中国人群33104例单基因病携带者筛查的多中心研究

目的 通过大规模多中心的多种遗传病携带者筛查,调查中国人群单基因病的流行病学特征以及突变谱,为制定适合中国人群的遗传病预防策略提供依据。方法 本研究在中国的12个临床中心共招募33 104例受检者(16 610例女性),基于高通量测序和多种PCR对223个基因的携带者状态进行检测。结果 197个常染色体基因的合并携带者频率为55.58%,26个X连锁基因的合并携带者频率为1.84%。在16 669例家系中,共检出874对(5.24%)高危夫妇。其中常染色体基因高危夫妇584对(3.50%),X连锁基因高危夫妇306对(1.84%),16对夫妇同时为常染色体基因和X连锁基因高危夫妇。最常检出的常染色体高危基因包括GJB2(常染色体隐性耳聋1A,393对),HBA1/HBA2(α-地中海贫血,36对)和PAH(苯丙酮尿症,14对),SMN1(脊髓性肌萎缩症,14对)。最常检出的X连锁高危基因包括G6PD(G6PD缺乏症,236对),DMD(进行性假肥大性肌营养不良,23对)和FMR1(脆性X综合征,17对)。除外G6PD后的高危夫妇率为3.91%(651/16 669),进一步除外GJB2 c.109G>A位点后,高危夫妇率为1.72%(287/16 669)。理论上严重的单基因病出生缺陷的发病率约为4.35‰(72.5/16 669)。对导致高危夫妇最多的22个基因进行筛查可检出95%以上的高危夫妇,对导致高危夫妇最多的54个基因进行筛查可检出99%以上的高危夫妇。结论 本研究揭示了我国人群中223种单基因病的携带者频率,为中国人群的携带者筛查策略制定和panel设计提供依据。在携带者筛查实践中,针对某些特殊基因或变异位点的遗传咨询可能会面临困难。这些特殊基因或变异需要在检测前告知受检夫妇,并在可能的情况下提供不筛查这些基因或变异的选择。

七氟烷预处理和右美托咪定对老年食管癌患者术后认知功能的影响

目的比较七氟烷预处理和右美托咪定(DEX)对老年食管癌患者术后认知功能障碍(POCD)的影响,并探讨其可能机制。方法120例老年食管癌手术患者按随机数字表法分成对照组、七氟烷组、DEX组、DEX+七氟烷组,每组30例。麻醉诱导前,对照组只给予吸氧,七氟烷组给予七氟烷预处理,DEX组给予DEX预处理,DEX+七氟烷组给予七氟烷预处理的同时给予DEX预处理。测定4组入室后、插管后及拔管时的心率(HR)及平均动脉压(MAP),术后48 h视觉模拟评分法(VAS)评分及术后1、3、7 d的POCD发生率,检测入室后、拔管后及术后l、3、7 d血浆S100β蛋白和神经元特异性烯醇化酶(NSE)的水平。结果入室后、插管后及拔管时2种麻醉药物对HR、MAP的影响均无交互作用(P>0.05);与对照组比较,七氟烷组仅插管后HR降低,DEX组及DEX+七氟烷组插管后及拔管时HR、MAP均降低(P<0.05),七氟烷组术后48 h镇痛满意和疼痛明显患者比例差异均无统计学意义;与对照组、七氟烷组比较,DEX组和DEX+七氟烷组镇痛满意患者比例增加,而疼痛明显患者比例降低(P<0.05)。与对照组比较,七氟烷组术后1 d的POCD发生率降低,DEX组术后1、7 d的POCD发生率降低,DEX+七氟烷组术后1、3、7 d的POCD发生率均降低(P<0.05)。拔管后和术后1、3、7 d 2种麻醉药物对血清中S100β蛋白、NSE蛋白表达水平的影响无交互作用(P>0.05)。与对照组比较,七氟烷组拔管后和术后1、3 d血清中S100β蛋白、NSE蛋白表达水平降低(P<0.05);DEX组拔管后和术后1、3、7 d血清中S100β蛋白、NSE蛋白水平均降低(P<0.05)。结论七氟醚和DEX预处理均能抑制老年食管癌手术患者术后血清中S100β蛋白、NSE蛋白水平的升高,从而降低POCD的发生率,DEX效果更好,但两药联用效果并不理想。

