页岩油藏渗吸驱油剂体系性能评价

由于页岩油藏的超低渗透率和复杂的孔隙结构,从页岩油储层中采油仍然是一个重大挑战。表面活性剂作为一种潜在的解决方案,通过降低界面张力和改变润湿性来提高非常规油藏的原油采收率。本研究旨在通过研究页岩油储层的自发渗吸行为,评价表面活性剂在页岩油藏中的应用潜力。结果表明,复配渗吸驱油体系0.15 wt%CA-90+0.15 wt%SDS,在地层条件下界面张力降低至1.03×10^(-2)mN/m;亲油岩心片润湿接触角降低了86°,岩石润湿性由油湿转变为水湿,毛管力由油渗吸驱油阻力转变为渗吸驱油动力;在含水率为70%时,乳状液黏度降低至23.4 mPa·s,其黏度接近原油黏度,但流动性更强,更有利于提高采收率;0.15 wt%CA-90和0.15 wt%SDS的动态吸附量分别为0.85和0.97 mg/g,具有较好的抗吸附能力,对页岩渗透率伤害率低于8%;滑溜水+复配体系的渗吸采收率可以达到31.27%,相比滑溜水体系中自发渗吸采收率(19.43%)提高了11.84%,渗吸驱油效率提高了60.94%,极大地提高了页岩油藏的采收率。

Melatonin delays leaf senescence in pak choi(Brassica rapa subsp.chinensis)by regulating biosynthesis of the second messenger cGMP

Melatonin(MT)is a low molecular weight compound with multiple biological functions in plants.It is known to delay leaf senescence in various species.However,no data are available on the MT signaling pathway in postharvest vegetables.This study demonstrates that MT increases cGMP concentration and the expression of the cGMP synthesis gene BcGC1 in pak choi.The c GMP inhibitor LY83583 destroys effect of MT delaying the leaf senescence.LY83583 also prevents MT treatment from reducing the expression of chlorophyll metabolism-related genes(BcNYC1,BcNOL,BcPPH1/2,BcSGR1/2,and BcPAO)and senescence genes(BcSAG12 and BcSAG21).It also inhibits MT from reducing the activity of the key chlorophyll catabolism enzymes Mg-dechelatase,pheophytinase,and pheide a oxygenase.Thus,the ability of MT to maintain high levels of chlorophyll metabolites is also destroyed.The Arabidopsis c GMP synthetic gene mutant atgc1 was used to confirm that delayed leaf senescence caused by MT is mediated,at least in part,by the second messenger c GMP.

<i>Ratanasampil</i>(Tibetan Medicine, RNSP) Reduces <i>β</i>-Amyloid Protein (Aβ) and Pro-Inflammatory Factor Levels and Improves Cognitive Functions in Mild-to-Moderate Alzheimer’s Disease (AD) Patients Living at High Altitude

Ratanasampil (RNSP) is a traditional Tibetan medicine used for the treatment of stroke and cerebrovascular diseases. Previous discoveries that RNSP can reduce β-amyloid protein levels and increase learning and memory in Alzheimer’s mouse models (Tg2576) led us to investigate whether RNSP can improve cognitive functions in Alzheimer’s patients. In this study, 146 AD patients living in Qinghai province received either one gram or 0.33 gram daily of RNSP for 16 weeks. Placebo patients received Piracetam. Serum Aβ40 and Aβ42 levels were measured at the beginning of the study and after 4 and 16 weeks of treatment. Compared to the same group before treatment, MMSE scores, ADAS-cog scores and ADL scores were significantly improved (p 0.05, p > 0.05). After 16-week treatment, serum TNF-α, IL-1β, IL-6 and Aβ42 levels were significantly decreased (p < 0. 01) in the high-dose RNSP group, whereas no significant differences were found in the low-dose and placebo groups. The Aβ42/Aβ40 ratio was significantly decreased after 4-week and 16-week treatment in the high-dose RNSP group (p < 0. 05, p < 0.01). Furthermore, serum Aβ42 concentrations had a strong positive correlation with TNF-α, IL-1β and IL-6 levels. There were no observable adverse effects in either treatment or control groups. We conclude that further clinical trials of RNSP in Alzheimer disease are warranted.

