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  • GB 23550-200935%水胺硫磷乳油35% Isocarbophos emulsifiable concentrates

    本标准规定了35%水胺硫磷乳油的要求、试验方法以及标志、标签、包装、贮运。<br>本标准适用于由水胺硫磷原药与乳化剂溶解在适宜的溶剂中配制而成的35%水胺硫磷乳油。...

    2022-06-08 09:20:14浏览:1 carrateconcentrate

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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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  • Comparison and Analysis of Fabric Deodorization Test Methods

    The test methods of deodorization fabric are studied in daily life.In view of different deodorization fabrics and source gases,the detector tube method and gas chromatography-flame ionization detector (GC-FID) method were chosen to test the deodorizing rates of fabric and the influencing factors on deodorization test were discussed.Through the two methods,the residual concentration of odorous substance after adsorption can be measured,and the deodorizing rates of deodorization fabric can be got by calculation.The results show that the two test methods are both appropriate for deodorization test of fabric....

    2020-12-06 21:11:24浏览:35 deodorizationfabricdeodorizingratedetectortubegaschromatography-flame

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  • Preparation of single-phase ammonium dimolybdate by combination process

    A novel method for the preparation of single-phase ammonium dimolybdate with industrial ammonium molybdate was studied.Various influential factors were evaluated in the paper,including reaction temperature,reaction time,initial molybdenum concentration,initial NH3/Mo molar ratio,and stirring speed.Under the optimum experimental conditions,the crystallization rate of product is 85.23%.The X-ray diffraction (XRD) analysis and chemical analysis show that the product is single-phase ammonium dimolybdate,and no impurity phases exist.The scanning electronic microscope (SEM) image reveals uniform particle size,good particle dispersion,and no agglomeration between particles.Meanwhile,the final pH value of acidification was investigated.The total molybdenum recovery can reach up to 99.40%,and the main phases of acidification product are the same as those of raw material with the final pH value of 1.5.This determines that the acidification product can be used as a raw material to produce single-phase ammonium dimolybdate....

    2020-11-11 22:33:38浏览:26 single-phaseammoniumdimolybdatecombinationprocesscrystallizationratephase

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  • Analysis of damage localization for ductile metal in process of shear band propagation

    Distribution of localized damage in shear band can' t be predicted theoretically based on classical elastoplastic theory. The average damage variable in shear band was considered to be a non-local variable. Based on non-local theory, an analytical expression for the localized damage in strain-softening region of shear band in the process of shear band propagation was presented using boundary condition and symmetry of local damage variable, etc. The results show that dynamic shear softening modulus, dynamic shear strength and shear elastic modulus influence the distribution of the localized damage in shear band. Internal length of ductile metal only governs the thickness of shear band. In the strain-softening region of shear band, the local damage variable along shear band's tangential and normal directions is non-linear and highly non-uniform. The non-uniformities in the normal and tangential directions of shear band stem from the interactions and interplaying among microstructures and the non-uniform distribution of shear stress, respectively. At the tail of the strain-softening region, the maximum value of local damage variable reaches 1. This means that material at this position fractures completely. At the tip of shear band and upper as well as lower boundaries, no damage occurs. Local damage variable increases as dynamic shear softening modulus decreases or shear elastic modulus increases, leading to difficulty in identification or detection of damage for less ductile metal material at higher strain rates....

    2020-11-11 22:33:38浏览:30 ShearbandductilemetaldamageLocalizationnon-localtheorystrainrate

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  • Impact of Human Activities on Depositional Process of Tidal Flat in Quanzhou Bay of China

    As a very important component of a coastal system, tidal flats come to be a focus of the studies on land-ocean interaction in the coastal zone because those areas are subjected to intense human activities and are highly sensitive to the global change. The Quanzhou Bay, located along the middle part of Fujian coast of China, covers about 136.4km2, and the area of coastal wetland in the entire bay from intertidal to subtidal with 6m of water depth accounts for 96% of the total area. Seven short cores were collected and divided in situ with the interval of 5cm on the coastal wetlands of Quanzhou Bay on April 19, 2006. The sediment samples were scattered and the grain sizes were measured by using Mastersizer 2000. Human beings' activities on tidal flat have disturbed the vertical distribution of sediments in stratigraphic sequence and accelerated the sedimentation rates. Grain size analysis results show that the grain size diameters increase and sediment becomes worse sorted towards the sea under the strong human disturbance; Spartina alterniflora can play a role of trapping the fine sediment; but near the bank, the sediment becomes coarse and there are two peak values on frequency curve influenced by the sandpile. The trough formed by human activities along the coastline changes the transport path of water and suspended sediment. The sediments are transported through the trough and deposit in it during the flood; the ebb flow is retarded by the flow output through the adjacent trough, and the deposited sediment can not be re-suspended; then, the sedimentation rate increases. In situ observation show that the sedimentation rate is about 8-10 cm/yr....

