Geometry and formation mechanism of tension gashes and their implication on the hydrocarbon accumulation in the deep-seated strata of sedimentary basin:A case from Shunnan area of Tarim Basin

With the theoretical and technological developments related to cratonic strike-slip faults,the Shuntuoguole Low Uplift in the Tarim Basin has attracted considerable attention recently.Affected by multi-stage tectonic movements,the strike-slip faults have controlled the distribution of hydrocarbon resources owing to the special fault characteristics and fault-related structures.In contrast,the kinematics and formation mechanism of strike-slip faults in buried sedimentary basins are difficult to investigate,limiting the discussion of these faults and hydrocarbon accumulation.In this study,we identified the characteristics of massive sigmoidal tension gashes(STGs)that formed in the Shunnan area of the Tarim Basin.High-resolution three-dimensional seismic data and attribute analyses were used to investigate their geometric and kinematic characteristics.Then,the stress state of each point of the STGs was calculated using seismic curvature attributes.Finally,the formation mechanism of the STGs and their roles in controlling hydrocarbon migration and accumulation were discussed.The results suggest that:(1)the STGs developed in the Shunnan area have a wide distribution,with a tensile fault arranged in an enéchelon pattern,showing an S-shaped bending.These STGs formed in multiple stages,and differential rotation occurred along the direction of strike-slip stress during formation.(2)Near the principal displacement zone of the strike-slip faults,the stress value of the STGs was higher,gradually decreasing at both ends.The shallow layer deformation was greater than the deep layer deformation.(3)STGs are critical for connecting source rocks,migrating oil and gas,sealing horizontally,and developing efficient reservoirs.This study not only provides seismic evidence for the formation and evolution of super large STGs,but also provides certain guidance for oil and gas exploration in this area.

Unveiling the silent link:Normal-tension glaucoma's enigmatic bond with cardiac blood flow

This comprehensive review embarks on a captivating journey into the complex relationship between cardiology and normal-tension glaucoma(NTG),a condition that continues to baffle clinicians and researchers alike.NTG,characterized by optic nerve damage and visual field loss despite normal intraocular pressure,has long puzzled clinicians.One emerging perspective suggests that alterations in ocular blood flow,particularly within the optic nerve head,may play a pivotal role in its pathogenesis.While NTG shares commonalities with its high-tension counterpart,its unique pathogenesis and potential ties to cardiovascular health make it a fascinating subject of exploration.It navigates through the complex web of vascular dysregulation,blood pressure and perfusion pressure,neurovascular coupling,and oxidative stress,seeking to uncover the hidden threads that tie the heart and eyes together in NTG.This review explores into the intricate mechanisms connecting cardiovascular factors to NTG,shedding light on how cardiac dynamics can influence ocular health,particularly in cases where intraocular pressure remains within the normal range.NTG's enigmatic nature,often characterized by seemingly contradictory risk factors and clinical profiles,underscores the need for a holistic approach to patient care.Drawing parallels to cardiac health,we examine into the shared vascular terrain connecting the heart and the eyes.Cardiovascular factors,including systemic blood flow,endothelial dysfunction,and microcirculatory anomalies,may exert a profound influence on ocular perfusion,impacting the delicate balance within the optic nerve head.By elucidating the subtle clues and potential associations between cardiology and NTG,this review invites clinicians to consider a broader perspective in their evaluation and management of this elusive condition.As the understanding of these connections evolves,so too may the prospects for early diagnosis and tailored interventions,ultimately enhancing the quality of life for those living with NTG.

Analysis of factors affecting diagonal tension and compression capacity of corner joints in furniture frames fabricated with dovetail key

This study was conducted to analyze the effect of joint type, and numbers and types of dovetail keys on diagonal tension and compression performance of corner joints in a furniture frame. Joint members were cut from white fir lumber. Butted and mitered joints were constructed with one and two dovetail key（s） with butterfly and H shapes. Joints were glued by polyvinyl acetate （PVAc） and cynoacrylate （CA）. Compression capacity of joints was higher than diagonal tension. Mitered joints were stronger than butted ones. Butterfly dovetail keys were superior to H shape keys. Double keys performed better than single key. Experimental joints glued with PVAc were stronger than those glued with CA glue and control specimens. In terms of strength, butterfly dovetailed joints were comparable with doweled joints.

