精准扶贫视域下河南乡村产业韧性化发展策略

随着扶贫工作的持续推进,过于刚性的外源式贫困干预造成产业扶贫缺少韧性和内在稳定性,各类问题随之显现。文章通过对精准扶贫视域下韧性化产业扶贫的解析,结合河南乡村产业扶贫现状和存在问题,从产业选择、产业布局、设施配套和组织治理四个方面进行探讨,并提出了构建集中与分散相结合的跨乡村产业集聚区(点)的具体路径,以期为河南乡村产业扶贫建设提供决策依据和理论支持,同时也为其他地区的乡村产业扶贫发展提供参考。

社区环境家具韧性化设计更新研究

后疫情时代,谨慎外出的社会导向使居民对社区环境的依赖性有所增加,但社区环境家具却表现出不能弹性应对突发事件,反应迟缓的问题。因此,文章通过研究韧性社区的相关理论,提出赋能环境家具韧性化设计的观点。通过归纳总结韧性理论的核心内涵,提炼出环境家具韧性化设计的基本特征和策略方法。从社区更新的时间、空间及人本三大维度进行环境家具韧性化特征的植入设计,增强社区环境的弹性适应力。说明宏观的城市韧性建设不一定非要从大尺度整体韧性入手,通过对微观层面的社区环境家具的韧性化设计,也可达到增效韧性服务功能的效果。

后扶贫时代对产业扶贫韧性化的思考——基于对许岭村和土桥村的调查研究

以2021年脱贫攻坚战的全面胜利为标志,中国进入了以相对贫困和次生贫困为特点,以巩固脱贫成果、注重农村可持续发展为要求的“后扶贫时代”,要求农村产业去探寻出一条更加可持续、更具韧性的的发展路径。河南省平顶山市叶县夏李乡许岭村和鲁山县瓦屋镇土桥村都是典型的产业扶贫村,并取得了卓有成效的扶贫成果,两村在产业扶贫中的实践对当今产业扶贫韧性化的发展极具借鉴和启示价值。

社会照顾治理中的制度增能:需求、路向及评价——基于制度“脆弱-韧性”嬗变视角

在我国家庭照顾面临严重压力的情境下,政府主导下的社会照顾治理制度能力的支持促进具有重要意义。目前,此方面的制度存在多重能力不足的脆弱性问题,亟待以制度增能加以克服。制度“脆弱-韧性”的嬗变,可视为这一增能实现的积极可行的路向选择,其逻辑机理在于,能够以制度进化增进主体协作治理能力,以制度适应性提升需求回应能力,以制度灵活性增强个性化照顾能力,以制度恢复力增强制度生命活力。韧性化的制度增能效应可从制度效能目标改善、实践过程优化、回应性增能、制度潜能激活及制度主体能力增进五个方面形成系统评价体系。

运河工程低碳建造基本技术问题及对策

探讨运河工程低碳建造面临的基本技术问题并提出技术发展应对策略,有助于完善我国运河工程低碳建造的理论与技术,为未来的国际国内运河工程建设提供参考。本文概要梳理了我国古代运河工程和现代运河的建设情况,从重大基础设施低碳发展共性、运河工程低碳建造个性的角度明确了运河工程低碳建造的必要性。新时期运河工程建造的难点是在保障运河工程可靠性的基础上提升建造低碳性,因而运河工程低碳建造的基本技术问题集中在低碳性保障方面;依托平陆运河这一世纪工程的低碳技术攻关实践,着重凝练了运河建筑材料高效运用、运河新旧构件高效利用、运河多维固废循环再生、运河耐久性保障及沿线生物多样保护、运河施工与运维低能耗等基本技术问题。提出了由减量化、再利用、循环再生、韧性化、可再生能源构成的5R低碳建造技术框架,精准应对运河工程低碳建造的基本技术问题。运河工程低碳建造处于起步阶段,建议学术界和工程界持续保持对这一新兴领域的关注、思考与研究。

超韧性改性雾化封层技术在公路养护工程中的应用

随着时间的推移,重载车辆的增加,道路出现了裂缝、车辙、坑槽等各种病害,致使公路养护需求呈现快速增长的趋势。结合工程施工项目,针对不同程度的路面病害,选取了超韧性改性雾化封层技术对硬路肩路面进行养护、维修,达到了预防养护的效果。实践证明,该技术不仅养护措施简单、耗时短、影响小,还间接节约了公路养护成本,对公路起到了有效的预防性养护作用。

