计学意义(P>0.05)。结论健康中青年男性FSHAE可导致机体出现氧化应激,可发生急性低氧性多系统性损伤,与此同时机体各系统出现缺氧适应性调节,各器官发生自我代偿修复,且各系统间可能存在相互影响的可能。

高燃压中型运载火箭发射地面低高度排导技术

综合高燃压中型运载火箭高密度发射燃气流地面排导需求及烧蚀风险分析,提出基于地面双面导流装置与高位挡流墙结合的地面低高度排导技术方案。利用火箭发射燃气动力学研究总结的燃气流膨胀特性以及导流型面设计方法,解决了地面低高度排导技术涉及的地面导流装置导流型面气动设计以及尺度控制两个关键问题。地面低高度排导技术方案设计与燃气流场瞬态仿真多轮叠代,实现了燃气流排导烧蚀范围合理控制,避免了燃气流低高度排导烧蚀反溅影响箭体。地面低高度排导技术采用专利支撑的喷水冷却防护方案实现高燃压中型运载火箭发射燃气流强烧蚀环境发射系统、发射设施综合防护。基于喷流缩比试验相似性控制方法研制了1∶10比例喷流缩比试验系统,通过喷流缩比试验验证确认高燃压中型运载火箭发射燃气流能够实现地面低高度安全、顺畅排导,同时与发射台、导流装置结构融合的阵列喷水方案能够行之有效解决高燃压中型运载火箭地面低高度排导强烧蚀难题。

逆向喷流对可回收火箭气动特性的影响研究

可回收火箭返回时,需要依靠发动机进行点火减速制动,为得到逆向喷流条件下箭体气动性能的变化规律,通过对低空和高空两次点火过程进行数值仿真,分析来流马赫数和攻角对箭体气动性能的影响,同时开展单喷管、多喷管喷流条件下的仿真研究。结果表明,低空状态,逆向喷流会导致全箭轴向力系数绝对值减小,且喷流数目越多,轴向力系数绝对值越小。小攻角条件下,逆向喷流会引起全箭压心大幅前移,随着开机台数增加,压心前移越多。高空条件下,喷流膨胀区和来流存在强烈的相互干扰,导致轴向力系数减小明显,其绝对值在0.04以内,0°~10°攻角内箭体法向力系数绝对值小于0.1,随着来流静压增加,法向力系数绝对值小于0.1的攻角区间减小。

复杂环境下异构无人机集群协同目标搜索方法

为实现无人机集群高效且精准的多目标搜索,考虑集群成员中探测范围广的高空无人机和机动能力较强的低空无人机,提出了一种新颖的异构无人机集群协同目标搜索方法,根据不同无人机的特性快速实现区域搜索以及多目标的精准搜索。高空无人机采用基于数字信息素的区域搜索算法确定目标存在区域,在较短时间内实现区域覆盖。低空无人机在其指引下前往目标区域,并根据目标信号强度采用改进狼群算法实现对目标的精准搜索。对于传统狼群算法信息共享不足、步长固定和易陷入局部最优的问题,采用粒子群算法、自适应参数调整和差分进化方法进行改进,提高了算法的全局寻优能力和收敛速度。仿真实验证明了所提出的模型与方法在复杂环境下目标搜索任务中的有效性和优越性。

低空倾斜摄影测量在马沥村大比例尺测图中的应用

低空高分辨率倾斜摄影测量是近年来兴起的一项热门技术,以广州市白云区钟落潭镇马沥村大比例尺测图为例,介绍运用低空高分辨率倾斜摄影建模与大比例尺测图技术。在大比例尺地形图测绘方面,相较于传统航测和人工测图技术,该方法具有减少外业人员劳动强度,外业采集更自主、更高效的优势,为城市密集区域地籍调查、农村土地确权、国土规划用图等领域以及在其他不方便外业人员作业的山区、高危地势地区开展大比例尺测图提供参考。

以新质生产力促进西藏低空经济高质量发展的策略研究

新质生产力是创新起主导作用,摆脱传统经济增长方式、生产力发展路径,具有高科技、高效能、高质量特征,符合新发展理念的先进生产力质态。本文从新质生产力核心内涵及其对高质量发展的现实意义为出发点,结合低空经济作为新兴产业所呈现的典型特征,分析新质生产力与低空经济之间的关系和内在联系。立足西藏自治区低空经济发展的实际情况,客观评价低空产业发展现状,深入剖析存在的难点问题,灵活运用新质生产力的方法论,从强化科技创新、促进产业融合、加强要素供给等方面,提出针对西藏的低空经济高高原发展策略,推动实现低空产业的高质量发展。