ANALYTICAL SOLUTIONS TO STRESS CONCENTRATION PROBLEM IN PLATES CONTAINING RECTANGULAR HOLE UNDER BIAXIAL TENSIONS

The stress concentration problem in structures with a circular or elliptic hole can be investigated by analytical methods. For the problem with a rectangular hole, only approximate results are derived. This paper deduces the analytical solutions to the stress concentration problem in plates with a rectangular hole under biaxial tensions. By using the U-transformation technique and the finite element method, the analytical displacement solutions of the finite element equations are derived in the series form. Therefore, the stress concentration can then be discussed easily and conveniently. For plate problem the bilinear rectangular element with four nodes is taken as an example to demonstrate the applicability of the proposed method. The stress concentration factors for various ratios of height to width of the hole are obtained.

Prestressed tensioning method and its application to testing anchor stress of anchor cables for side-slope stabilization

The anchor stress extent of a prestress anchor cable project has a direct relation with the project safety and performance. Prestressed tensioning method is a kind of nondestructive testing method, by which a reverse stretching load is applied on the external exposure section of anchor cable under construction or in service, and then the elongation variation of stress bars is measured to determine the anchor stress. We elaborated the theory and testing mechanism of prestressed tensioning method, and systematically studied key issues during the prestressed tensioning process of anchor cable by using physical model test, including the composition of tension stress-elongation curve, the variation of anchor stress, the compensation of locked anchor stress, and the judgment of anchor stress, and verified the theory feasibility of prestressed tensioning method. A case study on slope anchor cable of one highway project was conducted to further discuss on the test method, operation procedures and judgment of prestressed tensioning method on obtaining anchor stress, and then the test data of three situations were analyzed. The result provides a theoretical basis and technical base for the application of prestressed tensioning method to the evaluation of construction quality and operation conditions of anchor cable project.

Transverse Distributions of Front and Back Tension Stresses in Cold Strip Rolling

In this paper,such a new lateral displacement function is proposed that the lateral flow velocity is con- tinuous at the entry and the exit of deformation zone.A new kind of finite strip method—the third power B-spline finite strip method—is put forward to simulate strip rolling process.Front and back tension stresses are formulated.The computed results of the transverse distributions of the front and back tension stresses are close to the experimental results.The paper lays a foundation for further analysing the three-dimensional stresses and deformations of strip rolling.

THE STRESS SUBSPACE OF HYBRID STRESS ELEMENT AND THE DIAGONALIZATION METHOD FOR FLEXIBILITY MATRIX H

The following is proved: 1) The linear independence of assumed stress modes is the necessary and sufficient condition for the nonsingular flexibility matrix; 2) The equivalent assumed stress modes lead to the identical hybrid element. The Hilbert stress subspace of the assumed stress modes is established. So, it is easy to derive the equivalent orthogonal normal stress modes by Schmidt's method. Because of the resulting diagonal flexibility matrix, the identical hybrid element is free from the complex matrix inversion so that the hybrid efficiency, is improved greatly. The numerical examples show that the method is effective.

Design and Analysis of Tapered Stress Joint for Top Tensioned Riser System

Stress Joint （SJ） plays a key role in the Top Tensioned Riser （TTR） system for deep water engineering. A preliminary design method of tapered SJ is proposed in the paper, which could help designers obtain accurate design data. After a further sensitive analysis is carried out, the related parameters choice and control methods are recommended in the engineering practice. By taking the extreme environment conditions into consideration, the effects of bending stress reduction and curve control are analyzed, and the 3-D FE models are established by ABQOUS for numerical evaluation to verify the correctness of design results. At last, dynamic analysis and fatigue analysis, based on actual project, are carried out with designed stress joint. The analysis results prove the feasibility and guidance of this method in the practical engineering applications.

