mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
A Hybrid WENO Method with Modified Ghost Fluid Method for Compressible Two-Medium Flow Problems

In this paper, we develop a simplified hybrid weighted essentially non-oscillatory(WENO) method combined with the modified ghost fluid method(MGFM) [31] to simulate the compressible two-medium flow problems.The MGFM can turn the two-medium flow problems into two single-medium cases by defining the ghost fluids state in terms of the predicted the interface state, which makes the material interface "invisible".For the single medium flow case, we adapt between the linear upwind scheme and the WENO scheme automatically by identifying the regions of the extreme points for the reconstruction polynomial as same as the hybrid WENO scheme [55].Instead of calculating their exact locations, we only need to know the regions of the extreme points based on the zero point existence theorem, which is simpler for implementation and saves computation time.Meanwhile, it still keeps the robustness and has high efficiency.Extensive numerical results for both one and two dimensional two-medium flow problems are performed to demonstrate the good performances of the proposed method.
Association between common cardiovascular drugs and depression

Objective: Cardiovascular diseases are associated with an increased risk of depression, but it remains unclear whether treatment with cardiovascular agents decreases or increases this risk. The effects of drugs on individual usage are also often unknown. This review aimed to examine the correlation between depression and common cardiovascular drugs, develop more potent interventions for depression in cardiovascular patients, and further research on the bio-behavioural mechanisms linking cardiovascular drugs to depression. Data sources: The data in this review were obtained from articles included in PubMed, EMBASE, and Web of Science. Study selection: Clinical trials, observational studies, review literature, and guidelines about depression and cardiovascular drugs were selected for the article. Results: We systematically investigated whether the seven most used cardiovascular drugs were associated with altered risk of incident depression in this literature review. Statins have been proven to have antidepressant effects. Some studies believe angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blocker (ARB) can exert an antidepressant influence by acting on the renin-angiotensin system, but further clinical trials are needed to confirm this. Beta-blockers have previously been associated with depression, but the current study found no significant association between beta blockers and the risk of depression. Aspirin may have antidepressant effects by suppressing the immune response, but its role as an antidepressant remains controversial. calcium channel blockers (CCBs) can regulate nerve signal transduction by adjusting calcium channels, but whether this effect is beneficial or harmful to depression remains unclear. Finally, some cases have reported that nitrates and diuretics are associated with depression, but the current clinical evidence is insufficient. Conclusions: Statins have been proven to have antidepressant effect, and the antidepressant effects of ACEIs/ARB and aspirin are still controversial. CCBs are associated with depression, but it is unclear whether it is beneficial or harmful. No association has been found with β-blockers,diuretics, and nitrates.
Efficacy and safety of a parylene-coated occluder for atrial septal defect: a prospective, multi-center,randomized controlled clinical trial

Background: Nitinol-containing devices are widely used in clinical practice. However, there are concerns about nickel release after nitinol-containing device implantation. This study aimed to compare the efficacy and safety of a parylene-coated occluder vs. a traditional nitinol-containing device for atrial septal defect (ASD). Methods: One-hundred-and-eight patients with ASD were prospectively enrolled and randomly assigned to either the trial group to receive a parylene-coated occluder (n = 54) or the control group to receive a traditional occluder (n = 54). The plugging success rate at 6 months after device implantation and the pre- and post-implantation serum nickel levels were compared between the two groups. A non-inferiority design was used to prove that the therapeutic effect of the parylene-coated device was non-inferior to that of the traditional device. The Cochran-Mantel-Haenszel chi-squared test with adjustment for central effects was used for the comparison between groups. Results: At 6 months after implantation, successful ASD closure was achieved in 52 of 53 patients (98.11%) in both the trial and control groups (95% confidence interval (CI): [-4.90, 5.16]) based on per-protocol set analysis. The absolute value of the lower limit of the 95% CI was 4.90%, which was less than the specified non-inferiority margin of 8%. No deaths or severe complications occurred during 6 months of follow-up. The serum nickel levels were significantly increased at 2 weeks and reached the maximum value at 1 month after implantation in the control group (P < 0.05 vs. baseline). In the trial group, there was no significant difference in the serum nickel level before vs. after device implantation (P > 0.05). Conclusions: The efficacy of a parylene-coated ASD occluder is non-inferior to that of a traditional uncoated ASD occluder. The parylene-coated occluder prevents nickel release after device implantation and may be an alternative for ASD, especially in patients with a nickel allergy.
Long-term Stable 2D Dion-Jacobson Phase Perovskite Photodiode with Low Dark Current and High On/off Ratio