A new species in the genus Indoquedius Blackwelder(Coleoptera:Staphylinidae)from Yunnan,China

Indoquedius lii sp.nov.is described from Yunnan,China.The number of Indoquedius species has thus increased to 39.Color images of the habitus,sternites,tergite and aedeagus of this new species are included.A key to species in the genus Indoquedius of Yunnan is provided.

互动演变机制下产业集群对区域经济增长的影响研究

本文基于中国区域视角,采用相关行业2000年~2014年的数据,从实证的角度检验了专业市场,电子商务与产业集群互动演变机制下产业集群对区域经济增长的影响。结果表明,在引入专业市场与电子商务的情况下,产业专业化程度对区域经济增长的影响作用中东部地区最大、中部其次、西部最低,产业内的竞争程度则表现为是东、中、西依次递增,产业多化对区域经济增长则表现出不确定性。在分年限样本内产业集群内企业的竞争程度在不断增加,并在2010年~2014年问竞争程度达到最大。门限回归则表明随着专业市场与产业集群的互动程度随着互动程度的增加,产业竞争度、多样性均呈减弱趋势、产业专业化则有所增强;而专业市场发展指数、电子商务发展指数和市场化指数的改变,产业竞争度会有所减弱,说明外部市场的接入使得产业集群内更趋向于合作,促进经济增长。

Study of talcum charging status in parallel plate electrostatic separator based on particle trajectory analysis

Electrostatic separation has been extensively used in mineral processing,and has the potential to separate gangue minerals from raw talcum ore.As for electrostatic separation,the particle charging status is one of important influence factors.To describe the talcum particle charging status in a parallel plate electrostatic separator accurately,this paper proposes a modern images processing method.Based on the actual trajectories obtained from sequence images of particle movement and the analysis of physical forces applied on a charged particle,a numerical model is built,which could calculate the charge-to-mass ratios represented as the charging status of particle and simulate the particle trajectories.The simulated trajectories agree well with the experimental results obtained by images processing.In addition,chemical composition analysis is employed to reveal the relationship between ferrum gangue mineral content and charge-tomass ratios.Research results show that the proposed method is effective for describing the particle charging status in electrostatic separation.

Direct impact characteristics of magnesite fragmentation by pulsed discharge in water

To clarify direct impact characteristics(pressure and position) of middle-grade magnesite fragmentation by pulsed discharge in water, this work uses pressure film to accomplish passive measurement through pulsed discharge experiment and obtain the pressure. The impact position is determined by image analysis of fragmentation product morphology, crack edge and discharge channel. Then, pressure load on magnesite surface is numerically analyzed based on the measured pressure obtained from the film. Results indicate that, at 10 mm discharge gap, the impact pressure increases with the discharge voltage, and the discharge voltage to disintegrate magnesite is-40 kV. The impact position is normally in the boundary among different mineral components.Simulation analysis indicates that, the pressure load applied directly on magnesite surface is approximately 142.5 MPa at-40 kV and greater than the compressive strength of magnesite, thus leading to the fragmentation.

Viscoelastic solution of optimal reserved deformation for deep soft rocktunnels with large deformation

In the construction process of soft rock tunnels,determining a reasonable amount of reserved deformation is important to ensure the tunnel stability.This article presents the viscoelastic solution of reserved deformation for deep soft rock tunnels considering the support effects.Based on the analytical solution of the Burgers model,the expression of surrounding rock displacement was derived by considering reserved deformation and optimal reserved deformation.Subsequently,based on numerical simulation experiments,the variation laws and errors of the numerical and analytical solutions of the expressions of reserved deformation and surrounding rock displacement were analyzed.To gain a better understanding of the factors that affect reserved deformation,the factors influencing the expression of optimal reserved deformation were analyzed.The errors in the numerical simulation and analytical solution results were within 10%.This study could provide a theoretical basis for determining the amount of reserved deformation and analyzing the variation law of surrounding rock affected by the amount of reserved deformation.