地佐辛联合不同剂量右美托咪定用于OSAHS患者经鼻清醒插管的效果比较

目的观察地佐辛联合不同剂量右美托咪啶用于阻塞性睡眠呼吸低通气暂停综合征(OSAHS)患者行纤维支气管镜引导经鼻清醒气管插管(AFNI)的效果。方法OSAHS患者80例按随机数字表法分为地佐辛0.1 mg/kg组(C组)、地佐辛0.1 mg/kg+右美托咪定(DEX)0.5μg/kg组(D1组),地佐辛0.1 mg/kg+DEX 1μg/kg组(D2组),地佐辛0.1 mg/kg+DEX 1.5μg/kg组(D3组),每组20例。在给予全部患者静脉注射地佐辛0.1 mg/kg的同时,C组静脉泵注0.5μg/kg生理盐水,D1、D2、D3组分别静脉泵注DEX 0.5、1、1.5μg/kg(10 min泵完)。气管插管前5 min行鼻腔咽喉表面麻醉,药泵注结束行AFNI。比较4组入室时(T_(0))、插管前(T_(1))和插管后(T_(2))心率(HR)、平均动脉压(MAP)、血氧饱和度(SPO_(2))、脑电双频指数(BIS)值和Ramsay镇静评分、插管耐受度、插管时间、患者对插管的满意度、气道阻塞评分及不良反应(心动过缓、呼吸抑制、躁动、对插管有记忆)的发生率。结果时间和干预方式对HR、MAP、BIS值及Ramsay镇静评分有交互作用(P<0.05),对SPO_(2)无交互作用(P>0.05),只有时间因素影响SPO_(2)(P<0.05)。组间多重比较显示,D2组在T_(1)、T_(2)时点HR、MAP较C组降低,在T_(2)时点较D1组降低(P<0.05);D3组较C组、D1组在T_(1)、T_(2)时点HR、MAP降低;D3组心动过缓发生率较C组升高(P<0.05);与C组、D1组比较,D2、D3组在T_(1)、T_(2)时点的BIS值降低、Ramsay镇静评分升高,躁动和对插管有记忆的发生率降低,气管插管耐受度增强,气管插管时间缩短,插管满意度高(P<0.05)。结论地佐辛联合DEX可有效安全地用于OSAHS患者的AFNI,且以地佐辛0.1 mg/kg联合DEX 1μg/kg时,既能维持患者血流动力学稳定又能减少不良反应发生率。

群智优化路径技术在风景园林规划设计中的运用

风景园林规划设计过程中计算机辅助技术起到了越来越大的作用,特别是在园林道路路径设计方面,有效的最短路径规划可以提升游客的体验。因此,提出一种基于群智优化的dijkstra最短路径规划算法。首先基于风景园林应用创建环境地图;然后对典型的dijkstra最短路径算法进行分析;最后采用群智优化对dijkstra最短路径算法进行改进,并给出信息素浓度更新的方法。仿真测试结果表明,相比传统dijkstra算法,提出的群智优化算法的路径长度更小,可以有效满足园林道路规划的需求。

德育元素融入高校公共艺术课程教学对策研究

研究旨在用历史和文化资源强化高校艺术类课程德育建设,使思想政治课与艺术设计专业方向课相辅相成,达成协同效应。坚持思想道德建设和校内实践活动高效结合,激励学生能够做到知行合一。同时,强化成果在教学中的重要性,让课程成果转化为实际生产力,促进城市化进程的革新,为我国空间美学的探索起到最基础的推进作用。

Survival of transplanted neurotrophin-3 expressing human neural stem cells and motor function in a rat model of spinal cord injury