A two-dimensional(2D) organic-inorganic hybrid perovskite(OIHP) material is considered as a promising candidate for a long-term stable photodetector owing to its outstanding phase and environmental stability.Herein, we demonstrate a perovskite photodiode based on the DJ phase 2D perovskite(PDA)(MA)_(n-1)Pb_nI_(3n+1)(where PDA is 1,3-propylenediamine, MA is methylamine, nominal n = 4).The best-performance device exhibits a high detectivity of 4.57 ×10~(11) Jones,a responsivity of 0.25 A·W~(-1) at 480 nm, a low dark current density of 9.60 ×10~(-4) mA·cm~(-2), and a remarkable on/off ratio of 3.10 ×10~5.The unencapsulated device can maintain 95% of the initial photocurrent density after 90 days under an ambient atmosphere with relative humidity(RH) of 65%, demonstrating its improved stability than the 3D counterpart.The excellent stability of the photodiode based on 2D perovskite promises its bright commercial application future.
A review of fire-extinguishing agent on suppressing lithium-ion batteries fire

Safety issue of lithium-ion batteries (LIBs) such as fires and explosions is a significant challenge for their large scale applications.Considering the continuously increased battery energy density and wider largescale battery pack applications,the possibility of LIBs fire significantly increases.Because of the fast burning and the easy re-ignition characteristics of LIBs,achieving an efficient and prompt LIBs fire suppression is critical for minimizing the fire hazards.Different from conventional fire hazards,the LIBs fire shows complicated and comprehensive characteristics,and an effective and suitable fire-extinguishing agent particularly designed for LIBs is highly desirable.Considerable efforts have been devoted to this topic,to the best of our knowledge,a comprehensive review on this regard is still rare.Moreover,in practice,a guidance for the design and selections of a proper fire-extinguishing agent for LIBs is urgently needed.Herein,the special mechanisms and characteristics for LIBs fire and the corresponding design principles for LIBs fire-extinguishing agent were introduced.It is revealed that a fire-extinguishing agent developed for LIBs fire will most likely need a high heat capacity,high wetting,low viscosity and low electrical conductivity.After a comprehensive comparison of these agents in terms of these performances,water-based fire-extinguishing agents show best.Several typical fire-extinguishing agents such as gaseous agents,dry powders,water-based and aerosol fire-extinguishing agents were then introduced,and their fire extinguishment mechanisms were presented.Finally,their effectiveness in suppressing the fire were summarized.Water-based fire-extinguishing agents possess high cooling capacity and excellent antireflash performance for the fire.We believe this review could shed light on developing an efficient fire-extinguishing agent particularly designed for LIBs.
Bismuth based photoelectrodes for solar water splitting

Photoelectrochemical water splitting is a sustainable path to generate valuable hydrogen using sunlight and water as the only inputs.Despite significant efforts to date,it is still a challenge to achieve photoelectrode with superior performance and long-term stability.Many bismuth-based semiconductor materials have demonstrated excellent visible light harvesting capability and suitable band edge for water splitting.Herein,we summarized the latest studies conducted on bismuth-based photoelectrodes for photoelectrochemical water splitting.Specifically,photoelectrochemical properties of copper bismuth oxide (CuBi_2O_4),bismuth ferrites (BiFeO_3,Bi_2Fe_4O_9),bismuth vanadate (BiVO_4),bismuth tungstate (Bi_2WO_6),bismuth molybdate (Bi_2MoO_6) and bismuth oxyhalids (BiOX,X = I,Cl,Br) are presented.Strategies to achieve high stability and photolectrochemical performance were discussed in the aspects of nanostructure formation,heterostructure assembly,practical defect engineering,preferential facet growth and oxygen evolution catalyst incorporation.
A physics-based electromigration reliability model for interconnects lifetime prediction

