Microchannel reactive distillation for the conversion of aqueous ethanol to ethylene

Here we demonstrate the proof-of-concept for microchannel reactive distillation for alcohol-to-jet application:combining ethanol/water separation and ethanol dehydration in one unit operation.Ethanol is first distilled into the vapor phase,converted to ethylene and water,and then the water co-product is condensed to shift the reaction equilibrium.Process intensification is achieved through rapid mass transfer-ethanol stripping from thin wicks using novel microchannel architectures-leading to lower residence time and improved separation efficiency.Energy savings are realized with integration of unit operations.For example,heat of condensing water can offset vaporizing ethanol.Furthermore,the dehydration reaction equilibrium shifts towards completion by immediate removal of the water byproduct upon formation while maintaining aqueous feedstock in the condensed phase.For aqueous ethanol feedstock(40%_w),71% ethanol conversion with 91% selectivity to ethylene was demonstrated at 220℃,600psig,and 0.28 h^(-1) wt hour space velocity.2.7 stages of separation were also demonstrated,under these conditions,using a device length of 8.3 cm.This provides a height equivalent of a theoretical plate(HETP),a measure of separation efficiency,of ^(3).3 cm.By comparison,conventional distillation packing provides an HETP of ^(3)0 cm.Thus,9,1 × reduction in HETP was demonstrated over conventional technology,providing a means for significant energy savings and an example of process intensification.Finally,preliminary process economic analysis indicates that by using microchannel reactive distillation technology,the operating and capital costs for the ethanol separation and dehydration portion of an envisioned alcoholto-jet process could be reduced by at least 35% and 55%,respectively,relative to the incumbent technology,provided future improvements to microchannel reactive distillation design and operability are made.

A Hydrogen Iron Flow Battery with High Current Density and Long Cyclability Enabled Through Circular Water Management

The hydrogen-iron(HyFe)flow cell has great potential for long-duration energy storage by capitalizing on the advantages of both electrolyzers and flow batteries.However,its operation at high current density(high power)and over continuous cycling testing has yet to be demonstrated.In this article,we discuss our design and demonstration of a water-management strategy that supports high current and long-cycling performance of a HyFe flow cell.Water molecules associated with the movement of protons from the iron electrode to the hydrogen electrode are sufficient to hydrate the membrane and electrode at a low current density of 100 mA cm^(-2)during the charge process.At higher charge current density,more aggressive measures must be taken to counter back-diffusion driven by the acid concentration gradient between the iron and hydrogen electrodes.Our water-management approach is based on water vapor feeding in the hydrogen electrode and water evaporation in the iron electrode,thus enabling high current density operation of 300 mA cm^(-2).

A Hydrogen Iron Flow Battery with High Current Density and Long Cyclability Enabled Through Circular Water Management

The hydrogen-iron(HyFe)flow cell has great potential for long-duration energy storage by capitalizing on the advantages of both electrolyzers and flow batteries.However,its operation at high current density(high power)and over continuous cycling testing has yet to be demonstrated.In this paper,we discuss our design and demonstration of a water management strategy that supports high current and long cycling performance of a HyFe flow cell.Water molecules associated with the movement of protons from the iron electrode to the hydrogen electrode are sufficient to hydrate the membrane and electrode at a low current density of 100 mA cm^(-2)during the charge process.At higher charge current density,more aggressive measures must be taken to counter back-diffusion driven by the acid concentration gradient between the iron and hydrogen electrodes.Our water management approach is based on water vapor feeding in the hydrogen electrode,and water evaporation in the iron electrode,thus enabling the high current density operation of 300 mA cm^(-2).

