泥页岩水化稳定性评价指标的模糊聚类

测定了 30种泥页岩样品水化稳定性的九项评价指标 ,采用模糊聚类数学分析方法对九项评价指标进行了分类。

泥页岩水化稳定性综合评价指标研究

单一指标评价泥页岩的水化稳定性存在一定的局限性。本文采用多元统计分析方法建立了计算泥页岩水化稳定性综合评价指标的数学方法,即将样品的各个评价指标变量线性组合,挑选前面几个最大的综合因子作为主因子,根据主因子反映原始信息的多少进行加权加和,使多个评价指标变成一个综合评价指标。最后利用该方法对新疆、胜利、中原等油田40种泥页岩样品进行了综合稳定性的评价。

喀斯特区域的水化学不稳定性——以黔中地区为例

黔中地区是岩溶作用发育的喀斯特区域。１９９３年秋和１９９４年春末采自该地区不同类型水样的水化学分析表明：碳酸盐岩裂隙泉水呈中偏碱性，为［Ｃ］Ｃａ－Ｉ型；秋季离子总量、ＨＣＯ－３及Ｃａ２＋浓度大于春季。裂隙泉水流经地表一定距离后，ＨＣＯ－３降低，ｐＨ及ＳＯ２－４、Ｃｌ－、Ｋ＋、Ｎａ＋明显增高。黄果树的天星桥、水帘洞及落水潭三个部位河水的ＳＯ２－４、Ｎａ＋以及Ｆｅ３＋、ＮＯ－３等浓度的季节性变化也更加明显。春季因瀑布暴气，ＣＯ２的逸出，钙华生成更强烈一些。红枫湖作为喀斯特区域地表水的汇集地，ＨＣＯ－３与ＳＯ２－４的当量比值仅２．１～２．４；Ｃａ２＋与Ｍｇ２＋比值上升为２．４～４．２，Ｃｌ－浓度较碳酸盐岩裂隙泉水增高１倍；Ｎａ＋浓度增高一个数量级。说明流域内地表土层溶蚀及人为污染影响的增强。土层孔隙水属强矿化水，而湖水呈现过渡特征。碳酸盐沉淀作用、硫酸盐矿化作用及固氮氨化作用，导致水质组成的显著差异。

Al-NaI放射性嬗变靶材的制备及其水化学稳定性

采用通孔泡沫铝作基体的"包壳密封法"制备高含量NaI的Al-NaI放射性嬗变靶材。分别在20、50和80℃的蒸馏水中对未烧结和烧结过的Al-NaI放射性嬗变靶材进行水化学稳定性试验。用AAS-800原子吸收光谱仪对浸出时间分别为24、48、72和96 h的浸出溶液进行浓度测量,从而计算出不同条件下各种嬗变靶材在蒸馏水中的浸出率。结果表明,烧结后的靶材浸出率不会超过10%,远远低于未烧结的靶材,满足NaI嬗变率测量的实验要求。

饮用天然山泉水水化学组分稳定性分析评价——以融水苗族自治县四荣乡为例

文章以融水苗族自治县四荣乡为例,选取该区2021年平水期、枯水期、丰水期3期的样品,采用不稳定系数和变异系数的综合评价方法,对该区饮用天然山泉水水化学组分进行测试分析,分析结果显示,该区天然山泉水水化学类型属HCO_(3)-Ca·Na·Mg,为偏硅酸低溶解性总固体中性极软饮用天然泉水。其评价结果可为企业开发优质山泉水提供参考,对做强做优广西天然山泉水产业具有积极意义。

泥页岩水化膨胀的实验研究

在泥页岩地层的钻井过程中 ,井筒稳定性一直是人们最关注问题之一 ,因为泥页岩遇水基泥浆发生膨胀 ,使井壁应力发生变化。采用岩石力学三轴实验系统对水化膨胀进行了初步的实验研究 ,发现泥页岩遇水后在水平及垂直方向都会产生水化膨胀 ,而且垂向膨胀压力比水平方向大 ,水化膨胀压力的非线性迅速增加 ,一般发生在遇水后相对较短的时间内 ,随之是线性变化。

