Region-time-length algorithm and its application to the study of intermediate-short term earthquake precursor in North China

The Region-Time-Length Algorithm (RTL algorithm) is introduced and improved in the paper. Compared with the original definition, the influence of rupture length on RTL function is emphasized and the weights of epicentral distance function, time function, and rupture length function are ensured to be equal. The retrospective examinations of RTL algorithm in North China have indicated that the anomalies obtained by the improved RTL algorithm show the short or intermediate-short term precursory features in most cases. There are two types of RTL anomalous patterns before the main shock. For the I-type, the variation pattern of the VRTL, numerical values of the VRTL(x, y, z, t) function, is complete and most of them have shown the changing pattern of rising from 0 turning dropping or dropping from 0 turning rising. For the II-type, the variation pattern of VRTL is not complete, which increases or decreases quickly from 0 and there is no evident turning, the main shock generally occurs in the short period around the peak VRTL. The rising of VRTL indicates an increase of seismic activity relative to the background level, which means the enhancement of seismic activity, while the dropping of VRTL indicates the decrease of seismic activity relative to the background level, which represents the seismic quiescence to a certain extent. According to statistical examination results of RTL algorithm in North China, the methods to distinguish the intermediate and short-term anomalies and to estimate the occurrence time of the coming main shock are given in the paper. For both I and II-type RTL anomalies, the R-value, i.e., the forecasting score, is about 0.6 and 0.3 for the 3 months forecasting period and about 0.7 and 0.4 for the 6 months forecasting period. The preliminary discussion is also made for the influences of characteristic time-span t0, characteristic distance r0, and threshold magnitude M0 on computation of VRTL, as well as some other significant problems in application.

Application of the predictable model ofregional time-magnitude to North and Southwest China region

In this paper, the method which can combine different seismic data with the different precision and completeness, even the palaeo-earthquake data, has been applied to estimate the yearly seismic moment rate in the seismic region. Based on this, the predictable model of regional time-magnitude has been used in North China and Southwest China. The normal correlation between the time interval of the events and the magnitude of the last strong earthquake shows that the model is suitable. The value of the parameter c is less than the average value of 0.33 that is obtained from the events occurred in the plate boundary in the world. It is explained that the correlativity between the recurrence interval of the earthquake and the magnitude of the last strong event is not obvious. It is shown that the continental earthquakes in China are different from that occurred in the plate boundary and the recurrence model for the continental events are different from the one for the plate boundary events. Finally the seismic risk analysis based on this model for North China and Southwest China is given in this paper.

Analysis of Heavy Precipitation Process in North China from August 23 to 24, 2020

In order to better understand the formation mechanism of rainstorm in China and promote disaster prevention and reduction, based on the meteorological data of National Meteorological Information Center and Japan Meteorological Agency, this paper draws the isobaric surface map of 850 hPa and 500 hPa, relative humidity and precipitation distribution map. In this study, synoptic methods were used to analyze the heavy precipitation process in North China from August 23th to 24th, 2020. The results show that 1) The formation of short-term heavy precipitation requires sufficient water vapor and very strong upward movement;2) the heavy precipitation in August 23th to 24th 2020 in North China was influenced by the upper-level trough line, cold vortex and cold front, which made the warm and cold air strongly converge over North China, resulting in strong convective weather;3) the heavy rainfall over North China was also influenced by Typhoon Bawei, which caused maximum precipitation and air humidity.

Influences of the NAO on the North Atlantic CO2 Fluxes in Winter and Summer on the Interannual Scale

The differences in the influences of the North Atlantic Oscillation (NAO) on the air–sea CO2 fluxes (fCO2) in the North Atlantic (NA) between different seasons and between different regions are rarely fully investigated. We used observation-based data of fCO2, surface-ocean CO2 partial pressure (pCO2sea), wind speed and sea surface temperature (SST) to analyze the relationship between the NAO and fCO2 of the subtropical and subpolar NA in winter and summer on the interannual time scale. Based on power spectrum estimation, there are significant interannual signs with a 2–6 year cycle in the NAO indexes and area-averaged fCO2 anomalies in winter and summer from 1980 to 2015. Regression analysis with the 2–6 year filtered data shows that on the interannual scale the response of the fCO2 anomalies to the NAO has an obvious meridional wave-train-like pattern in winter, but a zonal distribution in summer. This seasonal difference is because in winter the fCO2 anomalies are mainly controlled by the NAO-driven wind speed anomalies, which have a meridional distribution pattern, while in summer they are dominated by the NAO-driven SST anomalies, which show distinct zonal difference in the subtropical NA. In addition, in the same season, there are different factors controlling the variation of pCO2sea in different regions. In summer, SST is important to the interannual variation of pCO2sea in the subtropical NA, while some biogeochemical variables probably control the pCO2sea variation in the subpolar NA.

