Direct-Seeded Rice: Genetic Improvement of Game-Changing Traits for Better Adaption

The sustainability of rice production continues to be a subject of uncertainty and inquiry attributed to shifts in climatic conditions. In light of the impending climate change crisis and the high labor and water costs accompanying it, direct-seeded rice(DSR) is unquestionably one of the most practical solutions. Despite its resource and climate-friendly advantages, early maturing rice faces weed competitiveness and seedling establishment challenges. Resolving these issues is crucial for promoting its wider adoption among farmers, presenting it as a more effective sustainable rice cultivation method globally. Diverse traditional and contemporary breeding methods are employed to mitigate the limitations of the DSR approach, leveraging advanced techniques such as speed breeding and genome editing. Focusing on key traits like mesocotyl length elongation, early seedling vigor, root system architecture, and weed competitiveness holds promise for transformative improvements in DSR adaptation at a broader scale within farming communities. This review aims to summarize how these features contribute to increased crop production in DSR conditions and explore the research efforts focusing on enhancing DSR adaptation through these traits. Emphasizing the pivotal role of these game-changing traits in DSR adaptation, our analysis sheds light on their potential transformative impact and offers valuable insights for advancing DSR practices.

China and the Changing Global Economic Order

A better understanding of China’s modernization presents an insight into a changing world.AS China has developed,so too has the global economy.For the past 200 years or so,the structure of the global economy was dominated first by the British empire,and more recently by the U.S.as the global economic hegemon.This system of center-and-peripheries is now decentering,with a diversification of networks and connections creating a multinodal system of value growth and circulation.

Changing Characteristics of Comfort Index of Human Body in Bengbu City in the Past 40 Years under the Background of Climate Change

Based on the daily meteorological data of Bengbu City during 1981-2020,the changing characteristics of three elements needed for the calculation of the comfort index of human body(CIHB)were discussed,and daily CIHB was classified and discussed.The results show that from 1981 to 2020,annual average temperature tended to increase significantly.Annual average wind speed and relative humidity showed a decreasing trend before 2011 but an increasing trend after 2011.The duration of the four seasons in Bengbu City mainly rose in spring,reduced in winter,declined first and then increased in summer,and rose first and then decreased in autumn.As CIHB was at grades 1 and 9(the most uncomfortable),the three factors had different effects on them.For cold weather,the influence of relative humidity and wind speed on CIHB can not be ignored besides temperature.In hot weather,the influence of temperature was dominant,and the change of annual average temperature could well correspond to the change in the number of very hot days.In the context of climate warming,the number of cold days tended to decline generally,but it was larger in the years with fewer very cold days.Under the background of climate warming,there was no obvious change in the number of days of the overall comfort of human body.The number of hot days was closely related to the duration of summer,and the number of days of grade 8 rose significantly in the years with an increase in the duration of summer.

Existence of Monotone Positive Solution for a Fourth-Order Three-Point BVP with Sign-Changing Green’s Function

This paper is concerned with the following fourth-order three-point boundary value problem , where , we discuss the existence of positive solutions to the above problem by applying to the fixed point theory in cones and iterative technique.

How Himalayan communities are changing cultivation practices in the context of climate change

