A Precursory Signal of June-July Precipitation over the Yangtze River Basin: December-January Tropospheric Temperature over the Tibetan Plateau

The prediction of summer precipitation over the Yangtze River basin(YRB)has long been challenging,especially during June-July(JJ),when the mei-yu generally occurs.This study explores the potential signal for the YRB precipitation in JJ and reveals that the Tibetan Plateau tropospheric temperature(TPTT)in the middle and upper levels during the preceding December-January(DJ)is significantly correlated with JJ YRB precipitation.The close connection between the DJ TPTT anomaly with JJ YRB precipitation may be due to the joint modulation of the DJ ENSO and spring TP soil temperatures.The lagged response to an anomalously cold TPTT during the preceding DJ is a TPTT that is still anomalously cold during the following JJ.The lower TPTT can lead to an anomalous anticyclone to the east of Lake Baikal,an anomalous cyclone at the middle latitudes of East Asia,and an anomalous anticyclone over the western North Pacific.Meanwhile,the East Asian westerly jet shifts southward in response to the meridional thermal gradient caused by the colder troposphere extending from the TP to the east of Lake Baikal.The above-mentioned circulation anomalies constitute the positive anomaly of the East Asia-Pacific pattern,known to be conducive to more precipitation over the YRB.Since the DJ TPTT contains both the land(TP soil temperature)and ocean(ENSO)signals,it has a closer relationship with the JJ precipitation over the YRB than the DJ ENSO alone.Therefore,the preceding DJ TPTT can be considered an alternative predictor of the JJ YRB precipitation.

王安石对王弼易学的继承与发展

王安石是北宋义理派易学的杰出代表,其易学思想虽不能归于“老庄宗”的畛域之内,但却有许多承继并发展王弼易学的地方,这主要表现在取义不废象、推崇“时”义、看重字义训诂、融汇儒道等方面。重新审视王安石易学与王弼易学间的密切关系,既是对古代义理派易学发展史的深入探究,也体现了“宋学”对“魏晋玄学”的继承与突破。

不同水平呼气末正压对新生儿急性呼吸窘迫综合征的疗效及血流动力学的影响

目的探究不同水平呼气末正压(PEEP)治疗新生儿急性呼吸窘迫综合征(ARDS)的疗效及其血流动力学影响。方法选取2017年3月—2019年5月天津市中心妇产科医院收治的112例ARDS新生儿。根据通气的不同分为研究组和对照组,研究组58例患儿接受高水平PEEP(6~<9 cm H2O)治疗,对照组54例患儿接受低水平PEEP(3~<6 cm H2O)治疗。观察两组患者治疗前及治疗稳定后24 h的心率(HR)、平均肺动脉压(MPAP)、中心静脉压(CVP)、pH值、动脉血二氧化碳分压(PaCO2)、氧合指数(OI)水平、气道阻力(Raw)、呼吸系统顺应性(Crs)。观察两组患者的机械通气时间、住院时间、死亡例数。结果研究组HR、MPAP降低的差值,以及CVP升高的差值均高于对照组(P<0.05);研究组pH值、OI升高的差值,以及PaCO2降低的差值均高于对照组(P<0.05);研究组Raw降低的差值及Crs升高的差值均高于对照组(P<0.05)。研究组机械通气时间、住院时间均短于对照组(P<0.05);研究组死亡率低于对照组(P<0.05)。结论高水平PEEP对新生儿血流动力学指标的改善作用更明显,对气体交换和呼吸力学的影响更大,能有效减少机械通气时间及住院时间,降低病死率。