When the technology node scales down to 14 nm,the backend-of-line (BEOL) in IC design faces the more serious challenges.The high-density integration induced by the technology innovation increases the number of interconnecting layers and reduces the metal pitch,making the placement and routing of BEOL more difficult.Meanwhile,due to the size effects,the maximum tolerable current density in narrow dimensions of metal lines can no longer meet the requirements of driving current density in interconnects.The high current density and rapidly increasing resistivity add a large power dissipation burden to interconnects,which accelerates the reliability degradation of metal lines.Currently,the reported work has shown the exploration of electromigration (EM) reliability in advanced technology nodes by using the empirical prediction equations or the finite element methods (FEM).However,the conventional methods without the consideration of microscopic physical effects would overestimate the time-to-failure (TTF) of EM.Although the FEM-based simulation guarantees the relatively high accuracy of EM assessment,the simulated process would be time-consuming,which is not acceptable for the large-scale prediction of BEOL.
Mo_3(C_6X_6)_2 (X = NH,S,O) monolayers:two-dimensional conductive metal-organic frameworks as effective electrocatalysts for the nitrogen reduction reaction

As a constituent element of amino acids,nitrogen plays an important role in nourishing plants,animals and other forms of life.Although the atmosphere is rich in nitrogen gas (N_2),the highly inert N≡N bond makes it difficult for most organisms to directly utilize N_2.The supply of nitrogen in the biological chain mainly depends on the slow conversion of N_2 to ammonia (NH_3) by biological nitrogen fixation.Today,NH_3 can be artificially synthesized from N_2 by the Haber-Bosch method,which has laid the foundation for modern agriculture and pharmaceutical synthesis.However,the Haber-Bosch method needs to be implemented under extreme conditions including high temperature (350-550 ℃) and high pressure (150-350 atm),which consumes a large amount of fossil fuel and causes serious environmental problems.To convert N_2 into NH_3 in an environmentally friendly way,an electrochemical nitrogen reduction reaction (NRR) strategy has been proposed.The NRR strategy is achieved by a series of proton-coupled electron transfer steps under mild conditions,imitating the nitrogen fixation process of a biological nitrogenase.
Secure communication in wireless powered communication networks with energy accumulation

Wireless powered communication network (WPCN) is a wireless network where user devices are powered wirelessly by harvesting radio frequency (RF) signals transmitted by dedicated power stations or nearby power sources.WPCN is attractive for wireless networks with low-power user devices,such as wireless sensor networks and backscatter networks.Meanwhile,physical layer security (PLS) is a technique that can guarantee secure communication from the aspect of the physical layer by exploring the randomness of physical channels.PLS in WPCN is different from that in non-WPCN mainly owing to the requirement of balancing between the RF energy harvesting and secure information transmission in WPCN.Existing studies on PLS inWPCN considered that the eavesdroppers are not legitimate users in the WPCN.For the situation when the legitimate user in the WPCN is interested in other user's information,the legitimate user can be treated as an eavesdropper for other users.Such a situation is more difficult to handle because each user has to balance between transmitting their own information and eavesdropping on other users.
Structurally Diverse Matrine-Based Alkaloids with Anti-inflam-matory Effects from Sophora alopecuroides

A phytochemical investigation on the seeds of Sophora alopecuroides led to obtaining fourteen structurally diverse matrine-based alkaloids(1-14), including eight new ones(1, 6, 8-12,14).Notably, alopecuroide F(1) represents the first dimeric matrine-type skeleton assembled via unprecedent C-13-C-12' connection.The new structures were determined through extensive spectroscopic data(UV, OR, HRESIMS, 1D, and 2D NMR), ECD calculations, and three instances, verified by X-ray crystallography.Biologically, all alkaloids were evaluated for cytotoxicity against four human cancer cell lines(HepG2, A549, THP-1, and MCF-7) and anti-inflammatory activities for two pro-inflammatory cytokines(TNF-a and IL-6).Alopecuroide F(1) can inhibit TNF-a and IL-6 productions in a dose-dependent manner, with IC_(50) values of 35.6 ± 0.5 and 41.7 ± 0.8 µmol/L, respectively.
Synthesis of Hyperbranched Polymer for 3D Printing

3D printing has been developing rapidly in recent years owing to its application in academic and industry areas, but the poor mechanical property of printing materials limits its application. Herein, a photocurable resin with good mechanical property was obtained based on hyperbranched polymer synthesized through the reaction of carboxylic acids with isocya nates catalyzed by magnesium stearate. Three kinds of hyperbranched polymers with different molecular weight were fabricated by modulating the content of isocya nates. By mixing hyperbranched polymer with acryloylmorpholine, polyethylene glycol diacrylate 400 and photoinitiator of 819, the photocurable resin was obtained. The influence of various factors on mechanical properties of samples was investigated such as molecular weight of hyperbranched polymer and the light exposure time. Comparing with the commercial resin, the flexural strength (116.06 MPa) and impact strength (34.59 kJ/m~2) of the resultant resin increased by 21.2% and 20.8%, respectively.
A High Selective Chemiluminescent Probe Derived from Iso-Iuminol Enabling High Sensitive Determination of Ferrous Ions in the Environmental Waters