Stress concentration factor expression for tension strip with eccentric elliptical hole

Two explicit expressions of the stress concentration factor for a tension finite-width strip with a central elliptical hole and an eccentric elliptical hole, respectively, are formulated by using a semi-analytical and semi-empiricai method. Accuracy of the results obtained from these expressions is better, and application scope is wider, than the results of Durelli＇s photo-elastic experiment and Isida＇s formula. When eccentricity of the elliptical hole is within a certain range, the error is less than 8%. Based on the relation between the stress concentration factor and the stress intensity factor, a stress intensity factor expression for tension strips with a center or an eccentric crack is derived with the obtained stress concentration factor expressions. Compared with the existing formulae and the finite element analysis, this stress intensity factor expression also has sufficient accuracy.

Effect of pre-tensioned rock bolts on stress redistribution around a roadway—insight from numerical modeling

The importance of the pre-tensioned force of rock bolts has been recognized by more and more researchers. To investi- gate the effect of pre-tensioned rock bolts on stress redistribution around roadways, a numerical analysis was carried out using FLAC3D and a special post-process methodology, using surfer, is proposed to process the numerical simulation results. The results indicate that pre-tensioned rock bolts have a significant effect on stress redistribution around a roadway. In the roof, pre-tensioned rock bolts greatly increase vertical stress; as a result, the strength of the rock mass increased significantly which results in a greater capacity of bearing a large horizontal stress. The horizontal stress decreases in the upper section of the roof, indicating that pre-tensioned rock bolts significantly reduce the coefficient and the size of the region concentration of horizontal stress. At the lat- eral side, pre-tensioned rock bolts greatly increase the horizontal stress; therefore, the rock mass strength significantly increases which results also in a greater capacity of bearing a large vertical stress. The greater the size of pre-tensioned force, the larger the region of stress redistribution around a roadway is affected and the higher the size of the stress on the roadway surface the more the rock mass strength increases.

Unified analytical stressstrain curve for quasibrittle geomaterial in uniaxial tension, direct shear and uniaxial compression

Considering strain localization in the form of a narrow band initiated just at peak stress, three analytical expressions for stressstrain curves of quasibrittle geomaterial (such as rock and concrete) in uniaxial tension, direct shear and uniaxial compression were presented, respectively. The three derived stressstrain curves were generalized as a unified formula. Beyond the onset of strain localization, a linear strain-softening constitutive relation for localized band was assigned. The size of the band was controlled by internal or characteristic length according to gradient-dependent plasticity. Elastic strain within the entire specimen was assumed to be uniform and decreased with the increase of plastic strain in localized band. Total strain of the specimen was decomposed into elastic and plastic parts. Plastic strain of the specimen was the average value of plastic strains in localized band over the entire specimen. For different heights, the predicted softening branches of the relative stressstrain curves in uniaxial compression are consistent with the previously experimental results for normal concrete specimens. The present expressions for the post-peak stressdeformation curves in uniaxial tension and direct shear agree with the previously numerical results based on gradient-dependent plasticity.

Stresses induced by post-tensioned anchor in jointed rock mass

A new analytical study on stresses around a post-tensioned anchor in rocks with two perpendicular joint sets is presented. The assumptions of orthotropic elastic rock with plane strain conditions are made in derivation of the formulations. A tri-linear bond-slip constitutive law is used for modeling the tendon-grout interface behavior and debonding of this interface. The bearing plate width is also considered in the analysis. The obtained solutions are in the integral forms and numerical techniques that have been used for evaluation. In the illustrative example given, the major principal stress is compressive in the anchor free zone and compressive stress concentrations of 815 k Pa and 727 k Pa(for the anchor load of 300 k N) are observed under the bearing plate and the bond length proximal end, respectively. However, large values of tensile stresses with the maximum of-434 k Pa are formed at the bond length distal end. The results obtained using the proposed solution are compared very those of numerical method(FEM).