Climate change can have significant impacts on crop yields and food security.This study assessed the linkages between climate change and crop yields to obtain a better understanding on the drivers of food security.The study was conducted in Pasagaun village of Lamjung District in Nepal,where household surveys and focus group discussions(FGDs)were used to collect data including crop cultivation,irrigation facilities,and adaptation strategies.Moreover,climate data(temperature and precipitation)from 1992 to 2020 were collected from the Khudi Bazar meteorological station and crop yield data were obtained from the Agri-Business Promotion and Statistics Division.Trend analysis of temperature and precipitation was conducted using MannKendall trend test and Sen’s slope method,and the results showed an increase in the average temperature of approximately 0.02℃/a and a decrease in the annual precipitation of 9.84 mm/a.The cultivation of traditional varieties of rice and foxtail millet(Kaguno)has vanished.Although,there was no significant impact of the maximum temperature on the yield of rice and maize,the regression analysis revealed that there are negative relationships between rice yield and annual minimum temperature(r=-0.44),between millet yield and annual precipitation(r=-0.30),and between maize yield and annual minimum temperature(r=-0.31),as well as positive relationship between rice yield and annual precipitation(r=0.16).Moreover,average rice yield and millet yield have decreased by 27.0% and 57.0% in 2000-2020,respectively.Despite other reasons for the decrease in crop yield such as the lack of irrigation facilities,out-migration of farmer,and increased pest infestation,respondents have adopted adaptation strategies(for example,shifts in cultivation time and changes in crop types)to minimize the impacts of climate change.More investigation and community-based farming education are needed to understand and alleviate the harmful impacts of climate change on crop yield,as effective adaptation coping strategies are still insufficient.This study provides insights into the adaptation strategies that are necessary to keep food security in the face of climate change.

Characteristics and utility of combined duplex color-coded ultrasonography in the cervical rotational position with head MRI and MRA in the differential diagnosis of apogeotropic direction-changing positional nystagmus

Objective:To determine whether cervical ultrasonography,magnetic resonance imaging(MRI),and magnetic resonance angiography(MRA)are useful in the differential diagnosis of etiology and understanding the pathophysiology in cases of apogeotropic direction-changing positional nystagmus(DCPN).Methods:Thirty patients with apogeotropic DCPN were classified into 11 cases of central disease,seven cases of mixed central and peripheral disease,and 12 cases of peripheral disease by differential diagnosis based on various balance function,neuro-otological,and imaging tests.Cervical ultrasonography using the cervical rotation method and MRI and MRA of the head and neck were performed in most patients with apogeotropic DCPN.We reviewed the presence of abnormal imaging findings according to the disease etiology.Results:Of the 30 patients with apogeotropic DCPN,23 showed vascular abnormalities or central lesions on imaging.Vascular lesions were found in six of the 12 patients with peripheral disease.Cervical ultrasonography with cervical rotation detected blood flow disturbance in the vertebral artery in eight patients in whom the disturbance could not be detected by MRI or MRA of the head and neck.Discussion:We hypothesize that the causative disease of apogeotropic DCPN may be strongly associated with circulatory insufficiency of the vertebrobasilar and carotid arteries,and that impaired blood flow in these vessels may affect peripheral vestibular and central function.In patients with apogeotropic DCPN,examinations of vestibular function,central nervous system symptoms,and brain hemodynamics are valuable for differential diagnosis.

The Risk of Flooding to Architecture and Infrastructure amidst a Changing Climate in Lake Baringo, Kenya

Climate change has grown more apparent in recent years with people becoming more aware of its potentially disastrous consequences. Flooding is one of the many consequences of a changing climate in Kenya known to cause immense devastation resulting in the loss of lives and property. This paper discusses the risk of flooding in Kenya as one of the many outcomes of climate change in the face of urgency to adapt Kenya’s built environment to flooding which is likely to continue to prevail in the decades as a result of the looming climate change. It also sought to evaluate the physical, traumatic, and psychological effects on communities affected by flood events. This cross-sectional survey, both qualitative and quantitative in nature, executed between 13th January 2021 and 14th July 2021 with 132 respondents along the western shoreline of Lake Baringo, near Marigat Town focused on the flood levels, structures, their materials, and quantities. Results show that the area covered by Lake Baringo increased by 18% from 236 km2 to 278 km2. The depth of floods ranged from 0.3 m to 1.2 m and exceeded 1.6 m during heavy rainfall up to 3.2 m with homes completely submerged by the lake. Flooding was experienced more by residents living in low areas nearer to the shoreline of the lake as compared to those living on higher grounds. 100% of the structures didn’t have the architectural technology to withstand the impacts of flooding with 59% of housing made of corrugated iron sheets both on wall and roofing, 22% of mud houses roofed with either corrugated iron sheets, 10% being timber with thatch and only 8% stoned walled houses. This predisposed all the residents to the harmful impacts of flooding. Piled sandbags by locals as a mitigating measure proved inadequate to withstand the forces of the rising waters. Flood walls were built around local lodges near the lake but the rising water level quickly breached these defences. The study recommends that county and national governing authorities develop flood adaptation strategies for resilience. These include long-term land-use planning, the establishment of early warning systems, evacuation plans, identification of vulnerable or high-risk populations, measures to ensure water quality, sanitation, and hygiene. Flood-resilient architecture including stilt and floating houses that mechanically rise and fall with respect to the highest water mark are recommended during flood events. Bridges on swollen rivers and resilient construction materials like reinforced concrete are to be used for sustainable development for flood risk adaptation.

