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  • GB/T 23789-2009低钠食品Foods with low-sodium content

    本标准规定了低钠食品的产品分类、技术要求、试验方法和标签。本标准适用于低钠食品的生产和流通。...

    2022-06-14 11:02:47浏览:2 食品sodiumcontent

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  • GB/T 2576-2005纤维增强塑料树脂不可溶分含量试验方法Test method for insoluble matter content of resin used in fiber reinforced plastics

    本标准规定了用萃取法测定纤维增强塑料树脂不可溶分含量(又称固化度)试验的试样、仪器与试剂、试验步骤、结果计算及试验报告。本标准适用于以玻璃纤维、碳纤维和芳纶为增强材料,以环氧、聚酯、酚醛类树脂为基体的纤维增强塑料。...

    2022-06-10 07:53:18浏览:4 contentplasticsreinforced

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  • FZ/T 50010.11-1998粘胶纤维用木浆粕 树脂含量的测定Wood pulp board for viscose fiber—Determination of resin content

    本标准规定了粘胶纤维用木浆粕中树脂含量的测定方法--二抓甲烷抽出法。<br>本标准适用于粘胶纤维用木浆粕。...

    2022-06-06 18:57:58浏览:1 contentterminationDetermination

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  • GB/T 19509-2004锯齿衣分试轧机Saw type gin for testing cotton content

    本标准规定了锯齿衣分试轧机的技术要求、试验方法、检验规则及标志、包装与贮存的要求。本标准适用于棉花检验用锯齿衣分试轧机。...

    2022-06-06 09:06:46浏览:1 cottontestingcontent

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  • GB/T 39715.4-2021塑料 生物基含量 第4部分:生物基物质含量的测定Plastics. Biobased content. Part 4: Determination of biobased mass content

    GB/T 39715.4-2021塑料 生物基含量 第4部分:生物基物质含量的测定Plastics. Biobased content. Part 4: Determination of biobased mass content...

    2022-03-18 17:24:56浏览:23 Determinationplasticscontent

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  • GB/T 40461-2021肥料中钠含量的测定Determination of sodium content for fertilizers

    GB/T 40461-2021肥料中钠含量的测定Determination of sodium content for fertilizers...

    2022-03-18 17:24:56浏览:13 Determinationfertilizercontent

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  • GB/T 22930.2-2021皮革和毛皮 金属含量的化学测定 第⒉部分:金属总量Leather and fur. Chemical determination of metal content. Part 2 : Total metal content

    GB/T 22930.2-2021皮革和毛皮 金属含量的化学测定 第⒉部分:金属总量Leather and fur. Chemical determination of metal content. Part 2 : Total metal content...

    2022-03-14 21:41:45浏览:11 Determinationchemicalcontent

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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:54 hyaluronicacidpolyethyleneglycolwatercontentdegradationrate

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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:68 hyaluronicacidviscoelasticitywatercontentdegradationcytotoxicity

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  • 晾晒和添加剂对菊苣青贮的影响

    为研究含水量和添加剂对菊苣(Cichorium intybus L)青贮的影响,以开花期菊苣鲜样和晾晒样为原料,分别添加甲酸(6mL/kg)或蔗糖(2%)处理,袋装并密封青贮360d后取样分析。结果表明,经晾晒后制作的菊苣青贮饲料的pH较高,乙酸和氨态氮含量极显著下降(P...

    2020-12-22 21:24:13浏览:24 菊苣含水量添加剂青贮ChicoryMoisturecontentadditivesSilage

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  • Structure change of 430 stainless steel in the heating process

    The microstructure analysis was employed for the ferritic stainless steel (SUS430) with the carbon content from 0.029wt% to 0.100wt% under the simulated heating process condition. The higher carbon sample (430H) contains the duplex phase micro-structure at the temperature of 1150℃; on the other hand, the lower carbon content sample (430L) does not touch two phase area even at the temperature of 1450℃ and has the single phase ferritic microstrucmre. The carbon content need be well controlled for the 430 ferritic stainless steel since it can significandy affect the heating process curve, and the heating process may not be done in the two phase area due to the uncontrolled carbon content. With the low carbon content and the proper soaking time, the grain size is not sensitive to the heating process temperature and the soaking time. In the present heat treatment experiments, the soaking time is about 10 rain, and the processing parameters can be chosen according to the requ'trernent of the gross energy, the efficiency and the continual forming....