LncRNA HIF1A-AS1在增生性糖尿病视网膜病变中的表达及诊断价值

目的:探讨长链非编码RNA(LncRNA)缺氧诱导因子-1α-反义链1(HIF1A-AS1)在增生性糖尿病视网膜病变(PDR)患者血清中的表达情况及诊断价值。方法:选取2019-07/2021-07本院收治的糖尿病视网膜病变(DR)患者160例,根据病变程度分为PDR组(80例)和非增生性糖尿病视网膜病变(NPDR)组(80例),同时选取本院100例健康体检者为对照组。检测并比较所有研究对象血清中甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、空腹血糖(FBG)、糖化血红蛋白(HbA1c)水平;采用实时荧光定量PCR(qRT-PCR)法检测血清中LncRNA HIF1A-AS1表达水平;通过Logistic回归分析影响PDR发生的危险因素;利用受试者工作特征曲线(ROC)分析LncRNA HIF1A-AS1水平诊断PDR的临床价值。结果:PDR组患者血清中LncRNA HIF1A-AS1表达水平明显高于NPDR组和对照组,NPDR组高于对照组(P<0.05);PDR组、NPDR组患者糖尿病病程、HbA1c、TC、TG、LDL-C、FBG水平显著高于对照组,PDR组HDL-C水平显著低于对照组(P<0.05);LncRNA HIF1A-AS1水平与糖尿病病程、HbA1c、TC、TG、LDL-C、FBG呈正相关(P<0.05),与HDL-C呈负相关(P<0.05)。Logistic回归分析结果显示,LncRNA HIF1A-AS1、病程、FBG、HbA1c、TC、TG、LDL-C均是PDR发生的危险因素(P<0.05)。ROC结果显示,LncRNA HIF1A-AS1水平预测PDR发生的曲线下面积(AUC)为0.766(95%CI:0.692~0.829),对应的敏感度为66.25%,特异度为78.75%。结论:PDR患者血清中LncRNA HIF1A-AS1水平上调,是PDR发生的危险因素,且可作为预测PDR发生的潜在血清学指标。

基于微课模式的混合式教学在超声诊断学应用思考

超声诊断学是一门涉及解剖学、临床医学及物理学等多专业的交叉性学科。随着信息时代的发展,传统的超声教学已经不符合时代发展的要求。推行以学生为主体,教师为主导的多元化混合教学势在必行。混合式教学是一种结合网络教学和传统教学优势,建设良好的教学环境,实现目标最优化的教学的模式,本文就基于微课模式的混合式教学在超声诊断学应用进行探讨思考。

骨肉瘤相关的lncRNA研究进展

骨肉瘤是临床常见的原发性恶性骨肿瘤,由于恶性程度高,转移发生早,骨肉瘤的治疗效果至今仍不理想,研究骨肉瘤恶性生物学特征的分子机制并探索高效的治疗方式,已成为国内外对骨肉瘤研究的热点。lncRNA(long non-coding RNA)是一类长链非编码RNA,参与多种细胞功能的调控,对肿瘤的发生发展起重要作用。近年来,lncRNA在骨肉瘤中的研究报道越来越多,lncRNA通过与蛋白质、mRNA、miRNA等相互作用,影响骨肉瘤细胞的增殖、侵袭和迁移。本文结合近年报道,对lncRNA在骨肉瘤分子机制中的研究做一综述。

The effects of emotional labor and competency on job satisfaction in nurses of China: A nationwide cross-sectional survey

Objectives:This study aimed to explore the status of job satisfaction,emotional labour,core competencies and job stress and the associations of emotional labour and core competencies with the job satisfaction of nurses in China.Methods:Data were collected by using a self-designed general information questionnaire,a job satisfaction questionnaire(McCloskey/Mueller Satisfaction Scale),a nurse emotional labour questionnaire,the Competency Inventory for Registered Nurses questionnaire,and a nurse job stressor questionnaire.A total of 13,448 nurses from 92 hospitals across mainland of China were surveyed,and 11,337 respondents(84.3%response rate)completed the questionnaires.Results:The survey results indicated that Chinese nurses had average job satisfaction(24.77±5.23),moderate job stress(86.84±21.12),moderate to high emotional labour experiences(55.08±9.63)and high competency(195.77±37.61).Multiple linear regression indicated that surface acting was negatively correlated with job satisfaction(P<0.01),while deep acting(P<0.01)and nurses'core competence(P<0.01)were positively associated with job satisfaction.Besides,The results also indicated job stress,geographical distribution,hospital category,gender,work shift,only children,parenting status,monthly salary,nursing experience,professional title,hospital area were the influencing factors of job satisfaction(P<0.05).Conclusion:The improvement of the emotional labour and competency of nurses may help enhance their job satisfaction.

