A technical method to improve NOx/NH3 mixing ratio in SCR system and its engineering applications

A technical method for diagnosing the distribution of NO_x flux within the cross-section area in front of ammonia injection grid (AIG) was proposed for guiding the valve-tuning of AIG branch-pipes, in order to optimize the NO_x/NH₃ mixing ratio in the selective catalytic reduction (SCR) system of power plant. The weight coefficient of each branch-pipe in AIG system can be quantitatively determined with regard to the distribution of NO_x flux in the corresponding sub-zone of the cross-section area. The control strategy of the valves for different AIG branch-pipes can be achieved for guiding the NH₃ injection and improving the NO_x/NH₃ mixing ratio within the whole cross-section area in front of AIG. The technology has been applied on one side of the SCR system flue-gas tunnels (normally two tunnels for the SCR system called as A-side and B-side) of a 660 MW plant for more than one year. The ammonia consumption rate of the SCR system was reduced about 12.62% and the uniformity of outlet NO_x distribution was estimated to be greatly improved by about 79.01% with regard to the standard deviation. The rising rate of the flue gas resistance of the air preheater was slown down by 39.18% compared to that of the other flue-gas tunnel of SCR system. This implied that the formation of the sticky ammonium bisulfate (ABS) on air preheater was significantly inhibited through the application of this technology.     

低稀土超稳分子筛制备过程交换降钠工艺的筛选

通过对低稀土超稳分子筛制备过程交换降钠工艺的试验对比，在考察稀土利用率以及物料过滤性能的基础上，筛选出工业化高效的工艺操作。     

双加压硝酸生产中两种清除铵盐方法的比较

双加压硝酸生产中根据铵盐的数值决定铂催化剂的使用寿命和装置的安全运行。结合我公司两套双加压法（105t／a、270t／a）的运行经验，对安全条件下的经济安全运行做一些探讨。     

用碳酸氢铵法制备硫酸亚锡的研究

通过实验和生产实践，提出用碳酸氢铵法制备试剂硫酸亚锡，研究结果表明这种方法比传统的用碳酸钠法制备硫酸亚锡更经济、实用，从而证明用碳酸氢铵法制备硫酸亚锡是可行的。     

阳离子聚合物研究IN，N─二甲基乙基丙烯酰胺氯化铵单体的制备及聚合

本文叙述了由丙烯酰胺、氯乙醇、二甲胺制备阳离子单体的方法。由制备的正氦阳离子单体合成了Ｎ，Ｎ—二甲基乙基丙烯酰的均聚物。Ｎ，Ｎ—二甲基乙基丙烯酰胺同丙烯酰胺的共聚物，并且确定了聚合的条件，对聚合物结构参数作了某些测定。对配装用粘土作了防膨性能同共聚物组成关系的分析，确定了聚合物随粘土防膨要求不同，阳离子度可由聚合条件给予调节。     

C6H2(NO2)3ONH4的单晶制备和晶体结构

This paper introduces the preparation method of single crystal and the molecular structure of ammonium picrate.The obtained results show that the crystal of ammonium picrate belongs to orthorhombic, Ibca space group.The crystal parameters of the ammonium picrate was given in the paper .a=7.131(1),b=13.487(1),c=19.810(2),V=1905.2(4)³,Z=8,D_c=1.716mg/cm³,μ=0.159mm^-1,F(000)=1008。     

Modification of alumina bubbles with ammonium aluminum sulphate

Ammonium aluminum sulphate was introduced to modify alumina bubbles by the wet chemical method. Distribution of ammonium aluminum sulphate, in situ decomposition characteristics, microstructure and mechanical properties of the modified alumina bubbles were investigated by SEM, XRD, BET and by a purposely designed experimental device for the measurement of compressive resistance. Experimental results showed that an ammonium aluminum sulphate thin film was formed on the surface of the alumina bubbles, at the same time, ammonium aluminum sulphate also infiltrated into the flaws and cavities of the alumina bubbles. After heat-treated at 900 °C, the ammonium aluminum sulphate on the alumina bubbles could be in situ decomposed to γ-Al₂O₃ with high activity. The compressive resistance of the modified alumina bubbles was enhanced from 15.6N to 38.7N after heat-treatment at 1700 °C for 2 h.     

Short communication: Effects of subacute ruminal acidosis on free-choice intake of sodium bicarbonate in lactating dairy cows

The effect of inducing subacute ruminal acidosis (SARA) on the free-choice intake of sodium bicarbonate (SB) was investigated in four midlactation Holstein cows in a switchover experiment with four 1-wk periods. The SARA was induced by replacing 25% of the ad libitum intake of total mixed ration (TMR) with pellets containing 50% ground wheat and 50% ground barley and restricting access to TMR from 0700 to 1700 h. Control consisted of feeding TMR ad libitum. Powdered SB was provided for ad libitum consumption. Rumen pH was measured continuously using indwelling pH probes. Induction of SARA reduced (P < 0.05) the average daily rumen pH from 6.08 to 5.87, increased (P < 0.05) the average duration of rumen pH below 6 from 547 min x d(-1) to 916 min x d(-1), and increased (P < 0.05) the average duration of rumen pH below 5.6 from 132 min x d(-1) to 397 min x d(-1) (P < 0.05) but did not significantly affect SB intake. Average intake of SB was 26.8 g x d(-1) during SARA and 34.5 g x d(-1) during control. These low SB intakes must not have substantially affected rumen pH. Sodium bicarbonate intake differed significantly (P < 0.05) between cows. These data indicate that cows did not select SB in order to attenuate SARA.     

Immersion nickel deposition on blank silicon in aqueous solution containing ammonium fluoride

Immersion deposition of Ni on p-Si (100) blank substrates was carried out in an aqueous NiSO₄ solution at a pH value of 8 through displacement reactions. Study of the early deposition stage revealed that incorporation of 2.5 M NH₄F in solution promoted Ni nucleation significantly. By adding fluoride, it was observed that metallic Ni was deposited constantly at the expense of Si and the deposition was not self-limited. Sponge-like Ni deposits were observed and it might explain the non-limiting feature of such immersion Ni deposition over Si. Transmission electron microscopic images of Ni/Si cross-sections showed that during the reactions, Si oxide played a role of the intermediate phase. The whole process could have involved successive Si oxidation steps. Eventually the oxide was etched away by fluoride resulting in a nanoporous Ni film.