高磷赤铁矿制备碳化铁的产物分离试验研究

利用高磷鲕状赤铁矿制备碳化铁,产物中含磷组分是影响碳化铁质量的关键因素。为了探究分离方式和添加剂对产物中含磷组分分离的影响,在1023K下分别用无添加、添加2%V2O5和添加5%Na2SO4的高磷鲕状赤铁矿制备碳化铁,将制得的产物球磨不同时间后采用磁选或离心+磁选的方式进行产物分离,最后分析产物中含磷组分的变化。结果表明,延长球磨时间可以提高产物的脱磷率,但球磨时间过长会降低产物的铁收得率,以球磨2h为宜;无添加剂时制备所得碳化铁试样球磨时间从1h延长至2h后,脱磷率从18.17%升至18.48%,再增加离心分离操作后,会进一步提升产物的脱磷率至23.04%;添加5%Na_2SO_4和2%V_2O_5均可破坏铁矿石的鲕状结构,有利于含Fe组分与脉石的分离,但添加Na_2SO_4会降低产物的碳化铁含量,而V_2O_5的添加则可同时促进碳化铁的生成以及提高产物的脱磷率,是一种较好的添加剂。     

聚三嗪亚胺的合成及从水溶液中吸附铀

利用熔盐法合成了聚三嗪亚胺(polytriazineimide,PTI),并用来吸附水中的U(VI)。在常温下,PTI对铀的最大饱和吸附量达到了135.5 mg/g,与g-C₃N₄相比,是g-C₃N₄饱和吸附量的54.2倍。通过对动力学与吸附等温线模型的探究,发现PTI对U(VI)的吸附符合准一级动力学模型,说明PTI吸附U(VI)属于物理吸附。同时,Langmuir吸附等温线模型能更好地拟合PTI对U(VI)的吸附过程,说明U(VI)在PTI上属于单层吸附。通过对吸附铀后的材料进行XPS表征,发现铀在吸附后的价态没有改变,仍为U(VI)。     

化学强化剂提高生物膜填料塔烟气同时脱硫脱氮性能的实验研究

对采用外加化学强化剂提高生物膜填料塔烟气同时脱硫脱氮的性能进行实验研究.结果表明,当按最优化学强化剂添加量添加硝酸镧0.25+硝酸铈0.25 mg/L、硫酸镁0.5 g/L、乙酸钠0.3 g/L时,生物膜填料塔的NOx净化效率可达61.78%,脱硫率为100%.进一步的长时间连续运行实验结果表明,在对SO2的净化效率达到100%的同时,按添加最优化学强化剂条件实验操作的生物膜填料塔的NOx净化效率明显高于对比空白实验的NOx净化效率,其NOx净化效率的平均值提高了14.78%.实验为研究形成提高生物法烟气同时脱硫脱氮性能(尤其对提高烟气脱氮效率)的新型化学强化技术方法奠定了基础.     

基于碱法机理减少船舶CO2排放研究

提出了利用NaOH溶液吸收船舶CO₂的方法,分析了船舶CO₂回收机理,依据6135G128ZCa型船舶柴油机的特点,设计了船舶CO₂吸收系统,推导出船舶CO₂吸收效率数学模型.通过实例分析了NaOH溶液浓度变化、反应温度变化对船舶尾气中CO₂吸收效率的影响.验证了利用NaOH溶液吸收船舶尾气中的CO₂,能够有效降低船舶CO₂排放量20%以上,为未来船舶CO₂的减排技术奠定基础.      

长春市大气中SO2与NO2长期污染特征及防治对策分析

通过对长春市2000~2010年SO2与NO2的长期监测数据分析,得到长春市SO2与NO2浓度的长期变化均为绝对浓度值增加的趋势,以及采暖期比非采暖期污染物浓度显著增加的变化规律。通过污染负荷系数指标的计算,确定SO2、NO2与PM10对长春市环境空气质量的影响是同样重要的。分析SO2与NO2排放源主要为工业生产和热力供应过程中的燃料燃烧和机动车尾气排放。总结了自然及人为产生原因和治理对策,为长春市区域大气污染治理防治提供理论依据。     

The fluid inclusions in jadeitite from Pharkant area, Myanmar

A lot of liquid-gas and liquid-gas-solid inclusions were found in Pharkant jadeitites, northwestern Myanmar and their characteristics, geological setting and porphyroclastic jadeites with inclusions in them were described in detail. The results analyzed by Raman spectrometer showed that the component of liquid-gas phase and solid phase (daughter minerals) in fluid inclusions is H₂O + CH₄ and jadeite separately. The results indicated that Pharkant jadeitites were crystallized from H₂O + CH₄ bearing jadeitic melt which may originate from mantle. The P-T conditions in which the jadeitites were crystallized were speculated to be T ＞650℃, P ＞1.5 GPa.     

