Resistance index and browning mechanism of apple peel under high temperature stress

Apples are one of the most important economic crops worldwide.Because of global warming and an aggravation of environmental,abnormally high temperatures occur frequently in fruit-growing season and seriously affect normal fruit growth and reduce fruit quality and yield.We took five-year-old Ruixue’(Qinfu 1×Pink Lady;CNA20151469.1) fruits as test materials,and the ambient temperature during fruit development was monitored.The results showed that during the fruit-growing season,especially during the rapid growth stage (July to August),the maximum daily temperature exceeded 30℃ and lasted for more than 40 days.To determine the effects of high temperature stress on the apple fruit resistance,we treated expanding,veraison,and maturity-period fruits at different temperatures.It was found that the fruits of the expanding period showed strong resistance to high temperature stress,whereas during veraison and maturity,fruit resistance to high temperature stress decreased,and the fruit peel browning phenotype appeared.Meanwhile,the content of malonaldehyde (MDA),hydrogen peroxide (H_(2)O_(2)),and superoxide anion (O._(2)^(-)) in the peel gradually increased with increasing temperature.The content of total phenols,flavanol,and flavonoids in the peel decreased substantially at 45℃.Moreover,it was found that polyphenol oxidase gene (MdPPO1) was most sensitive to high temperature stress in apple.Furthermore,transient and stable MdPPO1 overexpression significantly promoted peel browning.The transgenic materials were more sensitive to high temperatures,and browning was more severe compared to non-genetically modified organism (WT).Stable MdPPO1 knockout calli obtained via clustered regularly interspersed short palindromic repeats (CRISPR/Cas9) gene knockout technology reduced the browning phenotype,and the resultant fruits were not sensitive to the effects of high temperature stress.Thus,MdPPO1 expression may be a key factor of high temperature-related changes observed in the browning phenotype that provides a scientific theoretical basis for the selection of high temperature-resistant varieties and apple cultivation and management in the future.

Characteristics and dynamic analysis of the February 2021 long-runout disaster chain triggered by massive rock and ice avalanche at Chamoli, Indian Himalaya

A massive rock and ice avalanche occurred on the western slope of the Ronti Gad valley in the northern part of Chamoli,Indian Himalaya,on 7 February 7,2021.The avalanche on the high mountain slope at an elevation of 5600 m above sea level triggered a long runout disaster chain,including rock mass avalanche,debris avalanche,and flood.The disaster chain had a horizontal travel distance of larger than 17,600 m and an elevation difference of 4300 m.In this study,the disaster characteristics and dynamic process were analyzed by multitemporal satellite imagery.The results show that the massive rock and ice avalanche was caused by four large expanding discontinuity planes.The disaster chain was divided into five zones by satellite images and field observation,including source zone,transition zone,dynamic entrainment zone,flow deposition zone,and flood zone.The entrainment effect and melting water were recognized as the main causes of the long-runout distance.Based on the seismic wave records and field videos,the time progress of the disaster was analyzed and the velocity of frontal debris at different stages was calculated.The total analyzed disaster duration was 1247 s,and the frontal debris velocity colliding with the second hydropower station was approximately 23 m/s.This study also carried out the numerical simulation of the disaster by rapid mass movement simulation(RAMMS).The numerical results reproduced the dynamic process of the debris avalanche,and the mechanism of long-runout avalanche was further verified by parametric study.Furthermore,this study discussed the potential causes of disaster and flood and the roles of satellite images and seismic networks in the monitoring and early-warning.

“预判”提升解题质量——以解析几何为例

学会分析问题是解决问题的关键,本文主要研究预判在分析问题过程中的积极作用.利用解析几何的相关案例从三方面:明确目标,预判“方向”;巧设变量,预判“运算”;利用特殊情况(位置),预判“结论”来详细阐述观点.

Puerarin partly counteracts the inflammatory response after cerebral ischemia/reperfusion via activating the cholinergic anti-inflammatory pathway

