水泥组合粉磨技术的应用实践

为采用水泥组合粉磨技术,控制熟料和各种混合材的粒度分布,使得生产的成品水泥颗粒级配更加合理,适应不同的原料特性,高效利用宝贵的资源熟料,提升水泥工作性能和品质稳定性。采用组合粉磨技术后,较本厂前期联合粉磨P·O42.5R水泥吨水泥熟料用量节省5%,P·O42.5铁标水泥吨水泥熟料用量节省8%,M32.5砌筑水泥吨水泥熟料用量节省7%。

Ni－WC－RE组合粉喷焊层的磨损及腐蚀行为

采用固相团聚法进行Ｎｉ－ＷＣ－ＲＥ组合粉的研制，并探讨添加微量稀土（ＲＥ）及ＷＣ对组合粉工艺性、耐磨性、耐蚀性的影响。试验表明，组合粉具有良好的工艺性能，适量的ＲＥ使喷焊层耐磨性、耐蚀性提高，ＷＣ的增加，提高了喷焊层的耐磨性，但降低了耐蚀性。

高钙粉煤灰及水泥组合粉喷搅拌法加固地基的试验研究

高钙粉煤灰及水泥组合粉喷搅拌法加固地基的试验研究李恒中国城乡建设粉煤灰利用技术开发中心根据国家和上海市经济发展规划，在上海盛桥新建上海港罗径煤码头堆场工程，占地１５０万ｍ２，一期工程为４７万ｍ２，年堆存量为６０万ｔ。因新建煤码头堆场场地利用上海石洞口...

河北邯郸HZ-S孔第四纪孢粉组合的定量分析

孢粉组合的数值分析方法是第四纪孢粉学研究方法的重要内容。以邯郸HZ-S孔为例,采用因子分析、聚类分析、回归分析等多种数值分析方法对该孔第四纪孢粉资料进行孢粉组合带的定量划分。研究结果表明:邯郸HZ-S孔140件孢粉样品自下而上可以划分为5个孢粉组合带;数值分析是进行孢粉组合带划分的一种行之有效的辅助手段。随着计算机的普及和各种统计软件的大量使用,在定性研究的基础上采用多种数值方法,可以使孢粉组合带的划分更精确。

小型组合磨粉机组常见故障及原因

由几台小型对辊磨粉机,小麦清理及输送设备等组合而成的面粉加工机组,目前已以农村中广泛应用。它具有生产效率高、自动化水平高、劳动强度低,以及面粉质量好等特点,深受用户欢迎,但在使用过程中,常会出现一些故障。

小型组合磨粉机组常见故障的原因分析

由几台小型对辊磨粉机,小麦清理及输送设备等组合而成的面粉加工机组,目前已在农村中广泛应用。它具有生产效率高、自动化水平高、劳动强度低,以及面粉质量好等特点。

解析生产烩面专用粉

烩面是中原人民尤为喜爱的一种面食,烩面粉也是各大粉厂十分热衷生产的一种高附加值产品;生产烩面粉既要有高品质小麦,又要有科学的生产工艺,还要有成熟的消费群体,更要有一个科学合理又切合实际的生产配方;小麦的选择与粉流组合二者缺一不可;成品烩面坯既要保证不能在短时间内发滩,又要保证使用者能轻松拉成专业烩面师拉的烩面;看着晶莹剔透、吃着绵软而富有弹性、边不毛、汤不浑。

辊压机绿色低碳粉磨技术

本文围绕辊压机绿色低碳粉磨技术,介绍辊压机粉磨过程中的料床稳定性机理,以及辊压机与配套分选装备及系统的最新技术,实现辊压机粉磨系统进一步节能降耗。同时,通过优化不同组分在颗粒段的分布来促进胶凝材料活性的充分利用,开发了多种分别组合粉磨生产工艺方案,在保证水泥品质的同时,降低了熟料的用量,降低了企业生产成本,减少了水泥生产的碳排放。最后,通过两个工厂应用案例,分别介绍了辊压机生料终粉磨系统和水泥分别组合粉磨系统的实施效果。

Nutritional Value and Application of Broad Bean Nutrition Flour as a Combination of Staple Food

This paper introduced the definition and importance of combination of sta-ple food. With broad bean nutrition flour as a sample, the preparation of the combi-nation of staple food was also described. In addition, the main nutritional value of broad bean nutrition flour was introduced. Compared with those of other single flours, the nutritional value of broad bean nutrition flour was improved. Moreover, the nutrients in the broad bean nutrition flour would not be destroyed during the processing and preparation of staple food, and the processed steamed bread and raw noodle are more characteristic. The application value and prospects of broad bean nutrition flour, as a combination of staple food, were further discussed.

