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DB44/T 298-2006 豆瓣菜(西洋菜) water cress
本标准规定了豆瓣菜的术语和定义、要求、试验方法、检验规则、包装、标签、运输和贮藏。<br />本标准适用于鲜食豆瓣菜的生产、销售。不适用于豆瓣菜的加工。...
2023-07-25 03:00:01浏览：12
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Cr2O3在水煤浆气化过程中的行为
结合实验室和工业应用，阐述了高铬砖在水煤浆气化炉内服役过程中 Cr2 O3在熔渣中的溶解，Cr2 O3与煤渣中不同组分 FeO、CaO、碱金属氧化物、钒氧化物之间的反应，以及六价铬的生成条件和抑制方法。指出：高铬砖中只有微量 Cr2 O3溶解于熔渣中，高温下溶解于渣中的 Cr2 O3在冷却过程中与 FeO 反应析晶生成铁铬尖晶石；材料中的 Cr2 O3与熔渣中 FeO 于耐火材料表面层反应生成复合尖晶石相致密层，延缓熔渣向砖内部的渗透，而以CaO 为主长石类化合物继续向砖内渗透，碱金属氧化物和钒氧化物与 Cr2 O3反应，造成侵蚀；气化炉内局部具备Cr6＋生成条件，磷酸盐高温分解为酸性氧化物可抑制六价铬生成。...
2022-09-09 21:40:01浏览：23
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颗粒分布对高浓度水煤浆流变性能的影响
采用体积平均粒径分别为81.30μ m,14.62μm的6.07 μm的三种陕西长焰煤粉以不同级配混合后制备高浓度水煤浆,利用Dinger模型评估了级配前后煤颗粒的粒度分布,研究了不同颗粒分布对高浓度水煤浆流变性能的影响.试验结果表明:级配优化可使煤颗粒的实际分布更接近理论模型分布.当浆体浓度较高时,随着浆体体系中细颗粒的增多,水煤浆流型由剪切稀化逐渐向剪切稠化转变,依次呈现出屈服假塑型、Bingham型和胀流型三种流型,拟合出了相应的的流变学模型,利用流变机理解释了浆体流型转变的原因,得到了使水煤浆具有最优流变性能的配比方案....
2022-09-09 21:36:01浏览：28
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新型聚羧酸系水煤浆添加剂的制备及其对水煤浆性能的影响
以聚氧乙烯醚类大单体为基础进行接枝改性,制备新型聚羧酸系水煤浆添加剂,通过正交试验和单因素实验对其合成工艺进行优化,并对该添加剂进行化学结构分析和应用性能研究.结果表明:最优合成方案为丙烯酸用量6.0g,丙烯酰胺用量1.6g,反应时间2.0h,引发剂用量1.8g,链转移剂用量1.0g,反应温度80 ℃,大单体用量35.0 g;实测其固含量为35.4％;改性单体成功接枝到高分子主链上,双键基本反应完毕;仅需质量分数为0.4％的添加量就可为制备水煤浆提供合适的Zeta电位、良好的分散性和稳定性....
2022-09-09 20:28:02浏览：16
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精细煤粉提高化工用水煤浆质量浓度的研究
分析了陕煤集团神木张家峁矿业公司水煤浆厂生产的精细煤粉对神木化工水煤浆提浓后的各项指标影响,得出应用张家峁矿业公司的精细煤粉可大大提高神木化工 Texaco 气化炉的有效气体成分的含量,提升单炉产气量的结论,从而提高企业效益及市场竞争力....
2022-09-09 18:16:01浏览：17
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GB/T 18916.55-2021取水定额 第55部分：皮革Norm of water intake. Part 55:Leather
GB/T 18916.55-2021取水定额 第55部分：皮革Norm of water intake. Part 55:Leather...
2022-03-18 17:24:56浏览：52
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GB/T 40746-2021淡水有核珍珠Freshwater nucleated pearl
GB/T 40746-2021淡水有核珍珠Freshwater nucleated pearl...
2022-03-14 21:40:10浏览：35
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Characteristic of hyaluronic acid derivative films cross-linked by polyethylene glycol of low water
Objective: To test the characteristics of byaluronic acid (HA) derivative cross-linked by polyethylene glycol films of low water content. Methods: The cross-linked HA film with 200 μm thickness was got at atmospheric pressure at 25℃ for 5 d. After dried, cross-linked films of 10 mm×10 mm were weighed and immersed in phosphate buffered saline (PBS pH 7.45) at 37℃ for 24 h. Then the solution fraction and water content were estimated. Meanwhile, cross-linked HA derivative films were immersed in phosphate buffered saline (PBS: pH 7.45) at 37℃ for determined time and then implanted subcutaneously in the back of white rats to test in vitro or in vivo degradation characteristic. Results and Conclusion: HA hydrogel cross-linked by polyethylene glycol with water content is as low as 60% and this kind of HA derivative has a slow degradation rate....
2020-12-22 21:24:13浏览：99
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Rheological and Biological Characteristics of Hyaluronic Acid Derivative Modified by Polyethylene Gl
Hyaluronic acid (HA) was chemically modified by polyethylene glycol. Meanwhile,the dynamic mechanics properties of HA derivative and its viscoelastic changes were measured on 3ARES3 Rheometer (Japan) at 25 ℃. Dried cross-linked films of 10×10 mm2 were immersed in phosphate buffered saline(PBS: pH 7.4) at 37 ℃ with different time periods to measure its water content and in vitro degradation. Moreover, cell cultured solutions, which were in the different cultivation vesse with 1 mg/mL Solution of HA derivative as doing experimental sample for 2 d, 4 d and 7 d, were observed, respectively, by an inverted discrepancy microscope. The cell relative growth rate was analyzed with the SPSS10.0 mathematic statistic software. Based on the above experiments,structure-modified HA derivative can meet the requirements of biomaterials in view of rheological and degradation in vitro and cytotoxicity charactereistics from clinical medical aspect under this experiment conditions....