Towards More Snow Days in Summer since 2001 at the Great Wall Station,Antarctic Peninsula:The Role of the Amundsen Sea Low

The variation in the precipitation phase in polar regions represents an important indicator of climate change and variability.We studied the precipitation phase at the Great Wall Station and Antarctic Peninsula(AP)region,based on daily precipitation,synoptic records and ERA-Interim data during the austral summers of 1985?2014.Overall,there was no trend in the total precipitation amount or days,but the phase of summer precipitation(rainfall days versus snowfall days)showed opposite trends before and after 2001 at the AP.The total summer rain days/snow days increased/decreased during 1985?2001 and significantly decreased at a rate of?14.13 d(10 yr)?1/increased at a rate of 14.31 d(10 yr)?1 during 2001?2014,agreeing well with corresponding variations in the surface air temperature.Further,we found that the longitudinal location of the Amundsen Sea low(ASL)should account for the change in the precipitation phase since 2001,as it has shown a westward drift after 2001[?41.1°(10 yr)?1],leading to stronger cold southerly winds,colder water vapor flux,and more snow over the AP region during summertime.This study points out a supplementary factor for the climate variation on the AP.

A Semi-Blind Method to Estimate the I/Q Imbalanc of THz Orthogonal Modulator

In terahertz communication,the direct frequency conversion structure in which orthogonal mixer is the main frequency conversion unit,makes engineers get into trouble of in-phase(I)branch and quadrature(Q)branch imbalance,carrier wave leakage,etc.These damages result in system performance tremendous degrades.We proposed a semiblind method to estimate the I/Q imbalance of THz orthogonal modulator,based on predefined preamble and pilot symbols for quadrature amplitude modulation(QAM).In this paper,a transmitter with Y band quadrature mixer and 20Gbps base-band signal has been tested.The bandwidth of the baseband signal was 7GHz,and the modulation type was 16QAM.By this method,7dB improvement of the system’s symbol Mean Square Error(MSE)has been got.That means the proposed method can be used to eliminate the I/Q imbalance effectively.

全新吸油烟机气动布局研究

油烟机的气动布局是决定整机吸油烟效果的关键因素,通过对两种气动布局对比,得出风机卧式布置有利于负压外扩,减少流动损失,更适合中式厨房。创新的使用了水滴气动外形的导流罩,很好的与离心风机卧式布置方案匹配。为了减少流动分离,对三种蜗壳出口方案对比,优选最佳方案;并进行蜗壳小型化设计来满足橱柜设计标准,最大限度地利用集烟空间,使油烟流经过程中所受的阻力最小,以提高排油烟能力。

High-performance InAlGaN/GaN enhancement-mode MOS-HEMTs grown by pulsed metal organic chemical vapor deposition

Pulsed metal organic chemical vapor deposition was employed to grow nearly polarization matched InAlGaN/GaN heterostructures. A relatively low sheet carrier density of 1.8×10^(12)cm^(-2), together with a high electron mobility of1229.5 cm^2/V·s, was obtained for the prepared heterostructures. The surface morphology of the heterostructures was also significantly improved, i.e., with a root mean square roughness of 0.29 nm in a 2 μm×2 μm scan area. In addition to the improved properties, the enhancement-mode metal–oxide–semiconductor high electron mobility transistors(MOSHEMTs) processed on the heterostructures not only exhibited a high threshold voltage(VTH) of 3.1 V, but also demonstrated a significantly enhanced drain output current density of 669 m A/mm. These values probably represent the largest values obtained from the InAlGaN based enhancement-mode devices to the best of our knowledge. This study strongly indicates that the InAlGaN/GaN heterostructures grown by pulsed metal organic chemical vapor deposition could be promising for the applications of novel nitride-based electronic devices.