CRISPR/Cas9-based gene activation and base editing in Populus

The genus Populus has long been used for environmental,agroforestry and industrial applications worldwide.Today Populus is also recognized as a desirable crop for biofuel production and a model tree for physiological and ecological research.As such,various modern biotechnologies,including CRISPR/Cas9-based techniques,have been actively applied to Populus for genetic and genomic improvements for traits such as increased growth rate and tailored lignin composition.However,CRISPR/Cas9 has been primarily used as the active Cas9 form to create knockouts in the hybrid poplar clone“717-1B4”(P.tremula x P.alba clone INRA 717-1B4).Alternative CRISPR/Cas9-based technologies,e.g.those involving modified Cas9 for gene activation and base editing,have not been evaluated in most Populus species for their efficacy.Here we employed a deactivated Cas9(dCas9)-based CRISPR activation(CRISPRa)technique to fine-tune the expression of two target genes,TPX2 and LecRLK-G which play important roles in plant growth and defense response,in hybrid poplar clone“717-1B4”and poplar clone“WV94”(P.deltoides“WV94”),respectively.We observed that CRISPRa resulted in 1.2-fold to 7.0-fold increase in target gene expression through transient expression in protoplasts and Agrobacterium-mediated stable transformation,demonstrating the effectiveness of dCas9-based CRISPRa system in Populus.In addition,we applied Cas9 nickase(nCas9)-based cytosine base editor(CBE)to precisely introduce premature stop codons via C-to-T conversion,with an efficiency of 13%–14%,in the target gene PLATZ which encodes a transcription factor involved in plant fungal pathogen response in hybrid poplar clone“717-1B4”.Overall,we showcase the successful application of CRISPR/Cas-based technologies in gene expression regulation and precise gene engineering in two Populus species,facilitating the adoption of emerging genome editing tools in woody species.

不同焦油释放量卷烟烟气的细胞毒性和基因毒性研究

采用体外细胞微核试验方法测定对照卷烟和2种不同焦油释放量卷烟的基因毒性。将3T3细胞暴露于ISO标准抽吸条件下产生的卷烟烟气环境中，首先测试烟气的细胞毒性来决定微核试验的烟气暴露浓度，再通过测定暴露于烟气的细胞微核的增加量来测试卷烟烟气的基因毒性。结果显示随着烟气暴露浓度的增大，3种卷烟烟气引起细胞微核的机率显著增大；加入S9匀浆液不会增加细胞微核的产生机率，相反，＋S9组的3种卷烟烟气引起的细胞微核的增加比例较．S9组显著降低。此外3种卷烟相比，1号测试卷烟烟气的基因毒性明显高于2号测试卷烟和K2R4F对照卷烟，2号卷烟烟气的基因毒性最低。

3种不同焦油卷烟烟气的细胞毒性比较

采用中性红法测定了K2R4F参比卷烟和15、8和3mg/支焦油市售国产混合型卷烟烟气的细胞毒性。即卷烟主流烟气经洁净空气稀释后直接导入BALB/c3T3细胞培养瓶中染毒,而后采用中性红法测定细胞毒性,并计算出基于烟气总粒相物的相对细胞死亡率和LC50。结果表明:4种卷烟的细胞毒性依次为15mg/支焦油卷烟>>8mg/支焦油卷烟≈K2R4F>3mg/支焦油卷烟,与这3种国产卷烟样品烟气气相自由基、烟草特有N-亚硝胺和稠环芳烃的降低一致。说明卷烟减害降焦,可以降低其烟气的细胞毒性,降低吸烟对健康的危害。

大鼠类Alu重复序列的克隆及其在染色体DNA突变分析中的应用

从大鼠低Cot值DNA文库分离到一种类Alu的重复序列 ,命名为RALRS 1.对RALRS 1克隆并进行了测序 ,长度为 2 83bp ,发现其中含有单一的微卫星 (microsatellite)序列AG ,AGG和AGGG .RALRS 1DNA序列在大鼠单倍体基因组中的拷贝数为 15 0 0 0 0～ 330 0 0 0 .依RALRS 1中的一段序列合成了一 2 8寡核苷酸探针 (AGGG) 7,对大鼠正常组织和肿瘤组织DNA指纹谱分析时 ,不但能显示活动清晰的指纹谱带型 ,并能显示与正常组织间所存在的区别 .本研究证明我们所发展的方法能够快速而方便地获得同源重复序列探针 ,用于DNA指纹谱分析 .这类分析对研究基因组的变化提供了有价值的途径 .图 3参

