厢式压滤机滤板受力数值模拟及滤室边长优化设计

采用Ansys软件对厢式压滤机滤板受力和挠度形变进行数值模拟,着重分析凸台支柱数量的影响。基于变分法滤板挠度计算找出滤室边长尺寸与滤板设计厚度的关系,建立厢式压滤机滤板总体积、滤板组总长度与滤室边长的函数关系,以此对滤板结构进行优化设计。经优化后的滤板与1250型滤板相比,污泥脱水的工作效率得到明显提高——在整机滤室容积不变的情况下,虽滤板耗材增加了7.51%,但过滤面积增加了近50%,继而在泥饼达到同等含水率时压滤时间缩短了36.9%。     

疏松砂岩储层压裂液滤失规律实验研究

疏松砂岩储层渗透率变化范围大,压裂液滤失表现出较大差异。针对疏松砂岩储层压裂液滤失难以估量的问题,开展静态滤失实验研究不同胍胶浓度压裂液在不同压差环境下的滤失规律,确定滤失系数与压差关系。首先开展滤纸滤失实验,研究压裂液滤失对滤失压差的依赖性,随后针对疏松砂岩渗透率变化范围大的特点开展岩板滤失实验,探索岩板渗透率对压裂液滤失特性的影响。结果表明：压裂液的滤饼滤失系数与压差的幂指数成正比,与胶粉浓度的倒数平方根成正比。     

玻璃纤维海水专用砂滤器

本发明涉及用于水处理工程对废水内固体和液体进行分离的设备，具体为一种玻璃纤维海水专用砂滤器。该装置包括进排水管、石英砂滤层及反冲洗排污管，石英砂滤层安装于罐体内，所述石英砂滤层由滤水帽和滤水帽托板构成，石英砂置于安装有滤水帽的滤水帽托板上，滤水帽托板将罐体分成上下两个腔室，进水管和排水管穿过罐体侧壁，分别与滤水帽托板上、下相通，反冲洗排污管与滤水帽托板下部相通。     

压裂液降滤失技术研究

油层水力压裂是油气井增产、注水井增注的一项重要工艺措施。压裂施工的成功与否主要取决于所用的压裂液。而压裂液的滤失是影响压裂施工效果的重要因素之一。所以本文首先对压裂液滤失的危害进行了分析,综述了压裂液的滤失机理、影响因素。同时对降滤失技术进行了研究:目前常用的降滤失技术有提高压裂液粘度,添加压裂液降滤失剂和液氮降滤失技术等。最后对降滤失技术的发展进行了展望。     

生态滤坝处理微污染河水实验研究

采用沸石和砾石构建生态滤坝,研究不同组配方式下生态滤坝的污染物去除效果,同时将铁碳微电解技术引入生态滤坝,研究铁碳生态滤坝对微污染河水水质净化效果。结果表明,混合滤坝的NH3-N和TN的平均去除率比分层滤坝分别高9.75个和8.01个百分点,说明基质混合生态滤坝的污染物去除效果更好。铁碳生态滤坝的COD、NH3-N、NO2--N、TN的平均去除率分别比混合滤坝提高18.68个、4.17个、15.56个和8.99个百分点,说明添加铁碳可以增强生态滤坝对COD和TN等污染物的去除能力。通过微生物群落结构及多样性分析,铁碳滤坝微生物群落多样性较高,优势菌为假单胞菌属和狭义梭菌属。     

压裂液降滤失技术研究

油层水力压裂是油气井增产、注水井增注的一项重要工艺措施。压裂施工的成功与否主要取决于所用的压裂液。而压裂液的滤失是影响压裂施工效果的重要因素之一。所以本文首先对压裂液滤失的危害进行了分析,综述了压裂液的滤失机理、影响因素,同时对降滤失技术进行了研究,目前常用的降滤失技术能提高压裂液粘度,添加压裂液降滤失剂和液氮降滤失技术等。最后对降滤失技术的发展进行了展望。     

淀粉基降滤失剂的合成工艺及其降滤失机理研究

综述了国内外新型淀粉基钻井液降滤失剂的合成工艺,并分析了淀粉基降滤失剂的降滤失机理。研究结果表明,近期发展起来的淀粉基降滤失剂的合成工艺有半干法、微波辅助干法、微乳化法、双水相法等。淀粉基降滤失剂降滤失机理分为增黏机理、吸附-水化机理、捕集机理、物理堵塞机理等4种。研究结果可为开发淀粉基降滤失剂绿色制备工艺,以及研发新型淀粉基降滤失剂提供理论依据。     