BACKGROUND： Many methods have been attempted to repair nerves following spinal cord injury, including peripheral nerve transplantation, Schwann cell transplantation, olfactory ensheathing cell transplantation, and embryonic neural tissue transplantation. However, there is a need for improved outcomes. OBJECTIVE： To investigate the repair feasibility for rat spinal cord injury using human neural stem cells （hNSCs） genetically modified by lentivirus to express neurotrophin-3. DESIGN, TIME AND SETTING： In vitro cell biological experiment and in vivo randomized, controlled genetic engineering experiment were performed at the Third Military Medical University of Chinese PLA and First People＇s Hospital of Yibin, China from March 2006 to December 2007. MATERIALS： A total of 64 adult, female, Wistar rats were used for the in vivo study. Of them, 48 rats were used to establish models of spinal cord hemisection, and were subsequently equally and randomly assigned to model, genetically modified hNSC, and normal hNSC groups. The remaining 16 rats served as normal controls. METHODS： hNSCs were in vitro genetically modified by lentivirus to secrete both green fluorescence protein and neurotrophin-3. Neurotrophin-3 expression was measured by Western blot. Genetically modified hNSC or normal hNSC suspension （5 × 10^5） was injected into the rat spinal cord following T10 spinal cord hemisection. A total of 5μL Dulbecco＇s-modified Eagle＇s medium was infused into the rat spinal cord in the model grop. Transgene expression and survival of transplanted hNSCs were determined by immunohistochemistry. Motor function was evaluated using the Basso, Beattie, and Bresnahan （BBB） scale. MAIN OUTCOME MEASURES： The following parameters were measured： expression of neurotrophin-3 produced by genetically modified hNSCs, transgene expression and survival of hNSCs in rats, motor function in rats. RESULTS： hNSCs were successfully genetically modified by lentivirus to stably express neurotrophin-3. The transplanted hNSCs primarily gathered at, or around, the injection site two weeks following transplantation, and gradually migrated towards the surrounding tissue. Transplanted hNSCs were observed 7.0-8.0 mm away from the injection site. In addition, hNSCs were observed 10 weeks after transplantation. At week 4, BBB locomotor scores were significantly greater in the genetically modified hNSC and normal hNSC groups, compared with the model group （P 〈 0.05）, and scores were significantly greater in the genetically modified hNSC group compared with the normal hNSC group （P 〈 0.05）. CONCLUSION： hNSCs were genetically modified with lentivirus to stably secrete neurotrophin-3. hNSCs improved motor function recovery in rats following spinal cord injury.

Aqueous-phase catalytic hydrogenation of furfural to cyclopentanol over Cu-Mg-Al hydrotalcites derived catalysts:Model reaction for upgrading of bio-oil

A series of Cu-Mg-Al hydrotalcites derived oxides with a(Cu+Mg)/Al mole ratio of 3 and varied Cu/Mg mole ratio(from 0.07 to 0.30) were prepared by co-precipitation and calcination methods, then they were introduced to the hydrogenation of furfural in aqueous-phase. Effects of Cu/Mg mole ratio, reaction temperature, initial hydrogen pressure, reaction time and catalyst amount on the conversion rate of furfural as well as the selectivity toward desired product cyclopentanol were systematically investigated. The conversion of furfural over calcined hydrotalcite catalyst with a Cu/Mg mole ratio of 0.2 was up to 98.5% when the reaction was carried out under 140 ?C and the initial hydrogen pressure of 4 MPa for 10 h, while the selectivity toward cyclopentanol was up to 94.8%. The catalysts were characterized by XRD and SEM. XRD diffraction of all the samples showed characteristic pattern of hydrotalcite with varied peak intensity as a result of different Cu content. The catalytic activity was improved gradually with the increase of Cu component in the hydrotalcite.

Fluoxetine ameliorates depressive symptoms by regulating lncRNA expression in the mouse hippocampus

Depression is a prevalent mental disorder that is associated with aging and contributes to increased mortality and morbidity.The overall prevalence of geriatric depression with clinically significant symptoms is currently on the rise.Recent studies have demonstrated that altered expressions of long non-coding RNAs(lncRNAs)in the brain affect neurodevelopment and manifest modulating functions during the depression.However,most lncRNAs have not yet been studied.Herein,we analyzed the transcriptome of dysregulated lncRNAs to reveal their expressions in a mouse model exhibiting depressive-like behaviors,as well as their corresponding response following antidepressant fluoxetine treatment.A chronic unpredictable mild stress(CUMS)mouse model was applied.A sixweek fluoxetine intervention in CUMS-induced mice attenuated depressive-like behaviors.In addition,differential expression analysis of lncRNAs was performed following RNA-sequencing.A total of 282 lncRNAs(134 up-regulated and 148 down-regulated)were differentially expressed in CUMS-induced mice relative to non-stressed counterparts(P<0.05).Moreover,370 differentially expressed lncRNAs were identified in CUMS-induced mice after fluoxetine intervention.Gene Ontology(GO)analyses showed an association between significantly dysregulated lncRNAs and protein binding,oxygen binding,and transport activity,while the Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis indicated that these dysregulated lncRNAs might be involved in inflammatory response pathways.Fluoxetine effectively ameliorated the symptoms of depression in CUMS-induced mice by regulating the expression of lncRNAs in the hippocampus.The findings herein provide valuable insights into the potential mechanism underlying depression in elderly people.