Total least-squares EIO model,algorithms and applications

A functional model named EIO(Errors-In-Observations) is proposed for general TLS(total least-squares)adjustment. The EIO model only considers the correction of the observation vector, but doesn't consider to correct all elements in the design matrix as the EIV(Errors-In-Variables) model does, furthermore, the dimension of cofactor matrix is much smaller. Iterative algorithms for the parameter estimation and their precise covariance matrix are derived rigorously, and the computation steps are also presented. The proposed approach considers the correction of the observations in the coefficient matrix, and ensures their agreements in every matrix elements. Parameters and corrections can be solved at the same time.An approximate solution and a precise solution of the covariance matrix can be achieved by corresponding algorithms. Applications of EIO model and the proposed algorithms are demonstrated with several examples. The results and comparative studies show that the proposed EIO model and algorithms are feasible and reliable for general adjustment problems.

Design of Subharmonic Mixers above 100 GHz

This paper presents the design and simulation of several fixed-tuned sub-harmonic mixers cover frequencies from 110 GH to 130 GHz, 215 GH to 235 GHz, 310 GH to 350 GHz, and 400 GH to 440 GHz. Among them, 120 GHz, 225 GHz, 330 GHz subharmonic mixers are designed with flip-chipped planar schottky diode mounted onto a suspended quartz-based substrate, the 225 GHz and 425 GHz subharmonic mixers are GaAs membrane integrated, and the 115 GHz subharmonic mixer has been fabricated and tested already.

Cooling effect of convection-intensifying composite embankment with air doors on permafrost

One of the main construction problems in permafrost regions is protecting permafrost thermal stability. Although ventilating ducts and crushed-rock layers were successfully used in railway embankment construction, their effects might not meet large-width expressway requirements. The convection-intensifying composite embankment composed of perforated ventilation ducts and crushed-rock layers was numerically studied to investigate its cooling effects. Adopting a numerical model, the temperature fields for two kinds of composite embankment with and without air doors were analyzed considering air flow and heat transfer characteristics in porous media. The results show that wind velocity in the crushed-rock zone is intensified by the perforated ventilation duct. The underlying permafrost temperature obviously decreases, and the 0 °C isotherm position rises significantly due to composite embankment. The composite embankment with air doors is more effective than that without air doors. Therefore, the new convection-intensifying composite embankment is potentially a highly efficient cooling measure for construction in permafrost regions.

Quantum Secure Multiparty Computation with Symmetric Boolean Functions

We propose a class of n-variable Boolean functions which can be used to implement quantum secure multiparty computation.We also give an implementation of a special quantum secure multiparty computation protocol.An advantage of our protocol is that only 1 qubit is needed to compute the n-tuple pairwise AND function,which is more efficient comparing with previous protocols.We demonstrate our protocol on the IBM quantum cloud platform,with a probability of correct output as high as 94.63%.Therefore,our protocol presents a promising generalization in realization of various secure multipartite quantum tasks.

