Dynamical Predictability of Leading Interannual Variability Modes of the Asian-Australian Monsoon in Climate Models

The dynamical prediction of the Asian-Australian monsoon(AAM)has been an important and long-standing issue in climate science.In this study,the predictability of the first two leading modes of the AAM is studied using retrospective prediction datasets from the seasonal forecasting models in four operational centers worldwide.Results show that the model predictability of the leading AAM modes is sensitive to how they are defined in different seasonal sequences,especially for the second mode.The first AAM mode,from various seasonal sequences,coincides with the El Niño phase transition in the eastern-central Pacific.The second mode,initialized from boreal summer and autumn,leads El Niño by about one year but can exist during the decay phase of El Niño when initialized from boreal winter and spring.Our findings hint that ENSO,as an early signal,is conducive to better performance of model predictions in capturing the spatiotemporal variations of the leading AAM modes.Still,the persistence barrier of ENSO in spring leads to poor forecasting skills of spatial features.The multimodel ensemble(MME)mean shows some advantage in capturing the spatiotemporal variations of the AAM modes but does not provide a significant improvement in predicting its temporal features compared to the best individual models in predicting its temporal features.The BCC_CSM1.1M shows promising skill in predicting the two AAM indices associated with two leading AAM modes.The predictability demonstrated in this study is potentially useful for AAM prediction in operational and climate services.

Transition from the Southern Mode of the Mei-yu Front Cloud System to Other Leading Modes

Based on normalized six-hourly black body temperature （TBB） data of three geostationary meteorological satellites,the leading modes of the mei-yu cloud system between 1998 and 2008 were extracted by the Empirical Orthogonal Function （EOF） method,and the transition processes from the first typical leading mode to other leading modes were discussed and compared.The analysis shows that,when the southern mode （EOF1） transforms to the northeastern mode （EOF3）,in the mid-troposphere,a low trough develops and moves southeastward over central and eastern China.The circulation pattern is characterized by two highs and one low in the lower troposphere.A belt of low pressure is sandwiched between the weak high over central and western China and the strong western North Pacific subtropical high （WNPSH）.Cold air moves southward along the northerly flow behind the low,and meets the warm and moist air between the WNPSH and the forepart of the low trough,which leads to continuous convection.At the same time,the central extent of the WNPSH increases while its ridge extends westward.In addition,transitions from the southern mode to the dual centers mode and the tropical-low-influenced mode were found to be atypical,and so no common points could be concluded.Furthermore,the choice of threshold value can affect the number of samples discussed.

The Second Decadal Leading Mode of East Asian Summer Monsoon Rainfall

The first decadal leading mode of East Asian summer rainfall(EASR) is characterized by rainfall anomalies along the East Asian subtropical rain belt. This study focuses on the second decadal leading mode(2DLM), accounting for 17.3% of rainfall decadal variance, as distinct from the other two neighboring modes of EAMR, based on the state-of-the-art in-situ rainfall data.This mode is characterized by a South-China-wet–HuaiheRiver-dry pattern, and is dominated by a quasi-30-yr period. Further analysis reveals the 2DLM corresponds to an enhanced lower-level monsoon jet, an eastward extension of the western North Pacific subtropical high, and a weakened East Asian upper-level westerly jet flow. The Tibetan Plateau surface temperature and Pacific Decadal Oscillation(PDO) are closely linked with the 2DLM. The regressed SST pattern indicates the PDO-like pattern of sea surface temperature anomalies may have a teleconnection relationship with the 2DLM of EASR.

Technology Innovation Mode of Agricultural Leading Enterprise——Based on the Virtual Organization Mode

Based on the definition of technology innovation of agricultural leading enterprises by domestic and foreign experts and scholars,technology innovation of agricultural enterprises is a process of new market increment,which uses new knowledge,technology,process and production mode,produces new products,offers new services and realizes commercialization. Characteristics of agricultural technology innovation are introduced,such as obvious regionality,relatively high risk,long-term periodicity and public attribute. Predicament for technology innovation of leading enterprises is analyzed,such as technical constraints,financial constraints and personnel constraints. Technological Innovation Mode can be classified into three modes of independent innovation,imitative innovation and cooperative innovation by the method of technology innovation. Among them,since there are some defects in the technology innovation process,independent innovation and imitative innovation are generally not used for the innovation of agricultural enterprises. Cooperative Innovation Mode can rely on foreign aid,can realize complementary advantages and achievement sharing,and can be widely applied in the agricultural innovation enterprise. Virtual organization in cooperation innovation mode is described,which makes up for technology,capital and human resources barriers in the process of agricultural enterprise innovation. Therefore,this mode is popular among the agricultural innovation enterprise.

