Scientific Advances and Weather Services of the China Meteorological Administration’s National Forecasting Systems during the Beijing 2022 Winter Olympics

Since the Beijing 2022 Winter Olympics was the first Winter Olympics in history held in continental winter monsoon climate conditions across complex terrain areas,there is a deficiency of relevant research,operational techniques,and experience.This made providing meteorological services for this event particularly challenging.The China Meteorological Administration(CMA)Earth System Modeling and Prediction Centre,achieved breakthroughs in research on short-and medium-term deterministic and ensemble numerical predictions.Several key technologies crucial for precise winter weather services during the Winter Olympics were developed.A comprehensive framework,known as the Operational System for High-Precision Weather Forecasting for the Winter Olympics,was established.Some of these advancements represent the highest level of capabilities currently available in China.The meteorological service provided to the Beijing 2022 Games also exceeded previous Winter Olympic Games in both variety and quality.This included achievements such as the“100-meter level,minute level”downscaled spatiotemporal resolution and forecasts spanning 1 to 15 days.Around 30 new technologies and over 60 kinds of products that align with the requirements of the Winter Olympics Organizing Committee were developed,and many of these techniques have since been integrated into the CMA’s operational national forecasting systems.These accomplishments were facilitated by a dedicated weather forecasting and research initiative,in conjunction with the preexisting real-time operational forecasting systems of the CMA.This program represents one of the five subprograms of the WMO’s high-impact weather forecasting demonstration project(SMART2022),and continues to play an important role in their Regional Association(RA)II Research Development Project(Hangzhou RDP).Therefore,the research accomplishments and meteorological service experiences from this program will be carried forward into forthcoming highimpact weather forecasting activities.This article provides an overview and assessment of this program and the operational national forecasting systems.

接缝灌浆施工技术在双曲拱坝中的应用

混凝土拱坝是一高次超静定结构,坝体本身不设永久伸缩缝,但在混凝土拱坝施工时受浇筑能力限制,采用分层、分块交替上升的方法施工,将坝体分割成若干坝段,以防止坝体产生温度裂缝,需要设置诱导缝。需要对诱导缝进行灌浆,使坝体形成合力,将应力传递到两岸坝肩。这样才能保证坝体在操作过程中的整体性,应力才能得到有效的传递。鉴此,以马岭水利枢纽工程为例,介绍了混凝土双曲拱坝接缝采用橡胶套阀重复灌浆盒进行二次灌浆。实例说明该技术是有效可行的,在同类工程中是可以参考的。

Stress effect on lattice thermal conductivity of anode material NiNB_(2)O_(6)for lithium-ion batteries

The thermal transport properties of NiNB_(2)O_(6)as anode material for lithium-ion battery and the effect of strain were studied by machine learning interatomic potential combined with Boltzmann transport equation.The results show that the lattice thermal conductivity of NiNB_(2)O_(6)along the three crystal directions[100],[010],and[001]are 0.947 W·m^(-1)·K^(-1),0.727 W·m^(-1)·K^(-1),and 0.465 W·m^(-1)·K^(-1),respectively,indicating the anisotropy of the lattice thermal conductivity of NiNB_(2)O_(6).This anisotropy of the lattice thermal conductivity stems from the significant difference of phonon group velocities in different crystal directions of NiNB_(2)O_(6).When the tensile strain is applied along the[001]crystal direction,the lattice thermal conductivity in all three directions decreases.However,when the compressive strain is applied,the lattice thermal conductivity in the[100]and[010]crystal directions is increased,while the lattice thermal conductivity in the[001]crystal direction is abnormally reduced due to the significant inhibition of compressive strain on the group velocity.These indicate that the anisotropy of thermal conductivity of NiNB_(2)O_(6)can be enhanced by the compressive strain,and reduced by the tensile strain.