The electrochemical stability of ionic liquids and deep eutectic solvents

Room temperature ionic liquids （ILs） composed of cations and anions, as well as deep eutectic solvents （DESs） composed of hydrogen bond donors （HBDs） and hydrogen bond acceptors （HBAs）, are regarded as green solvents due to their low volatility. They have been used widely for electrochemically driven reactions because they exhibit high conductivity and excellent elec- trochemical stability. However, no systematic investigations on the electrochemical potential windows （EPWs）, which could be used to characterize the electrochemical stability, have been reported. In this regard, the EPWs of 33 ILs and 23 DESs have been studied utilizing cyclic voltammetry （CV） method and the effects of structural factors （cations and anions of ILs, and HBDs and HBAs of DESs） and external factors （electrode, water content） on the EPWs have been comprehensively investi- gated. The electrochemical stability of selected 1Ls comprising five traditional cations, namely imidazolium, pyridinium, pyr- rolidinium, piperidinium and ammonium and 13 kinds of versatile anions was studied. The results show that for ILs, both cati- on and anion play an important role on the reductive and oxidative potential limit. For a same IL at different working electrode, for example, glassy carbon （GC）, gold （Au） and platinum （Pt） electrode, the largest potential window is almost observed on the GC working electrode. The investigations on the EPWs of choline chloride （ChCl）, choline bromide （ChBr）, choline iodide （ChI）, and methyl urea based DESs show that the DES composed of ChCl and methyl urea has the largest potential window. This work may aid the selection of ILs or DESs for use as a direct electrolyte or a solvent in electrochemical applications.

NIR-Ⅱ fluorescence visualization of ultrasound-induced blood–brain barrier opening for enhanced photothermal therapy against glioblastoma using indocyanine green microbubbles

Focused ultrasound(FUS)-induced blood–brain barrier(BBB) opening is crucial for enhancing glioblastoma(GBM) therapies. However, an in vivo imaging approach with a high spatial–temporal resolution to monitor the BBB opening process in situ and synchronously is still lacking. Herein, we report the use of indocyanine green(ICG)-dopped microbubbles(MBs-ICG) for visualizing the FUS-induced BBB opening and enhancing the photothermal therapy(PTT) against GBM. The MBs-ICG show bright fluorescence in the second near-infrared window(NIR-II), ultrasound contrast, and ultrasound-induced size transformation properties. By virtue of complementary contrast properties, MBs-ICG can be successfully applied for cerebral vascular imaging with NIR-II fluorescence resolution of ~168.9 lm and ultrasound penetration depth of ~7 mm. We further demonstrate that MBs-ICG can be combined with FUS for in situ and synchronous visualization of the BBB opening with a NIR-II fluorescence signal-tobackground ratio of 6.2 ± 1.2. Finally, our data show that the MBs-ICG transform into lipid-ICG nanoparticles under FUS irradiation, which then rapidly penetrate the tumor tissues within 10 min and enhance PTT in orthotopic GBM-bearing mice. The multifunctional MBs-ICG approach provides a novel paradigm for monitoring BBB opening and enhancing GBM therapy.

Synthesis of polycyclic spiro-fused indolines via IBX-mediated cascade cyclization

We report a 2-iodoxybenzoic acid(IBX)-mediated intarmolecular oxidative spiro-fused tandem cyclization reaction of tryptophan analogs bearing an N-arylamides side-chain to rapidly afford polycyclic spiroindolines featuring multiple stereocenters including a quaternary stereocenters under mild reaction conditions.Among them,a novelty azaphosphol idine-containing spiroindoline compound is synthesized for the first time.It may open the door to azaphos pholidine-containing spiroindoline compound of potential interest in synthetic and medicinal chemistry.A plausible mechanism is proposed.

Graphene-based hemostatic sponge

Graphene-based sponge is a novel hemostatic material prepared by chemical cross-link of graphene oxide. It has a fast fluid absorption capacity to quickly absorb blood from wounds, activate clotting pathways, and achieve rapid hemostasis. In addition, graphene-based sponge is also a good platform carrier.It can be prepared by organic cross-linking, compounding with inorganic clay, and adding bioactive factors to enhance coagulation stimulation. By these methods, the hemostatic performance of the sponge is further improved, which shows great potential for application in the field of trauma hemostasis. This article reviews the research progress of graphene-based sponges from three different preparation strategies(organic cross-linking, inorganic compounding and adding bioactive factor), summarizes their hemostatic mechanisms, and prospects the development of graphene-based hemostatic sponges.