Introducing driving-force information increases the predictability of the North Atlantic Oscillation

The North Atlantic Oscillation(NAO)is the most prominent mode of atmospheric variability in the Northern Hemisphere.Because of the close relationship between the NAO and regional climate in Eurasia,North Atlantic,and North America,improving the prediction skill for the NAO has attracted much attention.Previous studies that focused on the predictability of the NAO were often based upon simulations by climate models.In this study,the authors took advantage of Slow Feature Analysis to extract information on the driving forces from daily NAO index and introduced it into phase-space reconstruction.By computing the largest Lyapunov exponent,the authors found that the predictability of daily NAO index shows a significant increase when its driving force signal is considered.Furthermore,the authors conducted a short-term prediction for the NAO by using a global prediction model for chaotic time series that incorporated the driving-force information.Results showed that the prediction skill for the NAO can be largely increased.In addition,results from wavelet analysis suggested that the driving-force signal of the NAO is associated with three basic drivers:the annual cycle(1.02 yr),the quasi-biennial oscillation(QBO)(2.44 yr);and the solar cycle(11.6 yr),which indicates the critical roles of the QBO and solar activities in the predictability of the NAO.

Characteristics of satellite-gravity variations in the North-South Seismic Belt before the 2013 Lushan earthquake

To study the characteristics of gravity variations in and near the North-South Seismic Belt before the 2013 Lushan earthquake,we used the geopotential-field models based on monthly data of the RI.~5 GRACE satellite to calculate the gravity changes. Here we present the patterns of annually cumulative variation, differentiatial variation and secular trend, as well as the continuous time-series at 4 characteristic sites during 2004 -2012. The result shows that the anomalous positive-to-negative transition zone, in which the epicenter of the 2008 Wenchuan earthquake was located, did not show any new gravity change before the Lushan earthquake, though located in the same zone.

High-frequency and low-amplitude relative sea-level changes in the Turonian Ferron Notom Delta, Henry Mountains region Utah, USA: implications for sequence stratigraphy and hydrocarbon exploration

The Turonian Notom Delta is one of the Ferron fluvial-deltaic wedges deposited in the foreland basins of the Cretaceous Seaway of North America.The wedge is exposed three dimensionally in the Henry Mountains region Utah,USA.High-resolution sequence stratigraphic analysis along a 35 km dip-oriented outcrop belt shows that the wedge consists of six depositional sequences.Ammonite and Inoceramid biostratigraphy and 40Ar/39Ar age dating of various bentonites show that the wedge was deposited from 91.25 Ma to 90.63 Ma,an interval of merely 0.62 Ma.Assuming each sequence is formed over a similar time span,each sequence,thus,represents about 105 yr,suggesting high-frequency depositional sequences.Amplitude of relative sea-level changes,built on shoreline trajectory,is 2-61 m,with an average of only 20 m.Fluvial incision during high-frequency and low-amplitude relative sealevel fall is mainly around the highstand prism.Incision diminishes rapidly up dip and down dip,and the resultant incised valleys are narrow and shallow.Such sea-level fluctuations also result in small,stratigraphically complex shoreline sandstones that need special attention during hydrocarbon exploration.