The Dipole Mode of the Summer Rainfall over East China during 1958–2001

By examining the second leading mode （EOF2） of the summer rainfall in China during 1958 2001 and associated circulations, the authors found that this prominent mode was a dipole pattern with rainfall decreasing to the north of the Yangtze River and increasing to the south. This reverse relationship of the rainfalls to the north and to the south of the Yangtze River was related with the meridional circulations within East Asia and the neighboring region, excited by SST in the South China Sea-northwestern Pacific. When the SST was warmer, the geopotential heights at 500 hPa were positive in the low and high latitudes and negative in the middle latitudes. The anticyclone in the low latitudes favored the subtropical high over the northwestern Pacific （SHNP） shifting southwestward, leading to additional moisture transport over southern China. The anomalous atmospheric circulations along the East Asian coast tends to enhance upward movement over the region. Subsequently, rainfall in southern China is enhanced.

Dominant Modes of Interannual Variability in Atmospheric Water Vapor Content over East Asia during Winter and Their Associated Mechanisms

Atmospheric water vapor content(WVC)is a critical factor for East Asian winter precipitation.This study investigates the dominant modes of interannual variability in WVC over East Asia during winter and their underlying mechanisms.Based on the empirical orthogonal function(EOF)method,the leading mode(EOF1,R2=28.9%)of the interannual variability in the East Asian winter WVC exhibits a meridional dipole pattern characterized by opposite WVC anomalies over northeastern China and eastern China;the second mode(EOF2,R2=24.3%)of the interannual variability in the East Asian winter WVC exhibits a monopole pattern characterized by consistent WVC anomalies over eastern China.EOF1 is mainly modulated by two anomalous zonal water vapor transport(WVT)branches over northeastern China and eastern China,which are associated with an anomalous atmospheric wave train over Eurasia affected by sea ice cover in the Kara Sea-Barents Sea(SIC-KSBS)area in the preceding October-November(ON).EOF2 is mainly modulated by an anomalous westerly WVT branch over eastern China,which is associated with a circumglobal atmospheric zonal wave train in the Northern Hemisphere.This circumglobal zonal wave train is modulated by concurrent central and eastern tropical Pacific sea surface temperature anomalies.The SIC-KSBS anomalies in ON and the concurrent SST anomalies over tropical Pacific may partially account for the interannual variability of EOF1 and EOF2 winter WVC,and thus may provide a theoretical basis for improving the prediction of winter climate over East Asia.

以学生为中心的物理化学课程教学模式的改革与实践

针对物理化学课程,提出了“四元三导一对分”线上线下混合式教学模式。教学效果表明,卷面成绩不及格率从传统讲授法的50%~70%区间逐渐降低至“四元三导一对分”教学法的15%~21%区间,平均分也由55分提升到70分,学生满意度较高,教学效果显著。

地球物理学专业“师带徒”教育模式的探索

地球物理学作为关乎国家自然资源调控和民生发展的学科,对于第一产业和第二产业发展至关重要。长久以来,地球物理学高等教育的侧重点集中在学生科学素质的培养,而忽视了学生动手实践、管理、宣传等其他能力。步入新时代,社会对于有较强动手实践能力的专业青年人才需求激增,学术教育转向实践和应用型教育的改革势在必行。正确运用“师带徒”制度,预计能有效提高学生的职业素养,培育多类型地球物理专业人才,在未来激烈的竞争中占据领先优势。

Evaluating CMIP6 models in simulating the North Pacific decadal variability in sea surface salinity

The North Pacific sea surface salinity(SSS)decadal variability(NPSDV)and its potential forcing were evaluated from 25 coupled models of the Coupled Model Intercomparison Project phase 6(CMIP6)considering the prospects for decadal climate predictions.The results indicated that the CMIP6 models generally reproduced the spatial patterns of NPSDV.The large standard deviation of the SSS anomaly over the strong current regions,such as the Kuroshio-Oyashio Extension(KOE),North Pacific Current(NPC),California Current System(CCS),and Alaskan Coastal Current(ACC),is reflected in the two leading modes of NPSDV:a dipole with out-of-phase loadings in the KOE-NPC versus CCS-ACC and a monopole with positive loading over the KOE-NPC.The order of modes is sensitive to individual models that exhibit discrepancies,especially in temporal phases and power spectra.An autoregressive model of order-1 was used to reconstruct the NPSDV with several forcing terms.The generally weaker influence of forcings in an autoregressive model of order-1 is partly related to the overestimated response time of NPSDV relative to forcings.Most NPSDV variances originate from the persistence of SSS anomalies,but the dominant forcing factors are diverse among models.The model diversity for the NPSDV simulation mainly arises from the influence of the tropical El Ni?o-Southern Oscillation through teleconnection on the North Pacific Oscillation or Aleutian Low with timescale dependence.Conversely,models that can reproduce the NPSDV well are not dependent on those with larger impacts from the North Pacific oceanic processes.

