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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：10
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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：11
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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：37
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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：63
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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：33
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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：25
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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：47
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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：28
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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：34
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流体高效输送节能技术在硫酸、磷复肥装置循环水系统中的应用分析
针对目前我国大部分硫酸、磷肥生产装置循环水系统中普遍存在水泵运行效率低、能耗高、振动噪声大以及汽蚀等问题,提出实施流体高效输送节能改造技术.大量的实验及成功的改造案例说明,实施该项技术改造后可以在节能的同时提高运行效率,并且能够取得良好的经济效益和社会效益....
2020-11-10 09:33:08浏览：25
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超超临界汽轮机循环水系统改造及运行优化
针对某电厂循环水系统存在的运行调整空间有限、厂用电率高和经济性差的问题,对循环水系统进行了改造并开展了汽轮机组微增出力、循环水泵在不同运行方式下的冷却水流量、循环水泵耗功以及凝汽器变工况试验研究,获得了循环水系统的经济调度运行方式,保证了汽轮机达到或接近最经济真空运行....
2020-11-10 09:33:08浏览：25
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无填料喷雾冷却塔在磷酸循环水系统中的应用
循环水冷却效果的好坏是影响磷酸生产的关键因素。由于传统填料冷却塔存在诸多问题，故对其进行改造。改用无填料和高效低压离心喷雾装置的空塔，有效解决了填料塔分水不均、飘雨严重、冷却效率下降等问题，循环水经冷却塔进出口温差提高1～2℃，且减轻了设备检修清堵和维护的工作量和费用。...
2020-11-10 09:33:08浏览：24
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自备热电厂循环水系统清洗预膜及水质稳定性分析
阐述了自备热电厂循环水系统停车在线剥离、清洗和预膜处理的方法及结果。探讨了循环水系统清洗、预膜的水质控制方法。...
2020-11-10 09:33:08浏览：17
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JKD - R40A1SS 冷却循环水系统的维护和修理
冷却循环水系统工作好坏直接影响到电镜的使用寿命，系统工作是否正常与平时做好维护是分不开的。...
2020-11-10 09:33:08浏览：32
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马莲台电厂循环水系统的运行控制及管理初探
循环冷却水是火力发电厂用水量的主要组成部分,循环水水质的好坏关系到发电机组是否能够满负荷正常运行.循环水水质不好,会造成凝汽器铜管结垢及腐蚀,严重时影响机组的安全经济运行.水的循环利用,浓缩倍数的提高,要求必须采取适当的水处理手段,以解决热力设备的结垢及腐蚀问题....
2020-11-10 09:33:08浏览：20
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净化厂循环水系统再生水回用的腐蚀控制
某净化厂循环水系统引入再生水后，腐蚀严重，严重影响了设备的正常使用，给净化厂的正常生产造成了一定的影响。针对此情况，对其循环水体系现况进行了详细的分析研究，发现其主要问题在于对再生回用水的不正确使用。对此开展了阻垢、缓蚀、杀菌等实验研究工作，开发出适合于该厂的循环水系统稳定运行方案，为现场应用提供了技术支持。...
2020-11-10 09:33:08浏览：26
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循环水系统采用水轮机替代风机电机节电改造
对反击混流式水轮机替代风机电机的改造方法、可行性、改造前后凉水塔的运行方式及改造后效益进行阐述。...
2020-11-10 09:33:08浏览：26
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浮法玻璃生产线循环水系统的腐蚀与防治
在浮法玻璃生产中,循环水在熔窑搅拌器、锡槽拉边机冷却水套等设备和仪表中是必不可少的,循环冷却水系统是保证浮法玻璃企业熔窑、锡槽、退火窑三大热工设备正常运行的重要设备,研究循环水系统的腐蚀并处理好腐蚀问题对保证生产运行意义重大。...
2020-11-10 09:33:08浏览：20
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炼化厂循环水系统菌藻粘泥控制方案应用研究
针对延长石油榆林炼油厂循环冷却水系统因菌藻粘泥滋生严重带来的不利因素进行全面分析，通过分析循环水水质指标及时准确掌握系统运行情况；同时根据水系统运行情况调整循环水系统菌藻黏泥控制方案，总结出对系统菌藻黏泥有效控制的方式与方法，确保装置长周期稳定运行；文章中详细介绍了近五年循环水系统菌藻粘泥控制方案的施行及其取得的效果。...
2020-11-10 09:33:08浏览：22
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无填料喷雾冷却塔在工业循环水系统中的应用
循环水冷却效果的好坏是影响生产的关键因素.由于传统填料冷却塔存在诸多问题,改用无填料喷雾冷却塔,有效解决了填料塔冷却效率不高、分水不均、飘雨严重,且减轻了设备的质量,检修和维护的工作量和费用大大减少....
2020-11-10 09:33:08浏览：24
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考虑再生单元水质约束的多杂质再生循环水系统优化
废水分类分级处理的再生模式是废水再生的方向,建立和完善该模式的多杂质再生循环水系统的模型具有重要意义.本文从工业实际情况出发,在现有数学模型的基础上,考虑了再生单元进口质量浓度的上下限约束,使得数学模型更加完善.通过实例研究,显示了增加该约束的必要性,并分析了该约束对水网络结构和系统新鲜水目标值的影响....
2020-11-10 09:33:08浏览：17
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炼钢软水密闭循环水系统工艺及冷却设备比较
对炼钢软水密闭循环水系统采用板式换热器和蒸发冷却器的两种不同工艺、设备、运行成本、降温效果等方面进行比较,前者工艺复杂、设备多、二次冷却水量大,但日常检查、检修维护方便,能及时发现问题及时处理,目前使用比较成熟;后者工艺简单、设备少、二次冷却水量小,降温能力强,降温速度快,千吨水耗电量低,但日常检查、检修不方便,不易发现问题.通过比较,优化出炼钢软水密闭循环水处理工艺,可为新建同类水处理系统提供参考....
2020-11-10 09:33:08浏览：24
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循环水系统氨泄漏的判断及处理措施
分析合成氨装置循环水系统氨泄漏的危害，阐述如何根据异常现象进行判断，并提出消除泄漏源、调整循环水pH值、增加水处理剂用量、降低浓缩倍数运行等处理措施。...
2020-11-10 09:33:08浏览：26
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黏胶纤维厂冷却循环水系统变频节能改造
针对黏胶纤维厂冷却循环水系统存在的能源浪费, 根据冷却水泵运行特点, 对冷却循环水系统变频节能改造, 有效解决能源浪费的问题....
2020-11-10 09:33:08浏览：22
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炼油厂循环水系统化学清洗预膜
研究了影响炼油厂循环水水质的因素,通过对循环水系统进行化学清洗、预膜,减少了工业污水排放,有利于节约水资源;同时经过水质稳定剂的处理,对管道、设备起到了缓蚀、阻垢的作用,提高了冷换效果,延长了设备的使用寿命....
2020-11-10 09:33:08浏览：19
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