Are diurnal time-budgets and activity patterns density-dependent in the Shelduck (Tadorna tadorna) wintering in Algeria? An analysis across multiple temporal scales

Background: The Shelduck (Tadorna tadorna) is a characteristic waterbird species of inland wetlands in northeastern Algeria. Its wintering behavior in relation to changes of local abundances and foraging group density is poorly known. Objectives: This study aims at monitoring patterns of diurnal activities and the variation of behavioral time-budgets in relation to numbers of wintering Shelducks. We investigate temporal variations of diurnal activities across multipletime scales and consider their interrelationships. Methods: Assessments of local population abundance were weekly surveyed during two wintering seasons (2010– 2012), whereas diurnal activities (feeding, sleeping, swimming, preening, loafing, flying, courtship, and antagonism) were studied three times a month during seven hours (08:00–16:00) using the Scan method. Time budget variations of each behavioral activity were tested using nested ANOVAs following multiple time scales. Generalized linear mixedeffects models (GLMM) tested whether variations in diurnal activities were density-dependent. Results: During the wintering season, Shelduck’s numbers followed a bell-shaped trend, which indicated that the species was typically a wintering migrant in Sabkha Djendli. The first individuals arrived onsite in October–November then numbers reached a peak in January (up to 2400 individuals in 2012) with steady density during December–February, afterward individuals left the site progressively until late April when the site is deserted. During both wintering seasons, diurnal activities were dominated by feeding (60%), followed by sleeping (12%) then swimming and preening with 9% and 8%, respectively. The rest of the activities (loafing, flying, courtship and antagonistic behaviors) had low proportions of time budget. ANOVAs showed that activity time budgets varied significantly following multiple time scales (year, season, month, day, semi-hour). Time budgets of diurnal activities during each wintering season were significantly interrelated. Correlations patterns between the two seasons were similar. GLMMs revealed that the variations of diurnal activities were not density-dependent, except for preening and swimming. Conclusion: During the wintering season, habitats of Sabkha Djendli are important for waterbirds, including the Shelduck that used the lake mainly for food-foraging and resting. The 2400 individuals censused in mid-winter are important locally and at the North African scale. This stresses the need to strengthen the protection status of this wetland and mitigate degradation sources that threaten wintering waterfowl.

Optimal Operation for Baoying Pumping Station in East Route Project of South-to-North Water Transfer

Baoying pumping station is a part of source pumping stations in East Route Project of South-to-North Water Transfer in China. Aiming at the characteristics of head varying, and making use of the function of pump adjustable blade, mathematical models of pumping station optimal operation are established and solved with genetic algorithm. For different total pumping discharge and total pumping volume of water per day, in order to minimize pumping station operation cost, the number and operation duties of running pump units are respectively determined at different periods of time in a day. The results indicate that the saving of electrical cost is significantly effected by the schemes of adjusting blade angles and time-varying electrical price when pumping certain water volume of water per day, and compared with conventional operation schemes （namely, the schemes of pumping station operation at design blade angles based on certain pumping discharge）, the electrical cost is saved by 4.73%-31.27%. Also, compared with the electrical cost of conventional operation schemes, the electrical cost is saved by 2.03%-5.79% by the schemes of adjusting blade angles when pumping certain discharge.

Study on the basement structure in the southeastern North China by blasting seismic

Since the Mesozoic, southeastern North China Craton has experienced intense crustal thinning and lithosphere destruction. Some of the responses of the deep activity in the upper crust crystalline basement have been retained in a series of tectonic evolution. The study of the upper crust velocity structure,especially the properties of the basement interface, is of great significance for studying the tectonic evolution and seismic hazard in the southeastern part of North China. In this study, we selected Pg waves of the blasting seismic data in the southeastern part of North China in recent years, which reflect the west Shandong uplift, offshore sedimentary basins and the Tanlu Fault zone and the Sulu orogenic transition zone, to study the structural and seismological characteristics of basement in North China Craton. The results of this study showed as follows: First, the obvious lag of Pg wave arrival time in Dongying depression and North Jiangsu basin reveals the thick sedimentary, low velocity and unstable basement structure. Second, the advance Pg wave arrival time with high apparent velocity, which reflects the basement structure of the west Shandong uplift, indicates the thin sediments and the shallow basement. Third, combined with many geophysical phenomena, such as electrical structure, density structure and terrestrial heat flow, we hold that the Tanlu tectonic belt and the Sulu orogenic belt have experienced great lithosphere destruction and there is shallow crust and the thinnest lithosphere in the vicinity of the Tanlu fault zone.