    2020-11-11 22:33:38浏览:21 TidalflatsedimentgrainsizeHumanactivitiessedimentationrateQuanzhouBay

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  • ENTROPY PRODUCTION RATE OF THE MINIMAL DIFFUSION PROCESS

    The entropy production rate of stationary minimal diffusion processes with smooth coefficients is calculated. As a byproduct, the continuity of paths of the minimal diffusion processes is discussed, and that the point at infinity is absorbing is proved....

    2020-11-11 22:33:38浏览:31 Minimaldiffusionprocessentropyproductionratecontinuouspath

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  • ACTIVE FRONT STEERING DURING BRAKING PROCESS

    An active front steering (AFS) intervention control during braking for vehicle stability is presented. Based on the investigation of AFS mechanism, a simplified model of steering system is established and integrated with vehicle model. Then the AFS control on vehicle handling dynamics during braking is designed. Due to the difficulties associated with the sideslip angle measurement of vehicle, a state observer is designed to provide real time estimation. Thereafter, the controller with the feedback of both sideslip and yaw angle is implemented. To evaluate the system control, the proposed AFS controlled vehicle has been tested in the Hardware-in-the-loop-simulation (HILS) system and compared with that of conventional vehicle. Results show that AFS can improve vehicle lateral stability effectively without reducing the braking performance....

    2020-11-10 09:33:08浏览:20 activefrontsteering(AFS)handlingStabilityYawrateSideslip

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  • Immigration process in catalytic medium

    The longtime behavior of the immigration process associated with a catalytic super-Brownian motion is studied. A large number law is proved in dimension d≤3 and a central limit theorem is proved for dimension d=3....

    2020-11-10 09:33:08浏览:14 immigrationprocessbranchingratefunctionalBrowniancollisionlocaltime

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  • 经济对煤炭的依赖与煤炭对经济的贡献分析

    本文在全面分析了煤炭消费与国民经济发展关系的基础上,采用定量分析的方法,对近期我国经济对煤炭的依赖程度和煤炭对国民经济的贡献率、吨煤经济效益进行了计算分析。研究结果表明:从过去20多年来看,我国经济发展对煤炭的依赖度并没有发生根本性的变化;“十一五”期间,我国煤炭生产和主要用煤行业对GDP总量和增量的总贡献率分别为15%和18%左右。...

    2020-11-09 23:27:06浏览:23 煤炭经济依赖度贡献率coaleconomicdependentindexcontributionrate

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  • Microstructure evolution of A1-Si semi-solid slurry by gas bubble stirring method

    A novel technique of introducing gas bubble stirring during solidification was studied to prepare Al-Si semi-solid slurry.The microstructure evolution of the slurry during slow cooling process after stirring was investigated.The effects of the solidification rate on the microstructure of the semi-solid slurry were investigated under three different solidification conditions.The results show that fine non-dendritic slurry can be obtained using the gas bubble stirring method.Ripening and coarsening of primary Al grains are observed during the slow cooling process,and at last coarsened eutectic Si appears.Primary Al grains with different sizes and eutectic Si are obtained,corresponding to three different solidification rates....

    2020-11-03 10:30:25浏览:29 gasbubblestirringsemi-solidslurrySolidificationratemicrostructure

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  • Settlement prediction model of slurry suspension based on sedimentation rate attenuation

    This paper introduces a slurry suspension settlement prediction model for cohesive sediment in a still water environment.With no sediment input and a still water environment condition,control forces between settling particles are significantly different in the process of sedimentation rate attenuation,and the settlement process includes the free sedimentation stage,the log-linear attenuation stage,and the stable consolidation stage according to sedimentation rate attenuation.Settlement equations for sedimentation height and time were established based on sedimentation rate attenuation properties of different sedimentation stages.Finally,a slurry suspension settlement prediction model based on slurry parameters was set up with a foundation being that the model parameters were determined by the basic parameters of slurry.The results of the settlement prediction model show good agreement with those of the settlement column experiment and reflect the main characteristics of cohesive sediment.The model can be applied to the prediction of cohesive soil settlement in still water environments....