Insight into Crosstalk Between Mitophagy and Apoptosis/Necroptosis:Mechanisms and Clinical Applications in Ischemic Stroke

Ischemic stroke is a serious cerebrovascular disease with high morbidity and mortality.As a result of ischemia-reperfusion,a cascade of pathophysiological responses is triggered by the imbalance in metabolic supply and demand,resulting in cell loss.These cellular injuries follow various molecular mechanisms solely or in combination with this disorder.Mitochondria play a driving role in the pathophysiological processes of ischemic stroke.Once ischemic stroke occurs,damaged cells would respond to such stress through mitophagy.Mitophagy is known as a conservatively selective autophagy,contributing to the removal of excessive protein aggregates and damaged intracellular components,as well as aging mitochondria.Moderate mitophagy may exert neuroprotection against stroke.Several pathways associated with the mitochondrial network collectively contribute to recovering the homeostasis of the neurovascular unit.However,excessive mitophagy would also promote ischemia-reperfusion injury.Therefore,mitophagy is a double-edged sword,which suggests that maximizing the benefits of mitophagy is one of the direction of future efforts.This review emphasized the role of mitophagy in ischemic stroke,and highlighted the crosstalk between mitophagy and apoptosis/necroptosis.

A natural gas hydrate-oil-gas system in the Qilian Mountain permafrost area, northeast of Qinghai-Tibet Plateau

Natural gas hydrate,oil and gas were all found together in the Qilian Mountain permafrost area,northeast of Qinghai-Tibet Plateau,China.They are closely associated with each other in space,but whether they are in any genetic relations are unknown yet.In this paper,a hydrocarbon gas-generation series,gas-fluid migration series and hydrocarbon gas-accumulation series are analyzed to probe the spatial,temporal and genetic relationships among natural natural gas hydrate,oil and gas.The subsequent results show that natural gas hydrate,oil and gas actually form a natural gas hydrate-oil-gas system.Based on the Middle Jurassic and the Upper Triassic hydrocarbon gas-generation series,it is divided into four major sub-systems in the study area:(1)A conventional Upper Triassic gas-bearing sub-system with peak hydrocarbon gas-generation in the late Middle Jurassic;(2)a conventional Middle Jurassic oil-bearing sub-system with low to mature hydrocarbon gas-generation in the late Middle Jurassic;(3)a natural gas hydrate sub-system with main gas source from the Upper Triassic gas-bearing sub-system and minor gas source from the Middle Jurassic oil-bearing sub-system as well as little gas source from the Middle Jurassic coal-bed gas and the microbial gas;(4)a shallower gas sub-system with microbial alteration of the main gas source from the Upper Triassic gas-bearing sub-system.This natural gas hydrate-oil-gas system and its sub-systems are not only theoretical but also practical,and thus they will play an important role in the further exploration of natural gas hydrate,oil and gas,even other energy resources in the study area.