Effect of microstructure on impact toughness of magnesium alloys

Microstructures of as-cast and extruded ZK60-xRE （RE=Dy, Ho and Gd, x=0-5, mass fraction） alloys were investigated. Meanwhile, the impact toughness was tested and then the relationship was discussed. The results show that as-cast microstructure is refined gradually with increasing the RE content. Mg-Zn-RE new phase increases gradually, while MgZn2 phase decreases gradually to disappear. Second phase tends to distribute along grain boundary in continuous network. Extruded microstructure is refined obviously to reach the micron level. Broken second phase tends to distribute along the extrusion direction in zonal shape. Impact toughness value -nK increases from 9-17 J/cm2 for as-cast state to 26-54 J/cm2 for extruded state. With increasing the value of -nK, fracture macro-morphology changes from a rough plane via multi-plane with step to V-type plane; and from single radiation zone to two zones of fiber and shear lip, respectively. Fracture micro-morphology changes from the brittle fracture to the ductile fracture. Fine grain and few fine dispersed second phase can enhance the impact toughness of magnesium alloys effectively.

Modification on epoxy-based adhesive

This research adopted four methods to toughen epoxy adhesives. They were liquid hydroxyl group terminated polybutadiene (HTPB) rubber modification, silicon rubber modification, polyacrylate multiplicity elastomer particulates emulsion modification and chemical grafting modification. After modification, the shearing strength and the rupture elongation were tested. The interface and the chemical reaction between the modifiers and the epoxy were analyzed by scanning electron microscope (SEM) and infrared optical spectrum. The results show that the elastomer particulates modification and the chemical grafting modification can reach the better toughening effects.

Effect of various melt and heat treatment conditions on impact toughness of A356 aluminum alloy

The microstructure and impact behavior of A356 aluminum alloy were studied after melt treatment processes of grain refinement and modification under both non-heat treated and T6 heat treated conditions. The modification and grain refinement were done with the addition of Al-10%Sr and Al-5Ti-1B master alloys, respectively. All casting parameters were kept constant in order to focus on the influence of mentioned treatments. The results indicate that the eutectic silicon morphology is the main parameter to control the impact behavior of alloy. Consequently, the individual grain refinement of as-cast alloy does not improve the impact toughness as the modification does. While, simultaneous grain refinement and modification provide higher impact toughness in comparison with individual treatments. T6 heat treatment of the alloy improves the impact toughness under all melt-treated conditions. This is related to the further modification of eutectic silicon particles. To verify the results and clarify the mechanisms, three-point bending test and fractography were used to interpret the improvement of impact toughness of the alloy.

Microstructure-fracture toughness relationships and toughening mechanism of TC21 titanium alloy with lamellar microstructure

The independent influence of microstructural features on fracture toughness of TC21alloy with lamellar microstructure was investigated.Triple heat treatments were designed to obtain lamellar microstructures with different parameters,which were characterized by OM and SEM.The size and content ofαplates were mainly determined by cooling rate from singleβphase field and solution temperature in two-phase field;while the precipitation behavior of secondaryαplatelets was dominantly controlled by aging temperature in two-phase field.The content and thickness ofαplates and the thickness of secondaryαplatelets were important microstructural features influencing the fracture toughness.Both increasing the content ofαplates and thickeningαplates(or secondaryαplatelets)could enhance the fracture toughness of TC21alloy.Based on energy consumption by the plastic zone of crack tip inαplates,a toughening mechanism for titanium alloys was proposed.

应重视动力变质作用对成矿的贡献

应重视动力变质作用对成矿的贡献任耀武（华北有色地质勘查局地质研究所，天津３００１８１）关键词动力变质，矿源层，韧性剪切糜棱岩化，成矿作用近年来动力变质在成矿过程中的作用已日益引起人们的重视，特别是通过产干韧性剪切带中金矿床的研究，变质变形作用对成矿的...