Puerarin, a major isoflavonoid derived from the Chinese medical herb radix puerariae （Gegen）, has been reported to inhibit neuronal apoptosis and play an anti-inflammatory role in focal cerebral ischemia model rats. Recent findings regarding stroke pathophysiology have recognized that anti-inflammation is an important target for the treatment of ischemic stroke. The cholinergic anti-inflammatory pathway is a highly robust neural-immune mechanism for inflammation control. This study was to investigate whether activating the cholinergic anti-inflammatory pathway can be involved in the mechanism of inhibiting the inflammatory response during puerarin-induced cerebral ischemia/reperfusion in rats. Results showed that puerarin pretreatment （intravenous injection） re- duced the ischemic infarct volume, improved neurological deficit after cerebral ischemia/reperfusion and decreased the levels of interleukin-1β, interleukin-6 and tumor necrosis factor-a in brain tissue. Pretreatment with puerarin （intravenous injection） attenuated the inflammatory response in rats, which was accompanied by janus-activated kinase 2 （JAK2） and signal transducers and activators of transcription 3 （STAT3） activation and nuclear factor kappa B （NF-KB） inhibition. These observa- tions were inhibited by the alpha7 nicotinic acetylcholine receptor （a7nAchR） antagonist a-bungarotoxin （a-BGT）. In addition, puerarin pretreatment increased the expression of a7nAchR mRNA in ischemic cerebral tissue. These data demonstrate that puerarin pretreatment strongly protects the brain against cerebral ischemia/reperfusion injury and inhibits the inflammatory re- sponse. Our results also indicated that the anti-inflammatory effect of puerarin may partly be medi- ated through the activation of the cholinergic anti-inflammatory pathway.

Nutrient Composition of Different Foxtail Millet Seeds

Ten millet cultivars from China and abroad were analyzed for their crude fat, amylose and amylopectin, crude protein and amino acid content. A wide variation was observed in amylopectin contain, ranging from 54.47% to 69.26%, while amylose content ranged from 11.26% to 23.22%. The average crude fat in all cultivates was 3.46%, and most cultivates ranged from 3.1% to 3.7%. Protein contents ranged from 8.61% to 15.54% with a mean value of 11.94%. For amino acid composition, the ten cultivates were particularly rich in leucine, and the mean was 34.57 mg/g. The millet cultivars were also high in glycine, glutamic acid and cysteine. Millet was known to be limiting in the essential amino lysine, and the mean was 5.18 mg/g. Other amino acids, tyrosine, histidine and arginine were also very low in the ten cultivars. In general, significant nutrient composition differences were observed between the different millet cultivars, and A2 （a kind of mother line of the hybrid millet） and hybrid millet registered a higher level of protein and amino acid composition which would be useful in millet breeding.

Analysis and Prospects of Innovation and Extension Mode of Agricultural Research Institutes:Hybrid Foxtail Millet Entering Ethiopia

Based on the initiative background of the Belt and Road,in order to promote the sustainability of agricultural cooperation between China and Africa,using hybrid foxtail millet as a medium,the research institutes have carried out basic research on the breeding,cultivation,and demonstration of hybrid foxtail millet in Africa in the early stage,jointed enterprises to carry out the construction of the joint research center and the construction of the industrial chain,and innovated the " scientific research units promoting agricultural " going out". The successful innovation of this mode has effectively exerted the public welfare of scientific research units and the marketability of enterprises. The organic combination of the two makes agricultural projects more healthy,sustainable and stable in African countries.

The Development Status and Countermeasures of Foxtail Millet Industry in Zhangjiakou City Under the Background of the Constructing Two Districts of the Capital

Foxtail millet is drought-resistant and water-saving.It is a typical environmentally friendly crop with high economic and social benefits.In the context of constructing"Two districts of the capital",it is imperative to develop the foxtail millet industry in view of the ecological conditions of Zhangjiakou City.Based on the analysis of the development status of the foxtail millet industry in Zhangjiakou City,this study pointed out the current problems in the development of the foxtail millet industry in Zhangjiakou City,and put forward specific suggestions for the development of the foxtail millet industry in Zhangjiakou City in the future.

Investigation on Agronomic Characters of Dwarf Mutant 778 in Broomcorn Millet(Panicum miliaceum L.)and Analysis of Its Sensitivity to GA