Nitrogen Dioxide, Carbon Monoxide, Natural and Anthropomorphic Effects, and Earth’s Changing Climate

This study will both compare and contrast the characteristics and roles of two pollutants: nitrogen dioxide and carbon monoxide. It will begin by tracing each gas’ negative contributions to the Earth’s spheres, as well as relate any negative links that each plays concerning human activity, health, and interaction with the environment. It will include an in-depth analysis of what the proliferation of such toxic gases indicates about human production and causality, plus reflect on any current attempts being made to improve the effects of these pollutants on the environment. This examination will also inspect three NASA missions, i.e., MOPITT/Terra, AIRS/Aqua, and OMI/Aura, the aim of which, among many other tasks, is to detect pollutants within the Earth’s various spheres, as well as analyze weather anomalies, improve prediction methodology, and chronicle meteorological patterns for future study. It will also cover some of the goals, engineering breakthroughs, and in one case, the limitations, of these three satellite missions. Finally, it should be noted that in all stages of this discussion, the author’s main aim will be to focus on the positives that need to be implemented in order to improve the current situations that both anthropogenic and natural disasters have created for the planet.

Assessment of first-order-moment-based sample reconstruction method for design flood estimation in changing environment

Estimating the design flood under nonstationary conditions is challenging. In this study, a sample reconstruction approach was developed to transform a nonstationary series into a stationary one in a future time window (FTW). In this approach, the first-order moment (EFTW) of an extreme flood series in the FTW was used, and two possible methods of estimating EFTW values in terms of point values and confidence intervals were developed. Three schemes were proposed to analyze the uncertainty of design flood estimation in terms of sample representativeness, uncertainty from EFTW estimation, and both factors, respectively. To investigate the performance of the sample reconstruction approach, synthesis experiments were designed based on the annual peak series of the Little Sugar Creek in the United States. The results showed that the sample reconstruction approach performed well when the high-order moment of the series did not change significantly in the specified FTW. Otherwise, its performance deteriorated. In addition, the uncertainty of design flood estimation caused by sample representativeness was greater than that caused by EFTW estimation.

Changing Lives

Implementation of the BRI projects has heralded positive changes in the lives of Tanzanian people Tanzania is an important Belt and Road Initiative(BRI)hub in Africa.It signed a BRI cooperation memorandum with China in 2018.Bilateral exchanges have been on the rise since then.On the occasion of the 10th anniversary of the launch of the initiative,ChinAfrica sat down with Mbelwa Kairuki,Tanzanian ambassador to China,to hear his insights on the BRI,especially the changes brought by the BRI to the local people’s lives.