Challenges and opportunities for using formate to store, transport, and use hydrogen

In this perspective article,the synthesis and thermodynamic properties of aqueous solutions of formate salts(FS,HCO2-)are described in relationship to the concept of H2carriers.The physiochemical properties of solid FS,aqueous formate solutions,and aqueous bicarbonate solutions set the limitations for storage capacity,deliverable capacity,and usable H2capacity of these H2carriers,respectively.These parameters will help in the design of systems that use H2carriers for storage and transport of H2for fuel cell power applications.FS,as well as admixtures with formic acid(FA,H2CO2),have potential to address the goals outlined in the U.S.Department of Energy’s H2@scale initiative to store in chemical bonds a significant quantity of energy(hundreds of megawatts)obtained from large scale renewable resources.

Opportunities and challenges for developing closed-loop bioelectronic medicines

The peripheral nervous system plays a major role in the maintenance of our physiology. Several peripheral nerves intimately regulate the state of the brain, spinal cord, and visceral systems. A new class of therapeutics, called bioelectronic medicines, are being developed to precisely regulate physiology and treat dysfunction using peripheral nerve stimulation. In this review, we first discuss new work using closed-loop bioelectronic medicine to treat upper limb paralysis. In contrast to open-loop bioelectronic medicines, closed-loop approaches trigger ‘on demand' peripheral nerve stimulation due to a change in function(e.g., during an upper limb movement or a change in cardiopulmonary state). We also outline our perspective on timing rules for closedloop bioelectronic stimulation, interface features for non-invasively stimulating peripheral nerves, and machine learning algorithms to recognize disease events for closed-loop stimulation control. Although there will be several challenges for this emerging field, we look forward to future bioelectronic medicines that can autonomously sense changes in the body, to provide closed-loop peripheral nerve stimulation and treat disease.

Friction-based riveting technique for AZ31 magnesium alloy

A new friction-based riveting technique, Rotating Hammer Riveting(RHR), is demonstrated to fully form AZ31 Mg rivet heads in a mere 0.23 s. Heat and pressure generated through severe plastic deformation during the process was sufficient to form the Mg rivet head without the need for a pre-heating operation. Due to preliminary twinning and followed by dynamic recrystallization, AZ31 Mg grains in the rivet head were refined during RHR, which enhance the formability of Mg rivets by triggering grain boundary sliding and reducing plastic anisotropy of Mg. In addition, RHR joints showed a metallurgical bond between the rivet head and top AZ31 Mg sheet, which eliminates a significant pathway for corrosion.

发展一种估算石油工业温室气体排放的一致的方法

要获得有意义的温室气体清单,重要的是清单中包括的内容的方法论和定义应该是一致的.国际石油工业环境保护协会(IPIECA)、国际石油和天然气生产者协会(OGP)以及美国石油学会(API)已经制定了温室气体排放计算和报告的准则.国际石油工业环境保护协会(IPIECA)报告温室气体排放的石油工业指南的重点是放在石油工业温室气体排放的计算和报告上.为了提供排放估算一致的方法论,美国石油工业协会制定了石油和天然气工业温室气体排放估算方法论概要.从美国石油学会可以得到一个估算排放的工具——SANGEATM能源和排放估算系统.