A new perspective on polyethylene-promoted lignin pyrolysis with mass transfer and radical explanation

Co-pyrolysis of lignin and waste plastics,for example polyethylene(PE),has been studied,but related reports are basically on condition optimizations.This study revealed a new perspective on PE-promoted lignin pyrolysis to phenolic monomers with mass transfer and radical explanation.Lignin and PE were first pyrolyzed individually to identify pyrolysis characteristics,pyrolytic products,as well as the suitable copyrolysis temperature.Then,co-pyrolysis of blended lignin/PE with various ratios was investigated.Yields of lignin products reached the maximum under lignin/PE ratio of 1:1,but blended approach always inhibited the production of lignin phenols.This resulted from the poor mass transfer and interactions between lignin and PE,in which PE pyrolysates could easily escape from the particle gaps.While in layered approach,PE pyrolysates had to pass through the lignin layer which contributed to the good interactions with lignin pyrolysis intermediates,thus the yields of lignin-derived products were significantly improved.Interactions between lignin and PE(or their pyrolysates)were mainly radical quenching reactions,and X-ray photoelectron spectrum(XPS)and electron paramagnetic resonance(EPR)of pyrolytic chars were conducted to verify these interactions controlled by mass transfer.The percentage of C]C(sp^(2))and concentration of organic stable radicals in layered lignin/PE char were both the lowest compared with those in blended lignin/PE and lignin char,indicating the stabilization of lignin-derived radicals by PE pyrolysates.Moreover,the spin concentration of radicals in the char from layered char/PE was lower than that in lignin char,which further affirmed the quenching of radicals by PE in the layered co-pyrolysis mode.

Enhancement of CO_(2) capture and microstructure evolution of the spent calcium-based sorbent by the self-reactivation process

The effect of self-reactivation on the CO_(2) capture capacity of the spent calcium based sorbent was investigated in a dual-fixed bed reactor.The sampled sorbents from the dual-fixed bed reactor were sent for XRD,SEM and N_2 adsorption analysis to explain the self-reactivation mechanism.The results show that the CaO in the spent sorbent discharged from the calciner absorbs the vapor in the air to form Ca(OH)_(2) and further Ca(OH)_(2)·2 H_(2) O under environmental conditions,during which process the CO_(2) capture capacity of the spent sorbent can be self-reactivated.The microstructure of the spent sorbent is improved by the self-reactivation process,resulting in more porous microstructure,higher BET surface area and pore volume.Compared with the calcined spent sorbent that has experienced 20 cycles,the pore volume and BET surface area are increased by 6.69 times and 56.3% after self-reactivation when φ=170%.The improved microstructure makes it easier for the CO_(2) diffusion and carbonation reaction in the sorbent.Therefore,the CO_(2) capture capacity of the spent sorbent is enhanced by self-reactivation process.A self-reactivation process coupled with calcium looping process was proposed to reuse the discharged spent calcium based sorbent from the calciner.Higher average carbonation conversion and CO_(2) capture efficiency can be achieved when self-reactivated spent sorbent is used as supplementary sorbent in the calciner rather than fresh CaCO_(3) under the same conditions.

1+1>2: Learning from the interfacial modulation on single-atom electrocatalysts to design dual-atom electrocatalysts for dinitrogen reduction

Developing efficient electrocatalysts for converting dinitrogen to ammonia through electrocatalysis is of significance to the decentralized ammonia production. Here, through high-throughput density functional theory calculations, we demonstrated that the interfacial modulation of hexagonal boron nitride/graphene(hBN-graphene) could sufficiently improve the catalytic activity of the single transition metal atom catalysts for nitrogen reduction reaction(NRR). It was revealed that Re@hBN-graphene and Os@hBN-graphene possessed remarkable NRR catalytic activity with low limiting potentials of 0.29 V and 0.33 V, respectively. Furthermore, the mechanism of the enhanced catalytic activity was investigated based on various descriptors of the adsorption energies of intermediates, where the synergistic effect of hBN and graphene in the hybrid substrate was found to play a key role. Motivated by the synergistic effect of hybrid substrate in single-atom catalysts, a novel strategy was proposed to efficiently design dual-atom catalysts by integrating the merits of both metal components. The as-designed dual-atom catalyst Fe-Mo@hBN exhibited more excellent NRR catalytic performance with a limiting potential of 0.17 V, manifesting the solidity of the design strategy. Our findings open new avenues for the search of heterostructure substrates for single-atom catalysts and the efficient design of dualatom catalysts for NRR.

