超临界反溶剂过程中液滴传质行为模拟研究

在超临界反溶剂(SAS)过程中,液滴的传质行为是影响微粒尺寸和尺寸分布的关键因素.建立了有机溶液液滴与超临界反溶剂之间的传质模型,用于模拟超临界反溶剂制备超细微粒的传质过程.根据所建的模型,在不同温度和压力下,对超临界CO2和丙酮液滴进行了传质模拟研究.研究结果表明,对于CO2-丙酮溶液系统,随着压力和温度的升高,液滴直径膨胀的比率增大,液滴寿命缩短,液滴中心密度最大值增大,液滴达到饱和需要的时间增长.由于液滴膨胀和寿命是影响微粒形态分布的主要因素,最大液滴直径越大,液滴的存在时间越短,则反溶剂过程越迅速;过饱和度越大,成核速率越大,系统的扰动程度越大,因而获得的微粒尺寸就越小而且尺寸分布越均匀.     

气体水合物晶体成核与生长机理研究

气体水合物的形成要经历溶解、成核、生长阶段，通过对均相成核和异相成核的理论研究，确定了晶核形成所需的的条件。根据对气体水合物晶体生长速率的影响因素分析，从理论上明确了生长速率与传热、传质以及动力学特性之间的规律。     

超临界溶液快速膨胀制备灰黄霉素超细微粒

研究了含夹带剂的超临界溶液快速膨胀制备灰黄霉素超细微粒。结果表明，预膨胀压力和夹带剂浓度越大，沉析微粒越小；预膨胀温度越高，沉析微粒越大。模拟了超临界溶液在喷嘴入口段、喷嘴以及喷嘴后自由喷射段中的流速、压力、温度、过饱和度以及成核速率的分布。     

琥珀酸氢十八酯(OHS)过饱和溶液的成核研究

为了探索培养ＯＨＳ优质单晶的优化条件，本义研究了过饱和ＯＨＳ 溶液的成核，测量了以诱导期表示的成核速率，报告了温度、过饱和度和溶剂对成核速率的影响，并根据经典成核理论计算了晶体的表面张力、成核自由能和临界成核半径。     

碳酸钙结晶动力学研究

采用SPIP软件对碳酸钙垢显微图像进行分析,从微观上得出过饱和度、盐含量和pH值对碳酸钙结垢动力学的影响。实验结果表明:随着过饱和度的增加,晶核数逐渐增加,诱导期逐渐缩短,当过饱和度超过443时,结晶速率迅速增加,同时得出了诱导期与过饱和度的关系;当NaCl的质量浓度小于50g/L时,随着其浓度的增大,晶核数减少,结垢诱导期增加,当NaCl质量浓度达到50g/L时,晶核数最少,与同条件无NaCl溶液相比,碳酸钙结垢晶核数减少了66.7%;当pH值大于6时,随着pH值的增加,晶核数目迅速增加,结垢诱导期迅速缩短。     

磁化增注机理的分子动力学模拟

采用分子动力学模拟方法，从分子水平对磁化增注的机理进行了模拟研究。计算结果表明在优化磁感应强度范围内，水的表面张力系数和粘滞系数降低，使水的渗透性和流动性增强，达到增注的目的；在此基础上，从结晶学的角度对磁化防垢的效果进行了分析，研究表明经优化磁场处理后，水溶液的临界晶核半径减小，晶体成核速率和生产速率明显增加，溶液的过饱和度迅速降低，晶体的长大受到限制而形成较小的结晶颗粒，析出的固相将有更多的部分悬浮于水中，易于随水流动而减少沉淀，从而达到防垢、增注的效果。磁化增注效果在B=0．25T时最为明显。     

超声作用下碳酸钙晶体的形态变化

为了解超声场对碳酸钙晶体形态的影响,揭示其作用机制,采用自行设计的超声设备(40 kHz,0.88W/cm2)来处理不同过饱和度的碳酸钙溶液,并比较有、无超声作用的碳酸钙晶体的形态和大小.研究结果表明:超声空化效应所产生的微观热量不仅能促进过饱和溶液中碳酸钙晶核的形成,迅速降低溶液的过饱和度,还能改变碳酸钙晶体的形态;经超声处理的碳酸钙过饱和溶液中形成了大量微小的碳酸钙晶体,其中绝大部分为文石,少量为细小方解石,它们长时间悬浮在溶液中;超声的机械效应对碳酸钙晶体形态的影响甚微.     

类水滑石晶粒尺寸控制方法的研究

将超声波应用到NiAl类水滑石化合物的制备中，探讨了超声作用机理，研究了超声辐射对颗粒的形成和晶粒尺寸的影响。研究表明，超声能量能加速类水滑石的成核，超声场下加入分散剂能有效地控制晶核的长大和团聚；成核过程中过饱和度对类水滑石晶粒尺寸有较大的影响，增大晶化过程过饱和度有利于制备小粒径的类水滑石。     

超临界CO2沉析HMX过程中过饱和度与颗粒尺寸的关系

用超临界CO2在丙酮溶液中沉析环四亚甲基硝胺(HMX),研究了溶液过饱和度与沉析颗粒尺寸及粒径分布之间的关系。结果表明：用超临界CO2沉析HMX,可在短时间内产生很大的过饱和度。当温度33～50℃,压力5．5～12．0MPa时,在前几分钟内,溶质HMX的浓度快速下降从而在短时间内产生很大的过饱和度。依据吉普斯能传统结晶理论估算了在一定过饱和度下的成核速率。过饱和度愈大、成核速率愈大,沉析的HMX颗粒度愈细。当过饱和度在短时间内形成并导致大量成核快速消耗过饱和度时,可以得到粒度更细,分布更窄的HMX颗粒,如33℃、12．0MPa时,能得到粒径5．1～7．1μm窄分布的HMX细颗粒。     

晶粒生长对铁磷酸盐玻璃陶瓷固化体化学稳定性的影响

铁磷酸盐玻璃陶瓷可用于固化高放核废物。通过改变原料粉末尺寸和热处理的升温速率来控制成核的均匀性和晶核的生长速度,研究了在独居石玻璃陶瓷固化体中晶粒生长对固化体化学稳定性的影响。结果表明：粉末尺寸越小,越有利于形成均匀的晶核,固化体的化学稳定性越好,当粉末粒度小于38μm时浸出率达到最低值;热处理的升温速率越慢,所形成的微晶尺寸越均匀,固化体的化学稳定性越好,当升温速率为1℃／min时,样品的浸出率最低。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…