页岩油藏油基钻井液技术

胜利油田罗家区块和乔庄地区沙三段泥页岩裂缝发育,在该区块钻井具有一定风险性。对该区块泥页岩水化稳定性进行了分析研究,进一步明确了该区块泥页岩水化分散机理。对钻井液体系进行了评价,同时对其应用效果进行了总结。通过在渤页平1井、渤页平2井及梁页1 HF井的现场应用,说明油基钻井液体系完全满足该区块钻井要求,具有良好的页岩抑制性和井眼清洁能力。最后指出了现场应用中存在的问题,并探讨了相关对策。该研究对提高页岩油藏井壁稳定性、保障井下安全具有指导意义。

Photosynthesis of Resurrection Angiosperms

Resurrection plants which are able to quickly reactivate after falling into a period of anabiosis caused by dehydration have been very rare among angiosperms, especially among dicotyledons whose chlorophyll content and chloroplast structure little changed in the course of desiccation, therefore has been called homoiochlorophyllous desiccation-tolerant plants (HDTs). Another type of resurrection angiosperms that lost its chlorophyll dining desiccation is called poikilochlorophyllous desiccation-tolerant plants (PDTs). HDTs have been received more attention because of simplicity of protection mechanism which is much easy to the study and utilization of the desiccation tolerance of resurrection angiosperms. Recent advances in studies of photosynthesis of resurrection angiosperms indicate that photochemical activities are sensitive indicators for the study of physiological state of resurrection angiosperms during desiccation and rehydration. Photochemical activities of resurrection angiosperms are inhibited with loss of water similar to those of general plants, however, the magic thing is that they could reactivate rapidly during rehydration even losing more than 95% water. Up-regulations in xanthophyll cycle and antioxidative systems as well as preservation in integrity and stability of photosynthetic membranes during desiccation may be very important to desiccation tolerance of resurrection angiosperms. The fact that phosphate treatment in rehydration stage also strongly influences resurrection indicated importance of studies on rehydration stages of resurrection angiosperms.

Density Functional Study on Structures and Relative Stability of Gd（H2O）n^3＋ （n=8,9）

Density functional theory calculations were performed to study the structures and relative stability of the gadolinium complexes, Gd（H2O）n^3＋ （n=8,9）, in vacuo and in aqueous solution. The polarizable continuum model with various radii for the solute cavity was used to study the relative stability in aqueous solution. The calculated molecular geometries for n=8 and 9 obtained in vacuo are consistent with those observed in experiments. It was found that while the nona-aqua complex is favored in the gas phase, in aqueous solution the octa-aqua conformation is preferred. This result, independent of the types of cavities employed, is in agreement with the experimental observation. The reliability of the present calculation was also addressed by comparing the calculated and experimental free energy of hydration, which revealed that the UA0, UAHF, and UAKS cavities are most appropriate when only the first solvation shell is treated explicitly.

A reconstruction strategy for the synthesis of Cu-SAPO-34 with excellent NH-SCR catalytic performance and hydrothermal stability

A reconstruction strategy has been developed to synthesize Cu-SAPO-34 with a wide crystallization phase region,high solid yield,and tunable Si and Cu contents.Cu-rich SAPO-34 was prepared from a Cu-amine complex,which acted as a precursor and Cu source for the reconstruction synthesis.The role of the Cu-amine complex as a template was restricted,which allowed easier control over the Cu and Si contents than in the previously reported"one-pot"synthesis method.Characterization of the material revealed that the Si(4Al)coordination environment dominates the synthesized Cu-SAPO-34 catalysts.High-temperature hydrothermal treatment increased the isolated Cu2+content slightly,and the acid sites in the low-silica catalyst are more resistant to hydrothermal treatment than those of the existing catalysts.The obtained materials,especially the low-silica Cu-SAPO-34 sample,exhibit excellent catalytic activity and hydrothermal stability for the selective catalytic reduction of NOx by NH3(NH3-SCR).In addition,the influence of the catalyst acidity on the NH3-SCR reaction was also investigated and is discussed.The high synthetic efficiency and outstanding catalytic performance make Cu-SAPO-34 synthesized by the reconstruction method a promising catalyst for the NH3-SCR process.