电解池电阻和容抗的快速测定仪

利用锁定放大器,恒电势仪,压控频率正弦波信号发生器等组装成电解池电阻和容抗的快速测定仪。可以快速地自动测是和绘出阻抗谱图和电阻/容抗~时间图。采用微小恒定振幅正弛交流电流(<10μA)作为微扰,数据可能较为可靠。给出了线路及所需滤波器元件的数据,说明仪器各部份之间的干扰可以减少。测定了滴汞电极在1mol LNaSO溶液中及1mol LNaSO被正庚醇饱和的溶液中的微分电容~电势数值。证明仪器工作良好。另外,从实验数据和理论分析,均表明D.C.Grahame的被广泛引用的有关经典数据有误。本文做了修正。还测定了半导体氧化铁电极在光照下黑暗中的阻抗谱图和氧化银电极充电和停止充电后开路下的电阻~时间图,显示了仪器在电化学研究中利用的可能性。

Coherent Vibrational Dynamics and High-resolution Nonlinear Spectroscopy： A Comparison with the Air/DMSO Liquid Interface

We present a comparative study on the C-H stretching vibrations at air/DMSO （dimethyl sulfoxide） interface with both the free-induction decay （FID） coherent vibrational dynamics and the sub-wavenumber high resolution sum-frequency generation vibrational spectroscopy measurements. In principle the frequency-domain and time-domain spectroscopic measurements should generate identical information for a given molecular system. However, when the molecular systems are with several coupled or overlapping vibrational modes, obtain- ing detailed spectroscopic and coherent dynamics information is not as straightforward and rather difficult from either the time-domain or the frequency domain measurements. For the case of air/DMSO interface that is with moderately complex vibrational spectra, we show that the frequency-domain measurement with sub-wavenumber high-resolution sum-frequency generation vibrational spectroscopy is probably more advantageous than the time- domain measurement in obtaining quantitative understanding of the structure and coherent dynamics of the molecular interface.

利用磁控管溅射沉积的硬而韧的低摩擦钼镀层

在精心控制的Ar-N_2气氛中沉积钼时,得到了溶解氮为0～10％(at)的均一体心立方相。厚度为10～20μm之镀层的X-射线图呈现很窄的谱线,并且具有平行于样品表面的(110)面的准理想取向。虽然这些镀层的努氏硬度为HK300～3000,但却仍然保持着相当良好的韧性和很低的摩擦系数,以及明显的“跑合”趋势,其摩擦系数由起始值0.1(机油润滑)很快就降低到0.07以下。当氮气分压高于0.1Pa时就出现氮化物相,同时镀层变脆且其X-射线衍射线变宽。与氧化钼的生成能(对于MoO_2,△H=-130cal/mol)相比,氮化钼的生成能(对于MoO_2N,△H=-8kcal/mol)很低,因而可以很好地控制氮含量。为了避免生成含有不稳定的面心立方相镀层,理想的温度应高于200℃。钨的行为与此十分相似,而铬尽管也能在同一体系中结晶,但却是以(100)面平行于样品表面,故其摩擦系数明显较高。

SPECTRAL/HP ELEMENT METHOD WITH HIERARCHICAL RECONSTRUCTION FOR SOLVING NONLINEAR HYPERBOLIC CONSERVATION LAWS

The hierarchical reconstruction （HR） [Liu, Shu, Tadmor and Zhang, SINUM ＇07] has been successfully applied to prevent oscillations in solutions computed by finite volume, Runge-Kutta discontinuous Galerkin, spectral volume schemes for solving hyperbolic conservation laws. In this paper, we demonstrate that HR can also be combined with spectral/hp element method for solving hyperbolic conservation laws. An orthogonal spectral basis written in terms of Jacobi polynomials is applied. High computational efficiency is obtained due to such matrix-free algorithm. The formulation is conservative, and essential nomoscillation is enforced by the HR limiter. We show that HR preserves the order of accuracy of the spectral/hp element method for smooth solution problems and generate essentially non-oscillatory solutions profiles for capturing discontinuous solutions without local characteristic decomposition. In addition, we introduce a postprocessing technique to improve HR for limiting high degree numerical solutions.