塑料滤毒罐正交试验分析

塑料滤毒罐各塑料件间的连接是通过超声波焊接工艺完成的装配,而塑料滤毒罐在使用过程中会出现焊口开裂的问题,即滤烟层与滤毒层焊口处。分析其原因,并形成塑料滤毒罐可靠性改进工作路线,通过运用正交试验分析方法,确定最佳的焊接工艺参数,进行环境适应性试验验证,来提高塑料滤毒罐超声波焊接的焊接质量,提升塑料滤毒罐使用过程中的可靠性。     

乳化剂对滤失量的影响分析

为了研究乳化剂对滤失量的影响,从静滤失方程出发,利用达西定律描述钻井液通过泥饼和滤纸的滤失速率,建立了油基钻井液的单因素和双因素滤失模型,并进行了对比分析。然后通过室内实验进行论证,表明乳化剂类型不同,配制的钻井液体系的滤失量不同,乳化率高的乳化剂对应的滤失量小;同时,乳化剂加量对体系的滤失量也有影响。     

浅谈井内钻井液的滤失性能

在采油过程中,钻井液起到重要的作用,但钻井液的滤失性能是钻井液的主要性能,对稳固井壁起到重要的作用,本文主要从静滤失、动滤失、瞬时滤失等三个方面综述了井内钻井液的滤失性能。     

Evaluation of surfactant-aided degumming of vegetable oils by membrane technology

The first step in the process of vegetable oil refining is degumming, in which phospholipids and mucilaginous gums are removed that otherwise result in a low-grade oil. A membrane process is remarkably simple yet potentially offers many advantages in degumming. Studies were conducted on surfactant-aided membrane degumming with soybean and rapeseed oils in a magnetically stirred flat membrane batch cell with different types of microfiltration membranes. The reduction of phospholipids in soybean oil was in the range of 85.8–92.8% during the membrane process. The phosphorus content of membrane permeates of soybean oil was in the range of 20–58 mg/kg. Crude rapeseed oil contained higher amount of nonhydratable phospholipids and hence resulted in lower reduction in phospholipids, in the range of 66.4–83.2%. Addition of hydratable phospholipids could improve the efficiency of degumming in the membrane process without using any electrolyte, resulting in improvement of quality as well as quantity of the phospholipids.     

Drying characteristics of porous material immersed in a bed of hygroscopic porous particles fluidized under reduced pressure

A relatively large wet material was immersed in a fluidized bed of hygroscopic porous particle (silica gel beads) under reduced pressure. And then the drying characteristics were compared with those in the case of inert particle (glass beads). The comparison of drying characteristics is performed experimentally and theoretically. In calculation, the water transfer from the sample to the fluidized bed was considered. The calculation results are in good agreement with the experimental data. The effects of the operational conditions (the pressure in the drying chamber and the temperature of the drying gas) on the drying characteristics were also examined in both fluidizing particles.The drying finishes earlier in the case of hygroscopic porous particle than in the case of inert particle regardless of pressure in the drying chamber, since the water transfer from the sample facilitates the drying in the case of hygroscopic porous particles. The temperature decrement in drying appears in the case of inert particle. This phenomenon is also observed in the case of hygroscopic porous particle, but the decrement degree of the temperature is much smaller than that in the case of inert particle. The difference of the minimum temperature in the sample in drying between the cases of hygroscopic porous particle and inert particle is very slight for different pressures in the drying chamber.     

污泥生物炭中氮硫行为及环境效应研究进展

污泥生物炭中氮硫元素含量高，其氮硫行为和环境效应对全球气候变化的影响不容忽视。以往的研究中，研究者往往以富碳生物炭作为主要研究对象，关注碳对全球气候变化的行为和功效，而对氮硫元素的作用关注不够。本文从原始污泥基本性质到其热解过程，再到生物炭的老化，逐步对污泥生物炭整个生命周期内氮硫的行为及其环境效应研究进行综述，并对未来应注重开展的研究方向进行展望，为生物炭中氮硫元素固定、释放及与之关联的环境效应和温室气体排放控制研究提供理论基础。分析表明，污泥中氮元素含量普遍高于硫元素，且热解过程中氮比硫更容易转移至气相产物。氮硫元素随热解温度的增加，在三相产物中的分配都是炭中持续减少，油中先增后减，气中一直增加。高温（＞800℃）条件下，气相中的氮含量高于固相，而硫元素则仍然主要存在于固相中。污泥生物炭老化及其环境效应研究表明，污泥生物炭氮硫元素与土壤的相互作用及其温室效应问题在今后的研究中应引起重视。     