A new chemiluminescence (CL) reagent named 4-amino-5-thiocyanato-phthalyl-hydrazine (/so-luminol-SCN) is synthesized by the bromide-mediated substitution reaction of iso-luminol with sodium thiocyanate in dimethyl formamide (DMF) at room temperature. Strong CL is observed for iso-luminol-SCN oxidized by hydrogen peroxide (H_2O_2) in the presence of Fe~(2+), with the CL intensity strongly depending on the concentration of Fe~(2+) and being hardly interferred by other common metal ions. Based on this fact, a flow injection CL method is established for the high sensitive and selective determination of Fe~(2+). The CL intensity was linearly correlated with the concentration of Fe~(2+) in the range of 1.0 × 10~(-8) mol·L~(-1) to 1.0 × 10~(-5) mol·L~(-1) following the equation CLnet = 166.3c + 57.7 (c, ×10~(-6) mol·L~(-1); n = 7; R~2 = 0.9988). The detection limit is calculated to be 3.2 × 10~(-9) mol·L~(-1) Fe~(2+) based on the 3So/K principle. The relative standard deviation (RSD) was 3.7% for 1.0 × 10~(-6) mol·L~(-1) Fe~(2+) (n = 11), a support for the precision of Fe~(2+) measurement. The recoveries of Fe~(2+) were obtained in the range of 98.8%-101.6% in three real water samples, showing the applicability and reliability by the proposed method. The possible CL mechanism is proposed based on the kinetic characteristic of the CL reaction and the CL spectrum.
柚皮素改善非酒精性脂肪性肝病的研究进展

随着人们生活水平的提高,非酒精性脂肪性肝病(NAFLD)的发病率逐年攀升,寻找干预NAFLD的有效药物显得尤为重要。柚皮素是一类重要的天然黄酮类化合物,广泛存在于柑橘类水果和茄科植物中。柚皮素已被证实在肥胖症和NAFLD的治疗方面具有显著的药理作用,包括减轻体重、改善氧化应激和胰岛素抵抗、减少炎症反应、调节脂质代谢、脂肪酸氧化和减少细胞凋亡等。笔者着重对柚皮素治疗NAFLD的效用及其分子机制进展进行综述,以期为柚皮素治疗NAFLD的临床应用提供良好的前景。
美丽乡村建设视野下农业旅游的可持续性研究

“美丽乡村”建设是我国社会主义新农村建设的一个升级阶段,是建设中国社会主义新农村进程中的一个重要组成部分,其核心在于解决乡村发展理念、乡村经济发展、乡村空间布局、乡村人居环境、乡村生态环境、乡村文化传承以及实施路径等问题。美丽乡村建设既是美丽中国建设的重要部分,也是城乡协调发展的重要组成部分。没有农业和农村的绿色发展,就没有整个中国的绿色发展;没有美丽乡村建设,也不会实现美丽中国。
朦胧倩影:中世纪寺院医学模式时期的围产医学和女性医学的萌芽

上期我们介绍了中世纪位于意大利的萨勒诺医学院。这所医学院是当时欧洲医学的中心,以古希腊医学家希波克拉底和古罗马医学家盖仑的理论作为教学核心,融合业已成熟的阿拉伯医学,组织人员翻译了大量医学典籍的拉丁语版本译著,一度为与当时宗教医学对立的世俗医学发展奠定了基础。
南京市蚊虫空间分布预测及土地利用驱动因素分析