对夹杂附近次表面的应力之估算

作者提出了一个预测在夹杂附近次表面应力的理论模型。该模型包括允许体系中杨氏模量变化的弹性方程的数值解。起决定性作用的方程是用标准行列式反演方法求解变形的二次椭圆微分方程。将软材料基体中硬质夹杂的计算值与参照的实验数据进行了比较。在夹杂周围存在着巨大的应力升值,这由应力等值线来表示。在表面上涂覆厚的硬质涂层能够大幅度地降低这些应力的升值。

Evaluation of HemogloBind^TMtreatment for preparation of samples for cholinesterase analysis

Acetylcholine is an essential neurotransmitter found throughout the nervous system. Its action on postsynaptic receptors is regulated through hydrolysis by various carboxylesterases, especially cholinesterases (ChEs). The acute toxicity of organophosphate (OP) compounds is directly linked to their action as inhibitors of ChE. One widely used assay for evaluating ChE activity is a spectrophotometric method developed by Ellman et al. When the enzyme source is from tissues or, in particular, blood, hemoglobin displays a spectrophotometric peak at the same wave-length used to analyze cholinergic activity. This creates a substantial background that interferes with the Ellman’s assay and must be overcome in order to accurately monitor cholinesterase activity. Herein, we directly compare blood processing methods: classical method (1.67 ± 0.30 U/mL) and HemogloBindTM treatment (1.51 ± 0.17 U/mL), and clearly demonstrate that pretreatment of blood samples with HemoglobindTM is both a sufficient and rapid sample preparation method for the assessment of ChE activity using the Ellman’s method.

Is the 2008 financial turmoil increasing the risk of a bank run？ An empirical research in Geneva

In this paper, the authors present the results of an empirical study that attempts to analyse the risk of bank run in Geneva, Switzerland. Two similar surveys have been conducted upon two independent samples of Geneva population （June 2008 and February 2009） to detect the existence of predictive signals leading to a bank run within the selected area. The authors discover that Geneva inhabitants are generally confident in Swiss banks; the risk of a bank run in the area is low. However, reliance to the national banking system is worsening： The number of people fearing about their savings and those thinking the default of a major Swiss bank as ＂possible＂ has significantly risen. Also, more and more people keep updated about the current financial crisis; overall trust in Swiss banks has slightly decreased.

Magnetic-Bottle and Velocity-Map Imaging Photoelectron Spectroscopy of APS-(A=C14H10 or Anthracene):Electron Structure,Spin-Orbit Coupling of APS,and Dipole-Bound State of APS-

Gaseous dibenzo-7-phosphanorbornadiene P-sulfide anions APS （A C14H10 or anthracene） were generated via electrospray ionization, and characterized by magnetic-bottle photoelec- tron spectroscopy, velocity-map imaging （VMI） photoelectron spectroscopy, and quantum chemical calculations. The electron affinity （EA） and spin-orbit （SO） splitting of the APS＂ radical are determined from the photoelectron spectra and Franck-Condon factor simulations to be EA （2.62-4-0.05） eV and SO splitting （43-4-7） meV. VMI photoelectron images show strong and sharp peaks near the detachment threshold with an identical electron kinetic energy （eKE） of 17.9 meV at three different detachment wavelengths, which are therefore assigned to autodetachment from dipole-bound anion states. The B3LYP/6-31＋＋G（d,p） calculations indicate APS has a dipole moment of 3.31 Debye, large enough to support a dipole-bound electron.

Uncanny valley for interactive social agents:an experimental study

Background The uncanny valley hypothesis states that users may experience discomfort when inter-acting with almost human-like artificial characters.Advancements in artificial intelligence,robotics,and computer graphics have led to the development of life-like virtual humans and humanoid robots.Revisiting this hypothesis is necessary to check whether they positively or negatively affect the current population,who are highly accustomed to the latest technologies.Methods In this study,we present a unique evaluation of the uncanny valley hypothesis by allowing participants to interact live with four humanoid robots that have varying levels of human-likeness.Each participant completed a survey questionnaire to evaluate the affinity of each robot.Additionally,we used deep learning methods to quantify the participants’emotional states using multimodal cues,including visual,audio,and text cues,by recording the participant-robot interactions.Results Multi-modal analysis and surveys provided interesting results and insights into the uncanny valley hypothesis.