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GB/T 18916.55-2021取水定額 第55部分：皮革Norm of water intake. Part 55:Leather
GB/T 18916.55-2021取水定額 第55部分：皮革Norm of water intake. Part 55:Leather...
2022-03-18 17:24:56瀏覽：7
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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瀏覽：9
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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瀏覽：30
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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瀏覽：61
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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瀏覽：28
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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瀏覽：22
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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瀏覽：40
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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瀏覽：24
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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瀏覽：31
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流體高效輸送節能技術在硫酸、磷復肥裝置循環水系統中的應用分析
針對目前我國大部分硫酸、磷肥生產裝置循環水系統中普遍存在水泵運行效率低、能耗高、振動噪聲大以及汽蝕等問題,提出實施流體高效輸送節能改造技術.大量的實驗及成功的改造案例說明,實施該項技術改造后可以在節能的同時提高運行效率,并且能夠取得良好的經濟效益和社會效益....
2020-11-10 09:33:08瀏覽：23
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超超臨界汽輪機循環水系統改造及運行優化
針對某電廠循環水系統存在的運行調整空間有限、廠用電率高和經濟性差的問題,對循環水系統進行了改造并開展了汽輪機組微增出力、循環水泵在不同運行方式下的冷卻水流量、循環水泵耗功以及凝汽器變工況試驗研究,獲得了循環水系統的經濟調度運行方式,保證了汽輪機達到或接近最經濟真空運行....
2020-11-10 09:33:08瀏覽：24
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無填料噴霧冷卻塔在磷酸循環水系統中的應用
循環水冷卻效果的好壞是影響磷酸生產的關鍵因素。由于傳統填料冷卻塔存在諸多問題，故對其進行改造。改用無填料和高效低壓離心噴霧裝置的空塔，有效解決了填料塔分水不均、飄雨嚴重、冷卻效率下降等問題，循環水經冷卻塔進出口溫差提高1～2℃，且減輕了設備檢修清堵和維護的工作量和費用。...
2020-11-10 09:33:08瀏覽：22
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自備熱電廠循環水系統清洗預膜及水質穩定性分析
闡述了自備熱電廠循環水系統停車在線剝離、清洗和預膜處理的方法及結果。探討了循環水系統清洗、預膜的水質控制方法。...
2020-11-10 09:33:08瀏覽：16
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JKD - R40A1SS 冷卻循環水系統的維護和修理
冷卻循環水系統工作好壞直接影響到電鏡的使用壽命，系統工作是否正常與平時做好維護是分不開的。...
2020-11-10 09:33:08瀏覽：30
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馬蓮臺電廠循環水系統的運行控制及管理初探
循環冷卻水是火力發電廠用水量的主要組成部分,循環水水質的好壞關系到發電機組是否能夠滿負荷正常運行.循環水水質不好,會造成凝汽器銅管結垢及腐蝕,嚴重時影響機組的安全經濟運行.水的循環利用,濃縮倍數的提高,要求必須采取適當的水處理手段,以解決熱力設備的結垢及腐蝕問題....
2020-11-10 09:33:08瀏覽：19
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凈化廠循環水系統再生水回用的腐蝕控制
某凈化廠循環水系統引入再生水后，腐蝕嚴重，嚴重影響了設備的正常使用，給凈化廠的正常生產造成了一定的影響。針對此情況，對其循環水體系現況進行了詳細的分析研究，發現其主要問題在于對再生回用水的不正確使用。對此開展了阻垢、緩蝕、殺菌等實驗研究工作，開發出適合于該廠的循環水系統穩定運行方案，為現場應用提供了技術支持。...
2020-11-10 09:33:08瀏覽：25
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循環水系統采用水輪機替代風機電機節電改造
對反擊混流式水輪機替代風機電機的改造方法、可行性、改造前后涼水塔的運行方式及改造后效益進行闡述。...
2020-11-10 09:33:08瀏覽：25
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浮法玻璃生產線循環水系統的腐蝕與防治
在浮法玻璃生產中,循環水在熔窯攪拌器、錫槽拉邊機冷卻水套等設備和儀表中是必不可少的,循環冷卻水系統是保證浮法玻璃企業熔窯、錫槽、退火窯三大熱工設備正常運行的重要設備,研究循環水系統的腐蝕并處理好腐蝕問題對保證生產運行意義重大。...
2020-11-10 09:33:08瀏覽：17
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煉化廠循環水系統菌藻粘泥控制方案應用研究
針對延長石油榆林煉油廠循環冷卻水系統因菌藻粘泥滋生嚴重帶來的不利因素進行全面分析，通過分析循環水水質指標及時準確掌握系統運行情況；同時根據水系統運行情況調整循環水系統菌藻黏泥控制方案，總結出對系統菌藻黏泥有效控制的方式與方法，確保裝置長周期穩定運行；文章中詳細介紹了近五年循環水系統菌藻粘泥控制方案的施行及其取得的效果。...
2020-11-10 09:33:08瀏覽：21
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無填料噴霧冷卻塔在工業循環水系統中的應用
循環水冷卻效果的好壞是影響生產的關鍵因素.由于傳統填料冷卻塔存在諸多問題,改用無填料噴霧冷卻塔,有效解決了填料塔冷卻效率不高、分水不均、飄雨嚴重,且減輕了設備的質量,檢修和維護的工作量和費用大大減少....
2020-11-10 09:33:08瀏覽：22
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考慮再生單元水質約束的多雜質再生循環水系統優化
廢水分類分級處理的再生模式是廢水再生的方向,建立和完善該模式的多雜質再生循環水系統的模型具有重要意義.本文從工業實際情況出發,在現有數學模型的基礎上,考慮了再生單元進口質量濃度的上下限約束,使得數學模型更加完善.通過實例研究,顯示了增加該約束的必要性,并分析了該約束對水網絡結構和系統新鮮水目標值的影響....
2020-11-10 09:33:08瀏覽：16
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煉鋼軟水密閉循環水系統工藝及冷卻設備比較
對煉鋼軟水密閉循環水系統采用板式換熱器和蒸發冷卻器的兩種不同工藝、設備、運行成本、降溫效果等方面進行比較,前者工藝復雜、設備多、二次冷卻水量大,但日常檢查、檢修維護方便,能及時發現問題及時處理,目前使用比較成熟;后者工藝簡單、設備少、二次冷卻水量小,降溫能力強,降溫速度快,千噸水耗電量低,但日常檢查、檢修不方便,不易發現問題.通過比較,優化出煉鋼軟水密閉循環水處理工藝,可為新建同類水處理系統提供參考....
2020-11-10 09:33:08瀏覽：23
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循環水系統氨泄漏的判斷及處理措施
分析合成氨裝置循環水系統氨泄漏的危害，闡述如何根據異?，F象進行判斷，并提出消除泄漏源、調整循環水pH值、增加水處理劑用量、降低濃縮倍數運行等處理措施。...
2020-11-10 09:33:08瀏覽：25
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黏膠纖維廠冷卻循環水系統變頻節能改造
針對黏膠纖維廠冷卻循環水系統存在的能源浪費, 根據冷卻水泵運行特點, 對冷卻循環水系統變頻節能改造, 有效解決能源浪費的問題....
2020-11-10 09:33:08瀏覽：20
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煉油廠循環水系統化學清洗預膜
研究了影響煉油廠循環水水質的因素,通過對循環水系統進行化學清洗、預膜,減少了工業污水排放,有利于節約水資源;同時經過水質穩定劑的處理,對管道、設備起到了緩蝕、阻垢的作用,提高了冷換效果,延長了設備的使用壽命....
2020-11-10 09:33:08瀏覽：17
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