目的:利用蚊虫监测点数据和遥感数据对南京市蚊虫空间分布进行预测,并对影响蚊虫的土地利用驱动因素进行分析。方法:基于ArcGIS地统计学的经验贝叶斯克里格模型进行空间预测并进行交叉验证,基于地理探测器对蚊虫土地利用驱动因素进行因子、交互和生态探测。结果:对蚊虫空间分布进行预测,发现南京市蚊虫空间分布整体呈北高南低的趋势,预测决定系数R~2=0.924 3;水田和水库坑塘、城镇用地和农村居民点分别是影响蚊虫分布的水域和城乡土地利用驱动因素。结论:利用经验贝叶斯克里金插值技术结合地理探测器可以对蚊虫空间分布进行预测并探索蚊虫土地利用驱动因素,结果能真实反映南京地区蚊虫侵害现状及土地利用驱动因素,可以为制定地区爱国卫生政策和开展蚊媒病预防控制提供科学依据。
仑伐替尼治疗晚期肝癌致单侧间质性肺炎并空洞形成1例

仑伐替尼作为分子靶向治疗的一线用药,应用较广,其不良反应需要关注。在此,报道一例晚期肝癌患者在口服仑伐替尼治疗期间出现单侧间质性肺炎伴空洞形成。
空气污染对过敏性疾病发生的影响研究进展

长期或短期暴露于空气污染会损害健康,空气污染是许多疾病(包括过敏性疾病)发病和死亡的原因。本文概述了空气污染对过敏性疾病影响的研究现状,重点介绍了空气污染对过敏性疾病影响的作用机制,并提出了未来的研究建议。
白脂素:运动防治代谢性疾病的新靶点

白脂素(Asprosin)是一种由禁食诱导的新型脂肪因子,具有促进食欲、升高血糖、引起胰岛β细胞炎症反应的作用。Asprosin在肥胖、2型糖尿病、多囊卵巢综合征等疾病发生发展中的作用已有报道。近些年来的研究表明,Asprosin受运动调控,并在改善机体代谢紊乱的过程中发挥一定作用。本文针对Asprosin在运动防治代谢性疾病中的作用进行综述,以期为运动防治代谢性疾病提供新的理论依据。
RMRP基因新发变异致软骨毛发发育不全并重症联合免疫缺陷病一例

1例合并重症联合免疫缺陷表现的软骨毛发发育不全患儿,临床主要表现为短肢矮小,干骺端发育不良,重症联合免疫缺陷以及骨髓造血衰竭。基因分析显示患儿RMRP基因存在新的复合杂合变异。该变异导致RMRP基因mRNA表达水平下降,可能引起细胞周期调控异常和端粒功能障碍。
KRT74基因变异致脱发一例

患儿男,14岁,因"生后毛发少,脱发4年"于2019年9月就诊于重庆医科大学附属儿童医院风湿免疫科,患儿自出生起全身毛发稀少,10岁开始出现脱发,全身皮肤无汗毛、腋毛及胡须生长,伴有指、趾甲发育不良。既往有甲状腺炎。基因检测发现KRT74基因变异(c.373delC),可致毛发稀少及青春期脱发症状,尚未见报道。
儿童风湿免疫性疾病的诊断与治疗:循证和精准的完美结合

儿童风湿免疫性疾病发病机制复杂,病情重且临床异质性强;诊断方法及治疗药物进展迅速,控制疾病同时要兼顾儿童的生长发育需要,诊断和治疗难度大。如何在运用已有的循证学证据的基础上,结合患儿的基因背景和个体差异,做到精准诊治,给儿童风湿免疫专科提出了很大的挑战,也是所有风湿免疫专科医生应该追求的完美医术。
第548例皮肤黏膜出血一咯血一胸痛一血小板减少一肺部实变影

本文报道1例病程中曾有皮肤黏膜出血、咯血、胸痛、血小板减少和肺部实变影的患者,经检查确诊为慢性弥漫性血管内凝血(DIC)合并肺栓塞,经抗凝治疗后病情明显缓解。DIC是一组以不同病因导致的凝血系统活化,凝血酶生成增加以及广泛微血栓形成为病生理特征的获得性临床综合征。其中慢性DIC发病隐匿,病程较长,部分实验室指标可因代偿而变化不明显,临床中难于识别和诊断。
全身麻醉下叠加高频喷射通气应用的研究进展