    2020-11-11 22:33:38浏览:30 ferriticstainlesssteelcarboncontentmicrostructureheatingcurve

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  • 补充水总铁对循环水系统缓蚀性能的影响研究

    在循环冷却水系统中,影响系统腐蚀的因素很多.通过试验证实在补充水总铁含量较高时,会影响缓蚀剂的缓蚀效果,甚至会加剧循环水对金属管材的腐蚀.将监测总铁项目增加到各类补充水的日常分析中,从循环水系统前端对总铁进行管控是处理循环水腐蚀问题的有效途径之一....

    2020-11-10 09:33:08浏览:18 总铁含量缓蚀剂补充水腐蚀速率thetotalironcontentcorrosioninhibitionmake-upwater

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  • 乙烯、丙烯中微量水含量的分析

    采用便携式微量水分析仪和库仑法微量水分析仪测定了乙烯、丙烯试样中的微量水含量,对试样的传输系统、进样量的控制、液体试样的气化和水标准气体的制备方法进行了改进,优化了测试条件.以低吸附惰性管线和小死体积单进单出的不锈钢减压器为试样传输系统,缩短了测试时间.采用液态烃闪蒸气化取样进样器气化液体试样并准确控制试样的进样量,可避免液体试样渐次气化对水含量测定结果的影响及对采样钢瓶大小的限制.采用渗透管发生器制备水标准气体,可验证分析结果的准确度.采用库仑法微量水分析仪测定水含量时,试样流量选择600 mL/min较适宜,开封保存15 d之内的卡尔·费休试剂对测定结果无影响.采用便携式微量水分析仪测定水含量时,选择试样流量在400~800 mL/min之间较适宜.两种仪器的测量结果相近,稳定性好,准确度高,回收率在102%~ 107%之间,相对偏差小于10%....

    2020-09-29 10:54:18浏览:19 乙烯丙烯微量水含量ethylenepropylenetracewatercontent

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  • The mechanism of the flowing ground water impacting on coalbed gas content

    The hydrogeological condition affects the coalbed gas storage dramatically. In an area of stronger hydrodynamics, the coal has a lower gas content, while a higher gas content exists in an area of weaker hydrodynamics. Obviously, the flowing groundwater is harmful to coalbed gas preservation. But few researches focus on the mechanism of how the flowing water diminishes the coalbed gas content.Based on the phenomenon that the flowing groundwater not only makes coalbed gas content lower, but also fractionates the carbon isotope, this research puts forward an idea that it is the water solution that diminishes the coalbed gas content,rather than the water-driven action or the gas dissipation through cap rocks. Only water-soluble action can both fractionate the carbon isotope and lessen the coalbed gas content,and it is an efficient way to take gas away and affect the gas content....

    2020-09-15 12:28:59浏览:26 Coalbedmethanecarbonisotopegroundwatergascontentdestruction

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  • Advances in gas content based on outburst control technology in Huainan, China

    The sudden and violent nature of coal and gas outbursts continues to pose a serious threat to coal mine safety in China. One of the key issues is to predict the occurrence of outbursts. Current methods that are used for predicting the outbursts in China are considered to be inadequate, inappropriate or impractical in some seam conditions. In recent years, Huainan Mining Industry Group (Huainan) in China and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia have been jointly developing technology based on gas content in coal seams to predict the occurrence of outbursts in Hua-inan. Significant progresses in the technology development have been made, including the development of a more rapid and accurate system in determining gas content in coal seams, the invention of a sam-pling-while-drilling unit for fast and pointed coal sampling, and the coupling of DEM and LBM codes for advanced numerical simulation of outburst initiation and propagation. These advances are described in this paper....