近62 a三峡地区区域性暴雨过程气候特征及长期变化规律

【目的】充分认识三峡地区区域暴雨过程的气候特征及长期变化规律对于科学防汛以及合理利用水资源具有重要意义。【方法】基于三峡地区33个国家级气象观测站1961—2022年逐日降水量资料和目前重庆市气候中心业务采用的区域性暴雨过程监测指标,对三峡地区区域性暴雨过程进行客观识别,并利用多种数理统计方法分析区域性暴雨过程的气候特征和长期变化规律。【结果】结果表明:(1)三峡地区近三分之二的暴雨以区域性过程形式出现,平均每年区域性暴雨过程有8.4次,主要出现在5—9月,尤以6—7月为集中发生时段。区域性暴雨过程首次开始日期多年平均为5月8日,末次结束日期为9月17日。平均每次过程的暴雨覆盖范围为8.6站,持续时间1.3 d,平均暴雨强度为74.7 mm/d。(2)三峡地区区域性暴雨过程年频次存在2~3 a和8 a左右的变化周期,年平均区域性暴雨过程覆盖范围存在4~6 a和8~11 a周期变化。(3)近62 a三峡地区区域性暴雨过程的首次开始日期显著提前,末次结束日期无明显变化,发生期显著变长;发生频次没有明显变化趋势、平均持续时间、平均覆盖范围、平均综合强度也均没有明显变化趋势,但平均暴雨强度呈增强趋势。(4)近62 a,三峡地区区域性暴雨过程的各项指标均未发生突变现象。【结论】研究成果为三峡地区防汛减灾、水资源管理以及回应三峡工程对局地气候影响的社会关切等提供科学支撑。

基于驾驶场景与决策规则的智能汽车换道决策

复杂交通环境中,换道决策直接影响智能汽车自主换道效果,然而在换道决策过程中依旧存在着预测正确率低以及决策安全的问题。因此,针对这一问题,提出了基于驾驶场景和决策规则的换道决策模型。考虑换道后的交通行驶状况对换道决策的影响,引入换道后的期望速度和换道前后与前车的距离作为新的特征变量,基于特征变量与换道决策的相关性建立了换道决策规则。建立了模拟真实驾驶环境的换道场景数据集,扩充了NGSIM换道场景数据集,并对其进行了有效性验证。针对换道决策的多参数和非线性问题,提出了基于贝叶斯优化核函数的支持向量机模型,在换道场景数据集上进行测试验证。结果表明:新引入的决策特征变量对换道行为有积极作用,换道场景数据集能够模拟真实的换道场景,可进一步应用到换道决策和轨迹规划的研究中,支持向量机模型对换道行为的预测正确率达95.40%,高于其他机器学习分类器,提高了换道行为的安全性。

社会变迁中心理与行为的稳定性: 以谦虚效应为例

面对百年未有之大变局及生活质量生活方式的剧烈变迁,人们的心理行为乃至文化会如何变异?作者假设尽管社会变迁会影响和改变人类的某些心理和行为,但有些心理行为,因其受深层文化影响,会十分稳定,不受社会变迁的影响。近30年的有关谦虚效应的跨文化研究为这一假设提供了佐证。谦虚是中国传统文化深层结构中的集体主义的产物,这种跨文化差异本质上来源于东西方文化中个人主义与集体主义的差异。总结谦虚效应的30年系列研究结果表明尽管中国的经济社会发生了前所未有的发展,这个跨文化效应基本不变,说明源于深层文化的心理和行为存在高度的稳定性。

跨学科主题学习:价值、困境与实施路径--以地理学科为例

跨学科主题学习具有打破学科界限、解决单一学科无法解决的复杂问题的特点。然而,我国对从传统的分科课程教学向跨学科课程教学转变的路径研究处于起步阶段,尤其是基于学科教师需求而建立的跨学科课程的研究尚且不足。研究认为,跨学科主题学习对学生素质培养、教师专业发展和学校改革创新有独特的价值表现;依据跨学科主题学习现状与需求的调研分析,课程设计、实施与评价难度大是大部分教师所面临的现实困境;选择学习主题、确立学习目标、设置核心任务、设置驱动问题、安排学习活动、开展评价与反思是满足一线教师教学需求的跨学科主题学习课程实践路径。

考虑激励幅值慢变的卷绕头转子系统动力学建模

卷绕头转子系统结构之间的耦合振动和时频变激励使振动问题十分复杂,为了更准确地研究其动力学特性,根据转子动力学理论,使用有限元方法建立了考虑多盘质量慢变的卷绕头非线性转子系统整机动力学模型,运用Newmark-β数值积分方法对其动力学特性求解,得到仅存在初始不平衡量以及卷装不良带来的激励频率、幅值慢变下的非线性动力学行为。通过分析轴心轨迹、时域波形和幅频特性曲线等结果,发现卷绕头转子系统对因卷装不良引起的激励幅值慢变较为敏感,出现新的频率成分。进一步对比分析了不同节点处的振动频谱,其结果可为卷绕头转子系统动力学设计和故障识别提供一定理论支持。