叠加高频喷射通气(SHFJV)是由Aloy等于1991年首次提出,即通过叠加常频(8~20次/min)和高频(400 ~ 800次/min)喷射通气以增加呼气末肺容积和改善氧合,而无需常规气管插管的一种通气方式。作为一种新的通气技术,该技术最早应用于成人的喉外科手术,后来该通气技术成功用于儿童喉外科手术。随着该技术及设备的日臻完善,SHFJV的适用范围得以拓展,在国外已被广泛应用于包括呼吸、ICU、耳鼻喉、急诊等临床科室。对某些特定疾病,尤其是气道相关疾病,SHFJV起到了很好的辅助治疗作用,增加了治疗的安全性和有效性,但该技术国内鲜有知晓,应用更无从谈起。为此,本文拟就SHFJV的工作原理、安全性和危险因素、临床应用等方面对其进行综述。
SARS-CoV-2 immunity and functional recovery of COVID-19 patients 1-year after infection

The long-term immunity and functional recovery after SARS-CoV-2 infection have implications in preventive measures and patient quality of life.Here we analyzed a prospective cohort of 121 recovered COVID-19 patients from Xiangyang, China at 1-year after diagnosis.Among them, chemiluminescence immunoassay-based screening showed 99% (95% CI, 98-100%)seroprevalence 10-12 months after infection, comparing to 0.8% (95% CI, 0.7-0.9%)in the general population.Total anti-receptor-binding domain (RBD)antibodies remained stable since discharge, while anti-RBD IgG and neutralization levels decreased over time.A predictive model estimates 17% (95% CI, 11-24%)and 87% (95% CI, 80-92%)participants were still 50% protected against detectable and severe re-infection of WT SARS-CoV-2, respectively, while neutralization levels against B.1.1.7 and B.1351 variants were significantly reduced.All non-severe patients showed normal chest CT and 21% reported COVID-19-related symptoms.In contrast, 53% severe patients had abnormal chest CT, decreased pulmonary function or cardiac involvement and 79% were still symptomatic.Our findings suggest long-lasting immune protection after SARS-CoV-2 infection, while also highlight the risk of immune evasive variants and long-term consequences for COVID-19 survivors.
Groundwater pollution and human health risk based on Monte Carlo simulation in a typical mining area in Northern Anhui Province, China

The main objective of this study was to evaluate eight kinds of trace element pollutants in groundwater from a typical coal mine area, and carry out a corresponding health risk assessment for the local populace. To do this, 34 shallow groundwater (SG) samples and 18 mid-layer groundwater (MG) samples were collected from the Sulin mining area. To minimize the uncertainties in the health risk assessment, this paper relied on Monte Carlo simulations and sensitivity analysis. The results revealed that Sr and Mn contents exceeded their corresponding WHO (Guidelines for drinking water quality, 4th edn. Geneva, 2011) guidelines and Chinese groundwater standards (GB/T14848–2017), while the other analyzed trace elements remain below those threshold values. The calculated hazard quotient and hazard index values for adults from ingestion exposure to SG and MG were well below the threshold limit of 1. Probabilistic simulations further show that the total cancer risk value above the limit of 1 × 10~(-6) is 0% for SG and 29.39% for MG. Sensitivity analysis identified the Sr and Cr contents as the most relevant element variables affecting the probabilistic non-carcinogenic and carcinogenic risk values in the model, respectively.
Characteristics of evolution of mining-induced stress field in the longwall panel: insights from physical modeling

The evolution of mining-induced stress field in longwall panel is closely related to the fracture field and the breaking characteristics of strata. Few laboratory experiments have been conducted to investigate the stress field. This study investigated its evolution by constructing a large-scale physical model according to the in situ conditions of the longwall panel. Theoretical analysis was used to reveal the mechanism of stress distribution in the overburden. The modelling results showed that: (1) The major principal stress field is arch-shaped, and the strata overlying both the solid zones and gob constitute a series of coordinated load-bearing structures. The stress increasing zone is like a macro stress arch. High stress is especially concentrated on both shoulders of the arch-shaped structure. The stress concentration of the solid zone in front of the gob is higher than the rear solid zone. (2) The characteristics of the vertical stress field in different regions are significantly different. Stress decreases in the zone above the gob and increases in solid zones on both sides of it. The mechanical analysis show that for a given stratum, the trajectories of principal stress are arch-shaped or inverselyarched, referred to as the ‘‘principal stress arch’’, irrespective of its initial breaking or periodic breaking, and determines the fracture morphology. That is, the trajectories of tensile principal stress are inversely arched before the first breaking of the strata, and cause the breaking lines to resemble an inverted funnel. In case of periodic breaking, the breaking line forms an obtuse angle with the advancing direction of the panel. Good agreement was obtained between the results of physical modeling and the theoretical analysis.