    2020-11-03 10:30:25浏览:20 cohesivesedimentsedimentationrateattenuationslurrysuspensionsettlement

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  • 基于WCA优化算法的空间桁架结构优化设计

    群智能优化算法已被证实可以用于解决实际工程的优化问题.水循环算法可对约束问题进行求解.基于自然界中水循环过程提出的一种新型智能优化算法——水循环算法(WCA),研究了其应用于空间桁架结构优化设计问题的可行性及有效性,论文对两个空间桁架结构进行了截面优化计算分析,并与已有文献优化结果进行了比较,研究结果表明:WCA优化算法相对于群搜索算法(GSO)、启发式粒子群优化算法(HPSO)等优化算法能够提供更快的收敛速度,收敛结果也更好....

    2020-09-29 10:54:18浏览:11 WCA空间桁架收敛速度优化设计spacialtrussstructureconvergencerateoptimaldesign

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  • 乙烯利对苦玄参生长的影响

    [目的]研究乙烯利对苦玄参种子发芽、种苗繁育、生长及苦玄参苷积累的影响,为苦玄参人工栽培及相关研究提供参考.[方法]设3个乙烯利浓度水平(25、50、75 mg/L),以清水为对照(CK),通过不同浓度乙烯利浸种、叶面喷施等,研究乙烯利对苦玄参各生长指标的影响.[结果]用50~75 mg/L的乙烯利浸种可显著促进苦玄参种子发芽;50~75 mg/L的乙烯利可促进幼苗茎径、根径、叶面积、单株鲜重、侧根的形成及提高种子的成苗率;25~75 mg/L的乙烯利对苦玄参植株的茎径、三级分枝、叶数及生物产量的形成有促进作用;但乙烯利对苦玄参生育进程及苦玄参苷的积累没有显著影响.[结论]用浓度为50 mg/L的乙烯利浸种或叶面喷施种苗可显著促进苦玄参种子发芽及种苗生长,最终提高种子的成苗率;对苦玄参植株喷施浓度为25 mg/L乙烯利可显著促进植株生长,提高苦玄参生物产量....

    2020-09-28 16:47:12浏览:19 苦玄参乙烯利成苗率生物产量Picriafel-terraeLour.ethrelseedlingratebiomassproduction

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  • 石煤提钒配煤焙烧试验研究

    以江西某地石煤为试验原料,采用氧化焙烧-水浸-酸浸工艺提取其中的钒,研究了原矿直接氧化焙烧及原矿经脱碳后氧化焙烧对浸出率的影响、原矿及脱碳样配煤氧化焙烧对浸出率和焙烧能耗的影响.结果表明,原矿经脱碳后氧化焙烧浸出率为80.12%,较原矿直接氧化焙烧提高11.71%;脱碳样配入5%的无烟煤,浸出率可达81.96%,氧化焙烧温度可降低30 ℃、焙烧时间缩短0.5 h,降低了生产成本....

    2020-09-15 12:28:59浏览:35 石煤焙烧无烟煤浸出率stonecoalvanadiumroastinganthraciteLeachingrate

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  • Effects of magnetic fields on HCFC-141b refrigerant gas hydrate formation

    Low-pressure refrigerant gas hydrates have brilliant prospects as a cool storage medium for air-conditioning systems. Intensive effects of some specific magnetic fields on the formation process of HCFC-141b refrigerant gas hydrate are depicted experimentally. Under influence of these specific magnetic fields, the orientation and growth region of gas hydrate are altered; induction time of hydrate crystallization can be shortened extremely, and it can be shortened to 40 min from 9 h; hydrate formation mass can be enhanced considerably, and hydration rate can arrive at 100% in some instances. Meanwhile, the relations of induction time and hydration rate changed with magnetic field intensity are depicted, and some elementary regulations are found....