基于Ⅰ型登革病毒全球统一基因分型协同监测策略的纳米孔测序溯源技术体系的建立与初步应用

目的基于全球统一DENV-1基因分型协同监测策略构建纳米孔测序溯源技术体系,并初步应用于患者血清样本测试。方法基于全球DENV整合序列资源数据库GISDD v1.2.1中DENV-1全基因组序列集,利用MEGA 7.0、primer-BLAST、MPprimer和GISDDrPrimer软件筛选、设计和评价特异性的靶向多重PCR引物对;提取血清样本RNA和逆转录;16对引物分配至2个引物池,多重PCR扩增靶标基因组序列;使用磁珠纯化,根据SQK-LSK109试剂盒操作流程构建文库,使用MinION测序;分析测序数据并组装基因组,以GISDD基因分型平台进行溯源分析。结果设计并鉴定了16对与GISDD所收录基因组序列具有高覆盖度的DENV-1引物,建立了DENV-1特异性多重PCR靶向纳米孔高通量测序技术体系。初步应用于13例广州登革热患者血清样本的全基因组检测,读长(reads)平均长度中值为1668.00 bp,测序平均质量中值为9.30,比对率中值为97.90%,比对上参考基因组NV46的平均长度中值为1677.90 bp,基因组平均深度中值为12886.40×。进一步基于GISDD基因分型和溯源分析发现,9个隶属DENV-1基因分支1E1、3个为1L1、1个为5C1。结论纳米孔测序DENV-1全基因组检测体系稳定可靠,可获得高质量DENV-1全基因组序列,为登革热疫情暴发中DENV-1基因组的快速侦检与溯源追踪提供了有效的技术方案,为建立登革热的全球协同监测控制体系奠定技术基础。

Remote estimates of suspended particulate matter in global lakes using machine learning models

Suspended particulate matter(SPM)in lakes exerts strong impact on light propagation,aquatic ecosystem productivity,which co-varies with nutrients,heavy metal and micro-pollutant in waters.In lakes,SPM exerts strong absorption and backscattering,ultimately affects water leaving signals that can be detected by satellite sensors.Simple regression models based on specific band or hand ratios have been widely used for SPM estimate in the past with moderate accuracy.There are still rooms for model accuracy improvements,and machine learning models may solve the non-linear relationships between spectral variable and SPM in waters.We assembled more than 16,400 in situ measured SPM in lakes from six continents(excluding the Antarctica continent),of which 9640 samples were matched with Landsat overpasses within±7 days.Seven machine learning algorithms and two simple regression methods(linear and partial least squares models)were used to estimate SPM in lakes and the performance were compared.To overcome the problem of imbalance datasets in regression,a Synthetic Minority Over-Sampling technique for regression with Gaussian Noise(SMOGN)was adopted in this study.Through comparison,we found that gradient boosting decision tree(GBDT),random forest(RF),and extreme gradient boosting(XGBoost)models demonstrated good spatiotemporal transferability with SMOGN processed dataset,and has potential to map SPM at different year with good quality of Landsat land surface reflectance images.In all the tested modeling approaches,the GBDT model has accurate calibration(n=6428,R^(2)=0.95,MAPE=29.8%)from SPM collected in 2235 lakes across the world,and the validation(n=3214,R^(2)=0.84,MAPE=38.8%)also exhibited stable performance.Further,the good performances were also exhibited by RF model with calibration(R^(2)=0.93)and validation(R^(2)=0.86,MAPE=24.2%)datasets.We applied GBDT and RF models to map SPM of typical lakes,and satisfactory result was obtained.In addition,the GBDT model was evaluated by historical SPM measurements coincident with different Landsat sensors(L5-TM,L7-ETM+,and L8-OLI),thus the model has the potential to map SPM of lakes for monitoring temporal variations,and tracks lake water SPM dynamics in approximately the past four decades(1984-2021)since Landsat-5/TM was launched in 1984.

Microstructure Evolution and Mechanical Properties of Friction Stir Welded Al-Cu-Li Alloy