联合神经阻滞镇痛用于老年患者髋部骨折手术的效果

目的探讨加速康复外科(ERAS)中优化老年髋部骨折患者围术期的镇痛方案。方法选择择期行髋部骨折手术的患者60例,年龄60~90岁,美国麻醉医师协会分级Ⅱ或Ⅲ级,随机分入联合神经阻滞镇痛组和对照组,每组30例。入院后两组均静脉注射NSAID,联合神经阻滞镇痛组同时行单次股神经阻滞,手术当日于蛛网膜下腔阻滞前30 min行连续髂筋膜间隙阻滞,术后持续镇痛。分别于入院后(T1)、术前做检查时(T2)、麻醉摆体位时(T3)、术后12 h(T4)、术后24 h(T5)和术后48 h(T6)各时间点进行静息和运动疼痛VAS评分,记录T1和T3时间点的患者平均动脉压(MAP)和心率,分别于术前和术后1 d测定CRP水平,记录补救镇痛情况、不良反应发生情况、住院时间和患者镇痛满意度。结果联合神经阻滞镇痛组T2至T5时间点的疼痛VAS评分均显著低于对照组同时间点(P值均<0.05),在T1、T6时间点,两组的疼痛VAS评分差异均无统计学意义(P值均>0.05)。联合神经阻滞镇痛组T3时间点的MAP显著低于对照组同时间点(P<0.05),T1时间点的MAP与对照组同时间点间的差异无统计学意义(P>0.05)。在T1、T3时间点,两组心率的差异均无统计学意义(P值均>0.05)。联合神经阻滞镇痛组术前、术后的血浆CRP水平分别为(39.07±32.55)、(63.74±29.91)mg/L,对照组分别为(26.50±21.79)、(69.16±39.92)mg/L,联合神经阻滞镇痛组患者术后血浆CRP水平显著低于对照组(P<0.05)。联合神经阻滞镇痛组术后发生不良反应5例(头痛1例、穿刺点疼痛1例、恶心呕吐3例),不良反应发生率为16.7%(5/30);对照组术后发生不良反应16例(头痛5例、恶心呕吐8例、谵妄3例),不良反应发生率为53.3%(16/30)。联合神经阻滞镇痛组术后不良反应发生率显著低于对照组(P<0.05)。联合神经阻滞镇痛组患者住院时间为(11.47±3.48)d,显著短于对照组的(15.10±5.72)d(P<0.05);镇痛满意度评分为(8.15±0.63)分,显著高于对照组的(6.52±0.51)分(P<0.05);补救镇痛率为3.3%(1/30),显著低于对照组的26.7%(8/30,P<0.05)。结论联合神经阻滞镇痛可安全、有效地应用于髋部骨折手术,不仅能提供良好的围术期镇痛,而且能减少应激和并发症发生,有利于老年髋部骨折患者加速康复。

山西中部引黄水源工程“四新技术”应用

中部引黄水源工程采用泉域区灌浆堵水技术、泉域补水区域小断面隧洞穿煤层段施工技术、高边坡综合治理技术、湿陷性黄土地基处理研究技术,解决了泉域区地下洞室群开挖施工技术难题和复杂地质条件下高边坡和湿陷性黄土基础处理难题;库区运行水位下预留岩埂关键技术,降低了高风险施工;采用倒挂井混凝土施工定型模板支撑装置工艺和潜孔钻进行岩锚梁锚杆钻孔工艺,确保了工程质量,加快了施工进度;组织安装了目前国内最大的立式单吸三级蜗壳式离心泵地下泵组。

海水浸泡低体温伤员复温课程的设置及实践

海水浸泡低体温症是海上军事训练相对比较常见的一种特殊病理状态,也是导致海军士兵伤亡的独立风险因素。本研究通过分析海水浸泡低体温伤的特点,设置海水浸泡低体温伤员复温课程,并从理论知识和动物模型实践两个环节进行教学,以提升受训学员的理论及实践水平,以及常用复温方法的应用效果。

多源融合定位算法综述

随着机器人、无人车等自主导航系统的大量涌现,定位导航技术在最近20年得到迅猛发展,用户对新一代的定位导航技术提出了新的要求,即在任意环境、任意时刻、任意平台都能具备可靠的定位导航能力.多源融合定位算法是实现该目标的唯一有效途径.本文从传感器观测模型、环境场景模型、载体运动行为模型出发,综述了卫星导航、惯性导航、视觉传感器、激光雷达单一传感器的定位方法,分析了定位导航运行的环境场景对多源融合定位的影响,以及载体运动行为对定位的影响.最后,从融合框架层面将多源融合定位算法分为优化和滤波两大类进行深入分析.