超临界CO2萃取裂殖壶藻粗脂工艺研究

研究超临界CO_2萃取裂殖壶藻粗脂的最佳条件,利于后续制备生物柴油.通过单因素试验考察超声波预处理、原料湿度以及不同携带剂对裂殖壶藻粗脂萃取率的影响,并通过正交试验优化设计试验条件.研究结果表明:超声强化虽然对产油量影响不大,但是通过预处理缩短了反应时间;试验前最好对微藻藻粉进行干燥处理.经对比甲醇、乙醇和乙酸乙酯,发现萃取率由大到小依次为:甲醇,乙醇,乙酸乙酯,考虑到甲醇的毒性和安全问题,可使用乙醇做携带剂.超临界CO_2萃取裂殖壶藻粗脂试验最佳工艺条件为:压力40MPa,温度65℃,时间1h,液固比1∶1.在最佳工艺条件下萃取率可达18.7%.     

TETA溶液脱除模拟烟气中CO2的试验研究

CO₂作为全球温室气体,正在危害人类赖以生存的环境,而工业上现正在大力发展有机胺溶液用于脱除烟气中的CO₂,并已得到了广泛的应用和极好的发展趋势.由于三乙烯四胺（TETA）溶液具有稳定性好、吸收效率高等优势,再对比传统胺试剂试验的浓度,试验选取0.2~0.8 mol/L体积浓度范围的TETA作为吸收剂吸收模拟烟气中的CO₂.当温度在25~40℃时,其温度对CO₂吸收速率的影响不明显;当溶剂体积浓度在0.2~0.8 mol/L和CO₂体积分数在10%~18%时,溶剂体积浓度和CO₂体积分数对CO₂吸收速率的影响明显.     

Methane emissions from wetlands on the Qinghai-Tibet Plateau

The areal extent of cold freshwater wetlands on the Qinghai-Tibet Plateau (QTP) is estimated at 0.133 × 10⁶ km², suggesting a significant methane potential. Methane fluxes from wet alpine meadows, peatlands,Hippuris vulgaris mires and secondary marshes were 43.18, 12.96, −0.28 and 45.90 mg · m⁻² · d⁻¹, respectively based on the transect flux studies at the Huashixia Permafrost Station (HPS) from July to August 1996. Average CH₄ fluxes in the thaw season were extrapolated at 5.68 g · m⁻² according to the areal percentage of wetland areas in the Huashixia region. The CH₄ fluxes at four fixed sites, representative of similar ecosystems, ranged from −19.384–347.15 mg · m⁻² · d⁻¹, and the average CH₄ fluxes varied from 6.54 to 71.97 mg · m⁻² · d⁻¹ at each site during the observation period from April to September 1997. The CH₄ emissions at each site during the entire thaw season was estimated from 1.21 to 10.65 g · m⁻², displaying strong spatial variations. Seasonal variations of CH₄ fluxes also were observed at four sites: CH₄ outbursts occurred upon the spring thaw in May and June, CH₄ fluxes increased afterwards with rising soil temperatures. Episodic fluxes were observed in summer, which influenced the average CH₄ fluxes considerably. Annual CH₄ emissions from cold wetlands on the QTP were estimated at about 0.7–0.9 Tg based on the distribution of wetlands, representative CH₄ fluxes, and number of thaw days. The centers of CH₄ releasing were located in the sources of the Yangtze and Yellow rivers, and Zoigê Peatlands.     