In order to investigate the differences between agronomic traits of dwarf mutant and original material 260 and whether the cause of dwarf is related to GA synthesis or signaling pathway,this experiment used dwarf mutant 778 and its original material 260 as experimental materials.Morphological observation and determination were performed for agronomic traits on plant height,ear length,internode length,internode number,seed length,seed width and number of seeds in different growth periods and different concentrations.The plants were treated by GA spraying,and the changes of plant height,root length,stem width,leaf length and leaf width were measured.The results are as follows:①The plant height of the dwarf mutant material was significantly different from that of the original high material,which was mainly caused by the difference between above-ground basal part and the length of the first and second elongation joints.②Comparing and analyzing the differences of traits between dwarf mutant material 778 and original high material 260,it was found that the plant height,ear length,internode number,grain number per ear and internode length of dwarf mutant 778 were significantly lower than that of high stalk 260(P<0.01),and the seed length of dwarf mutant 778 was significantly higher than that of high stalk 260(P<0.05).③Different concentrations of gibberellin(0,50,100,200 mg/L)had no significant effect on plant height and root length of dwarf mutant 778(P>0.05).Different concentrations of gibberellin had significant effects on plant height,root length and sensitivity coefficient of high stalk 260(P<0.05).And compared with the control group,all high materials 260 treated with different concentrations of gibberellin performed differently in plant morphology and growth potential.④Under the conditions of 100 and 200 mg/L GA,the difference of plant height between the dwarf mutant and the high stalk control decreased with time,and there was no difference at the end.There were no differences in sensitivity coefficient GRI between different concentrations of gibberellin treatment groups,indicating that the external gibberellin could restore the scorpion dwarf mutant to the original high stalk,and the gene that causes the mutation might be related with the gibberellin synthesis pathway.

Preliminary Study on Hybrid Foxtail Millet Entering Burkina Faso

Burkina Faso is one of the least developed countries in the world,and is located on the edge of the desert.Drought and water shortage,backward agricultural infrastructure,lacking of water conservancy and irrigation facilities have caused a great threat to the country’s food security.Promoting the cultivation of hybrid foxtail millet in Burkina Faso can well achieve the"going out"of Chinese agriculture and assist in the completion of agricultural assistance to Burkina Faso after the resumption of diplomatic relations with Burkina Faso.In 2019,Zhangjiakou City Academy of Agricultural Sciences cooperated with CGCOC Agriculture Co.,Ltd.to plant hybrid foxtail millet in Burkina Faso,selected three pearl millet varieties that are better promoted locally as control varieties,and found that planting Zhangzagu No.8,No.16 and No.18 with a density of 667000 plant/hm^2(plant spacing 0.12 m×0.25 m,2 plants per hole)and a fertilization amount of 0.3 t/hm2 and sowing in late July are suitable for production management technical regulations of hybrid foxtail millet in Burkina Faso.Because hybrid foxtail millet is superior to local pearl millet in terms of yield,resistance to powdery mildew,and its lodging resistance,it has good prospects for promotion in Burkina Faso.

基于后燃烧技术的CFB锅炉低氮燃烧数值模拟

为促进循环流化床(Circulating Fluidized Bed,CFB)锅炉氮氧化物(NO_(x))深度抑制,采用计算颗粒流体动力学(Computational Particle Fluid Dynamics,CPFD)方法建立了CFB锅炉全回路流动及燃烧数值模型,通过与锅炉运行数据的对比验证了模型的可靠性。耦合后燃烧技术后,分别研究循环流化床中过量空气比、一次风率和上下二次风比对炉膛燃烧和NO_(x)排放的影响。结果表明,贫氧燃烧造成的高CO摩尔分数区有利于NO_(x)还原。使用后燃烧技术后,炉膛还原氛围增强,NO_(x)排放由174.6 mg/m^(3)降至114.2 mg/m^(3)。结合空气分级,优化一次风率及上下二次风比例后,CO排放由基础工况的3.4×10^(-5)增至7.1×10^(-5),燃烧效率略微降低,NO_(x)排放进一步减少。较优工况下,NO_(x)排放由174.6 mg/m^(3)降至76.3 mg/m^(3),NO_(x)排放减少了56.3%,炉膛温度分布均匀。研究结果可为后燃烧技术应用于CFB锅炉提供理论支持。

Engineering S-scheme W_(18)O_(49)/ZnIn_(2)S_(4)heterojunction by Co_(x)P nanoclusters for enhanced charge transfer capability and solar hydrogen evolution

Enhancement of the light-absorption response and utilization of the photogenerated carriers represent a robust strategy for the design of high-performance photocatalyst.In this work,grafting Co_(x)P nanoclusters onto S-scheme heterojunction of W18O49/ZnIn2S4(WO/ZIS-CoxP)with strong response to the ultraviolet-visible-near infrared ray(UV-vis-NIR)region has been achieved,which possesses efficient electron-transfer-channel,and boosts charge-separation and transport kinetics.The as-prepared WO/ZIS-Co_(x)P yields an impressive solar-driven hydrogen production rate of 45 mmol·g^(-1)·h^(-1).The increased photocatalytic performance is attributed to the synergistic effect of the composite catalyst:(1)The local surface plasmon resonance-induced“hot electron”injection of W_(18)O_(49)significantly increases the electron density;(2)the engineered S-scheme directional electron transfer promotes charge separation and enhances the reducing capability of photoexcited electrons;and(3)Co_(x)P as electron-trap site for accelerating surface proton reduction reaction.This work provides a platform to impart nonprecious co-catalyst for engineering S-scheme heterojunction,serving a class of efficient solar-driven photocatalyst towards hydrogen production.