Defoliation Affects Chemical Defenses in All Plant Parts of Rye Seedlings

The effect of defoliation and consecutive defoliation (condefoliation) of rye seedlings on the allocation patterns of biomass and hydroxamic acids (Hx) was evaluated five days after treatment. Growth of condefoliated seedlings was lower than that of defoliated and nondefoliated ones. Concentration of Hx decreased in shoots of condefoliated seedlings compared to nondefoliated ones, while concentration of Hx in root exudates increased. Allocation of Hx to roots and root exudates increased at the expense of allocation to the shoots in condefoliated seedlings. The ratio of Hx-aglucone to Hx-glucoside was higher in shoots of defoliated and condefoliated seedlings. The decrease in quantity of defense in shoots was accompanied by an increase in its quality, given that aglucones are more toxic than glucosides. The increase in concentration of Hx—an allelopathic compound also involved in mineral uptake by roots—in root exudates of condefoliated seedlings was suggested to lead to an advantage in the acquisition of resources for the regeneration of lost biomass.     

HGF and TSG-6 Released by Mesenchymal Stem Cells Attenuate Colon Radiation-Induced Fibrosis

Fibrosis is a leading cause of death in occidental states. The increasing number of patients with fibrosis requires innovative approaches. Despite the proven beneficial effects of mesenchymal stem cell (MSC) therapy on fibrosis, there is little evidence of their anti-fibrotic effects in colorectal fibrosis. The ability of MSCs to reduce radiation-induced colorectal fibrosis has been studied in vivo in Sprague–Dawley rats. After local radiation exposure, rats were injected with MSCs before an initiation of fibrosis. MSCs mediated a downregulation of fibrogenesis by a control of extra cellular matrix (ECM) turnover. For a better understanding of the mechanisms, we used an in vitro model of irradiated cocultured colorectal fibrosis in the presence of human MSCs. Pro-fibrotic cells in the colon are mainly intestinal fibroblasts and smooth muscle cells. Intestinal fibroblasts and smooth muscle cells were irradiated and cocultured in the presence of unirradiated MSCs. MSCs mediated a decrease in profibrotic gene expression and proteins secretion. Silencing hepatocyte growth factor (HGF) and tumor necrosis factor-stimulated gene 6 (TSG-6) in MSCs confirmed the complementary effects of these two genes. HGF and TSG-6 limited the progression of fibrosis by reducing activation of the smooth muscle cells and myofibroblast. To settle in vivo the contribution of HGF and TSG-6 in MSC-antifibrotic effects, rats were treated with MSCs silenced for HGF or TSG-6. HGF and TSG-6 silencing in transplanted MSCs resulted in a significant increase in ECM deposition in colon. These results emphasize the potential of MSCs to influence the pathophysiology of fibrosis-related diseases, which represent a challenging area for innovative treatments.     

精-异丙甲草胺在大豆及土壤中的残留动态

为了评价精-异丙甲草胺在大豆上的残留动态及环境安全性,在天津、吉林两地同时进行了精-异丙甲草胺在大豆上的残留动态试验.结果表明,天津地区精-异丙甲草胺在大豆植株中的半衰期为19.1 d,在土壤中的半衰期为27.9 d;吉林地区精-异丙甲草胺在大豆植株中的半衰期为21.4 d,在土壤中的半衰期为34.1 d.收获的大豆籽粒中精-异丙甲草胺最终残留量均为未检出.     