Classification of Vegetation in North Tibet Plateau Based on MODIS Time-Series Data

Based on the 16d-composite MODIS （moderate resolution imaging spectroradiometer）-NDVI（normalized difference vegetation index） time-series data in 2004, vegetation in North Tibet Plateau was classified and seasonal variations on the pixels selected from different vegetation type were analyzed. The Savitzky-Golay filtering algorithm was applied to perform a filtration processing for MODIS-NDVI time-series data. The processed time-series curves can reflect a real variation trend of vegetation growth. The NDVI time-series curves of coniferous forest, high-cold meadow, high-cold meadow steppe and high-cold steppe all appear a mono-peak model during vegetation growth with the maximum peak occurring in August. A decision-tree classification model was established according to either NDVI time-series data or land surface temperature data. And then, both classifying and processing for vegetations were carried out through the model based on NDVI time-series curves. An accuracy test illustrates that classification results are of high accuracy and credibility and the model is conducive for studying a climate variation and estimating a vegetation production at regional even global scale.

Time-to-go weighted optimal trajectory shaping guidance law

For maneuvering target, the optimal trajectory shaping guidance law which can simultaneously achieve the designed specifications on miss distance and final impact angle was deduced using optimal control theory based on the time-to-go weighted function. Based on the same cost function, the closed-form solutions of the guidance law were derived when the initial displacement of missile, final impact angle, heading error and target maneuver was introduced into the lag-free guidance system. To validate the closed-form solutions, the simulation of the lag-free system was done and the simulation results exactly matched the closed-form solutions and only when the exponent is greater than zero, the final acceleration approaches to zero.

Uppermost mantle structure of the North China Craton: Constraints from interstation Pn travel time difference tomography

The uppermost mantle is the key area for exchange of heat flux and material convection between the crust and lithospheric mantle. Spatial variations of lithospheric thinning and dynamic processes in the North China Craton could inevitably induce the velocity heterogeneity in the uppermost mantle.In this study,we used Pn arrivals from permanent seismic stations in North China and surrounding regions to construct a tomographic image of the North China Craton.The tomographic method with Pn travel time difference data were used to study the velocity variations in the uppermost mantle.Pn velocities in the uppermost mantle varied significantly in the Eastern,Central and Western blocks of the North China Craton.This suggests that the lithosphere beneath different blocks of the North China Craton have experienced distinct tectonic evolutions and dynamic processes since the Paleo- zoic.The current uppermost mantle has been imprinted by these tectonic and dynamic processes.Fast Pn velocities are prominent beneath the Bohai Bay Basin in the Eastern Block of the North China Craton,suggesting residuals of the Archean lithospheric mantle.Beneath the Tanlu Fault Zone and Bohai Sea,slow Pn velocities are present in the uppermost mantle,which can be attributed to significant lithospheric thinning and asthenospheric upwelling.The newly formed lithospheric mantle beneath Yanshan Mountain may be the dominant reason for the existence of slow Pn velocities in this region.Conversely,the ancient lower crust and lithospheric mantle already have been delaminated.In the Central Block,significant slow Pn velocities are present in Taihangshan Mountain,which also extends northward to the Yinchuan-Hetao Rift on the northern margin of the Ordos Block and Yinshan Orogen.This characteristic probably is a result of hot asthenospheric upwelling along the active tectonic boundary on the margin of the Western Block.The protracted thermal erosion and underplating of hot asthenospheric upwelling may induce lithospheric thinning and significant slow velocities in the uppermost mantle.Fast velocities beneath the Western Block suggest that the thick,cold and refractory Archean lithospheric keel of craton still is retained without apparent destruction.

Sedimentary and tectonic evolution of the Banquan pull-apart basin and implications for late Cenozoic dextral strike-slip movement of the Tanlu Fault Zone