    2020-09-15 12:28:59浏览:35 magneticfieldsgashydrateinductiontimehydrationratecoolstorage

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  • A NEW CALCULATION METHOD FOR GAS-WELL LIQUID LOADING CAPACITY

    This article proposes a new model for calculating the gas-well liquid loading capacity,which is critical to an accurate prediction of gas well production.Based on analysis of flow regime during the gas well production with water,which is regarded as many single particles in the model,with the shape of particles being assumed as disk-like ellipsoid instead of traditional sphere and changing according to the forces exerted on them,the influences of non-Darcy flow,compressibility,and non-sphere shape on friction factor are analyzed.The differences between the new model and other models are discussed and a new formula for calculating the critical flow rate is obtained.The calculation results and a comparison with other two models show that the new model is more consistent with the actual situation and is practical....

    2020-09-15 12:28:59浏览:19 gaswellaccumulatedliquiddragfactorcriticalflowrate

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  • Theoretical Study on the Reaction Mechanism of SiCl4 with H in the Gas Phase

    The reaction mechanism of SiCl4 with H2 has been studied theoretically using Gaussian 98 program at B3LYP/6-311G* level. Three different reaction paths (a, b, c) in the gas phase were obtained. The geometries, vibrational frequencies and energies of every stagnation point in the reaction channel were calculated and the mechanisms have been confirmed. The results show that path a has an activation energy of 79.12 kcal/mol, which was considered as the main reaction path. Comparably, paths b and c have the energy barriers of 125.07 and 136.25 kcal/mol, res- pectively. The reaction rate constant was calculated by TST method over a wide temperature range of 900~1600 K, which further confirmed that path a was the main reaction channel....

    2020-09-15 12:28:59浏览:25 densityfunctionaltheorytransitionstatereactionmechanismrateConstant

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  • Kinetic model on coke oven gas with steam reforming

    The effects of factors such as the molar ratio of H2O to CH4 (n(H2O)/n(CH4)), methane conversion temperature and time on methane conversion rate were investigated to build kinetic model for reforming of coke-oven gas with steam. The results of experiments show that the optimal conditions for methane conversion are that the molar ratio of H2O to CH4 varies from 1.1 to 1.3and the conversion temperature varies from 1 223 to 1 273 K. The methane conversion rate is more than 95% when the molar ratio ofH2O to CH4 is 1.2, the conversion temperature is above 1 223 K and the conversion time is longer than 0.75 s. Kinetic model of methane conversion was proposed. All results demonstrate that the calculated values by the kinetic model accord with the experimental data well, and the error is less than 1.5%....

    2020-09-13 23:35:02浏览:16 cokeovengassteamreformingkineticmodelconversionrate

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  • Affecting Factors and Improving Measures for Converter Gas Recovery

    To change the undesirable present situation of recovering and using converter gas in steel plants in China,the basic approaches to improving the converter gas recovery rate were analyzed theoretically along with the change curves of the converter gas component content, based on the converter gas recovery system of Baosteel No. 2 steelmaking plant. The effects of converter device, raw material, air imbibed quantity, recovery restricted condition, and intensity of oxygen blowing on the converter gas recovery rate were studied. Among these, the effects of the air imbibed quantity, recovery restricted condition, and intensity of oxygen blowing are remarkable. Comprehensive measures were put forward for improving the converter gas recovery from the point of devices, etc. , and good results were achieved....

    2020-09-13 23:35:02浏览:35 steelplantconvertergasrecoveryrateaffectingfactor

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  • Thermal simulation of the formation and evolution of coalbed gas

    Thermal simulation experiment of gas generation from the peat and the coals were performed using the high temperature and pressure apparatus, at temperature ranging from 336.8-600℃, a pressure of 50MPa and two heating rates of 20℃/h and 2℃/h, and the evolution and formation of coalbed gas components were studied. Results show that for the coals, the gaseous products are mainly composed of hydrocarbon gases. However, for the peat the content of hydrocarbon gases in gaseous products is lower than that of non-hydrocarbon components. In the generated hydrocarbon gases methane is predominant and heavy hydrocarbon gases (C2-5) are present in small amount.Meanwhile, carbon dioxide (CO2) predominates the generated non-hydrocarbon gases, and hydrogen (H2) and sulfurated hydrogen (H2S) are existent in trace amount. It is also observed that temperature is the main factor controlling the evolution of coalbed gas generation. With increasing vitrinite reflectance, methane rapidly increases, CO2 sightly increases, and C2-5 hydrocarbons first increase and then decrease. The peat and Shanxi formation coal have a higher generative potential of coalbed gases than coals and Taiyuan formation coal, respectively, reflecting the effect of the property of organic matter on the characteristics of coalbed gas component generation. In this study, it is found that low heating rate is favorable for the generation of methane, H2and CO2, and the decomposition of C2-5 hydrocarbons. This shows that heating time plays an important controlling role in the generation and evolution of coalbed gases. The results obtained from the simulation experiment in the study of coalbed gases in natural system are also discussed....