Effect of Sb on microstructure and mechanical properties in Mg-10Zn-5Al high zinc magnesium alloys

In view of high strength and poor impact toughness of the high-zinc magnesium alloys,the method of micro-alloying was adopted to improve the impact-toughness of Mg-10Zn-5Al high zinc magnesium alloys by adjusting the addition of Sb.The results show that:the dystectic Mg3Sb2 particles formed by Sb and Mg are distributed in the front of dendrite,restrain the growth of the secondary phase and then change the morphology of the secondary phases,which refines the matrix in some extent and improves the impact-toughness of the alloy significantly.But with further increase of Sb addition,Mg3Sb2 particles congregate and form needle-like Mg3Sb2 phase,which dissevers the matrix and leads to the reduction of the strength and impact-toughness of the alloys.Hence,the mechanical prosperities of ZA105 high zinc magnesium alloy are significantly improved with appropriate Sb addition,which provides a new way to extend the application fields of high zinc magnesium alloy.

Resarch on Welding Robotic System with Petri Net

Petri net (PN) theory model was adopted for complexity in welding flexible manufacturing system (WFMS). A scheduling arithmetic was devised to optimize the process of controlling system. With this scheduling way, model simulation experiment was designed to validate the model. And a sort of controlling software was designed on local net. Besides, a special welding experiment had been designed to check the controlling way. Results show the controlling process rightly and feasibly.

Effects of laser shock peening on fatigue crack growth rate and fracture properties of AA2524 aluminum alloy

In order to prolong the service life of aircraft skin made from AA2524, the effects of laser shock peening(LSP) on fatigue crack growth(FCG) rate and fracture toughness(K_(c)) of AA2524 were investigated. Multiple LSP treatment was performed on compact tension(CT) specimen from single side and double sides. The surface integrity was measured with Vickers hardness tester, X-ray diffractometer and confocal laser scanning microscope, respectively. FCG rate test and fracture toughness test under plane stress were carried out after LSP treatment. The microstructure features of cross-sections were observed with scanning electron microscope. The results showed that the micro-hardness and residual stress of CT specimens were increased dramatically after LSP treatment. Compared to the base metal(BM), the fatigue life was prolonged by 2.4 times and fracture toughness was increased by 22% after multiple LSP.

Microstructure,formation mechanism and properties of plasma-sprayed Cr_(7)C_(3)−CrSi_(2)−Al_(2)O_(3)coatings

The Cr_(7)C_(3)−CrSi_(2)−Al_(2)O_(3)composite coatings were prepared by plasma spraying Cr_(7)C_(3)−CrSi_(2)−Al_(2)O_(3)and Al−Cr2O3−SiC composite powders,respectively.The microstructure,formation mechanism and properties of the two Cr_(7)C_(3)−CrSi_(2)−Al_(2)O_(3)composite coatings obtained by plasma spraying were investigated,and the reaction mechanism of the Al−Cr_(2)O_(3)−SiC system was explored.The results show that the coating obtained by plasma spraying Al−Cr_(2)O_(3)−SiC composite powders had thinner lamella and more tortuous interlayer interface,and the in-situ synthesized Cr_(7)C_(3),CrSi_(2) and Al_(2)O_(3) in the coating were all nano-crystallines.Compared with the Cr_(7)C_(3)−CrSi_(2)−Al_(2)O_(3)coating prepared by plasma spraying Cr_(7)C_(3)−CrSi_(2)−Al_(2)O_(3)composite powders,the plasma-sprayed Cr_(7)C_(3)−CrSi_(2)−Al_(2)O_(3)coating obtained from Al−Cr_(2)O_(3)−SiC composite powders had higher density,higher microhardness(increased by 20%),better fracture toughness and lower wear rate(reduced by 28%).

Robust Background Subtraction Method via Low-Rank and Structured Sparse Decomposition

Background subtraction is a challenging problem in surveillance scenes. Although the low-rank and sparse decomposition(LRSD) methods offer an appropriate framework for background modeling, they fail to account for image's local structure, which is favorable for this problem. Based on this, we propose a background subtraction method via low-rank and SILTP-based structured sparse decomposition, named LRSSD. In this method, a novel SILTP-inducing sparsity norm is introduced to enhance the structured presentation of the foreground region. As an assistance, saliency detection is employed to render a rough shape and location of foreground. The final refined foreground is decided jointly by sparse component and attention map. Experimental results on different datasets show its superiority over the competing methods, especially under noise and changing illumination scenarios.