Investigation of low-temperature hydrothermal stability of Cu-SAPO-34 for selective catalytic reduction of NO_x with NH_3

The low‐temperature hydrothermal stabilities of Cu‐SAPO‐34samples with various Si contents and Cu loadings were systematically investigated.The NH3oxidation activities and NH3‐selective catalytic reduction(SCR)activities(mainly the low‐temperature activities)of all the Cu‐SAPO‐34catalysts declined after low‐temperature steam treatment(LTST).These results show that the texture and acid density of Cu‐SAPO‐34can be better preserved by increasing the Cu loading,although the hydrolysis of Si-O-Al bonds is inevitable.The stability of Cu ions and the stability of the SAPO framework were positively correlated at relatively low Cu loadings.However,a high Cu loading(e.g.,3.67wt%)resulted in a significant decrease in the number of isolated Cu ions.Aggregation of CuO particles also occurred during the LTST,which accounts for the decreasing NH3oxidation activities of the catalysts.Among the catalysts,Cu‐SAPO‐34with a high Si content and medium Cu content(1.37wt%)showed the lowest decrease in NH3‐SCR because its Cu2+content was well retained and its acid density was well preserved.

Stabilization of heterogeneous hydrogenation catalysts for the aqueous-phase reactions of renewable feedstocks

The conversion of biomass-derived products to fine chemicals and fuels is extremely important for the utilization of renewable energy sources.Water is not only a by-product formed during the hydrogenation of biomass-derived oxygenated chemicals,but also an inexpensive and nontoxic solvent.The instability of solid catalysts for aqueous-phase reactions caused by metal leaching and the collapse of a catalyst support represents a significant challenge.In this work,various catalyst stabilization strategies including the nanospace and interfacial confinements that prevent sintering and leaching of metal nanoparticles as well as modification methods for increasing the support stability are summarized and systemically discussed.In addition,feasible approaches to designing stable and efficient heterogeneous catalysts for aqueous-phase reactions are proposed.

Study on Modification of Ultra-Stable Zeolite Prepared by Hydrothermal Method

The ultra-stable zeolite DASY-0.0 was prepared by hydrothermal method in commercial scale. Its structure was further modified via the treatment for cleaning of pores （CP）. The zeolite samples before and after CP treating were analyzed and characterized by XRF, XRD, NMR, IR, BET and DTA. The results showed that, in comparison with the conventional ultra-stable zeolite DASY-0.0 prepared by the hydrothermal process, the CP-modified zeolite SOY0 exhibited a higher relative crystallinity, a larger surface area and pore volume, a higher thermal stability and contained less amorohous non-framework A1.

Study on Hydrothermal Stability and Catalytic Activity of Al-SBA-15 Mesoporous Materials Prepared by Impregnation Method

The mesoporous Al-SBA-15 zeolite was obtained via impregnation of pure silica-based SBA-15 zeolite with aluminum nitrate.The Al-SBA-15 sample was calcined in air at 800 ℃ for 6 h and hydrothermally treated at near 100 ℃ for 120 h,respectively,and then the thermal and hydrothermal stability of Al-SBA-15 sample was investigated by X-ray diffractometry (XRD),scanning electron microscopy (SEM),transmission electron microscopy (TEM) and nitrogen adsorption and desorption techniques.The Al-SBA-15 sample was also studied by 27 Al nuclear magnetic resonance (27 Al NMR) and ammonia temperature programmed desorption (NH 3-TPD) techniques.In addition,the catalytic activity of Al-SBA-15 zeolite was investigated by the Friedel-Crafts reactions of 2,4-di-tert-butylphenol with cinnamyl alcohol.The test results showed that the thermal and hydrothermal stability of Al-SBA-15 zeolite was better than that of SBA-15 zeo-lite.The Al-SBA-15 zeolite sample prepared by impregnation method exhibits more framework aluminum species and Al-O-Si units.Therefore,the number of the surface hydroxyl groups was reduced,resulting in the stabilization of framework structure ofAl-SBA-15 zeolite.The aluminum species can form weak and medium-strong acid sites with catalytic activity.