异常权限配置下的角色挖掘方案

角色挖掘是构建RBAC系统的常用方法,但目前的角色挖掘方案在设计时未考虑原始系统存在异常权限配置问题,导致角色挖掘的结果可能包含错误的角色权限配置,给系统带来极大的安全风险。针对该问题,文章提出一种异常权限配置下的角色挖掘方案。首先在用户聚类部分引入Canopy预聚类,通过预聚类提取子集交叠数据,缩小后续谱聚类计算量;然后结合预聚类结果优化谱聚类的初始值选取,并针对访问控制数据由布尔值表示的特点,采用杰卡德距离和汉明距离相结合的方式对Canopy预聚类和谱聚类的距离进行度量,提高用户聚类效果;最后对异常权限配置检测规则进行细化,利用修正后的用户聚类结果进行角色挖掘。实验结果表明,该方案能够有效发现异常权限配置,提高角色挖掘效率。

咀嚼口香糖不能加速Lenke 5型青少年特发性脊柱侧凸患者后路融合术后胃肠道功能恢复:一项前瞻性单盲随机对照研究

目的:探讨咀嚼口香糖对Lenke 5型青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)患者后路融合术后胃肠道功能恢复的影响。方法:2016年1月至2018年1月海军军医大学附属长征医院收治的行后路融合手术的Lenke 5型AIS患者随机分为口香糖组和对照组(注册号:ChiCTR-IOR-17013449)。口香糖组患者术后第1~3天每天8:00、12:00、18:00咀嚼口香糖20~30min;对照组不给予咀嚼口香糖处理。主要终点指标:术后初次通气时间、初次肠蠕动时间、术后住院时间及进食时间。次要终点指标:术后镇痛药用量、腹部疼痛及恶心评分、术后并发症。结果:最终纳入99例患者,其中口香糖组49例,对照组50例。两组患者术后首次通气时间(P=0.162)、肠蠕动时间(P=0.387)、首次进食时间、术后住院时间(P=0.730)差异均无统计学意义。两组患者术后并发症发生率、镇痛药用量、腹痛及恶心评分差异无统计学意义。结论:Lenke 5型AIS患者后路融合术后咀嚼口香糖不能加速胃肠道功能恢复。

Effects of Dexmedetomidine combined with Sufentanil on the hemodynamics and stress state in the wake of general anesthesia in elderly patients with lower limb fracture surgery

Objective:To study the effects of Dexmedetomidine combined with Sufentanil on hemodynamics, stress state, helper T cytokines and pain degree during the waking period of general anesthesia in elderly patients with lower limb fracture surgery were studied.Methods:From June 2017 to July 2018, 95 elderly patients with lower limb fracture who visited First Affiliated Hospital of Xi 'an Jiaotong University and received fracture surgery and general anesthesia were collected. According to their different anesthesia methods, 46 patients were divided into the sufentanil maintenance anesthesia group (Sufentanil group), and 49 patients were divided into the metopidine combined with sufentanil maintenance anesthesia group (Joint group). Changes in hemodynamics (HR, SpO2, MAP) of the two groups were monitored at different times throughout the operation. Using enzyme-linked immunoassay detection of two groups of patients in maintain anesthesia and anesthesia to stress index (Cor, E, FIns and HOMA-IR). The the changes of pain mediators (NO,β-EP, SP) and helper T cytokines (IFN-γ, TNF-α) were compared between the two groups before and 24 hours after surgery. Results:In the combined group, HR, SpO2, MAP and sufentanil groups showed little change in SpO2 during anesthesia, with no significant difference. The HR and MAP of T2 and T3 in the sufentanil group were significantly higher than those in the combined group at T2 and T3. The stress indicators Cor, E, FIns and HOMA-IR in the anesthesia of the two groups were significantly higher than those in the anesthesia maintenance. The serum stress indexes of Cor, E, FIns and HOMA-IR were significantly lower in the combined group than in the sufentanil group. The IFN-γ level of the combined group was significantly higher than that of the sufentanil group, and the TNF-α level was significantly lower than that of the control group. Serum levels of NO,β-EP and SP were significantly higher in the two groups 24 h after surgery. Serum pain mediators NO,β-EP and SP in the combined group were significantly lower than those in the sufentanil group before and 24 h after surgery.Conclusion: Combined anesthesia with Remifentanil and Propofol can stabilize the hemodynamic state of patients undergoing craniotomy, reduce cardiovascular stress response and inflammatory response, reduce nerve damage, and play a role in brain protection.