Role of gelatinous layer in growth stress generation in tension wood

To elucidate what controls the magnitude of longitudinal growth stress in tension wood, anatomical measurements of gelatinous fibres were carried out on poplar tension wood (Populus I4551). Sections were cut from embedded blocks to avoid a border artefact described earlier. Results showed that: 1) no gelatinous fibres were observed under a growth strain level from 0.06% to 0.08%; 2) almost all of the non-conductive tissues contained gelatinous fibres above a growth strain level from 0.15% to 0.19%; 3) the amount of fibres, the amount of fibres with gelatinous layer, per unit of tissue area, and the thickness of the gelatinous layers controlled most of the magnitude of growth stress; 4) the contribution of the S2 layer in both fibre types could also play a role in the growth stress generation.

Regulatory mechanisms of retinal ganglion cell death in normal tension glaucoma and potential therapies

Normal tension glaucoma(NTG)is a multifactorial optic neuropathy characterized by normal intraocular pressure,progressive retinal ganglion cell(RGC)death,and glaucomatous visual field loss.Recent studies have described the mechanisms underlying the pathogenesis of NTG.In addition to controlling intraocular pressure,neuroprotection and reduction of RGC degeneration may be beneficial therapies for NTG.In this review,we summarized the main regulatory mechanisms of RGC death in NTG,including autophagy,glutamate neurotoxicity,oxidative stress,neuroinflammation,immunity,and vasoconstriction.Autophagy can be induced by retinal hypoxia and axonal damage.In this process,ischemia can cause mutations of optineurin and activate the nuclear factor-kappa B pathway.Glutamate neurotoxicity is induced by the over-stimulation of N-methyl-D-aspartate membrane receptors by glutamate,which occurs in RGCs and induces progressive glaucomatous optic neuropathy.Oxidative stress also participates in NTG-related glaucomatous optic neuropathy.It impairs the mitochondrial and DNA function of RGCs through the apoptosis signal-regulating kinase-JUN N-terminal kinase pathway.Moreover,it increases inflammation and the immune response of RGCs.Endothelin 1 causes endothelial dysfunction and impairment of ocular blood flow,promoting vasospasm and glaucomatous optic neuropathy,as a result of NTG.In conclusion,we discussed research progress on potential options for the protection of RGCs,including TANK binding kinase 1 inhibitors regulating autophagy,N-methyl-D-aspartate receptor antagonists inhibiting glutamate toxicity,ASK1 inhibitors regulating mitochondrial function,and antioxidants inhibiting oxidative stress.In NTG,RGC death is regulated by a network of mechanisms,while various potential targets protect RGCs.Collectively,these findings provide insight into the pathogenesis of NTG and potential therapeutic strategies.

Charactersitics of Stress-strain Curve of High Strength Steel Fiber Reinforced Concrete under Uniaxial Tension

A whole of 110 specimens divided into 22 groups were tested with varying the volume fraction of steel fibers and the matrix strength of these specimens. The stress-strain behaviors of four types of steel fiber reinforced concrete （SFRC） under uniaxial tension were studied experimentally. When the matrix strength and the fiber content increase, the tensile stress and tensile strain vary differently according to the fiber type. The mechanisms of reinforcing effect for different types of fiber were analyzed and the stress-strain curves of the specimens were plotted. Some experimental factors for stress or strain of SFRC were given. A tensile toughness modulus Re0.5 was introduced to evaluate the toughness characters of SFRC under uniaxial tension. Moreover, the formula of the tensile stress-strain curve of SFRC was regressed. The theoretical curve and the experimental ones fit well, which can be used for references in construction.

The Load-Displacement Curves of Deep Fascia in Response to Tension Stress Principle during Limb Lengthening: a Preliminary Study

Objective:To investigate the load displacement curves of deep fascia of leg in response to the Tension Stress principle during limb lengthening. Methods:Limb lengthening animal model was established in New Zealand white rabbits using a unilateral external fixator applied with four pins to the medial surface of tibia and monofocal proximal diaphysis with closed multiple drill holes and osteoclasis between the second and the third pins.Seven days after operation,distraction was initiated at distraction rates of 1mm/day and 2mm/day in two steps,and proceeded until increases of 10% and 20% in the initial length of tibia had been achieved.The fascia samples of 30mm×10mm were clamped with the Instron 1122 tensile test device at room temperature with the constant tensile rate of 5mm/min.After 5 load download tensile tests had been performed,the samples were elongated until rupture.And the load displacement curves were automatically generated. Results:The normal fascias showed typical load displacement rule of collagenous tissues.And each experimental group of fascias kept the characteristics.The curves of fascias at a rate of 1mm/day were closer to the curves of normal fascias.For the normal fascias,the ultimate tension strength was avarage 2.69N,and the strain at rupture was avarage 14.11%.And the ultimate tension strength of the fascias after limb lengthening increased. Conclusion:These results prove that the Tension Stress during limb lengthening has great effect upon the load displacement curves of fascia.The curves of fascia at a distraction rate of 1mm/day were closer to the curves of normal fascia.