Middle Jurassic Sporo-pollen Assemblage from the Yan'an Formation of Dongsheng, Nei Monggol, China

The Middle Jurassic palynomorphs from the Yan'an Formation in Dongsheng region of Nei Monggol, consist of 63 species of fossil spores and pollen grains belonging to 34 genera, of which two species were described as new. Based on statistical analysis of 3 863 specimens identified in 10 samples from Hantaichuan, Nianpanlianggou and Liugou sections, the sporo-pollen assemblage from the Yan'an Formation in Dongsheng region was established, which is generally characterized by the slight dominance of gymnospermous pollen grains (generally attaining proportion of 51%-54%), whereas the pteridophytic spores reach 46%-49% in abundance. In comparison with those of adjacent regions as well as Eurasia and North America, the present sporo-pollen assemblage is regarded to early Middle Jurassic (corresponding to Bajocian Stage) in geological age. According to the climatic conditions reflected by the palynoflora, the paleoclimate in Dongsheng region is suggested to be warm temperate or subtropical warm and humid during the early Middle Jurassic.

Research on Laws of Starch Accumulation in Micro-endosperm Maize Kernel

[Objective] The experiment aimed to study laws of accumulation of starch in micro-endosperm maize kernel. [Method] The laws of accumulation of starch in maize embryo and OSK(the other section of a kernel except embryo) of MEM(micro-endosperm maize) were studied in this experiment by taking Gaoyou 115 maize as control. [Result] The starch accumulation speed of MEM embryo was slightly lower than that of Gaoyou115 and the starch accumulation speed of MEM OSK was far lower than that of Gaoyou 115, so the starch content of the whole kernel of Gaoyou 115 was 3.4 to 4.5 times as high as that of MEM during harvesting. The embryo starch weight ration of Gaoyou 115 maize during harvesting was only 3% to 4% while that of MEM was 16% to 22%. Moreover, starch accumulation speeds of different MEM materials were different and there were significant differences in starch content during harvesting among different MEM materials. [Conclusion] The starch accumulation in MEM was slow, and MEM has widely variation on starch accumulation.

Microstructures of PM Ti-45Al-10Nb alloy fabricated by reactive sintering

Powder metallurgy Ti-45Al-10 Nb alloys was successfully fabricated by reactive sintering of milled powders at 1350 °C for 2 h in vacuum. The microstructure, in particular, constituent phases, grain size, precipitates of the product was investigated in detail. The results indicate that a double phase γ＋α2 microstructure containing Ti2 Al C precipitate is obtained under the sintering condition, and the alloy exhibits a fine and homogenous microstructure compared with traditional Ti Al base. In fine grain structure, the average grain sizes for the γ and α2 phases are（2.3±0.05） and（5.6±0.05） μm, respectively. Additionally, numerous dislocations are observed in the alloy, and the dislocation density in γ phase is significantly higher than that in α2 phase. The formation mechanisms of the dislocation in the present alloy were also discussed in detail.

Microstructural evolution of gas atomized Al-Zn-Mg-Cu-Zr powders during semi-solid rolling process

Under H2 atmosphere, the green strips were prepared from Al-5.8Zn-1.63Mg-2.22Cu-0.12Zr(mass fraction, %) powders by the semi-solid rolling process with a relative density from 76.1% to 88.0%. The role of temperature on microstructure and mechanical properties was investigated. With increasing rolling temperature from 580 to 610 °C, the disappearance of primary powder boundary and isolated pores, inter-diffusion of species and the change of grain boundary were accelerated. Moreover, the mechanism of microstructure evolution changes from the densification dominant regime to the coarsening dominant regime; the amount of η(MgZn2) phase decreased and more Al2 Cu particles precipitated at grain boundaries. The optimum temperature for semi-solid rolling of Al-5.8Zn-1.63Mg-2.22Cu-0.12 Zr powders was determined. The liquid fraction in the range of 53% to 67% corresponds with a high density level of green strips. The present experimental analysis suggests that semi-solid powder rolling can be optimized to manufacture strips with high mechanical properties.