Seven million-year iron geochemistry record from a thick eolian red clay-loess sequence in Chinese Loess Plateau and the implications for paleomonsoon evolution

Recently, the Tertiary red clay sequence underlying Pleistocene loess has attracted much attention. The remarkable progress is the recognition that the Tertiary red clay sequence is also wind-blown in origin, thus providing a good opportunity to reconstruct long-term monsoon changes. In contrast to the loess deposits, the magnetic susceptibility and the pedogenic characteristics are almost independent of each other in the red clay, thus challenging the validity of the readily measurable magnetic susceptibility in describing the monsoon history recorded by the red clay. With the objective to address the long-term East Asia summer monsoon evolution, the free to total Fe₂O₃ ratios were calculated in a continuous eolian red clay-loess sequence at Lingtai, the Chinese Loess Plateau, which has a thickness of 305 m and a basal age of 7.0 Ma. The seven million-year Fe₂O₃ ratio record from the red clay-loess sequence indicates that (ⅰ) variations of the free to total Fe₂O₃ ratios of the loess can correlate generally with the alternations of the loess and paleosol horizons; (ⅱ) the East Asia summer monsoon was stronger as a whole in Neogene than that in Quaternary; (ⅲ) the strongest East Asia summer monsoon may occur between 4.0 and 4.8 Ma. The relatively small ice volume and high global temperature may be responsible for the strong summer monsoon during the early Pliocene.     

Morphological characteristics of α-Al2O3 crystallites obtained direct1y from hydro /solvothermal solvents

The morphological characteristics of α-Al₂O₃ crystallites obtained directly from hydro/solv othermal solvents are reported and the formation mechanisms of corundum morphology are discussed from crystal growth and crystal chemistry principles. The crystal growth process is considered as a process of incorporation of growth units on the growth interfaces, and the crystal morphology is determined by the linkage of the coordinated polyhedra.     

大肠杆菌磷酸烯醇式丙酮酸羧化酶的克隆和表达

为了更好地研究磷酸烯醇式丙酮酸羧化酶的结构和功能,采用PCR(聚合酶链式反应)、双酶切和细胞转化等基因工程方法对磷酸烯醇式丙酮酸羧化酶基因进行克隆并使用SDS-聚丙烯酰胺凝胶电泳进行表达分析,扩增出一个新的大肠杆菌磷酸烯醇式丙酮酸羧化酶基因,将其基因克隆到原核表达载体pET-30a上,并导入到大肠杆菌表达菌株BL21(DE3)中。通过IPTG诱导成功表达出大肠杆菌的磷酸烯醇式丙酮酸羧化酶。所提出的方法能够高效表达磷酸烯醇式丙酮酸羧化酶,为进一步大规模表达纯化和应用提供参考。     

Photoluminescence from Ge-SiO2 thin films and its mechanism

Ge-SiO₂ thin films were deposited on p-type Si substrates using the radio frequency (rf) magnetron sputtering technique with a Ge-SiO₂ composite target. Films were annealed in N₂ ambience for 30 min at 300℃—1000℃ with an interval of 100℃. Through the X-ray diffraction, the average size of Ge nanocrystals (nc-Ge) was determined. They increased from 3.9 to 6.1 nm with increasing annealing temperature in the range of 600℃—1000℃. Under ultraviolet excitation, all samples emit a strong violet band centered at 396 nm. With the formation of nc-Ge, the samples exhibit another emission of orange band with the peak at 580 nm and its intensity increases with the increasing size of nc-Ge. The peak positions of two bands do not shift obviously. Experimental data indicate that the violet band comes from GeO defect and the orange band originates mainly from the luminescence centers at the interface between the nc-Ge and SiO₂ matrix.     

The formation and stability of Si1-x C x alloys in Si implanted with carbon ions

Si_1-xC_x alloys of carbon (C) concentration between 0.6%—1.0% were grown in Si by ion implantation and high temperature annealing. The formation of Si_1-xC_x alloys under different ion doses and their stability during annealing were studied. If the implanted dose was less than that for amorphizing Si crystals, the implanted C atoms would like to combine with defects produced during implantation and it was difficult to form Si_1-xC_x alloys after being annealed at 850℃. With the increment of implanted C ion doses, the lattice damage increased and it was easier to form Si_1-xC_x alloys. But the lattice strain would become saturate and only part of implanted carbon atoms would occupy the substitutional positions to form Si_1-xC_x alloys as the implanted carbon dose increased to a certain degree. Once Si_1-xC_x alloys were formed, they were stable at 950℃, but part of their strain would release as the annealing temperature increased to 1 000℃. Stability of the alloys became worse with the increment of carbon concentration in the alloys.     