Tensile stress regulated microstructures and ferroelectric properties of Hf_(0.5)Zr_(0.5)O_(2) films

The discovery of ferroelectricity in HfO_(2) based materials reactivated the research on ferroelectric memory.However,the complete mechanism underlying its ferroelectricity remains to be fully elucidated.In this study,we conducted a systematic study on the microstructures and ferroelectric properties of Hf_(0.5)Zr_(0.5)O_(2)(HZO)thin films with various annealing rates in the rapid thermal annealing.It was observed that the HZO thin films with higher annealing rates demonstrate smaller grain size,reduced surface roughness and a higher portion of orthorhombic phase.Moreover,these films exhibited enhanced polarization values and better fatigue cycles compared to those treated with lower annealing rates.The grazing incidence x-ray diffraction measurements revealed the existence of tension stress in the HZO thin films,which was weakened with decreasing annealing rate.Our findings revealed that this internal stress,along with the stress originating from the top/bottom electrode,plays a crucial role in modulating the microstructure and ferroelectric properties of the HZO thin films.By carefully controlling the annealing rate,we could effectively regulate the tension stress within HZO thin films,thus achieving precise control over their ferroelectric properties.This work established a valuable pathway for tailoring the performance of HZO thin films for various applications.

The relationship between microstructure and stress-strain behavior in tension in high strength pipeline steel

In this paper the relationship between microstructure and stress-strain behavior in tensile test of high strength pipeline steel was investigated.The steel with polygonal ferrite-bainite(PF + B) microstructure has a "round-house" type tensile stress-strain curve with low Y/T ratio,highly uniform elongation and high n-value,which means PF + B microstructure has the best deformability(i.e.Ideal stress-strain behavior) among the four microstructures.The steel with acicular ferrite-martensite&austenite(AF + MA) microstructure has a "continuous-yielding" type tensile stress-strain curve,whose deformability is worse than that of PF + B microstructure.Both the steels of polygonal ferrite-acicular ferrite(PF + AF) and polygonal ferrite-pearlite (PF+P) microstructure have "luders elongation" type tensile stress-strain curve with high Y/T ratio,low uniform elongation and low n-value,which means PF + AF and PF + P microstructures have the worst deformability among the four microstructures.

套筒灌浆搭接及对接接头高应力反复拉压试验

为比较套筒灌浆搭接及对接接头间力学性能差异,进行了41个搭接接头和20个对接接头的单拉及高应力反复拉压试验。结果表明:单拉及高应力反复拉压时,两种接头均能实现最大力下总伸长率大于6%、延性系数大于4,强度基本满足规范要求;高应力反复拉压后单拉时,两种接头承载力均有所提高,但接头初始刚度和延性下降;防偏转措施可减少搭接接头残余变形,但其约束刚度有限,搭接接头残余变形略大于对接接头,防偏转搭接接头及对接接头残余变形基本满足规范要求;高应力反复拉压后单拉时,搭接接头套筒中部截面在加载前期纵向受拉、环向受压,加载后期纵向受压、环向受拉,对接接头套筒加载过程中均为纵向受拉、环向受压;高应力反复拉压结束后单拉时,防偏转、不防偏转搭接接头套筒中部截面近钢筋侧最大纵向拉应变分别为对接接头的0.10~0.39倍、0.13~0.18倍,最大环向压应变分别为对接接头的0.09~0.49倍、0.02~0.32倍,搭接接头对套筒材性要求较低;钢筋直径相同时搭接接头材料成本较对接接头降低约35%。