基于网络信息体系的结构力及其生成模式

随着战争形态的改变,战斗力生成模式也在不断变化。围绕智能化战争形态和作战理念,提出了基于结构力的战斗力生成模式,阐述了结构力概念以及组织结构力、信息结构力2大核心要素的作用机理,构建了基于网络信息体系的结构力生成范式,分析了基于组织中台架构的结构力生成技术,为发展弹性网络信息体系提供结构力生成方法论和理论参考。

Microstructure and mechanical properties of Mg-Gd-Y-Zr alloy cast by metal mould and lost foam casting

The microstructure and mechanical properties of Mg-10.1Gd-3.74Y-0.25Zr （mass fraction, %） alloy （GW104 alloy） cast by metal mould casting （MMC） and lost foam casting （LFC） were evaluated, respectively. It is revealed that different forming modes do not influence the phase composition of as-cast alloy. In the as-cast specimens, the microstructures are similar and composed of α-Mg solid solution, eutectic compound of α-Mg＋Mg 24 （Gd, Y） 5 and cuboid-shaped Mg 5 （Gd, Y） phase; whereas the average grain size of the alloy produced by metal mould casting is smaller than that by lost foam casting. The eutectic compound of the alloy is completely dissolved after solution treatment at 525 ℃for 6 h, while the Mg 5 （Gd, Y） phase still exists after solution treatment. After peak-ageing, the lost foam cast alloy exhibits the maximum ultimate tensile strength of 285 MPa, and metal mould cast specimen 325 MPa at room temperature, while the tensile yield strengths of them are comparable. It can be concluded that GW104 alloy cast by lost foam casting possesses similar microstructure and evidently lower mechanical strength compared with metal mould cast alloy, due to slow solidification rate and proneness to form shrinkage porosities during lost foam casting process.

Microstructure and mechanical properties of TiAl-based alloy prepared by double mechanical milling and spark plasma sintering

A fine-grained TiAl alloy with a composition of Ti-45Al-2Cr-2Nb-1B-0.5Ta-0.225Y （mole fraction, %） was prepared by double mechanical milling（DMM） and spark plasma sintering（SPS）. The relationship among sintering temperature, microstructure and mechanical properties was studied. The results show that the morphology of double mechanical milled powder is regular with size in the range of 20-40 μm and mainly composed of TiAl and Ti3Al phases. The main phase TiAl and few phases Ti3Al, Ti2Al and TiB2 were observed in the SPSed alloys. For samples sintered at 900 ℃ the equiaxed crystal grain microstructure is achieved with size in the range of 100-200 nm. With increasing the SPS temperature from 900 ℃to 1000 ℃ the size of equiaxed crystal grain obviously increases, the microhardness decreases from HV658 to HV616, and the bending strength decreases from 781 MPa to 652 MPa. In the meantime, the compression fracture strength also decreases from 2769 MPa to 2669 MPa, and the strain to fracture in compression increases from 11.69% to 17.76%. On the base of analysis of fractographies, it shows that the compression fracture transform of the SPSed alloys is intergranular rupture.

Effect of Zn addition on microstructure and mechanical properties of cast Mg-Gd-Y-Zr alloys

The effects of Zn addition on the microstructure and mechanical properties of Mg.10Gd.3Y.0.6Zr(wt.%)alloys in the as-cast,solution-treated,and peak-aged conditions were investigated.Experimental results reveal that the microstructure of the as-cast alloy without Zn consists ofα-Mg and Mg24(Gd,Y)5 phases,and the alloy with 0.5 wt.%Zn consists ofα-Mg,(Mg,Zn)3(Gd,Y)and Mg24(Gd,Y,Zn)5 phases.With the addition of Zn increasing to 1 wt.%,the Mg24(Gd,Y,Zn)5 phase disappears and some needle-like stacking faults distribute along the grain boundaries.Moreover,the 18R long-period stacking ordered(LPSO)phase is observed in the as-cast alloy with 2 wt.%Zn.After solution treatment,the Mg24(Gd,Y)5 and Mg24(Gd,Y,Zn)5 eutectic phases are completely dissolved,and the(Mg,Zn)3(Gd,Y)phase,needle-like stacking faults and 18R LPSO phase all transform into 14H LPSO phase.Both the suitable volume fraction of 14H LPSO phases and the fine ellipsoidal-shapedβ′phases make the peak-aged alloy with 0.5 wt.%Zn exhibit excellent comprehensive mechanical properties and the UTS,YS and elongation are 338 MPa,201 MPa and 6.8%,respectively.

Microstructure and tensile properties of rapid-cooling friction-stir-welded AZ31B Mg alloy along thickness direction

Rapid-cooling friction-stir-welding(FSW)was used to join AZ31B magnesium alloy plates of 6 mm in thickness.The microstructure and mechanical properties in thickness direction were carefully investigated with electron backscattered diffractometer,and transmission electron microscope.The obtained results showed that ultrafine grains with high dislocation density were obtained in the top region of the weld due to liquid CO2 cooling.A large number of{1012}twins and second-phase particles were also induced in these refined grains.The basal texture intensity was significantly reduced due to the appearance of{1012}twins.The top region showed the higher strength and elongation compared with the bottom region,and the welding efficiency reached 93%.This work provided a simple and efficient strategy for manufacturing a gradient structure in the FSW Mg alloy joint.