Efficient hydrogen production through the chemical looping redox cycle of YSZ supported iron oxides

The chemical looping process,where an oxygen carrier is reduced and oxidized in a cyclic manner,offers a promising option for hydrogen production through splitting water because of the much higher water splitting efficiency than solar electrocatalytic and photocatalytic process.A typical oxygen carrier has to comprise a significant amount of inert support,to maintain stability in multiple redox cycles,thereby resulting in a trade-off between the reaction reactivity and stability.Herein,we proposed the use of ion-conductive yttria-stabilized zirconia(YSZ)support Fe_(2)O_(3)to prepare oxygen carriers materials.The obtained Fe_(2)O_(3)/YSZ composites showed high reactivity and stability.Particularly,Fe_(2)O_(3)/YSZ-20(oxygen storage capacity,24.13%)exhibited high hydrogen yield of~10.30 mmol g^(-1) and hydrogen production rate of~0.66 mmol g^(-1) min^(-1) which was twice as high as that of Fe_(2)O_(3)/Al_(2)O_(3).Further,the transient pulse test indicated that active oxygen diffusion was the ratelimiting step during the redox process.The electrochemical impedance spectroscopy(EIS)measurement revealed that the YSZ support addition facilitated oxygen diffusion of materials,which contributed to the improved hydrogen production performance.The support effect obtained in this work provides a potentially efficient route for the modification of oxygen carrier materials.

Efficient CO2 to CO conversion at moderate temperatures enabled by the cobalt and copper co-doped ferrite oxygen carrier

Chemical looping technology holds great potential on efficient CO2 splitting with much higher CO production and CO2 splitting rate than photocatalytic processes.Conventional oxygen carrier requires high temperature(typically 850–1000°C)to ensure sufficient redox activity,but the stable and high CO2 conversion is favored at a lower temperature,leading to the degrading on the reaction kinetics as well as the low CO production and CO2 splitting rate.In this paper,we prepared several ternary spinels and demonstrated their performance for chemical looping CO2 splitting at moderate temperatures.Using the promotion effect of Cu to cobalt ferrite reduction and reversible phase change of the reduced metals,Cu0.4 Co0.6 Fe2 O4 exhibits high CO2 splitting rate(144.6μmol g–1 min–1)and total CO production(9100μmol g–1)at 650°C.The high performance of this earth-abundant spinel material is also consistent in repeated redox cycles,enabling their potential in industrial use.

Earth abundant spinel for hydrogen production in a chemical looping scheme at 550℃

Operating chemical looping process at mid-temperatures(550–750℃)presents exciting potential for the stable production of hydrogen.However,the reactivity of oxygen carriers is compromised by the detrimental effect of the relatively low temperatures on the redox kinetics.Although the reactivity at mid-temperature can be improved by the addition of noble metals,the high cost of these noble metal containing materials significantly hindered their scalable applications.In the current work,we propose to incorporate earth-abundant metals into the ironbased spinel for hydrogen production in a chemical looping scheme at mid-temperatures.Mn0.2Co0.4Fe2.4O4 shows a high hydrogen production performance at the average rate of~0.62 mmol g^(-1) min^(-1) and a hydrogen yield of~9.29 mmol g^(-1) with satisfactory stability over 20 cycles at 550℃.The mechanism studies manifest that the enhanced hydrogen production performance is a result of the improved oxygen-ion conductivity to enhance reduction reaction and high reactivity of reduced samples with steam.The performance of the oxygen carriers in this work is comparable to those noble-metal containing materials,enabling their potential for industrial applications.

Simulation research of a counter‑fow rotary kiln hazardous waste incineration system

As industrialization accelerates and the amount of hazardous waste generated gradually increases,the means of disposal of hazardous waste is of increasing concern.In this paper,a 40 t/d counter-fow rotary kiln incineration system owned by a Jiangsu environmental protection company was researched.The software Aspen Plus was used to build the mixed pyrolysis model and the software Fluent was used to build the computational fuid dynamics model of the incineration system.The infuence of the calorifc value of the hazardous waste,the operating temperature and the air supply on the operational efectiveness of the incineration system were analyzed by varying the simulation conditions.The results show that the SO_(x)and NO_(x)content of the product is lower when the operating temperature is above 800℃.The incineration system could only operate above 800℃when the calorifc value of the hazardous waste is not less than 1500 kcal/kg.The incineration system operated best at a primary air velocity of 1.5 m/s.The simulation results in this paper serve as a guide for the operation of counter-fow rotary kiln incineration systems.

