Failure behavior around a circular opening in a rock mass with non-persistent joints:A parallel-bond stress corrosion approach

The stability of underground excavations is influenced by discontinuities interspaced in surrounding rock masses as well as the stress condition. In this work, a numerical study was undertaken on the failure behavior around a circular opening in a rock mass having non-persistent open joints using PFC software package. A parallel-bond stress corrosion(PSC) approach was incorporated to drive the failure of rock mass around the circular opening, such that the whole progressive failure process after excavation was reproduced. Based on the determined micro parameters for intact material and joint segments, the failure process around the circular opening agrees very well with that obtained through laboratory experiment. A subsequent parametric study was then carried out to look into the influence of lateral pressure coefficient, joint dip angle and joint persistency on the failure pattern and crack evolution of the rock mass around the circular opening. Three failure patterns identified are step path failure, planar failure and rotation failure depending on the lateral pressure coefficient. Moreover, the increment of joint dip angle and joint persistency aggravates the rock mass failure around the opening. This study offers guideline on stability estimation of underground excavations.

Numerical simulations of failure behavior around a circular opening in a non-persistently jointed rock mass under biaxial compression

Pre-existing discontinuities change the mechanical properties of rock masses,and further influence failure behavior around an underground opening.In present study,the failure behavior in both Inner and Outer zones around a circular opening in a non-persistently jointed rock mass under biaxial compression was investigated through numerical simulations.First,the micro parameters of the PFC^(3D) model were carefully calibrated using the macro mechanical properties determined in physical experiments implemented on jointed rock models.Then,a parametrical study was undertaken of the effect of stress condition,joint dip angle and joint persistency.Under low initial stress,the confining stress improves the mechanical behavior of the surrounding rock masses;while under high initial stress,the surrounding rock mass failed immediately following excavation.At small dip angles the cracks around the circular opening developed generally outwards in a step-path failure pattern;whereas,at high dip angles the surrounding rock mass failed in an instantaneous intact rock failure pattern.Moreover,the stability of the rock mass around the circular opening deteriorated significantly with increasing joint persistency.

Research on Open Block's Pedestrian System Based on the EnvironmentBehavior Theory: A Case Study of Shenzhen Oct-loft

In the context of banning gated communities, blocks returning to the human-oriented scale become the new normal, and pedestrian system design will be paid more attention in the urban planning field. Oct-Loft Creative Park is a template for open blocks in Shenzhen, with a convenient and humanized pedestrian system. This paper selects the creative park's pedestrian system as the research object, using the environment-behavior theory for analysis. Finally, optimization strategies of pedestrian system will be put forward.

Shear Behavior of Open Steel Tube Connectors in Steel⁃UHPC Composite Decks

Steel and ultra⁃high performance concrete(UHPC)composite decks are effective at reducing fatigue cracking and asphalt pavement damage.The shear behavior of innovative open steel tube(OST)connectors in steel⁃UHPC composite decks was investigated by conducting push⁃out tests.The test parameter is the presence of reinforcement in the deck.The load⁃slip curves and shear behavior of the push⁃out specimens were obtained and discussed.The test results indicate that as compared with plain concrete specimens,the limit slip of reinforced specimens decreased by 32%and the shear stiffness increased by 10%,but the ultimate shear capacity was almost the same.The use of UHPC influenced the failure process as it was observed that the OST connector was sheared off at its lower semi⁃tube,followed by the pull⁃out failure of the upper semi⁃tube.A finite element model was verified by tests and was then used to analyze the deformation and failure behaviors of the composite deck with open tubes.The model demonstrates that there is a stress concentration zone at the connector root,and the lower semi⁃tube is the main component that is subject to loads.