高原型无人机活塞发动机涡轮增压器匹配研究

目的为了研究利用汽车发动机开发低成本民用航空无人机活塞发动机的应用价值,方法提出基于汽车涡轮增压发动机的高海拔性能劣化补偿目标的开发方法。选取某型车用活塞式涡轮增压发动机,分析变海拔环境下的增压器-发动机匹配条件,评估汽车涡轮增压发动机在无人机飞行包线的边界内性能变差程度。通过目标海拔高度条件下的仿真计算,获得新涡轮增压器的目标增压压比和发动机进气流量。以此计算结果为目标新增压器的性能边界,选定某型号涡轮增压器,其性能输出特性能够覆盖该发动机作为无人机动力的进气目标增压压力和流量。在平原和高高原条件下开展无人机飞行性能验证,对新开发增压器的压气叶轮和涡轮叶轮产生的压比、膨胀比以及各自的折合流量分别进行校核,分析无人机在不同海拔环境下的飞行测试数据。结果结果表明,新匹配的涡轮增压器在海拔4200 m的高高原条件下搭载试验发动机,压气机压比为3.2,换算流量0.092 kg/s,运行区间在增压器叶轮的MAP包络线以内,能够使无人机达到28.2%的悬停有效载荷比,性能达到高高原载重飞行的技术要求。结论利用汽车涡轮增压发动机,按照无人机飞行包线内工况,重新匹配涡轮增压器的压气机,并校核涡轮机运行工况,能够实现满足民用航空无人机对高高原低空载重飞行性能的基本要求,匹配方法为新产品开发应用提供了理论指导。

高海拔地区低体重儿发生状况及影响因素分析

目的探讨高海拔地区低体重儿的发生情况及影响因素。方法选取我院帮带西藏自治区安多县人民医院(当地平均海拔5200 m)在2022年4月至2023年4月分娩的活产儿340例,统计低体重儿发生情况,并分析母亲一般资料、妊娠期及围生期合并症、妊娠晚期血清5种金属元素(Ca、Fe、Mg、Zn、Cu)水平对低体重儿发生的影响。结果本次调查发现低体重儿发生率为18.24%(62/340)。母亲年龄、孕次、产次、妊娠初期BMI、不良孕产史、妊娠期糖尿病及新生儿性别与低体重儿发生情况无明显关系。妊娠期高血压、妊娠期肝内胆汁淤积症、妊娠期贫血、胎膜早破、羊水过少、早产组低体重儿发生率分别高于无妊娠期高血压、无妊娠期肝内胆汁淤积症、无妊娠期贫血、无胎膜早破、无羊水过少、足月产组,差异有统计学意义(均P<0.001);低体重儿组母亲妊娠晚期血清Ca、Fe、Mg、Zn和Cu水平低于非低体重儿组,差异有统计学意义(均P<0.001)。多因素logistic回归分析结果显示,妊娠期高血压、妊娠期肝内胆汁淤积症、胎膜早破、早产及母亲妊娠晚期血清Ca、Zn和Cu水平是引起低体重儿的影响因素(均P<0.001)。结论高海拔地区低体重儿的发生受妊娠期高血压、妊娠期肝内胆汁淤积症、胎膜早破、早产等多种因素的影响,同时与母亲妊娠晚期血清Ca、Zn和Cu水平有关。

高海拔地区用温拌抗光老化沥青低温性能研究

针对高海拔地区沥青路面易诱发紫外老化、低温开裂问题,采用3种光稳定剂制备出改性温拌抗光老化沥青,通过低温延度、差示扫描量热分析和弯曲蠕变劲度试验以及Burgers黏弹模型,对光老化前后的沥青开展多指标低温性能评价,并借助灰色关联度法分析各低温指标的相关性。结果表明:表面活性温拌剂对沥青的低温性能有不利影响;3种光稳定剂均对沥青抗光老化性能有改善作用,其中UV326能明显改善温拌沥青低温性能,抗光老化效果最佳,Burgers模型能准确描述沥青在弯曲蠕变劲度试验中的低温蠕变行为。根据灰色关联分析结果,推荐蠕变速率、-18℃低温综合柔量参数和玻璃态转变温度可作为高海拔地区沥青胶结料的选型指标。

西藏高海拔牧区市新生儿出生体重调查分析——以那曲市为例

以2016年1月至12月那曲市某医院妇产科接生登记表为依据,对新生儿及产妇的情况进行回顾性分析。结果显示,2016年该市某医院共登记新生儿总数为2500例,其中男婴1293例,女婴1207例,性别比为1.07∶1.00;95.5%的新生儿自然分娩出生;新生儿平均出生体重为2943.19±532.93 g,1.7%为极低出生体重儿,12.6%为低体重儿,巨大儿为1.1%。用Apgar评分评估新生儿,4.0%的新生儿轻度窒息,4.4%的重度窒息。单因素分析显示新生儿出生体重与其性别、出生季节、产妇年龄及孕次因素有关。那曲市新生儿出生体重低于全国平均水平,低于西藏其他地市水平,低体重儿比例较高;新生儿出生体重受多因素影响,应采取不同措施加以干预,从而使西藏高海拔牧区市新生儿体重合理增长。