The Banquan Basin is a pull-apart basin with the largest scale and the most prominent structure due to dextral slip of the Tanlu Fault Zone(TLFZ) in late Cenozoic. The depositional history of the basin records the start time and evolution of the right-lateral strike-slip movement of the TLFZ. This paper studies the sedimentary and tectonic evolution of the Banquan Basin by seismic reflection exploration, borehole detection and cosmogenic nuclide chronology. We analyze the coupling relationship between the pull-apart basin and the strike-slip fault and discuss the start time and tectonic significance of the right-lateral strikeslip of the TLFZ. Our study indicates that the Banquan Basin has undergone three evolutionary stages: weak rifting during the pre-pull-apart period, strong extension during the syn-pull-apart period and subsidence during the post-pull-apart period. This implies that the TLFZ, which controls the evolution of the basin, experienced an evolutionary process of weak activity,intensified activity and migration of activity toward the central basin. The sedimentary filling of the basin has strong response to the episodic pull-apart and extension of the basin. Lying upon the basement of the basin, a thin layer of Miocene mudstone slowly accumulated due to local rifting before the strong pull-apart event. Along with the dextral slipping and pull-apart process, the basin was filled with alluvial fan facies, fluvial facies and floodplain facies strata from bottom to top. The latest tectonic movement of the TLFZ in the North China Block in late Cenozoic was dominated by episodic dextral strike-slip motion, and this deformation pattern started at 4.01±1.27 Ma. The latest tectonic deformation in North China since late Cenozoic was governed by eastward extrusion and tectonic orogenesis of the eastern margin of the Qinghai-Xizang Plateau since late Miocene. The eastward thrusting of the Liupanshan fault zone and sinistral shearing of the Qinling fault zone led to the anticlockwise rotation and pushing of secondary blocks in North China, resulting in a planar bookshelf faulting and rotation pattern. This unique deformation pattern transferred eastwards to the North China Plain at ~4.01 Ma and the process continues to the present time.This planar bookshelf rotation, accompanied with regional sinistral strike-slip movement of the ~EW-trending boundary fault zones to the north and south of the North China Block and dextral strike-slip motion of the NNE-trending boundary faults between secondary blocks, is likely to be the long-range effect of the strong extrusion of the eastern margin of the QinghaiXizang Plateau.

Timing,scale and mechanism of the destruction of the North China Craton

The North China Craton (NCC) is a classical example of ancient destroyed cratons.Since the initiation of the North China Craton Destruction Project by the National Natural Science Foundation of China,numerous studies have been conducted on the timing,scale,and mechanism of this destruction through combined interdisciplinary research.Available data suggest that the destruction occurred mainly in the eastern NCC,whereas the western NCC was only locally modified.The sedimentation,magmatic activities and structural deformation after cratonization at ～1.8 Ga indicate that the NCC destruction took place in the Mesozoic with a peak age of ca 125 Ma.A global comparison suggests that most cratons on Earth are not destroyed,although they have commonly experienced lithospheric thinning;destruction is likely to occur only when the craton has been disturbed by oceanic subduction.The destruction of the NCC was coincident with globally active plate tectonics and high mantle temperatures during the Cretaceous.The subducted Pacific slab destabilized mantle convection beneath the eastern NCC,which resulted in cratonic destruction in the eastern NCC.Delamination and/or thermal-mechanical-chemical erosion resulted from the destabilization of mantle convection.

太行山复杂地形下华北暖季极端降水的时空分布特征

基于2012—2021年5—9月华北五省的逐日降水资料和台站地形高度数据,统计分析了华北全区及各子区域极端降水事件的降水量及其强度和频次的时空分布特征;并运用地理加权回归(GWR)模型分析得到极端降水事件的降水量、强度及频次与海拔高度之间的关系。结果表明:1)华北区域极端降水量的时间变化均呈多波动特征且区域差异性显著,太行山以西高原和以东平原降水频次多、波动明显且强度较弱,太行山南段以南平原降水频次少、变化平缓而强度明显偏强。2)极端降水量的空间分布呈现南北少、中间多的型态分布,降水量大值区分别位于燕山东南侧和太行山南段晋冀豫三省交界处;极端降水高频站点主要聚集在晋东南地区;日最大降水量超过300 mm的站点主要集中在太行山脉和燕山山脉与华北平原的过渡地带。3)华北区域38°N以北,极端降水量、降水频次、强度和日最大降水量均随海拔高度的升高而减小;38°N以南,山西南部临运地区降水量随海拔高度的升高而显著增加。由于降水频次和强度与地形均存在正相关而导致,太行山附近降水量随海拔高度的升高而减小的贡献主要在于降水强度而非降水频次。