Suicide risk in juvenile open angle glaucoma patients

AIM:To investigate the association between juvenile open angle glaucoma(JOAG)and mental health among Koreans.METHODS:This study used nationally representative data from the 8th Korea National Health and Nutrition Examination Survey(KNHANES)2021.Glaucoma diagnosis followed the International Society of Geographical and Epidemiological Ophthalmology criteria based on glaucomatous structural defects,visual field defects,corrected vision,and intraocular pressure.As outcomes,suicidal behaviors,psychiatric counseling,and depression were evaluated through mental health questionnaires.Odds ratios(ORs)with 95%confidence intervals(CIs)were estimated using logistic regression models,adjusting for covariates.RESULTS:Among 7090 participants,3446 met the inclusion criteria for analysis,and 88(2.6%)were diagnosed with open angle glaucoma(OAG).After adjusting for age,sex,and best-corrected visual acuity(VA),participants with OAG were revealed to have significantly higher odds of suicidal behaviors(i.e.,ideation,planning,or attempts)compared with those without OAG(OR:2.70;95%CI:1.12-6.54;P=0.028).This association remained significant after further adjustments for socioeconomic status,lifestyle factors,and presence of chronic conditions(P=0.031 and 0.035,respectively).However,there was no significant difference for the other two outcomes,psychiatric counseling and depression.An age-stratified analysis revealed a stronger association between OAG and suicidal behaviors in younger JOAG participants(<40y)than in older OAG participants(≥40y;OR:3.80 vs 2.22;95%CI:0.79-18.22 vs 0.56-8.80,respectively).CONCLUSION:OAG patients show a higher risk of suicidal behaviors than those without glaucoma particularly in JOAG patients.

基于Open Inventor的虚拟数控培训系统开发

针对传统数控培训中存在的场地受限、经费不足等问题,结合虚拟现实与人机交互等技术,提出了一种基于Open Inventor的数控培训系统实现方案。阐述了虚拟数控培训系统的软硬件开发平台,给出了软件系统的结构框架及开发流程。重点研究了虚拟加工场景的绘制及其模型优化、数控代码编译处理,给出事件处理的编程模型,并以直线进给为例阐述了机床的运动行为仿真。运用Open Inventor工具包在Visual C++6.0环境下实现初步原型系统,该系统运行效果良好。

宁心解郁胶囊对慢性应激抑郁模型大鼠Open-Field行为的影响

[目的]探讨宁心解郁胶囊的抗抑郁作用及可能的机制。[方法]以孤养加慢性轻度不可预见性应激方法建立大鼠抑郁模型,用Open-Field方法进行行为学评定,观察模型大鼠给药前后的行为学变化。[结果]经过孤养加慢性轻度不可预见性应激方法造模后的大鼠,Open-Field行为学评定中模型组大鼠的总路程、平均速度、中央活动路程、中央活动时间、各角的活动路程和时间均较空白组有统计学差异(P<0.05)。治疗后大鼠的总活动路程、平均速度、中央活动时间、中央活动路程、下边活动路程、下边活动时间、各角的活动路程和时间均较模型组有统计学差异(P<0.05),活动路程较模型组增加,活动时间较模型组增加,且以中剂量组效果显著。[结论]宁心解郁胶囊具有抗抑郁作用,对大鼠抑郁行为有明显改善。

应用OpenSees计算双钢管高强砼柱的水平力—位移滞回曲线

应用OpenSees计算外方内圆复合钢管高强混凝土柱(简称双钢管高强混凝土柱)的水平力—位移滞回曲线。分析了双钢管高强混凝土柱的单元和截面纤维划分。钢管材料采用双线性模型Steel02,混凝土模型采用Concrete02,圆钢管内和钢管之间的混凝土采用Susantha模型,考虑钢管对混凝土的约束作用,计算得到的水平力—位移滞回曲线与试验结果符合较好。在此基础上,应用OpenSees对双钢管高强混凝土柱进行参数影响分析,讨论了轴压比、方钢管壁厚(宽厚比)、径宽比、径厚比对双钢管高强混凝土柱抗震性能的影响。结果表明:增大轴压比,延性降低;增大方钢管壁厚(减小宽厚比),水平承载力增大;增大圆钢管直径和壁厚,有助于提高双钢管高强混凝土柱的竖向和水平承载力能力,增大耗能能力。

Development of a PC-based Open Architecture Software-CNC System

As a key te..hnology in the field of advanced manufacturing, an open architecture controller is studied. In order to develop an open architecture software-CNC system on personal computer （PC） according to open modular architecture controllers （OMAC）. First, the software and hardware platform is chosen and software realization methodology for the CNC system is determined. Second, static modeling methods of an open architecture controller inclusive of object-oriented （OO） programming technology, dynamic link library （DLL） technology and system modules partition are investigated. Third, the dynamical behavioral modeling and the data flow representation of open architecture controller are discussed, which are both described in hierarchy fmite state machine （FSM） model. Fourth, a reusable software module model is established to develop software function module library. Finally, a 3-axis milling machine tool test-bed, named for HIT-CNC, is successfully designed by means of the constructed software function module library and the system configuring method. The experimental results show that, besides increasing the degree of reusability and openness, application of above-mentioned method- ology leads to significant decrease of development time as well as maintenance cost.