IQABC-Based Hybrid Deployment Algorithm for Mobile Robotic Agents Providing Network Coverage

Working as aerial base stations,mobile robotic agents can be formed as a wireless robotic network to provide network services for on-ground mobile devices in a target area.Herein,a challenging issue is how to deploy these mobile robotic agents to provide network services with good quality for more users,while considering the mobility of on-ground devices.In this paper,to solve this issue,we decouple the coverage problem into the vertical dimension and the horizontal dimension without any loss of optimization and introduce the network coverage model with maximum coverage range.Then,we propose a hybrid deployment algorithm based on the improved quick artificial bee colony.The algorithm is composed of a centralized deployment algorithm and a distributed one.The proposed deployment algorithm deploy a given number of mobile robotic agents to provide network services for the on-ground devices that are independent and identically distributed.Simulation results have demonstrated that the proposed algorithm deploys agents appropriately to cover more ground area and provide better coverage uniformity.

Esketamine use for anesthesia induction in an ectopic pregnancy patient with hemorrhagic shock:a case report

Background Anesthesia induction is challenging in patients with hemodynamic instability.Esketamine has hypnotic,analgesic,and sympathomimetic effects and is the only anesthetic that can increase sympathetic tension.Therefore,it may be more suitable for patients with hypovolemic shock.Case summary A 40-year-old female patient presented to the emergency department with new-onset abdominal pain and vaginal bleeding for 2 hours.Menstruation of the patient was regular,her self-reported urine pregnancy test was positive half a month earlier,and she had been diagnosed at another hospital 12 days earlier based on a positive blood human chorionic gonadotropin test.Gynecological ultrasonography demonstrated no pregnancy sac in utero,confirming ectopic pregnancy.Emergency laparoscopy for ectopic pregnancy should be performed immediately.We administered esketamine for induction.Conclusion Esketamine-based total intravenous anesthesia results in mild hypotension in ectopic pregnancies with hemorrhagic shock.

新时期我国国民营养与粮食安全

粮食安全是关乎国家长治久安和国计民生的重大战略性、科学性和综合性问题.随着我国经济社会和现代化建设进入新的历史时期,粮食安全在粮食生产、流通和消费等方面面临新的挑战与风险.如何消除这些挑战和风险,实现合理有序的粮食生产和消费,是当前及今后一定时期保障国民营养和粮食安全的关键.本文从粮食供需的各个方面出发,梳理当前国民营养和粮食需求与供给方面的主要变化,同时剖析农业资源环境压力与风险及其与粮食安全的关联,并提出综合性战略与政策建议.作者认为,在乡村振兴和我国实现社会主义现代化的大的时代背景下,我国农业发展正处于"提质增效"的新的历史时期,国民营养与粮食安全仍然是我国"三农问题"的重中之重.粮食生产有关政策需要同我国城市化进程、老龄化社会、农业现代化趋势相衔接,并与中国新时代国家战略相协调;认为有必要将我国粮食安全的体制机制和战略都统一到绿色、开放、共享、可持续的理念中去,更好发挥市场作用.与此同时,在"一带一路"的战略框架下,充分利用国内国外"两种资源,两个市场",实现农业转型、国家粮食安全和绿色发展.

How Does Focal Firms' Dual Embeddedness in Symbiotic Networks Influence Value Cocreation in Innovation Ecosystems?

Under the current complex and competitive economic environment,more and more firms are embedding themselves into symbiotic networks for value co-creation,since this has become a good strategy to obtain competitive advantages.Thus,it is important to examine the impacts of firms’embeddedness in symbiotic networks on value co-creation in innovation ecosystems.This study analyzes the mechanisms and contextual factors of firms’dual embeddedness(i.e.,relational and knowledge embeddedness)in symbiotic networks and how each influences value co-creation within innovation ecosystems.Using a sample of 1,972 observations,our findings show,firstly,that firms’dual embeddedness in symbiotic networks positively impacts on value co-creation in innovation ecosystems;secondly,that firms’dual embeddedness in symbiotic networks positively impacts on innovation ecosystem resilience;thirdly,that innovation ecosystem resilience mediates the relationships between firms’dual embeddedness in symbiotic networks and value co-creation in innovation ecosystems;and,fourthly,that innovative ecological environments positively moderate the relationship between firms’dual embeddedness and value co-creation in innovation ecosystems.These results not only enrich the theoretical framework concerning value co-creation within innovation ecosystems but also provide managerial suggestions for firms to efficiently enhance the degree of embeddedness in symbiotic networks and build highly resilient innovation ecosystems,thus promoting value co-creation among innovation ecosystem populations.