Stabilizing CuO photocathode with a Cu_(3)N protection shell

CuO,as a promising photocathode material,suffers from severe photocorrosion in photoelectrochemical water splitting applications.Herein,a Cu_(3)N protection shell was used to protect the CuO photocathode for the first time to effectively suppress the photocorrosion of CuO.Consequently,the Cu_(3)N‐protected CuO photocathode shows improved stability,retaining 80% of its initial current density in a 20‐min test,while only 10%of the initial current density can be retained for the bare photocathode.This work may provide an important strategy for using Cu_(3)N shells to stabilize unstable photocathodes.

Stability of Pd-Cu-Cl_x/Al_2O_3 catalyst for CO oxidation

By taking advantage of silylanization, Al2O3 support was modified by organosilane and supported Pd-Cu-Clx/Al2O3 catalysts were prepared. The effects of hydrophobicity on catalyst stability during CO oxidation were investigated. The physicochemical properties and redox potential of the catalyst were characterized by N2 adsorption-desorption, XRD, H2-TPR, and XPS. In order to understand the relationship between the oxidation stability of CO and the presence of water, the CO oxidation mechanism was studied by in situ DRIFT. Support pretreatment markedly promoted catalyst stability during CO oxidation; CO conversion was 78% after 150 h at saturated humidity and freezing point. Modification led to an obvious decrease in chloride ion concentration and enhancement in hydrophobicity. The role of water in CO oxidation was complicated. The presence of water favored CO oxidation over active Pd~＋ species and Pd0 reoxidation by Cu^（2＋） species. Meanwhile, water also inhibited the formation of the active Pd~＋ species and helped to produce carbonate species. Compared with the form of the carbonate species, the inhibition of water to produce active Pd~＋ species played the main detrimental role in catalyst stability.

Gas separation using sol–gel derived microporous zirconia membranes with high hydrothermal stability

A microporous zirconia membrane with hydrogen permeance about 5 × 10-8mol·m-2·s-1·Pa-1, H2/CO2 permselectivity of ca. 14, and excellent hydrothermal stability under steam pressure of 100 k Pa was fabricated via polymeric sol–gel process. The effect of calcination temperature on single gas permeance of sol–gel derived zirconia membranes was investigated. Zirconia membranes calcined at 350 °C and 400 °C showed similar single gas permeance, with permselectivities of hydrogen towards other gases, such as oxygen, nitrogen, methane, and sulfur hexa fluoride, around Knudsen values. A much lower CO2permeance（3.7 × 10-9mol·m-2·s-1·Pa-1）was observed due to the interaction between CO2 molecules and pore wall of membrane. Higher calcination temperature, 500 °C, led to the formation of mesoporous structure and, hence, the membrane lost its molecular sieving property towards hydrogen and carbon dioxide. The stability of zirconia membrane in the presence of hot steam was also investigated. Exposed to 100 k Pa steam for 400 h, the membrane performance kept unchanged in comparison with freshly prepared one, with hydrogen and carbon dioxide permeances of 4.7 × 10-8and ~ 3 × 10-9mol·m-2·s-1·Pa-1, respectively. Both H2 and CO2permeances of the zirconia membrane decreased with exposure time to 100 k Pa steam. With a total exposure time of 1250 h, the membrane presented hydrogen permeance of 2.4 × 10-8mol·m-2·s-1·Pa-1and H2/CO2 permselectivity of 28, indicating that the membrane retains its microporous structure.