Open-Innovation in the Electrical and Electronic Industries: Engineered Bio-Fluid Compositions Are Paving the Way, and Testing Therewith

Engineered Biofluids are paving the way to industrialized and specifically produced and tailored functional fluids such as coolant and dielectric, high purity traceable media, for the electrical and electronic industries. Dielectric fluid compositions are commonly used in electrical devices, particularly in transformers. These liquids have the aim to isolate the various conductive elements of the device and to limit the heating of the equipment during its operation;in order to minimize, or maintain at higher power, the size of the device and to increase the lifespan of it. Concomitantly a number of bio and traditional processing advancements are made associated with pioneering process technologies which are outlined within the prime context of this paper. Enzyme Engineering and Cocktailing add “A New Dimension to Softer Greener Chem-Bio Approaches” which are referenced beyond curiosity purpose. Some of them are possibly “revolutionary” more than evolutionary. Testing has to evolve accordingly to appreciate the challenges ahead in semi-extreme conditions which are relevant to climate changes as well. A significant part of this orientation work addresses and exemplifies these necessary testing innovations, likely adaptable to smart and responsive connecting, and further down the line bigger data role and learning machine evolutionary concepts. One other innovative part of this exploratory work, is the influence that such illustrative localized testing, with integrated sensors/induced-tracers, and online interpretation, may have on the smart grid developments;whereby production, transmission, distribution and consumption of energy can be made more reliable, more effective and more predictive and can also have an impact on the performance, reliability and sustainability of the equipment itself. Those technologies and associated testing can support environmental, technological and societal awareness;helping to revert some trends being climate changes, fossil fuel preservation and other planetary challenges to maintain the overall and localized fundamental equilibriums.

基于OpenPose的自动扶梯智能监控系统应用研究

基于OpenPose算法的研究与改进,从目标检测、特征提取及分类、行为识别算法等理论问题研究入手,进行系统方案设计,开发针对自动扶梯乘降人员摔倒等异常行为的智能监控及预警系统。通过智能算法对乘降人员摔倒等异常行为的分析,及时对自动扶梯的运行状态进行预警报警,从而提高人员乘坐自动扶梯的安全性。

Finite Element Modelling of Steel Beams with Web Openings

Height limitations are not uncommon in multi-storey buildings due to economic requirements and esthetical considerations. Substantial spaces are normally required to enable the passage of large pipes and ducts beneath steel beams leading to uneconomic floor heights. The most adopted solution for this issue is the use of steel beam web openings to provide the required space for services. These openings could lead to a significant decrease of the beam load carrying capacity depending on the adopted openings shape, size and location. These aspects motivated the present study based on FE simulations calibrated against numerical and test results. The results accuracy enabled a comprehensive parametric analysis of beams with web openings to be made focused on the profile size, web opening location, among others. The study also investigated the efficiency of longitudinal stiffeners welded at the opening region and benefits of using an adequate edge concordance radius in beams with rectangular and square openings. The obtained results showed the need of using welded longitudinal stiffeners in order to increase the beams ultimate load carrying capacity. This adoption can double or even triple the ultimate load of beams with rectangular and square opening heights equal to 0.75 H, respectively.

A Pair of 3D Homochiral Coordination Polymers with Open Channels Constructed by Lactic Acid Derivative Ligands and In-situ Formed Anions

With the help of in-situ formed CH_3COO- anion, a pair of 3D homochiral coordination polymers with open channels were constructed by the assembly of lactic acid derivative ligands, 1.4-DIB ligands and Cd（II） ions, namely [Cd3（（R）-CIA）2（CH3CO2）_2（1.4-DIB）2（H2O）2]·x（Guest）（1-D） and [Cd3（（S）-CIA）2（CH3CO2）2（1.4-DIB）2（H2O）2]·x（Guest）（1-L）. They contain 1D interesting ladder-like Cd-（R）-CIA（3-） chains and exhibit SHG-active behavior and photoluminescent property.