1980—2016年北京市食物消费的土地需求

社会经济发展和居民食物消费对土地需求之间的矛盾,已成为中国可持续发展亟待解决的关键问题,也是当今社会关注的热点问题之一。然而,目前对城市尺度食物消费的土地需求研究仍存在不足。本文利用CPI指数法,估算了北京市城乡居民1980—2016年的食物消费情况,揭示了居民食物消费结构改变对土地需求的演变特征,并探讨了未来不同消费模式下的土地需求情况,以期为实现居民的可持续消费提供参考,从而更好地解决社会经济发展和居民食物消费对土地需求之间的矛盾。结果表明:北京市食物消费结构已经由“粮食主导”的消费模式逐渐变为多元化的消费模式,且城乡之间存在明显差异;1980—2016年,北京市居民人均食物消费的土地需求量呈“U”型的变化特征,其中粮食消费的土地需求不断减少,而蔬果和动物性食物的土地需求不断增加;在2016年,北京市居民人均食物消费的土地需求量达到了1227.04 m^2/人,使得北京市居民消费的土地需求总量达到了266.62万hm^2,其中动物性食物消费占70.36%,城市居民食物消费占95%以上;在2016年,北京市居民食物消费的土地需求压力达到了14。健康合理的食物消费结构不仅有利于身体健康,也能够缓解食物消费对土地资源的压力;在健康饮食情景下,北京市每年居民食物消费最多可节约95.20~153.32万hm^2的土地面积,相当于北京市现有耕地和果园面积的5~8倍。因此,通过合理的饮食结构调整对解决社会经济发展和居民食物消费对土地需求之间的矛盾具有重要的意义。

Ultrathin MoS2 with expanded interlayers supported on hierarchical polypyrrole-derived amorphous N-doped carbon tubular structures for high-performance Li/Na-ion

Layered molybdenum disulfide （MoS2） has received much attention as one of the most promising energy-storage and conversion materials for Li/Na ion batteries. Here, a simple and effective approach is proposed for the rational design and preparation of hierarchical three-d imensional （3D） amorphous N-doped carbon nanotube@MoS2 nanosheets （3D-ANCNT@MoS2） via a simple hydrothermal method, followed by an annealing process. With such a unique nanoarchitecture, ultrathin MoS2 nanosheets grown on the external surfaces of polypyrrole-derived ANCNTs are assembled to form a hierarchical 3D nanoarchitecture, where the adopted ANCNTs serve not only as the template and continuous conductive matrix, but can also prevent MoS2 from aggregating and restacking, and help to buffer the volumetric expansion of MoS2 during cycling. More importantly, when evaluated as an anode material for lithium-ion batteries, the 3D-ANCNT@MoS2 composite exhibits excellent cycling stability, superior rate performance, and reversible specific capacity as high as 893.4 mAh·g^-1 at 0.2 A·g^-1 after 200 cycles in a half battery, and 669.4 mAh·g^-1 at 0.2 A·g^-1 after 100 cycles in the 3D-ANCNT@Mo2//LiCoO2 full battery. With respect to sodium-ion batteries, the outstanding reversible capacity, excellent rate behavior, and good cycling performance of 3D-ANCNT@MoS2 composites are also achieved.

Spin filtering in transition-metal phthalocyanine molecules from first principles

Using first-principles calculations based on density functional theory and the nonequilibrium Green＇s function formalism, we studied the spin transport through metal-phthalocyanine （MPc, M=Ni, Fe, Co, Mn, Cr） molecules connected to aurum nanowire electrodes. We found that the MnPc, FePc, and CrPc molecular devices exhibit a perfect spin filtering effect compared to CoPc and NiPc. Moreover, negative differential resistance appears in FePc molecular devices. The transmission coefficients at different bias voltages were further presented to understand this phenomenon. These results would be useful in designing devices for future nanotechnology.