Jamming in confined geometry:Criticality of the jamming transition and implications of structural relaxation in confined supercooled liquids

In marginally jammed solids confined by walls,we calculate the particle and ensemble averaged value of an order parameter,Ψ(r),as a function of the distance to the wall,r.Being a microscopic indicator of structural disorder and particle mobility in solids,Ψis by definition the response of the mean square particle displacement to the increase of temperature in the harmonic approximation and can be directly calculated from the normal modes of vibration of the zerotemperature solids.We find that,in confined jammed solids,Ψ(r)curves at different pressures can collapse onto the same master curve following a scaling function,indicating the criticality of the jamming transition.The scaling collapse suggests a diverging length scale and marginal instability at the jamming transition,which should be accessible to sophisticatedly designed experiments.Moreover,Ψ(r)is found to be significantly suppressed when approaching the wall and anisotropic in directions perpendicular and parallel to the wall.This finding can be applied to understand the r-dependence and anisotropy of the structural relaxation in confined supercooled liquids,providing another example of understanding or predicting behaviors of supercooled liquids from the perspective of the zero-temperature amorphous solids.

Coupling between Particle Shape and Long-Range Interaction in the High-Density Regime

We experimentally probe the coupling between particle shape and long-range interaction,using long-range interacting polygons.For two typical space-filling polygons,square and triangle,we find two types of coupling modes that predominantly control the structure formation.Specifically,the rotational ordering of squares brings a lattice deformation that produces a hexagonal-to-rhombic transition in the high density regime,whereas the alignment of triangles introduces a large geometric frustration that causes an order-to-disorder transition.Moreover,the two coupling modes lead to small and large“internal roughness”of the two systems,and thus predominantly control their structure relaxations.Our study thus provides a physical picture to the coupling between long-range interaction effect and short-range shape effect in the high-density regime unexplored before.

Sn-doped cobalt containing perovskite as the air electrode for highly active and durable reversible protonic ceramic electrochemical cells

One potential solution to the problems of energy storage and conversion is the use of reversible protonic ceramic electrochemical cells(R-PCEC),which are based on the solid oxide fuel cell(SOFC)technology and offer a flexible route to the generation of renewable fuels.However,the R-PCEC development faces a range of significant challenges,including slow oxygen reaction kinetics,inadequate durability,and poor round-trip efficiency resulting from the inadequacy of an air electrode.To address these issues,we report novel B-sites doped Pr_(0.5)Ba_(0.5)Co_(0.7)Fe_(0.3)O_(3−δ)(PBCF)with varying amounts of Sn as the air electrode for R-PCEC to further enhance electrochemical performance at lower temperatures.At 600℃,R-PCEC with an air electrode consisting of Pr_(0.5)Ba_(0.5)Co_(0.7)Fe_(0.25)Sn_(0.05)O_(3+δ)has achieved peak power density of 1.12 W∙cm^(−2) in the fuel cell mode and current density of 1.79 A∙cm^(−2) in the electrolysis mode at a voltage of 1.3 V.Moreover,R-PCECs have shown good stability in the electrolysis mode of 100 h.This study presents a practical method for developing durable high-performance air electrodes for R-PCECs.