Lymphatic Transport of α-Linolenic Acid and Its Conversion to Long Chain n-3 Fatty Acids in Rats Fed Microemulsions of Linseed Oil

In the present study we evaluated the uptake of ALA and its conversion to EPA + DHA in rats given linseed oil (LSO) in native form or as a microemulsion in whey protein or in lipoid. In a single oral dose study in which rats maintained on rodent pellets deficient in ω-3 fatty acids were intubated with 0.35 g LSO in lipoid, the amount of ALA present in lymph was increased reaching a maximum concentration of 16.23 mg/ml at 2.5 h. The amount of ALA present in lymph was increased to a maximum level of 10.95 mg/ml at 4 h in rats given LSO as a microemulsion in whey protein. When LSO was given without emulsification, the amount of ALA present in lymph was found to reach a maximum level of 7.08 mg/ml at 6 h. A similar result was observed when weaning rats were intubated with 0.15 g of LSO per day for a period of 60 days. Higher levels of ALA by 41 and 103 % were observed in lymph lipids of rats given microemulsions of LSO in whey protein and in lipoid respectively as compared to rats given LSO without pre-emulsification. Very little conversion of ALA to EPA and DHA was observed in lymph lipids but higher amounts of EPA + DHA was observed in liver and serum of rats given LSO in microemulsion form. This study indicated that ALA concentration in lymph lipids was increased when LSO was given in microemulsion form in lipoid and further conversion to EPA and DHA was facilitated in liver and serum.     

Oral Administration of Dihomo-γ-Linolenic Acid Prevents Development of Atopic Dermatitis in NC/Nga Mice

Disorders of the metabolism of essential fatty acids (EFAs) are related to atopic dermatitis (AD). Concentrations of dihomo-γ-linolenic acid (DGLA), an EFA, in the serum of AD patients are lower than those in healthy volunteers. Recently we developed a fermented DGLA oil, and examined whether oral administration of DGLA prevents development of dermatitis in NC/Nga mice, which spontaneously develop human AD-like skin lesions. NC/Nga mice were fed a diet either containing or not containing DGLA for 8 weeks under in air-uncontrolled conventional circumstances. Clinical skin severity scores were significantly lower in mice fed DGLA than in mice not fed it. Scratching behavior and plasma total IgE levels were also reduced in the DGLA group, in association with histological improvement. DGLA suppressed clinical severity of skin lesions dose-dependently, with an increase in DGLA contents in phospholipids of skin, spleen, and plasma. Discontinuation of DGLA administration resulted in the onset of dermatitis and a decrease in DGLA contents in skin, spleen, and plasma. These findings indicate that oral administration of DGLA effectively prevents the development of AD in NC/Nga mice, and that DGLA in phospholipids is a compound of key importance in the development and prevention of dermatitis.     

Activin A and Cell-Surface GRP78 Are Novel Targetable RhoA Activators for Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the leading cause of kidney failure. RhoA/Rho-associated protein kinase (ROCK) signaling is a recognized mediator of its pathogenesis, largely through mediating the profibrotic response. While RhoA activation is not feasible due to the central role it plays in normal physiology, ROCK inhibition has been found to be effective in attenuating DKD in preclinical models. However, this has not been evaluated in clinical studies as of yet. Alternate means of inhibiting RhoA/ROCK signaling involve the identification of disease-specific activators. This report presents evidence showing the activation of RhoA/ROCK signaling both in vitro in glomerular mesangial cells and in vivo in diabetic kidneys by two recently described novel pathogenic mediators of fibrosis in DKD, activins and cell-surface GRP78. Neither are present in normal kidneys. Activin inhibition with follistatin and neutralization of cell-surface GRP78 using a specific antibody blocked RhoA activation in mesangial cells and in diabetic kidneys. These data identify two novel RhoA/ROCK activators in diabetic kidneys that can be evaluated for their efficacy in inhibiting the progression of DKD.     

Stress Distribution in Single Lap Joints with a Cracked Composite Adherend—Part II: Laminated Adherends

The effect of a crack in the overlap region of an adhesive single lap joint is studied on the shear stress distribution in adhesive layer. Each adherend is considered to be a laminated composite material with unidirectional fibers aligned in the direction of the applied load. Crack location is selected to be in the top adherend laminate, in the form of cut fibers and matrix bays. The crack can occur in any layer. The shear-lag model is used to derive the equilibrium equations which are then solved by means of eigenvector expansion. The effects of adhesive thickness, crack size, and location in the adherend, total number of layers in each adherends, volume fraction of fibers, and type of fibers are investigated on the shear distribution in the adhesive as well as load distribution in the intact fiber at the crack tip located in the top adherend. The effect of dissimilar laminated adherends is also investigated on the adhesive shear stress distribution. According to the results, in the presence of a crack, the peak shear stress in the adhesive layer and load concentration in the fibers are very susceptible to the adhesive thickness and number of layers in laminated adherends.