基于全部参数自适应Smith预估补偿的永磁同步电机滑模前馈控制及扰动抑制

在永磁同步电机控制系统中,逆变器的延迟效应会降低系统的跟踪性能和稳定裕度。引入Smith预估补偿器可以补偿延迟环节对系统性能的影响,但Smith预估补偿器要求延迟时间和被控对象模型参数已知,这不符合实际情况。为此提出时变模型自适应预估方法,分别对延迟时间和被控对象模型参数进行自适应估计,实现Smith预估补偿器的全参数自适应。设计基于位置输出超前值预测和扰动抑制的滑模前馈控制器,与全参数自适应Smith预估补偿控制相结合,确保控制系统的全局稳定,降低系统对参数不确定的敏感性,并提高系统的抗扰性。仿真结果表明,与传统及多种改进的Smith预估补偿方法相比,该方法有着更高的跟踪精度,即使在非理想条件下,对参数不确定依然具有较强的鲁棒性,对随机扰动依然具有较强的干扰抑制能力。

倾斜薄状铅锌矿体开采方法研究

对倾斜薄状矿体进行开采时,常常会面临采矿方法选择难的问题。某矿区内的铅锌矿体主要赋存于断裂带中,矿区内待开采的矿体属于倾斜薄状矿体。为了开采矿区内的铅锌矿资源,采用平硐+盲斜井的开拓方式,并根据矿区内矿体特征和开采技术条件,确定采用留矿全面采矿法对该铅锌矿进行开采。对留矿全面采矿法的采场矿块结构、采准、切割工程、回采落矿工艺进行了设计。结合相关经济指标,认为该采矿方法能够满足矿山实际生产需求,采用的留矿全面采矿法适合开采矿岩较稳固的倾斜薄状矿体,可为相关铅锌矿体的开采提供参考。

基于硫化铅量子点可饱和吸收体的锁模光纤激光器

通过优化后的热注入法制备得到硫化铅胶体量子点,再利用匀胶机两步旋涂的方法使材料平铺在小块羧甲基纤维素薄膜上,并将其作为可饱和吸收体应用于光纤激光器中,实现稳定的锁模。制备的硫化铅量子点可饱和吸收薄膜的调制深度和饱和强度分别约为26.46%和6.75 MW/cm^(2),非饱和损耗为6.42%。测试结果表明该薄膜具有更小的非饱和损耗以及更好的重复性和一致性。采用该薄膜作为可饱和吸收体的光纤激光器能在47 mW的泵浦功率处开始实现自启动锁模,且能够实现长时间稳定的锁模激光输出。研究结果为硫化铅量子点可饱和吸收体在光纤激光器中的后续应用奠定了基础。

弹性工作制联合带组护士管理模式在眼科日间手术中的应用效果

目的探讨弹性工作制联合带组护士管理模式在眼科日间手术中的应用效果。方法于2022年9月-2023年3月在某三甲医院眼科日间手术室实施弹性工作制联合带组护士管理模式,比较模式实施前后患者出院指导质量、手术取消率、不良事件发生率及护士职业认同感。结果实施弹性工作制联合带组护士管理模式后,患者出院指导质量总分和护士职业认同感总分均较实施前提升(P<0.05),患者手术取消率和不良事件发生率均较实施前有所下降(P<0.05)。结论弹性工作制联合带组护士管理模式能够提升患者出院指导质量,助力日间手术管理,提升护士职业认同感。

“红墙先锋、红色温度”城市街道社区党建工作的思考与实践——深圳市横岗模式调研与借鉴

“红色管家联盟”是深圳市横岗街道在党建引领社会建设、社会基层治理中一次有意义的探索与实践。实践的目标在于建立、建设共建、共治、共享的社区,在现代城市发展和治理过程中积极探索,让改革开放成果更好地惠及百姓。北京市百万庄东社区党建引领社会基层治理模式创新,社区治理、服务的实践总结为:“红墙先锋红色温度”,即一个核心、两项工程、三条主线、四个抓手。党建引领共治,强化基层党组织的引领作用,注重基层组织的建设,积极探索多元治理机制,构建共建共治共享的基层治理新格局。

水电站蓄电池组多模块协同阻断技术研究

蓄电池作为水电站中常用的储能设备,能够为电力系统提供稳定的备用电源,并满足水电站在电网停电或负荷波动时的供电需求。铅酸蓄电池以其容量大、寿命长、成本相对较低、充放电效率高和维护成本低等优点而在水电站得到广泛应用。然而,由于频繁的充放电,铅酸蓄电池易发生老化,所以当蓄电池出现开路故障时,会对整个水电站的电源安全构成严重威胁。因此文章基于目前较成熟的开路续流装置设计了一种新型铅酸蓄电池组装置,用于解决水电站铅酸蓄电池组开路故障问题。