Sacrificial Anode Stability and Polarization Potential Variation in a Ternary Al-xZn-xMg Alloy in a Seawater-Marine Environment

In this paper, the effects of zinc （Zn） and magnesium （Mg） addition on the performance of an aluminum-based sacrificial anode in seawater were investigated using a potential measurement method. Anodic efficiency, protection efficiency, and polarized potential were the parameters used. The percentages of Zn and Mg in the anodes were varied from 2% to 8% Zn and 1% to 4% Mg. The alloys produced were tested as sacrificial anodes for the protection of mild steel in seawater at room temperature. Current efficiency as high as 88.36% was obtained in alloys containing 6% Zn and 1% Mg. The polarization potentials obtained for the coupled （steel/Al-based alloys） are as given in the Pourbaix diagrams, with steel lying within the immunity region/cathodic region and the sacrificial anodes within the anodic region. The protection offered by the sacrificial anodes to the steel after the 7th and 8th week was measured and protection efficiency values as high as 99.66% and 99.47% were achieved for the A1-6%Zn-l%Mg cast anode. The microstructures of the cast anodes comprise of intermetallic structures of hexagonal Mg3Zn2 and body-centered cubic A12Mg3Zn3. These are probably responsible for the breakdown of the passive alumina film, thus enhancing the anode efficiency.

Synthesis and Application of a Zeolite-containing Composite Material Made from Spent FCC Catalyst

Novel composite material with a wide pore distribution was synthesized by an in situ technique using spent FCC catalyst as raw material. The characterization results indicated that the composite material contained 56.7% of zeolite Y and exhibited a much larger specific surface area and pore volume as well as strong hydrothermal stability. Fluid catalytic cracking(FCC) catalyst was prepared based on the composite material. The results indicated that the as-prepared catalyst possessed a unique pore structure that was advantageous to the diffusion-controlled reactions. In addition, the attrition resistance, activity and hydrothermal stability of the studied catalyst were superior to those of the reference catalyst. The catalyst also exhibited excellent nickel and vanadium passivation performance, strong bottoms upgrading selectivity, and better gasoline and coke selectivity. In comparison to the reference catalyst, the yields of the gasoline and light oil increased by 1.61 and 1.31 percentage points, respectively, and the coke yield decreased by 0.22 percentage points, and the olefin content in the produced gasoline reduced by 2.51 percentage points, with the research octane number increased by 0.7 unit.

Enhancing Structural Stability and Pervaporation Performance of Composite Membranes by Coating Gelatin onto Hydrophilically Modified Support Layer

The interfacial compatibility of composite membrane is an important factor to its structural stability, andseparation performance. In this study, poly （ether sulfone） （PES） support layer was first hydrophilically modified with poly（vinyl alcohol） （PVA） via surface segregation during the phase inversion process. Gelatin （GE） was then cast on the PVA-modified PES support layer as the active layer followed by crosslinking to fabricate composite membranes for ethanol dehydration. The enrichment of PVA on the surface of support layer improved interfacial compatibility of the as-prepared GE/PVA-PES composite membrane. The water contact angle measurement and X-ray photoelectron spectroscopy （XPS） data confirmed the surface segregation of PVA with a surface coverage density of -80%. T-peel test showed that the maxima/force to separate the support layer and the active layer was enhanced by 3 times compared with the GE/PES membrane. The effects of PVA content in the support layer, crosslinking of GE active layer and operating parameters on the pervaporative dehydration performance were investigated. The operational stability of the composite membrane was tested by immersing the membrane in ethanol aqueous solution for a period of time. Stable pervaporation performance for dehydration of 90% ethanol solution was obtained for GE/PVA-PES membrane with a separation factor of -60 and a permeation flux of -1910 g.m^-2.h1 without peeling over 28 days immersion.