从高砷锑烟灰碱浸液中脱除砷

高砷锑烟灰的碱性氧压浸出液中,砷质量浓度在25 g/L以上,研究了采用硫酸-铁盐法去除砷。结果表明:铁盐用量为n(Fe)/n(As)=1.75,用硫酸调溶液pH=6,在60℃下反应1.5 h,砷脱除率在99.5%以上,除砷效果较好。     

硫酸盐溶液电解镍过程中As(Ⅲ)和Sb(Ⅲ)的行为

<正>R.R.Samal等研究了质量浓度在0~1 000mg/L范围的As(Ⅲ)和Sb(Ⅲ)对从硫酸盐溶液中电解镍的影响。砷和锑的存在使阴极电流效率降低,同时能耗增加。当加入硫酸镍溶液时,砷和锑都使阴极去极化,导致在更大阳极电位条件下,镍在阴极上还原。X射线衍射仪研究结果表明,As(Ⅲ)和Sb(Ⅲ)     

流动注射分光光度法测定废水中砷

建立了测定砷(Ⅲ)的流动注射光度分析法。在0.5 mol/L的硫酸介质中,溴酸钾的强氧化性将砷(Ⅲ)氧化成砷(Ⅴ),剩余的溴酸钾与碘化钾反应生成单质碘,利用碘与淀粉形成蓝色络合物,间接测定微量砷(Ⅲ)。方法的线性范围为0.04~1.20μg/mL,检出限为6.2×10-3μg/mL(3倍噪音);除IO3,IO4,Cr2O27-等强氧化性阴离子外,其余阴离子以及大量常见阳离子对砷的测定没有干扰。对质量浓度为0.30μg/mL的As(Ⅲ)标准溶液连续进样11次测定,相对标准偏差为1.8%。该方法用于废水中砷的     

钒钨钛脱硝催化剂再生过程废水脱砷研究

对碱浸脱砷反应后的废水进行脱砷研究。考察工艺流程、添加剂种类及用量、反应体系pH值、反应温度,反应时间对脱砷效果的影响。确定最佳工艺参数:氧化剂H2O2用量H2O2:As=5 (化学计量比)、氧化温度T=30℃、氧化时间15 min;采用铁盐(浓度为4. 4 g/L)控制溶液p H=11;沉淀剂CaO用量Ca/(As+V+W)=5∶1 (化学计量比)、沉淀温度T=85℃、沉淀时间30 min。此法对废水进行脱砷处理后As含量最低可达0. 45 mg/L,达到国家排放标准,脱砷废液可循环利用,脱砷残渣为直接堆置的无害残渣。     

低质量浓度含砷废水处理工艺试验研究

试验研究了铁砷质量比、氧化钙用量、反应时间、氧化剂用量等因素对低质量浓度含砷废水处理的影响,结果表明:GCI-8具有强氧化性,有助于As的去除;在原水p H值为5~6,As质量浓度约为1.6 mg/L时,处理后As质量浓度与铁砷质量比、反应时间关系较大;p H值对砷酸铁和砷酸钙沉淀物的溶出有影响;在相同铁砷质量比为30的条件下,铁盐沉淀法反应30 min,处理后As质量浓度满足《地表水环境质量标准》Ⅲ类标准,而铁盐高级氧化沉淀法反应5 min,处理后As质量浓度满足《地表水环境质量标准》Ⅲ类标准;铁盐高级氧化沉淀法可以极大地提高反应效率,缩短反应时间。     