计时起立-行走测试对老年2型糖尿病周围神经病变病人跌倒预测与风险评估价值研究

目的:分析计时起立-行走测试(TUGT)对老年2型糖尿病周围神经病变病人跌倒风险的评估价值。方法:回顾性分析2020年1月—2022年12月在我院内分泌科纳入治疗的2型糖尿病周围神经病变病人120例为研究对象,收集病人一般资料、TUGT测试结果,采用SPSS 22.0、R Studio 1.4.1103进行联合数据分析,研究相关性和预测价值。结果:本研究纳入的120例病人均顺利完成TUGT测试,完成率为100%,数据收集率为100%。所有病人TUGT时间为(16.03±3.29)s。Spearman相关性分析结果显示,TUGT时间与跌倒史、性别之间呈正相关(P<0.05);TUGT时间与2型糖尿病病程、合并周围神经病变病程、年龄之间无明显相关关系。TUGT时间用于预测老年2型糖尿病周围神经病变病人跌倒风险的最佳临界值为14.19 s,受试者工作特征曲线(ROC)曲线下面积(AUC)值为0.773,敏感度为86.29%,特异度为67.16%。结论:跌倒史、性别是影响老年2型糖尿病周围神经病变病人TUGT时间的危险因素,同时,TUGT时间对老年2型糖尿病周围神经病变病人跌倒具有良好的预测价值。

《莫失莫忘》的成长叙事与伦理反思

石黑一雄在《莫失莫忘》中抛弃了常规的线性时间序列,转而采用现在与过去交替并行的波形叙事时间结构,使人物在回忆与现实中来回穿梭,在情感的跌宕起伏中推动情节的展开。克隆人生活在“惩戒规训”和“调节控制”泛滥的社会,虽然有从自我意识到思想启蒙的成长,但逃避不了从空间隔绝到暴力政治带来的生命权利的反成长。小说中的时间结构与成长叙事融为一体,把过去与现在连接起来,将梦想与现实交错呈现,实现了人与物从“现实”之此岸到“过去”之彼岸与从“过去”之彼岸到“现实”之此岸的跨越。波形时间建构的非线性叙事彰显了善意与恶意、希望与绝望、成长与反成长的对抗,引起读者对后现代社会中人的存在与意义的反思。

On the timing and duration of the destruction of the North China Craton

The timing and duration of the destruction of the North China Craton, which is pivotal to understanding the destruction mechanism and its geodynamic controlling factors, still remain controversial. On the basis of the principles of magma genesis and evolution, first we outline magmatic expressions that can be related to cratonic destruction, then use magmatic and basin evolution trends to constrain the timescale of the lithospheric thinning in North China. The main conclusions include: (1) the thinning of the lithosphere beneath the North China Craton might have started, at least locally, since late Carboniferous-late Triassic, attained its climax during the late Jurassic-early Cretaceous, and continued till the end of late Cretaceous-early Cenozoic. The destruction of the North China Craton was a relatively slow, rather than a dramatic process. (2) The weakened lithospheric zones along the margins and interiors of the craton played an important role in cratonic destruction, partly accounting for the heterogeneous pattern of cratonic destruction. (3) The tectonic factors that controlled the destruction of the North China Craton may be multiple. The late Carboniferous southward subduction of the Paleo-Asian plate and the late Triassic collision between North China and South China may have re-activated the craton by influencing the thermal and integral structure of the craton. The Pacific subduction underneath the eastern Asian continent played a determinant role in the cratonic destruction, governing the distribution patterns of post-Mesozoic basins and major tectonic configuration, temporal change of magmatism and formation of the North-South gravity lineament.

PNF训练对膝骨关节炎老年患者的康复效果研究

目的:探索6周神经肌肉本体感觉促进技术(PNF)训练对膝骨关节炎(KOA)老年患者关节疼痛、身体稳定性和楼梯步态的影响。方法:将36名老年志愿者随机分入PNF组和对照组,分别进行每周3次、每次1h、持续6周的PNF训练及健康宣教。干预前、后分别评估其疼痛、身体稳定性、主动关节活动度(ROM)、关节角度和力矩等,并应用双因素重复性方差分析评估干预效果。结果:相比干预前,干预后PNF组疼痛分数降低,伯格平衡分数提高,起立行走测试时间缩短,下肢主动ROM增加,下楼梯时髋内收峰值力矩增加,上楼梯时膝内收峰值力矩减小。结论:PNF训练干预能有效缓解KOA老年患者的关节疼痛,提高其身体稳定性和改善楼梯行走功能,可推广应用于KOA的临床治疗。