Microstructure evolution and recrystallization behavior of cold-rolled Zr-1Sn-0.3Nb-0.3Fe-0.1Cr alloy during annealing

The effects of cold-rolling reduction,annealing temperature,and time on recrystallization behavior and kinetics of cold-rolled Zr-1Sn-0.3Nb-0.3Fe-0.1Cr alloy were investigated using the Vickers hardness test,scanning electronic microscopy(SEM),transmission electron microscopy(TEM)and electron backscatter diffractometry(EBSD).The results show that the rate of the recrystallization increased with increasing annealing temperature and rolling reduction.Recrystallized grains nucleated preferentially at sites with high density dislocation and deformation stored energy and then grew into integral grains.Recrystallization texture changed from-1010-//RD to-1120-//RD.The grain orientation changed from random orientation to the orientation with the maximum misorientation around 30°.Recrystallization kinetics and maps were constructed based on the Johnson-Mehl-Avrami-Kolmogorov(JMAK)equation to derive parameters sensitive to the microstructure.The activation energies for recrystallization of 30%,50%and 70%cold-rolling reductions were determined to be 240,249 and 180 kJ/mol,respectively.

Die sinter bonding in air using copper formate preform for formation of full-density bondline

Pressure-assisted sinter bonding was performed in air at 250−350℃ using a preform comprising copper formate particles to form a bondline that is sustainable at high temperatures.H2 and CO generated concurrently by the pyrolysis of copper formate at 210℃ during the sinter bonding removed the native oxide and other oxides grown on bulk Cu finishes,enabling interface bonding.Moreover,Cu produced in situ by the reduction of Cu(II)accelerated the sinter bonding.Consequently,the bonding achieved at 300−350℃ under 5 MPa exhibited sufficient shear strength of 20.0−31.5 MPa after 180−300 min of sinter bonding.In addition,an increase in pressure to 10 MPa resulted in shear strength of 21.9 MPa after an extremely short time of 30 s at 250℃,and a near-full-density bondline was achieved after 300 s.The obtained results indicate the promising potential of the preform comprising copper formate particles for high-speed sinter bonding.

Microstructural evolution and mechanical properties of new multi-phase NiAl-based alloy during heat treatments

Microstructural evolution and the relationship between microstructure and property during heat treatments in a new NiAl-based alloy(Ni-26.6Al-13.4Cr-8.1Co-4.3Ti-1.3W-0.9Mo,molar fraction,%))were investigated.The as-cast alloy is composed of NiAl matrix and Cr3Ni2 phase with poor ductility.The Cr3Ni2 phase is distributed as a network along the NiAl grain boundaries.Subsequent heat treatment(1 523 K,20 h,air cooling+1 123 K,16 h,furnace cooling)leads to the dissolution of Cr3Ni2 phase and the precipitation of lath-shaped Ni3Al phase andα-Cr particles,resulting in the improvement of compressive properties and fracture toughness at room temperature.Followed by long-term thermal exposure(1 173 K,8 500 h),it is found that the residual Cr3Ni2 phase keeps stable while theα-Cr particles coarsen and a great mass of lath-shaped Ni3Al precipitates are degenerated,which compromises most of the above improvements of mechanical properties through heat treatment.

Leadership, Control Mechanisms and Networks for Sustainable Fishing

The purpose of this article was to analyse how fisheries governance can be improved when there is low enforcement capacity by state＇s institutions. Based on the theoretical arguments from the neo-institutionalism and the social capital approaches, the findings of this research point to the role of fishing cooperatives＇ structural organization on the attitude of individuals to comply with regulations. Using a most similar comparative method, it was found that fishers with higher scores of compliance belong to cooperatives that have an outstanding leader, control mechanisms, as well as multi-actor external networks which connect the organization with other networks and thus facilitate the access to knowledge, technology and activities related to conservation and sustainable fishing. The findings of the research coincide with other studies about the importance of leadership that enable good fishing management. This may help in the design of different strategies to address situations with low state capacity to ensure compliance and contribute to solve problems of commons, such as the one in marine fisheries.

Structural Changes That Generate Competitive Ability to the Metal Working Industry

This article presents the results of a study conducted in a Metallurgical industry located in the town of Santa Rosa--Rio Grande do Sul State, Brazil. Its central goal was to obtain a better understanding of the structural changes in the organization and identify its working practices through both case and bibliographic studies, taking into consideration the technological advances and the new management being implemented in the company, due to its acquisition by a multinational company. The proposal of a new organizational structure which has brought inevitable changes to the organizations but the structure needs to be well defined to lead to the company under study and its employees the best way, through continuous improvement and competitive entrepreneurship. The results obtained enable a better understanding of the history and nature of changes in the organization, considering it as a living and changing system.

How Should We Construct Mind-Readers？

Structured models of kinds of mind-readers are explanatory tools in philosophy and psychology. Structure means that a structure like a theory with certain properties organizes the model of a kind of a reader. Structured models serve to explain mind-reading capabilities in opposition to pure behavior-reading capabilities by explicating properties of the structure that bring on specific capabilities of mind-reading. Typically, grades of fulfilling reading-capabilities are related to grades of rationality. But it is unclear： （1） when we are legitimated to title a reader a mind-reader or behavior-reader, and （2） how the kinds of readers are related with each other （if they can be related by a measure）. I argue that we know a reader if we can construct it and this gives legitimation. But it is unclear how to construct border-cases of readers, for example, minimal mind-readers. Should minimal mind-readers be constructed on the base of ＂reduced＂ mind-readers, or should they be constructed as ＂enriched＂ behavior-readers？ This is the specific question concerning the relations between readers the essay deals with by trying to reduce a maximal mind-reader by Craig-reduction. Because this kind of reduction-method fails, constructing specific kinds of mind-readers needs further research.

挑战与发展:休闲度假型酒店的创新

随着各国旅游服务业的发展,国内外的休闲度假型酒店投资与发展的成果引人注目。要应对复杂的自然变化、经济文化的差异以及社会消费需求的多样化等多方面的挑战,休闲度假型酒店的发展离不开产品与服务创新、组织结构与领导力的创新和产品技术的换代创新,方能将挑战转化为机遇,获得持续发展的生命力。