    2020-09-13 23:35:02浏览:32 Coalbedgasgenerationandevolutionpyrolysispeatcoalheatingrate

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  • Application of deviation rate in oil and gas reservoir exploration

    Three dimensional geophysical models were abstracted and established according to characteristics of oil and gas reservoir. Then direct current fields for different models were simulated with finite element software (finite element program generator) by hole-to-surface resistivity method. Numerical solution was compared with analytical one for the homogeneity earth model. And a new parameter of deviation rate was proposed by analyzing different plot curves. The results show that the relative error of solution for homogeneity earth model may attain to 0.043%. And deviation rate decreases from 18% to 1% and its anomaly range becomes wide gradually when the depth of oil and gas reservoir increases from 200 to 1 500 m. If resistivity ratio of oil and gas reservoir to sur- rounding rock decreases from 100 to 10 for the resistive oil and gas reservoir, the amplitude attenuation of deviation rate nearly reaches 8%. When there exists stratum above oil and gas reservoir, and influence of resistive stratum may be eliminated or weakened and anomaly of oil and gas reservoir can be strengthened....

    2020-09-13 23:35:02浏览:24 numericalsimulationdeviationrateoilandgasreservoirhole-to-surface

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  • 硝酸酯热分解的机理分析

    使用加速量热仪研究硝酸正丙酯(NPN)、硝酸异丙酯(IPN)和硝酸异辛酯(EHN)的热分解过程.分析了在绝热条件下热分解反应动力学, 根据实验数据计算出表观活化能、指前因子和反应热等参数.根据NPN、IPN和EHN热分解的起始温度和反应热数据,给出了三种硝酸酯在75 ℃时的反应风险指数,分析得到三种物质的热失稳风险度.分别在B3LYP/6-31+G(2df,2p)和B3P86/6-31+G(2df,2p)的理论水平下,计算得到NPN、IPN和EHN的O-NO_2键离解能(BDE).由NPN、IPN和EHN的O-NO_2键离解能在很大程度上符合由加速量热仪测试得到的活化能,推知三种硝酸酯的热分解反应只是单分子O-NO_2键的均裂反应....

    2020-09-02 20:01:33浏览:27 硝酸酯加速量热仪(ARC)反应风险指数密度泛函理论键离解能(BDE)nitratesacceleratingratecalorimetry

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  • 松脂的氧化动力学研究

    为研究松脂的氧化反应动力学,采用紫外分光光度法定量测定固态枞酸在聚乙烯膜上的吸光度变化,求出松脂参与氧化反应的反应量,进而研究松脂氧化反应动力学。实验结果表明,松脂的热氧化和光氧化反应动力学均呈现表观一级反应。热氧化反应温度为35、40、45℃时的表观速率常数分别为3.000×10-4、5.000×10-4、1.100×10-3 min-1,反应活化能Ea为105.8 kJ/mol。254 nm紫外灯辐照下,温度为35、40、45℃时,光强度与表观速率常数的关系分别k=1.162×10-4 I+2.626×10-4、k=1.248×10-4 I+4.588×10-4、k=1.298×10-4 I+0.0011。...

    2020-08-30 18:25:27浏览:38 松脂氧化反应动力学速率常数pinegumoxidationreactionkineticsrateConstant

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  • 八钢欧冶炉单气化炉生产实践

    八钢欧冶炉生产期间上料工序出现故障,为避免炉缸冻结,采取了单气化炉生产模式。生产实践表明,单气化生产方案可行,并获得了大量单气化炉生产运行数据。...

    2020-07-12 21:36:56浏览:26 欧冶炉气化炉熔炼率OYfurnacegasifiersmeltingrate

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