Urban Development Boundary Simulation Based on“Double Evaluation”and FLUS Model

The delimitation of urban development boundaries plays an important role in optimizing the nation land space.“Double evaluation”is one of the important means to study and predict the scale of new construction land in the future and to determine the spatial distribution of urban construction land.This study combines the“double evaluation”with the FLUS(Future Land-Use Simulation)model to study the delimitation of the urban development boundary of Yichang.The results show that:(1)the“double evaluation”method comprehensively considers the carrying capacity of the resource environmental bear and the suitability of urban development;(2)the FLUS model can better couple the“double evaluation”method for Land Use/Land Cover(LULC)suitability evaluation,Land Use/land Cover Change(LUCC)simulation and urban development boundary delineation,and the overall accuracy of the simulation reaches 96%;(3)according to the requirements of relevant national policies,this study divides the urban development boundary of the study area into concentrated construction areas,elastic development areas and special purpose areas.This function-based division can meet the requirements of urban flexible development,ecological protection and urban safety.This research combines the FLUS model,which is widely used in the simulation of LUCC,with the double evaluation method used in China’s new round of land and space planning to obtain the result of the urban development boundary.This result is consistent with the existing plan of the study area.

Natural gas hydrates in the Qinghai-Tibet Plateau: Characteristics, formation, and evolution

The Qinghai-Tibet Plateau(also referred to as the Plateau)is the largest area bearing alpine permafrost region in the world and thus is endowed with great formation conditions and prospecting potential of natural gas hydrates(NGH).Up to now,one NGH accumulation,two inferred NGH accumulations,and a series of NGH-related anomalous indicators have been discovered in the Plateau,with NGH resources predicted to be up to 8.88×10^(12) m^(3).The NGH in the Qinghai-Tibet Plateau have complex gas components and are dominated by deep thermogenic gas.They occur in the Permian-Jurassic strata and are subject to thin permafrost and sensitive to environment.Furthermore,they are distinctly different from the NGH in the high-latitude permafrost in the arctic regions and are more different from marine NGH.The formation of the NGH in the Plateau obviously couples with the uplift and permafrost evolution of the Plateau in spatial-temporal terms.The permafrost and NGH in the Qilian Mountains and the main body of the Qinghai-Tibet Plateau possibly formed during 2.0–1.28 Ma BP and about 0.8 Ma BP,respectively.Under the context of global warming,the permafrost in the Qinghai-Tibet Plateau is continually degrading,which will lead to the changes in the stability of NGH.Therefore,The NGH of the Qinghai-Tibet Plateau can not be ignored in the study of the global climate change and ecological environment.

Spatial Interaction Network Analysis of Crude Oil Trade Relations between Countries along the Belt and Road

Based on the theories and methods of complex network,crude oil trade flows between countries along the Belt and Road(B&R,hereafter)are inserted into the Geo-space of B&R and form a spatial interaction network which takes the countries as nodes and takes the trade relations as edges.The networked mining and evolution analysis can provide important references for the research on trade relations among the B&R countries and the formulation of trade policy.This paper researches and discusses the construction,statistical analysis,top networks and stability of the crude oil trade network between the B&R countries from 2001 to 2020 from the perspectives of Geo-Computation for Social Sciences(GCSS)and spatial interaction.Firstly,evolutions of out-degree,in-degree,out-strength and in-strength of the top 10 countries in the crude oil trade network are computed and analyzed.Secondly,the top network method is used to explore the evolution characteristics of hierarchical structures.And finally,the sequential evolution characteristics of the crude oil trade network stability are analyzed utilizing the network stability measure method based on the trade relationship autocorrelation function.The analysis results show that Russia has the largest out-degree and out-strength,and China has the largest in-degree and in-strength.The crude oil trade volume of the top 10 import and export networks between 2001—2020 accounts for over 90%of the total trade volume of the crude oil trade network,and the proportion remains relatively stable.However,the stability of the network showed strong fluctuations in 2009,2012 and 2014,which may be closely related to major international events in these years,which could furtherly be used to build a correlation model between network volatility and major events.This paper explores how to construct and analyze the spatial interaction network of crude oil trade and can provide references for trade relations research and trade policy formulation of B&R countries.