2020-12-22 21:24:13浏览：121
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Analysis of black water aggregation in Taihu Lake
Black water aggregation (BWA) in Taihu Lake is a disaster for the lake environment.It is a phenomenon resulting from water environmental deterioration and eutrophication caused by accumulation of pollutants in the lake,according to research on the water quality,pollutants of BWA,and occurrence mechanisms of BWA.Dead algae are the material base of BWA,the polluted sediment is an important factor for the formation of BWA,and hydrological and meteorological conditions such as sun light,air temperature,wind speed,and water flow are the other factors that may lead to the formation of BWA.Thioether substances such as dimethyl trisulfide are the representative pollutants of BWA.Parameters such as chlorophyll-a,DO,pH,and water temperature are sensitive indicators of BWA.Measures such as algae collection,ecological dredging,pollution control,and water diversion from the Yangtze River to the lake,are effective,and strengthening aeration is an emergency measure to control BWA....
2020-12-06 21:11:24浏览：102
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Laboratory study and analysis of the instability of alongshore currents
A laboratory experiment on the instability of alongshore currents was conducted on a plane beach with slope 1:40. Low-frequency fluctuations of alongshore currents with the period of approximately 100 s were observed. The dominant frequency and amplitudes of the oscillations of alongshore currents were determined using the maximum entropy method and the regression method of trigonometric function. The variations across the beach cross-section of the oscillation amplitudes of the alongshore current were given. The linear shear instability theory was used to analyze the mechanism of the oscillation, and the calculated results agreed with measurements. This confirms that the observed fluctuation of alongshore currents is due to the shear instability of alongshore currents....
2020-12-06 21:11:24浏览：63
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Transport Process of Isopropanol Aqueous Solution by Pervaporation
To study the transport process of isopropanol aqueous solution by pervaporation, the transport model of isopropanol and that of water at 323 K in polyvinyl alcohol(PVA) membrane were obtained in this paper. Theoretical predictions agreed well with the experimental results. The interactional parameter between water and PVA membrane is less than that between isopropanol and PVA membrane, which shows that water is preferentially dissolved in PVA membrane. The plasticizing coefficient and diffusion coefficient at infinite dilution of water are larger than those of isopropanol,which shows that the dissolution and permeation in PVA membrane of water are greater than those of isopropanol. Both the interactional parameter between water and isopropanol in the membrane and that in feed rise with the increase of isopropanol content in feed, which shows that the larger isopropanol content is, the higher selectivity of the membrane is and the more remarkable separation effect of pervaporation is....
2020-11-10 09:33:08浏览：124
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RILL EROSION PROCESS AND RILL FLOW HYDRAULIC PARAMETERS
In the rill erosion process,run-on water and sediment from upslope areas,and rill flow hydraulic parameters have significant effects on sediment detachment and transport.However,there is a lack of data to quantify the effects of run-on water and sediment and rill flow hydraulic parameters on rill erosion process at steep hillslopes,especially in the Loess Plateau of China.A dual-box system,consisting of a 2-m-long feeder box and a 5-m-long test box with 26.8% slope gradient was used to quantify the effects of upslope runoff and sediment,and of rill flow hydraulic parameters on the rill erosion process.The results showed that detachment-transport was dominated in rill erosion processes; upslope runoff always caused the net rill detachment at the downslope rill flow channel,and the net rill detachment caused by upslope runoff increased with a decrease of runoff sediment concentration from the feeder box or an increase of rainfall intensity.Upslope runoff discharging into the rill flow channel or an increase of rainfall intensity caused the rill flow to shift from a stratum flow into a turbulent flow.Upslope runoff had an important effect on rill flow hydraulic parameters,such as rill flow velocity,hydraulic radius,Reynolds number,Froude number and the Darcy-Weisbach resistance coefficient.The net rill detachment caused by upslope runoff increased as the relative increments of rill flow velocity,Reynolds number and Froude number caused by upslope runoff increased.In contrast,the net rill detachment decreased with an increase of the relative decrement of the Darcy-Weisbach resistance coefficient caused by upslope runoff.These findings will help to improve the understanding of the effects of run-on water and sediment on the erosion process and to find control strategies to minimize the impact of run-on water....
2020-11-10 09:33:08浏览：77
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Calculation of Solidification Process of Continuous Cast Bar
In this paper, it presents the results of calculation of solidification process of copper continuous cast bar by cross section size 120 mm×70 mm with application of ProCast 2010 software. The estimation of mould design effect on solidification process of continuos copper cast bar is completed at various speeds of casting. Profiles of liquid metal cavities and temperature allocations in the cast bar at various casting speeds are defined. The analysis of received liquid metal cavity profiles shows that a new mold construction allows significantly decrease of the length of the liquid metal cavity during continuous copper casting at HAZELETT? casting machine and the increase of maximum casting speed from 10 to 11 m/min. Adequacy of the results of copper continuous cast bar solidification process calculation is confirmed by the experimental data....
2020-11-10 09:33:08浏览：86
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