A comprehensive review of recent progresses in cathode materials for Proton-conducting SOFCs

Solid oxide fuel cells(SOFCs)are widely recognized as efficient energy sources that have the potential to shape the future of energy development.Among various types of SOFCs,the low-temperature operation of protonconducting SOFCs(H–SOFCs)offers distinct advantages for wide commercialization compared to oxygen-ion conducting SOFCs(O–SOFCs).However,the commercialization of H–SOFCs is hindered by several challenges,including slow oxygen reduction kinetics and long-term instability of cathode materials.The electrochemical performance of the cathode system in H–SOFCs is limited by the poor proton conductivity of the cathode material and the scarcity of surface reaction sites.Additionally,the presence of undesirable phases induced by elements such as Cr and CO_(2)adversely affects the chemical stability and catalytic activity of the cathode.Thermal stress arising from the mismatch in coefficient of thermal expansion between the cathode and electrolyte further adds to the challenges.Therefore,this comprehensive review presents underlying mechanisms and potential solutions to overcome the challenges in H–SOFCs,leading to higher efficiency and wider commercialization of H–SOFCs.

Wideband tunable REC-DFB laser array using thin-film heaters on the submount

A wideband wavelength-tunable 4×5 distributed feedback(DFB)semiconductor laser array based on the reconstructionequivalent-chirp(REC)technique using a simple tuning scheme is demonstrated.It consists of 20 DFB lasers with 4×5matrix interleaving distributions,two-level cascaded Y-branch optical combiners,and one active semiconductor opticalamplifier(SOA),all in-series integrated on one chip.Unlike the traditional thermal-electric cooler(TEC)-based wavelength-tuning scheme,the tunable 4×5 REC-DFB laser array achieves a faster and broader continuous wavelength-tuningrange using TaN thin-film heaters integrated on the AlN submount.By changing the injection current of the TaN resistorfrom 0 to 190 mA,the proposed tunable laser achieves a wavelength-tuning range of∼2.5 nm per channel and a total tuningof over 50 nm.This study opens up new avenues for realizing cost-effective and wide-tuning-range semiconductor lasers.

Stretchable Luminescent Perovskite‑Polymer Hydrogels for Visual‑Digital Wearable Strain Sensor Textiles

The integration of a display function with wearable interactive sensors offers a promising way to synchronously detect physiological signals and visualize pressure/stimuli.However,combining these two functions in a strain sensor textile is a longstanding challenge due to the physical separation of sensors and display units.Here,a water-stable luminescent perovskite hydrogel(emission band approximately 25 nm)is constructed by blending as-prepared CsPbBr_(3)@PbBr(OH)with stretchable polyacrylamide(PAM)hydrogels.The facile introduction of CsPbBr_(3)@PbBr(OH)endows the hydrogels with excellent optical properties and a high mechanical strength of 51.3 kPa at a fracture strain of 740%.Interestingly,the resulting hydrogels retain bright green fluorescence under conditions including water,ultraviolet light,and extensive stretching(>700%).As a proof-of-concept,a novel wearable stretchable strain sensor textile based on these hydrogels is developed,and it displays visual-digital synergetic strain detection ability.It can perceive various motions on the human body in real time with electronic output signals from changes in resistance and simultaneously readable optical output signals,whether on land or underwater.This work provides a meaningful guide to rationally design perovskite hydrogels and accelerates the development of wearable visual-digital strain sensor textiles.