Influence of nitric oxide synthase inhibitor on gerbil behavior after hyperbaric oxygen-induced convulsion

BACKGROUND：Studies have reported that nitric oxide synthase （NOS） inhibitor can prolong the latency of hyperbaric oxygen-induced convulsion （HBOC）. However, there are very few reports addressing the influence of NOS inhibitor on mental behavior. OBJECTIVE： To investigate behavioral changes after HBOC in gerbils, as well as the influence of NOS inhibitor. DESIGN, TIME AND SETTING： Randomized experiments were performed in the Laboratory of Hyperbaric Pressure and Diving Physiology, Naval Medical Research Institute of Chinese PLA （Shanghai, China） from March 2005 to June 2007. MATERIALS： Forty male gerbils were randomly divided into five groups： HBOC, saline control, NOS inhibitor, pressure control, and normal control. Each group contained eight animals. METHODS： In the HBOC group, once depression induction ended, animals were removed from the chamber five minutes after the first appearance of generalized convulsion induced by 0.5 MPa hyperbaric oxygen. Ten minutes before entering the chamber, saline control and NOS inhibitor animals were intraperitoneally injected with 1 mL saline and 20 mg/kg NG-nitro-L-arginine, respectively. The pressure control group was only exposed to 0.5 MPa. The remaining procedures in these three groups were identical to the HBOC group. The normal control group received no intervention. MAIN OUTCOME MEASURES： Open field test scores in gerbils prior to HBOC, as well as immediately, 24 hours, and 72 hours after decompression ended. RESULTS： HBOC was not detected in either the normal control or the pressure control group, and there were no significant differences in open field test scores prior to and after HBOC （P 〉 0.05）. HBOC occurred in the HBOC, saline control, and NOS inhibitor groups, with significant differences in open field test scores after decompression ended compared to normal control and pressure control groups （P 〈 0.05–0.01）. Compared to the HBOC and saline control groups, the NOS inhibitor group exhibited a significantly lower score in the open field test immediately after decompression, and a higher score at 24 and 72 hours （P 〈 0.05–0.01）. CONCLUSION： NOS inhibitor can regulate behavioral changes in gerbils after HBOC.

Consumer Knowledge, Brand Image, Openness to Experience and Involvement: A Case in Cosmetic Consumption

The study adopted the theory of planned behavior (TPB) as research model to inspect what factors would influence consumers to purchase cosmetics by adding brand image, involvement, consumer knowledge and openness to experience to the model. A 7-point Likert scale questionnaire was designed to measure TPB items and totally 400 valid respondents were collected online. The results show that among the above, only “perceived behavioral control” has positive influence on intention of purchasing cosmetics. Neither attitude nor subjective norm has significant influence on purchasing intention. In addition, brand image and involvement have no significant influence on purchasing intention but consumer knowledge and openness to experience were found to have positive influence on purchasing intention.

Numerical Simulation of the Behavior of Cracked Reinforced Concrete Members

Refined non-linear static or dynamic analyses of reinforced concrete structures require the knowledge of the actual force-displacement or bending moment-rotation curves of each structural member, which depend on the crack widths and on the crack pattern, and after all on the slip between concrete and reinforcing steel. For this reason the definition of improved local models taking into account all these local aspects is a fundamental prerequisite for advanced assessment of r.c. structures. A numerical procedure which allows to predict the relative displacement between steel reinforcement and the surrounding concrete in a reinforced concrete element, once assigned the stress in the naked steel bar and the bond-slip law is discussed. The method provides as final outcomes the sequence of crack openings and the individual crack widths, regardless of the particular bond-slip correlation adopted. The proposed procedure is implemented referring to two relevant experimental case studies, demonstrating that it is able to predict satisfactorily actual strain fields and slips along the investigated reinforced concrete elements.