吉林省集安市活龙金矿床成因探讨及找矿方向

活龙金矿与韧性剪切带关系十分密切,它控制了该矿化(体)分布,韧性剪切带是本矿床形成的重要机制。查清区域内韧性剪切带分布特征,有望发现新的金矿床。

Mechanical properties of AISI 1045 ceramic coated materials by nano indentation and crack opening displacement method

Abstract： An effective approach was conducted for estimating fracture toughness using the crack opening displacement （COD） method for plasma enhanced chemical vapor deposition （PECVD） coating materials. For this evaluation, an elastoplastic analysis was used to estimate critical COD values for single edge notched bending （SENB） specimens. The relationship between fracture toughness （Kic） and critical COD for SENB specimens was obtained. Microstructure of the interface between AleO3-TiO2 composite ceramic coatings and AISI 1045 steel substrates was studied by using scanning electron microscope （SEM）. Chemical compositions were clarified by energy-dispersive X-ray spectroscopy （EDS）. The results show that the interface between of Al203-TiO2 and substrate has mechanical combining. The nanohardness of the coatings can reach 1 200 GPa examined by nanoindentation. The Klc was calculated according to this relationship from critical COD. The bending process produces a significant relationship of COD independent of the axial force applied. Fractographic analysis was conducted to determine the crack length. From the physical analysis of nanoindentation curves, the elastic modulus of 1045/AI2O3-TiO2 is 180 GPa for the 50 μm film. The highest value of fracture toughness for 1045/A1203-TiO2-250 μm is 348 MPa·mv2.

Dense and pure high-entropy metal diboride ceramics sintered from self-synthesized powders via boro/carbothermal reduction approach

Equimolar quinary diboride powders,with nominal composition of(Ti0.2 Hf0.2 Zr0.2 Nb0.2 Ta0.2)B2,were synthesized by boro/carbothermal reduction(BCTR)of oxide mixtures(MOx,M=Ti,Hf,Zr,Nb and Ta)using B4 C as source of B and C in vacuum.By adjusting the B4 C/MOxratios,diboride mixtures without detectable MOxwere obtained at 1600℃,while high-entropy diboride(HEB)powders with particle size of<1μm was obtained at 1800℃.The phase,morphology and solid solution evolution process of the HEB powders during the BCTR process were comprehensively investigated.Although X-ray diffraction pattern indicated the powders synthesized at 1800℃ were in a single-phase Al B2 structure,elemental mappings showed that(Ta,Ti)-rich and(Zr,Nb)-rich solid solution coexisted in the HEB powders.The distribution of niobium and zirconium atoms in HEB was unable to reach uniform until the HEB powders were spark plasma sintered at 2000°C.(Ti0.2 Hf0.2 Zr0.2 Nb0.2 Ta0.2)B2 ceramics with a relative density of 97.9%were obtained after spark plasma sintering the HEB powders at 2050℃ under 50 MPa.Rapid grain growth was found in this composition when the sintering temperature was increased from 2000 to 2050℃,and the averaged grain size increased from 6.67 to 41.2μm.HEB ceramics sintered at 2000℃ had a Vickers hardness of 22.44±0.56 GPa(under a load of 1 kg),a Young’s modulus of^500 GPa and a fracture toughness of 2.83±0.15 MPa m1/2.This is the first report for obtaining high density HEB ceramics without residual oxide phase,benefiting from the high quality HEB powders obtained.

Embrittlement and toughening in CGHAZ of ASTM4130 steel

In the present investigation, a thermal welding simulation technique was used to investigate the mechanical properties and microstructure features of the coarse-grained heat-affected zone (CGHAZ) of ASTM4130 steel. The effect of post welding heat treatment (PWHT) and welding heat inputs on the toughness of CGHAZ was also analyzed. The results show that CGHAZ has the lowest toughness, which is only 5.5%-7.1% of the base metal. CGHAZ is mainly composed of dislocation martensite, up-per and lower bainite, and M-A constituents. But after PWHT, carbides precipitate from non-equilibrium microstructures of CGHAZ accompanying some retained austenite which transforms into low bainite, thereby enhancing toughness over the base metal. Therefore, the key microstructure factors affecting fracture toughness are lathlike non-equilibrium microstructure and lowered supersaturation before and after PWHT respectively. When welding heat input is between 12 kJ/cm and 28 kJ/cm, the mechanical properties in CGHAZ of ASTM4130 with single-pass welding can satisfy the requirements when PWHT is applied.