Role of disorder in determining the vibrational properties of mass-spring networks

By introducing four fundamental types of disorders into a two-dimensional triangular lattice separately, we determine the role of each type of disorder in the vibration of the resulting mass-spring networks. We are concerned mainly with the origin of the boson peak and the connection between the boson peak and the transverse Ioffe-Regel limit. For all types of disorders, we observe the emergence of the boson peak and Ioffe-Regel limits. With increasing disorder, the boson peak frequency ωBP, transverse Ioffe-Regel frequency ω^TIR, and longitudinal Ioffe-Regel frequency wLn all decrease. We find that there are two ways for the boson peak to form： developing from and coexisting with （but remaining independent of） the transverse van Hove singularity without and with local coordination number fluctuation. In the presence of a single type of disorder, ωTR 〉 wBp, and ωTIR≈BP only when the disorder is sufficiently strong and causes spatial fluctuation of the local coordination number. Moreover, if there is no positional disorder, ωTIR ≈ωLIR. Therefore, the argument that the boson peak is equivalent to the transverse Ioffe-Regel limit is not general. Our results suggest that both local coordination number and positional disorder are necessary for the argument to hold, which is actually the case for most disordered solids such as marginally jammed solids and structural glasses. We further combine two types of disorders to cause disorder in both the local coordination number and lattice site position. The density of vibrational states of the resulting networks resembles that of marginally jammed solids well. However, the relation between the boson peak and the transverse Ioffe-Regel limit is still indefinite and condition-dependent. Therefore, the interplay between different types of disorders is complicated, and more in-depth studies are required to sort it out.

Endoplasmic reticulum stress-induced apoptosis in the development of reproduction

Proteins synthesized in the endoplasmic reticulum （ER） are properly folded with the assistance of ER chaperones. Accumulation of misfolded protein in the ER triggers an adaptive ER stress （ERS） response termed the unfolded protein response. Recent interest has focused on the possibility that the accumulation of misfolded proteins can also contribute to reproductive response, including preimplantation embryos, testicular germ cell, placenta, and unexplained intrauterine growth restriction （IUGR）. The major ERS pathway constituents are present at all stages of preimplantation development and that the activation of ERS pathways can be induced at the 8-cell, morula and blastocyst stage. This review mainly introduced the research progress of ERS induced apoptosis of reproductive cells, providing a new direction for the research of reproductive disease therapy.

Affection mechanism research of initiation crack pressure of perforation parameters of horizontal well

Horizontal wells show better affect and higher success rate in low water ratio cement,complex fracture zone,crevice and heavy oil blocks,it is the main measures to expand control area of a single well.Hydraulic fracturing technology is the most financial way to improve the penetration of the reservoir to increase the production.However,compare with the vertical wells,the fracture of Horizontal wells are more complex,and lead to the initiation crack pressure is much higher than vertical wells.In this paper,defined the crack judging basis,and established the finite element model which could compute the initial crack pressure,to research the affection mechanism of perforation azimuth angle,density,diameter and depth,to provide references of perforation project's design and optimize.The research of this paper has significances on further understanding the affection mechanism of perforation parameters.

Evaluation of circulating tumor DNA as a biomarker for gynecological tumors

Circulating tumor DNA(ctDNA)is a DNA fragment released into the peripheral blood by apoptotic or necrotic tumor cells,which carry the basic genetic information after gene mutation.The detection and analysis of ctDNA can provide genomic information on the size and development of tumor;therefore,it is considered as an emerging and promising tumor biomarker for cancer progression,reoccurrence,and routine monitoring after surgery.Albeit the isolation method is relatively simple due to the stability of ctDNA,the abundance of ctDNA is extremely low,and result from the high content of background cell free DNA(cfDNA),the large difference between individuals,and the need of predicted detection sites,it is necessary to analyze ctDNA in a comprehensive way.At present,the main methods that meet the needs of ctDNA detection with sensitivity and specificity are amplification refractory mutation system PCR(ARMS-PCR),digital-PCR(dPCR)and high-throughput sequencing.Among them,dPCR has advantages in practicality,which can realize absolute quantification of single-molecule DNA,detect and trace DNA molecules and conduct quantitative analysis,providing a reliable basis for clinical monitoring of tumor recurrence and minimal residual diseases.The study reviews the detection and potential value of ctDNA in gynecologic tumors.