先锋褐煤二硫化碳和甲醇萃取物的分析

分别以CS2和甲醇为溶剂,辅以超声波对先锋褐煤进行常温萃取,利用傅里叶变换红外光谱(FTIR)和气相色谱/质谱(GC/MS)分析萃取物的组成及结构。结果表明,两种萃取物中共检测到124种有机化合物;CS2萃取物中烃类化合物相对含量较高,占CS2萃取物总量的52.08%,从C14~C30(除C23外)烷连续分布;甲醇萃取物中含氧和含氮化合物相对含量较高,分别占甲醇萃取物总量的39.28%和20.95%;此外还检测到多种生物标示物。     

The P2O5 content of feldspars from the Yashan granites, Jiangxi Province, South China

The P₂O₅ contents of feldspars in the Yashan F-rich and P-rich granite yield a maximum value of 0.93% (In albite) and a maximum average value of 0.65% (hereinafter weight percent) (in K-feldspar), and is generally between 0.10% and 0.35%. Most of the distribution coefficient D_p[Ab/Kt] values are greater than 1(1.13–28.9). The study shows that phosphorus could preferably enter the albite structure mainly by PAISi₂ substitution relative to K-feldspar.     

流型、植物种类和基质厚度对人工湿地去除废水中氨氮的影响

实验模拟人工湿地,以沙、土混合物为基质,比较了水平潜流和垂直流、不同植物、不同基质厚度对氨氮(NH_4~+-N)处理效果的影响,并分别进行了分析。实验表明,水平潜流和垂直流NH_4~+-N去除率分别达到59%和68%,垂直流人工湿地处理效果较好的原因是垂直流为硝化创造了有利的条件。金边吊兰、金钱草、绿萝对NH_4~+-N的平均去除率依次为46%、60%和70%,分析认为根系是影响NH_4~+-N去除效果的主要因素。以金钱草做湿地植物,基质厚度为6 cm时去除效果最好,最大去除率达到74%,表明基质厚度与植物根系长度相适应时,NH_4~+-N的去除效果最佳。研究结果为深化湿地去除NH_4~+-N的理论研究和应用推广提供了支撑。     

氧化吸收法同步脱除燃烧烟气中SO2，NOx和CO2的化学热力学及其评价

湿化学法同步脱除烟气中气态污染物是燃烧源大气污染控制的重要方法之一,为探究采用不同氧化吸收策略同时脱除燃烧烟气中SO_2,NO_x和CO_2的可行性,基于化学热力学原理,分析了9种联合氧化吸收策略的性能,具体的氧化吸收策略包括:H_2O_2-NH_3·H_2O,H_2O_2-MDEA,H_2O_2-NaOH,O3-NH_3·H_2O,O3-MDEA,O3-NaOH,NaClO_2-NH_3·H_2O,NaClO_2-MDEA和NaClO_2-NaOH,并提出新的动态加权法对其性能进行综合评价。结果表明:上述所有策略均具有SO_2,NO_x和CO_2捕获的可行性。O3-NaOH,NaClO_2-MDEA和NaOH做吸收剂的氧化吸收溶液分别对单一脱硫、脱硝和脱碳效果最好。当综合考虑同步脱除SO_2,NO_x和CO_2时,NaClO_2-MDEA优于其他策略,其结果可为燃烧烟气中的气体污染物的联合脱除提供参考。     

Distribution and characterization of C31 sterane from cretaceous sediments and oils, Songliao Basin, China

Relatively high abundance of C₃₁ steranes has been identified from cretaceous source rocks and crude oils in the Songliao Basin, China. C₃₁ steranes which occur as ten isomers were tentatively identified as 4, 22, 23, 24-tetrametyhlcholestane based on their retention time and mass spectrum. They bear a lower thermal stability and occur as important components in the immature oils of Chaochang region because they have three-methyl groups in their side chain. The relatively high abundance of C₃₁ steranes in the samples can indicate the source input of some special algae in the brackish and saline environment. Therefore they can be used as very useful bimarkers for organic facies analysis and oil correlation. Their biological source perhaps related to the dinoflagellate such asG. foliaceum andP. foliaceum. The gorgostanol are considered as possible precursors for the putative C₃₁4-methyl sterane which formed in the stage of diagenesis.