数字化转型、开放式创新有效性与企业核心技术突破

加速数字化转型和推进开放式创新作为企业提升创新能力的重要策略,对于企业推进制造领域的核心技术突破同样至关重要。文章在筛选匹配企业研发专利数据与制造领域核心技术专利IPC分类号的基础上,基于2013—2021年A股上市企业数据,实证检验数字化转型对企业核心技术突破的推进作用以及开放式创新是否为该过程的有效传导机制。研究结果表明:数字化转型有助于企业推进制造领域的核心技术突破,企业推进开放式创新的具体程度会在此过程中发挥中介效应机制,且技术供给方企业、非国有企业和东部地区企业推进开放式创新的有效性更高;而企业是否推进开放式创新可能受其策略性行为影响,并不是有效的中介机制。进一步研究发现,金融科技发展水平和知识产权保护水平越高的地区,数字化转型背景下的开放式创新对企业核心技术突破的推进作用越强。本文不仅为企业通过数字化转型推进制造领域核心技术突破提供了新的研究思路,也侧面证明在数字化转型背景下更为重要的是企业推进开放式创新的具体程度和有效性,以及金融科技、知识产权保护等创新辅助要素对“新型举国体制”的赋能作用,进而为实现国家科技自立自强提供了有益对策启示。

开放性公共场所人员疏散行为倾向分析

开放性公共场所人群聚集风险突出,常规的疏散措施不能有效缓解场所内外的人群聚集风险态势,需要掌握突发情况人员疏散行为特征。选择深圳东门步行街为研究区,开展人员疏散行为问卷调查,根据人群聚集状态拟定人员疏导服从性、聚集拥堵应对和应急疏散响应3类疏散行为倾向场景,并采用SPSS 25.0卡方检验分析性别、年龄段、群组等基本特征与人员疏散行为倾向之间的相关性。研究结果表明:步行街存在老幼群体、携带包裹、环境熟悉度低等影响疏散效率的因素;小部分人在面对疏导、遭遇聚集拥堵情形后可能采取继续停留拍照、长时间等候、围观等聚集行为,以及在被疏散至安全地带后围观甚至返回,这些行为可能导致场所内部聚集得不到有效缓解,并在外围形成新的人群聚集风险点;“男性、大群组、短期游客”三类群体的疏散行为表现不佳,聚集围观、停留以及返回的比例更高,尤其是同行人数4人及以上的大群组更可能采取往前挤这种危害行为。

打开同行评议的“黑匣子”:专家评审行为特征分析

传统同行评议制度由于数据不透明、缺乏监督等问题饱受诟病,开放同行评议为揭开同行评议的黑盒、加强同行评议过程监督、规范评审行为提供了契机。文章基于Open Review平台2017-2019年ICLR会议的2,534篇论文及7,602份专家评审意见,结合定量和定性的方法从专家自信度、评审模式和论文评议结果等3个维度分析专家的评审行为特征分布。研究发现:在专家自信度上,自信度高的评审专家更了解论文的研究内容,更能给出差异化的评审打分和针对性的评审意见;在评审模式上,相较于单盲评审,双盲评审模式下评审专家打分更加严格,更少提及论文语言表达方面的不足;在评审决议结果维度上,评审专家对论文核心内容的评价是决定论文最终评议的重要依据,在实验设计和原创水平方面得到更多正面评价的论文,更有可能获得更好的评审决议。文章从评审专家的遴选、评审模式的选择和评审指标的设置等3个方面提出建议,以提高同行评议质量、推动同行评议改革。

资本市场开放与企业策略性创新行为——基于外部监督的分析

文章立足于“沪港通”的制度背景,选取2010—2022年沪深A股非金融上市公司为研究对象,研究资本市场开放与企业策略性创新行为的关系。实证研究发现:第一,资本市场开放能提高授权专利中发明专利的占比,显著改善企业专利结构,提高专利质量;第二,从外部监督的角度机制分析发现,资本市场开放会通过增加监管机构和媒体监督产生聚光灯效应,进而减少通过策略性创新的市值管理行为;第三,动机分析发现,在资本市场开放下,企业出于防范崩盘风险和向市场传递特质性信息的目的,会减少策略性创新行为,提高专利质量;第四,资本市场开放对非国有企业和信息不对称较高的企业策略性创新行为抑制作用更加明显。本研究对于充分利用资本市场开放助力实体经济发展,推动企业实质性创新具有借鉴意义。