The investigation concentrates on friction stir welded(FSW)Al-Cu-Li alloy concerning its local microstructural evolution and mechanical properties.The grain features were characterized by electron back scattered diffraction(EBSD)technology,while precipitate characterization was conducted by using transmission electron microscopy(TEM)aligned along[011]Al and[001]Al zone axes.The mechanical properties are evaluated through micro-hardness and tensile testing.It can be found that nugget zones exhibit finely equiaxed grains evolved through complete dynamic recrystallization(DRX),primarily occurring in continuous dynamic recrystallization(CDRX)and discontinuous dynamic recrystallization(DDRX).In the thermal-mechanically affected zone(TMAZ),numerous sub-structured grains,exhibiting an elongated morphology,were created due to partial DRX,signifying the dominance of CDRX,DDRX,and geometric dynamic recrystallization(GDRX)in this region.T_(1)completely dissolves in the nugget zone(NZ)leading to the formation of Guinier-Preston zones and increase ofδ′,β′and S′.Conversely,T_(1)partially solubilizes in TMAZ,the lowest hardness zone(LHZ)and heat affected zone(HAZ),and the residual T_(1)undergoes marked coarsening,revealing various T_(1)variants.The solubilization and coarsening of T_(1)are primary contributors to the degradation of hardness and strength.θ′primarily dissolves and coarsens in NZ and TMAZ,whilst this precipitate largely coarsens in HAZ and LHZ.σ,TB,grain boundary phases(GBPs)and precipitate-free zone(PFZ)are newly generated during FSW.σexists in the TMAZ,LHZ and HAZ,whereas TB nucleates in NZ.GBPs and PFZ mostly develop in LHZ and HAZ,which can cause strain localization during tensile deformation,potentially leading to LHZ joint fracture.

Re-estimating China's lake CO_(2)flux considering spatiotemporal variability

The spatiotemporal variability of lake partial carbon dioxide pressure(pCO_(2))introduces uncertainty into CO_(2)fluxestimates at the lakewater-air interface.Knowing the variationpattern of pCO_(2)isimportant for obtaining accurate global estimation.Here we examine seasonal and trophic variations in lake pCO_(2)based on 13 field campaigns conducted in Chinese lakes from 2017 to 2021.We found significant seasonal fluctuations in pCO_(2),with decreasing values as trophic states intensify within the same region.Saline lakes exhibit lower pCO_(2)levels thanfreshwater lakes.These pCO_(2)dynamics result invariable areal CO_(2)emissions,withlakes exhibiting different trophic states(oligotrophication>mesotrophication>eutrophication)and saline lakes differing from freshwater lakes(-23.1±17.4 vs.19.3±18.3 mmol m^(-2)d^(-1)).These spatiotemporal pCO_(2)variations complicate total CO_(2)emission estimations.Using area proportions of lakes with varying trophic states and salinity in China,we estimate China's lake CO_(2)flux at 8.07 Tg C yr^(-1).In future studies,the importance of accounting for lake salinity,seasonal dynamics,and trophic statesmust be noticed to enhance the accuracy of large-scale carbon emission estimates from lake ecosystems in the context of climate change.

Double-composite rectangular truss bridge and its joint analysis

This paper describes a novel composite tubular truss bridge with concrete slab and concrete-filled rectangular chords. With concrete slab plus truss system and joints rein- forced with concrete and Perfobond Leiste rib, double composite truss bridge proved to be a fairly suitable solution in negative moment area. Perfobond Leiste shear connector （PBL） is widely implemented in the composite structure for its outstanding fatigue resistance. In this pilot bridge, Perfobond Leister ribs （PBR） were installed in the truss girder＇s joints, which played double roles as shear connector and stiffener. An erection method and overall bridge structural analysis were then presented. Typical joints in the pilot bridge were selected to analyze the effect of PBR. Investigation of the effect of PBR in concrete- filled tubular joints was elaborated. Comparison has revealed that concrete-filled tubular joints with PBR have much higher constraint capability than joints without PBR. For rect- angular tubular truss, the punching shear force of the concrete filled joint with PBR is approximately 43% larger than that of the joint without PBR. Fatigue performance of the joint installed with PBR was improved, which was found through analysis of the stress concentration factor of joint. The PBR installed in the joints mitigated the stress concen- tration factor in the chord face. Therefore, the advantages of this new type of bridge are demonstrated, including the convenience of construction using rectangular truss, inno- vative concept of structural design and better global and local performances.