Interannual Variations in Synoptic-Scale Disturbances over the Western North Pacific

The present study investigates the interannual variation of June-November synoptic disturbance activity over the western North Pacific（WNP） and its relationship with large-scale circulation for the period 1958-2014. Two leading modes of eddy kinetic energy for the disturbance variability over the WNP are obtained by EOF analysis, characterized by anomalous eddy kinetic energy over the subtropical WNP and around the Philippines, respectively. These modes explain a large portion of the interannual variance of synoptic disturbance activity over the WNP. Both are associated with lower-level cyclonic anomalies, but with different locations： over the subtropical WNP for the first mode and over the South China Sea for the second mode. Considering the impact of ENSO on synoptic disturbance activity over the WNP, we repeat the analyses after removing the effect of ENSO, which is simply defined as the components linearly regressed onto the Ni o3.4 index, and find similar results, suggesting that the leading modes and their relationships with large-scale circulation exist without SST effects.Further analyses suggest that the meridional shear of zonal winds caused by cyclonic anomalies is crucial for maintaining the leading modes through barotropic conversion.

Distribution, modes of occurrence, and main factors influencing lead enrichment in Chinese coals

Lead is a potentially harmful element that has caused serious environmental pollution during its mining and use along with serious human health problems.This study assessed lead in Chinese coals based on published literature,with a particular focus on data reported since 2004.The analysis included 9447 individual samples from 103 coalfields or mines in 28 provinces in China.The arithmetic mean content of lead in the studied coals was 15.0μg/g.Considering the coal reserves,the weighted-average lead concentration in Chinese coals was calculated to be 19.6μg/g.Lead was significantly enriched in the coals from Henan Province and enriched in the coals from the Tibet Autonomous Region.The coals from Tibet–Western Yunnan and the southern areas of China had elevated lead concentrations.Sulfides are the primary hosts of lead in Chinese coals,although other hosts include silicates,organic matter,carbonates,and other minerals.Source rocks in the sediment-source region and marine environments may be the most significant factors contributing to lead enrichment in Chinese coals.Hydrothermal fluids and peat-forming plants also contribute to lead enrichment in some Chinese coals.

Overcoming the contradiction between promoting economic growth and transforming the economic growth pattern

Promoting economic growth has become the first and foremost objective of macro-control since China experienced a drastic economic downturn in the fourth quarter of 2008. Now China is at a special stage of transition characterized by the transformation of the economic growth mode. While promoting economic growth, the government must effectively coordinate the relationship between economic growth and the transformation of growth mode. This is not a task that can be done easily. To promote economic growth, the central government has selected a number of industries and formulated an industrial revitalization plan for each of these them. Revitalizing these industries helps promote economic growth at the present stage but propelling these industries alone still cannot fully meet the requirements for transforming the economic growth pattern. To coordinate the relationship between promoting economic growth and transforming the economic growth pattern, it is currently imperative to adjust China’s industrial upgrading strategy and to pay attention to intra-industrial upgrading, particularly process upgrading.

Rapid Synthesis and FT-Raman Spectroscopic Study of Lanthanum Modified Lead Titanate Nanocrystals

Pb_ 1-xLa_xTi_ 1-x/4O_3 nanocrystals with different amounts of lanthanum were prepared by modified sol-gel method and detected by FT-Raman spectra at 288 and 378 K, respectively. The improved synthetic technique used in this paper could obtain nanocrystals with apparently promoted synthetic speed from a few days to several hours (4 times faster of hydrolytic process than that of traditional sol-gel method and reduced preparation period of gel from 24 h to several hours) at relatively lower temperature by hydrolysis of sol to gel through adding methyl alcohol/water solution into sol under vigorous stirring and annealed the fresh gel directly. The effects of lanthanum′s amount, annealed temperature and nanocrystals′ grain size of Pb_ 0.9La_ 0.1Ti_ 0.975O_3 nanocrystals on frequency, shape and width of the phonon peak were also discussed in detail.

Failure Modes of Lead Free Solder Bumps Formed by Induction Spontaneous Heating Reflow

The shear failure modes and respective failure mechanism of Sn3.5Ag and Sn3.0Ag0.5Cu lead-free solder bumping on Au/Ni/Cu metallization formed by induction spontaneous heating reflow process have been investigated through the shear test after aging at 120℃ for 0, 1, 4, 9 and 16 d. Different typical shear failure behaviors have been found in the loading curves （shear force vs displacement）. From the results of interracial morphology analysis of the fracture surfaces and cross-sections, two main typical failure modes have been identified. The probabilities of the failure modes occurrence are inconsistent when the joints were aged for different times. The evolution of the brittle NiaSn4 and Cu-Ni-Au-Sn layers and the grains coarsening of the solder bulk are the basic reasons for the change of shear failure modes.