    2020-09-15 12:28:59浏览:42 coalminingoutburstpredictiongascontentnumericalmodeling

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  • 空气干燥系统的改造

    分析了空气干燥系统的现状,找出了存在的隐患,提出了解决措施及对空气系统设计的建议。...

    2020-09-03 16:42:35浏览:34 空气干燥系统含水量干燥器再生压力露点airdryingsystemMoisturecontentdryerregeneration

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  • 滇池水葫芦的热重分析

    [目的]明确水葫芦的热解特性.[方法]采用热重分析方法对滇池中的水葫芦进行热解试验,绘制水葫芦叶、根、整株的热重曲线.[结果]水葫芦热解从易到难的顺序为整株、叶、根,整株水葫芦在289 ~531℃的热解失重率为35.52%,叶在279 ~497℃的热解失重率为54.11%,根在288 ~488℃的热解失重率为40.88%.[结论]试验结果为水葫芦的燃料和发酵利用提供了参考....

    2020-08-31 10:42:30浏览:38 水葫芦灰分热解热重分析Eichharniacrassipesashcontentpyrolysisthermalgravimetric

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  • Effect of suction change on water content and total volume of an expansive clay

    A laboratory study was carried out on both natural and compacted specimens to investigate the complex soil-water interaction in an unsaturated expansive clay. The laboratory study includes the measurement of soil-water characteristic curves, 1D free swelling tests, measurement of swelling pressure and shrinkage tests. The test results revealed that the air-entry value of the natural specimen was quite low due to cracks and fissures present. The hydraulic hysteresis of the natural specimen was relatively insignificant as compared with the compacted specimen. Within a suction range 0 to 500 kPa, a bilinear relationship between free swelling strain (or swelling pressure) and initial soil suction was observed for both the natural and compacted specimens. As a result of over-consolidation and secondary structures such as cementation and cracks, the natural specimens exhibited significant lower swelling (or swelling pressure) than the compacted specimen. The change of matric suction exerts a more significant effect on the water phase than on the soil skeleton for this expansive clay....

    2020-07-08 21:52:19浏览:20 ExpansivesoilwatercontentSuctionswellingShrinkage

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  • Water content distribution in the surface layer of Maoping slope

    The water content distribution in the surface layer of Maoping slope has been studied by testing the water content at 31 control sites. The water content profiles at these sites have also been determined. The water content distributions at different segments have been obtained by using the Kriging method of geostatistics. By comparing the water content distributions with the landform of the slope, it was shown that the water content is closely dependent on the landform of the slope. The water content distribution in the surface layer provided a fundamental basis for landslide predication and treatment....

    2020-07-08 08:49:41浏览:28 landslidewatercontentinsitutestKrigingmethodgeostatistics

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  • Determination of Water Content of Water-soluble Paints by Gas Chromatography

    This paper describes the determination of water content of water-soluble paints by gas chromatography. The water in paints is extracted by dimethyl formamide (DMF) as a solvent.Isopropanol is used as an internal standard. The mixture is separated by low-speed centrifugation.Then a 1-uL sample of the supernatant from the prepared solution is injected into the gas chromatograph. The water content is determined by internal standard calibration curve. The rate of recovery of added standard of this method is more than 98%. Relative mean deviation is less than 3‰.The linearity of calibration curve is good and relativity coefficient is higher than 0.998....