氢化物发生-电感耦合等离子体原子发射光谱法测定土壤中汞和砷

汞和砷是土壤环境质量监测中的管控元素,由于两者含量差异较大,使用氢化物发生-原子荧光光谱法难以同时准确测定,而使用电感耦合等离子体原子发射光谱法(ICP-AES)测定砷、汞时有灵敏度偏低的问题。试验探讨了自制简易氢化物发生装置与电感耦合等离子体原子发射光谱仪联用同时测定土壤中汞和砷。使用王水(1+1)消解样品,保持样品溶液的酸度为15%,还原剂为15 g/L硼氢化钾溶液;设置ICP-AES最佳工作条件为入射功率1 450 W、蠕动泵转速1.7 mL/min、等离子体气流量16 L/min、雾化气流量0.45 L/min。方法中汞和砷的线性范围分别为0.50～10.0μg/L和5.00～100μg/L,线性相关系数均为0.999 8,检出限分别为0.016μg/g和0.12μg/g,定量限分别为0.064μg/g和0.48μg/g。按照实验方法测定土壤标准物质和实际土壤样品中汞和砷,土壤标准物质的测定值与认定值相一致;实际样品测定结果的相对标准偏差(RSD,n=6)为3.1%～4.8%。同时采用实验方法和原子荧光光谱法对实际土壤样品中汞和砷进行测定,并通过t检验法检验显示两种方法测定结果...     

石灰乳-聚合硫酸铁两段法除硫酸锌溶液中高含量砷锑的研究

含As 2.01 g/L、Sb 222. 64 mg/L,pH值为3.0左右的硫酸锌溶液,可以采用两段法除As。第一段加入双氧水和氢氧化钙,可将As除到50 mg/L以下,Sb除到100 mg/L以下;第二段加入5 g/L的石灰粉,3 g/L的聚合硫酸铁,可将As、Sb分别降至1 mg/L以下。两段法除砷锑效果明显,除氟率也在50%以上,即实现了高含量砷、锑开路,又降低生产成本。     

无机盐改性麦糟在低浓度含砷水中的吸附性能研究

含砷废水的排放已成为国内外饮用水源最大的安全隐患之一.采用无机盐改性麦糟作为吸附剂,对低浓度含砷水进行吸附试验研究.确定最佳改性条件为1.5 mol/L NaCl 与麦糟按1 L∶100 g 混合均匀,室温下改性12 h.在不调节pH 值（溶液pH 值为7）,改性麦糟投加量5 g/L 条件下,初始浓度为0.1 mg/L 的含砷水可在60 min 达到吸附平衡,且最终使出水满足《生活饮用水卫生标准》（GB5749-2006）中砷含量（0.01 mg/L）要求.考察了溶液共存阴离子对改性麦糟吸附含砷水的影响,并验证了NaCl 改性麦糟处理含砷水源地水的效果.      

氢化物发生-原子荧光光谱法测定精碲中微量砷

提出了一种氢化物发生-原子荧光光谱法测定精碲中微量砷的方法。用硝酸溶解样品,氢氧化钾和盐酸调节溶液酸度至pH 5.5~6.5,碲水解沉淀析出。除去了大量基体后,溶液中碲量少于50μg/mL。在盐酸介质中用硫脲-抗坏血酸将砷(预还原为砷(Ⅲ),以标准加入法绘制校准曲线,氢化物发生-原子荧光光谱法测定砷量。方法的检出限为0.02μg/L,砷量在0.02~40μg/L范围内有良好的线性关系。方法操作简便、快速,应用于精碲中痕量砷的测定,测定结果与正戊醇萃取砷钼蓝分光光度法的结果相符,相对标准偏差为4.2%~8.5%,样品的加标回收率在93%~104%之间。     

含铁复配药剂钝化土壤中砷和锑的效果及机理

以矿渣、钢渣、脱硫石膏和氢氧化钙为主要原料,复配硫酸铁盐制备含铁复配药剂,考察其对土壤中砷和锑的钝化效果,研究土壤中砷、锑和铁的形态分布,土壤物相组成及砷、锑价态的变化,探究砷和锑的钝化机理。结果表明,当含铁复配药剂掺加15%(质量分数)的硫酸亚铁,使用量为20%,搭配质量浓度为2%的过氧化氢使用,砷和锑的浸出浓度分别从69.72和172.67μg/L下降到6.95和1.61μg/L。钝化处理后,土壤中砷和锑的非特异性吸附态(F1)分别降低了7.3%和11.7%,特异性吸附态(F2)分别降低了2.7%和0.9%,有效态砷、锑转变成铁/铝氧化物结合态和残渣态;土壤中无定形和结晶态铁氧化物含量显著增加,出现针铁矿和水铁矿相,部分砷由As(Ⅲ)转变成As(Ⅴ),钝化修复后土壤中砷、锑生成Fe-As、Fe-Sb和Ca-Sb沉淀。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.