太阳能利用工程对生态系统、生物多样性及环境的影响与应对

太阳能利用工程是减缓气候变化、实现“双碳”目标的重要措施,全面认识这些工程对生态环境的影响,对科学规划和实施工程有重要的理论和现实意义.该文总结分析了太阳能利用工程对生态系统、生物多样性与环境的影响及应对方面的研究,对存在的问题进行了讨论,并对未来的研究方向提出了展望.结果表明:①在一些太阳能利用工程区,土壤有机质和养分含量及植被盖度增加,而一些工程区却降低;工程建设对植被和土壤的干扰导致水土流失;工程占用土地和耗水及影响微气候条件等对生态系统碳排放和能量平衡造成影响;区域性布局这些工程对植被功能也将产生一定的影响,包括工程设备遮荫造成一些作物产量下降或增加.②工程设施引起的水分改变和遮荫使一些植物的丰富度增加,使一些植物种子在土壤种子库中的存活率提高,但光伏板对鸟类和昆虫等动物将会造成碰撞以及不适宜的产卵而将可能带来死亡风险;施工过程导致的植被清除和景观破碎化等对生物多样性也将造成不利影响;施工过程造成的水网损失、破碎化以及洗涤沙尘而耗水对水生生物多样性也将造成不同程度的影响;光伏板对草地土壤微生物多样性也造成一定影响.③施工期和运营期间将带来扬尘、噪声、废弃物等污染;不合理生产、利用光伏材料对生态环境也将造成负面影响.有效应对这些不利影响的措施包括:①科学规划选址,加强生物多样性保护措施的规划设计,循环利用光伏材料和加强科学管理等;②加强环境影响评价,实施生态恢复方案,加强生态系统及生物多样性保护和水土流失治理等;③发展屋顶和浮动式太阳能装置及光伏农业技术;合理选择和利用光伏材料,加强固体废弃物治理和风险管理,有效落实环境影响评价措施等.目前研究太阳能利用工程对生态系统、生物多样性与环境影响及应对方面尚不充分,随着太阳能利用工程规模的扩大,需要加强这些工程对生态系统、生物多样性及环境方面的不同影响与应对方面的研究.

气候变化和人类活动对中国生态敏感性的影响分析与改善路径——基于响应曲面法

生态敏感性是指生态系统对外界干扰的反应程度。随着气候变化和人类活动日益加剧,二者分别以单独和交互作用的方式影响生态敏感性,进而暴露出整体或区域性的人口、资源与环境问题。因此,厘清气候变化和人类活动对生态敏感性的影响程度,并分级进行改善,有利于提升地区生态环境的韧性和可持续发展水平。该研究以中国31个省份为研究对象,基于2001—2020年的气象、遥感和统计数据,构建气候变化、人类活动和生态敏感性指标体系,运用主成分分析提取气候变化和人类活动的影响因子,利用响应曲面法(response surface methodology,RSM)分析各地区气候变化和人类活动单因子及交互作用对生态敏感性的影响,并以包含生态和气候敏感性的复合敏感值为依据,划分优化区、管控区和治理区,探究了敏感值较高的治理区的改善路径。结果表明:(1)中国生态敏感值在时间上呈波动下降态势,2001—2020年总体下降了2.2%;空间上呈现出“西高东低、北高南低”的空间布局,与2001年相比,2020年重度敏感及以上的省份数量减少了7.1%。(2)经济发展、气候变化、人口规模对不同省份生态敏感性的影响存在差异,受单因子影响的省份占比分别为77.4%、67.7%和54.8%;因子交互作用中,负交互效应占比为69.6%,说明大部分因子对另一因子影响生态敏感性的效应产生反向作用。(3)为减少气候变化对生态敏感性的负面影响,针对治理区内自然条件和发展速度不同的区域,需要有针对性地协调经济发展或人口增长,以确保在生态承载范围内推动经济社会可持续发展。