    2020-07-08 08:49:41浏览:24 watercontentpaintsgaschromatography

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  • Comparing potentials for gas outburst in a Chinese anthracite and an Australian bituminous coal mine

    Gas outbursts in underground mining occur under conditions of high gas desorption rate and gas content, combined with high stress regime, low coal strength and high Young’s modulus. This combination of gas and stress factors occurs more often in deep mining. Hence, as the depth of mining increases, the poten-tial for outburst increases. This study proposes a conceptual model to evaluate outburst potential in terms of an outburst indicator. The model was used to evaluate the potential for gas outburst in two mines, by comparing numerical simulations of gas flow behavior under typical stress regimes in an Australian gassy mine extracting a medium-volatile bituminous coal, and a Chinese gassy coal mine in Qinshui Basin (Shanxi province) extracting anthracite coal. We coupled the stress simulation program (FLAC3D) with the gas simulation program (SIMED II) to compute the stress and gas pressure and gas content distribution following development of a roadway into the targeted coal seams. The data from gas content and stress distribution were then used to quantify the intensity of energy release in the event of an outburst....

    2020-06-12 16:19:40浏览:1395 coaloutburstgascontentpermeabilitystressenergy

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  • Quantitative inverse modeling of nitrogen content from hyperion data under stress of exhausted coal

    Monitoring and evaluating the nutritional status of vegetation under stress from exhausted coal mining sites by hy-per-spectral remote sensing is important in future ecological restoration engineering. The Wangpingcun coal mine, located in the Mentougou district of Beijing, was chosen as a ease study. The ecological damage was analyzed by 3S technology, field investiga-tion and from chemical data. The derivative spectra of the diagnostic absorption bands are derived from the spectra measured in the field and used as characteristic spectral variables. A correlation analysis was conducted for the nitrogen content of the vegetation samples and the first derivative spectrum and the estimation model of nitrogen content established by a multiple stepwise linear regression method. The spatial distribution of nitrogen content was extracted by a parameter mapping method from the Hyperion data which revealed the distribution of the nitrogen content. In addition, the estimation model was evaluated for two evaluation indicators which are important for the precision of the model. Experimental results indicate that by linear regression and parameter mapping, the estimation model precision was very high. The coefficient of determination, R2, was 0.795 and the standard deviation of residual (SDR) 0.19. The nitrogen content of most samples was about 1.03% and the nitrogen content in the study site seems inversely proportional to the distance from the piles of coal waste. Therefore, we can conclude that inversely modeling nitrogen content by hyper-speetral remote sensing in exhausted coal mining sites is feasible and our study can be taken as reference in spe-cies selection and in subsequent management and maintenance in ecological restoration....

    2020-06-12 16:18:02浏览:1382 Hyperionnitrogencontentestimationmodellinearregression

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  • A general solution and approximation for the diffusion of gas in a spherical coal sample

    The square root relationship of gas release in the early stage of desorption is widely used to provide a simple and fast estimation of the lost gas in coal mines. However, questions arise as to how the relation-ship was theoretically derived, what are the assumptions and applicable conditions and how large the error will be. In this paper, the analytical solutions of gas concentration and fractional gas loss for the dif-fusion of gas in a spherical coal sample were given with detailed mathematical derivations based on the diffusion equation. The analytical solutions were approximated in case of small values of time and the error analyses associated with the approximation were also undertaken. The results indicate that the square root relationship of gas release is the first term of the approximation, and care must be taken in using the square root relationship as a significant error might be introduced with increase in the lost time and decrease in effective diameter of a spherical coal sample....

    2020-06-12 16:17:40浏览:1389 coalcontentLostgasSphericalsamplediffusionApproximationerror

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  • Evaluation of coal bed methane content using BET adsorption isotherm equation

    Coal bed methane is unconventional raw natural gas stored in coal seam with considerable reserves in China.In recent years,as the coal bed methane production,the safety and the use of resources have been paid more attentions.Evaluating coal bed methane content is an urgent problem.A BET adsorption isotherm equation is used to process the experimental data.The various parameters of BET equation under different temperatures are obtained; a theoretical gas content correction factor is proposed,and an evaluation method of actual coal bed methane is established....

    2020-06-12 16:17:05浏览:1391 BETadsorptionisothermcoalbedmethanegeophysicalwelllogginggascontent

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