Microstructure and mechanical properties of powder metallurgy Ti-Al-Mo-V-Ag alloy

The Ti-Al-Mo-V-Ag α＋β alloys were processed by powder metallurgy（PM） using the blended elemental（BE） technique.The effects of Ag addition and sintering temperature on microstructure and properties of the Ti-5Al-4Mo-4V alloys were investigated using X-ray diffraction,optical microscope,scanning electron microscope and mechanical properties tests.The results show that adding Ag element increases the relative density and improves the mechanical properties of PM Ti-5Al-4Mo-4V alloy.After sintering at 1 250 ℃ for 4 h,the relative density and compression strength of Ti-5Al-4Mo-4V-5Ag alloy are 96.3% and 1 656 MPa,respectively.

Modern pollen assemblages of the forest communities and their relationships with vegetation and climate in northern China

53 pollen traps and surface samples were collected in order to detect the characteristics of pollen assemblages and their relationships with vegetation and climate in 16 forest communities located in 10 mountains in northern China. The results show that 72% of the pollen taxa (80 taxa) are the same between the traps and the surface samples. The dominant taxa in the plant communities are consistent with the main pollen taxa in the pollen assemblages at the same sites. In Pinus plant communities, both Pinus pollen influx and concentration are higher, indicating the high pollen productivity and good pollen preservation ability of Pinus. In Picea and Abies plant communities, Picea and Abies have lower pollen influxes but higher concentrations, suggesting their low pollen productivities but better pollen preservation abilities. In Betula and Quercus plant communities, Betula and Quercus have higher pollen influxes but lower concentrations, revealing their high pollen productivities but poor pollen preservation abilities. The study of relationships between pollen and vegetation with discriminant analysis shows that pollen assemblages from both trap and surface samples can reflect the characteristics of different communities and distinguish different ecological areas, but surface samples can reflect the dominant components of communities much better than the traps. The study on correlations between pollen assemblages and climate with DCCA reveals that significant correlations exist between pollen assemblages and mean temperature of the coldest month (r = 0.84 for trap samples, r = 0.72 for surface samples), and then annual mean precipitation (r = 0.73 for trap samples, r = 0.71 for surface samples).

Effects of Fe content on microstructure and properties of Cu−Fe alloy

Cu−Fe alloys with different Fe contents were prepared by vacuum hot pressing.After hot rolling and aging treatment,the effects of Fe content on microstructure,mechanical properties and electrical conductivity of Cu−Fe alloys were studied.The results show that,when w(Fe)<60%,the dynamic recrystallization extent of both Cu phase and Fe phase increases.When w(Fe)≥60%,Cu phase is uniformly distributed into the Fe phase and the deformation of alloy is more uniform.With the increase of the Fe content,the tensile strength of Cu−5wt.%Fe alloy increases from 305 MPa to 736 MPa of Cu−70wt.%Fe alloy,the elongation decreases from 23%to 17%and the electrical conductivity decreases from 31%IACS to 19%IACS.These results provide a guidance for the composition and processing design of Cu−Fe alloys.

Precision Tension Control System Using Magnetic Particle Clutch

The control of the stability of the filament tension is one of the crucial techniques ensuring the component quality of the composite materials. The open-loop tension control system, with industrial control computer as the core, magnetic particle clutch as the actuator, equipped with compensation technique is researched and manufactured. It can assure the tension control stability of the yarn in filament winding process and increase the control precision of the whole system.

Microstructure and tensile property of SLM 316L stainless steel manufactured with fine and coarse powder mixtures

Selective laser melting(SLM)technology is the prevailing method of manufacturing components with complex geometries.However,the cost of the additive manufacturing(AM)fine powder is relatively high,which significantly limits the development of the SLM.In this study,the 316L fine powder and coarse powder with a mass ratio of 80:20,70:30 and 60:40 were mixed using a ball milling and the samples with a relative density greater than 97%were prepared by SLM.The results show that the intricate temperature gradients and surface tension gradients in SLM will produce Marangoni flow,forming a typical molten pool morphology,cellular and strip subgrain structures.And as the proportion of coarse powder increases,the scanning track morphology changes from smooth to undulating;the morphology of the molten pool and subgrain structure are weakened.Meanwhile,the unmelted particles appear on the surface of the SLM sample.On the premise of an introducing appropriate amount of large particle size powder(20%),the SLM samples still have good mechanical properties(662 MPa,47%).