动态风向变化下风力机叶片和塔架应力及功率特性分析

风向变化显著影响风力机气动载荷分布,从而影响风力机稳定高效的运行,而气动载荷是风力机结构应力和功率变化主要影响因素之一。该文以S翼型三叶片水平轴风力机为研究对象,在旋转平台上进行风洞实验,对不同风向变化速度(0.5°、1°、1.5°、2°/s)下风力机叶片和塔架的应力以及风力机功率特性进行分析。结果表明:风向变化速度为0.5°/s时,在风向由0°变化到30°时,叶片弦向和展向应力值和风力机功率下降幅度最大;在风向由0°变化到20°时,叶片应力值和功率下降较为缓慢,风向变化结束后,风力机应力与功率会进一步减小;风向变化角度在0°~20°范围内,受叶片转速和气动载荷下降速度与风向变化耦合作用的影响,塔架应力值出现较大波动,并随风向变化速度的增加,波动出现的区间从15°~20°提前到0°~5°;风向变化结束后,叶片转速持续下降,造成塔架应力仍有不同程度的波动。结果可为考虑风向变化下运行的风力机结构设计提供一定理论依据。

过去20年城乡高中生的教育效用与教育志向:基于三个出生队列的历史比较研究

本研究采用时间滞后设计,考察过去20年我国高中生教育效用和教育志向水平的年代和城乡差异,以及二者与个体学业成绩、父母学历之间关系的年代和城乡差异。分别在1999年、2010年、2018年对来自相同的三个地区(包括城市和农村)、相同学校的高中生进行问卷调查,使用协方差分析和回归分析进行数据分析。结果发现:(1)自1999年至2018年,城乡高中生的教育效用都遵循先下降、后回升的变化趋势;在教育志向上,城市高中生无明显变化,而农村高中生教育志向上升并超越城市高中生;(2)高中生教育效用、教育志向受父母学历和学业成绩等微观因素影响,且受年代和城乡宏观社会历史因素调节。相比于其他年份,2010年时成绩较差学生的教育效用更低、2018年时成绩较差学生的教育志向更高;自1999年至2018年,低父母学历对农村高中生教育志向的影响方式由“枷锁效应”转变为“鞭策效应”。我国过去20年的社会变迁使城乡高中生对教育的价值认同发生系统性变化,且宏观社会历史因素的演变改变了教育的价值认同形成的微观机制。

橘汁发酵过程中柑橘香气及其贡献化合物的分析

柑橘香气是柑橘果酒重要香气属性之一。为研究柑橘果酒加工过程中柑橘香气形成及影响机制,采用固相萃取法和正向硅胶色谱法结合气相色谱嗅闻仪、气相色谱质谱仪和感官评价对柑橘香气及其贡献化合物和异味物质在橘汁发酵中的变化趋势进行分析。结果表明,从橘汁中共鉴定出29种关键香气物质,主要为果香气、柑橘香气、花香气、清香气和乳脂香气化合物,其中月桂烯、庚醛、柠檬烯、γ-松油烯、癸醇、辛醛、辛醇、香茅醇和橙花醇被鉴定为柑橘香气重要贡献化合物。在橘汁发酵前4 d,柑橘香气强度呈显著增加的趋势,随后显著减弱。Pearson相关性分析显示,柑橘香气强度的变化与柠檬烯、γ-松油烯、辛醇和橙花醇含量增减密切相关(P<0.05)。伴随着柑橘香气化合物含量降低,异丁酸、丁酸、2-甲基丁酸、戊酸、己酸、庚酸和辛酸等酸败刺激性气味物质含量显著增加,这些异味物质对柑橘香气的形成具有显著的遮盖作用。研究结果可为今后柑橘果酒工艺改进及香气品质提升提供一定的理论依据。