Design,test,and verification of in-situ condition preserved coring and analysis system in lunar-based simulation environment

The lunar surface and its deep layers contain abundant resources and valuable information resources,the exploration and exploitation of which are important for the sustainable development of the human economy and society.Technological exploration and research in the field of deep space science,especially lunar-based exploration,is a scientific strategy that has been pursued in China and worldwide.Drilling and sampling are key to accurate exploration of the desirable characteristics of deep lunar resources.In this study,an in-situ condition preserved coring(ICP-Coring)and analysis system,which can be used to test drilling tools and develop effective sampling strategies,was designed.The key features of the system include:(1)capability to replicate the extreme temperature fluctuations of the lunar environment(-185 to 200℃)with intelligent temperature control;(2)ability to maintain a vacuum environment at a scale of 10^(-3) Pa,both under unloaded conditions within Ф580 mm×1000 mm test chamber,and under loaded conditions using Ф400 mm×800 mm lunar rock simulant;(3)application of axial pressures up to 4 MPa and confining pressures up to 3.5 MPa;(4)sample rotation at any angle with a maximum sampling length of 800 mm;and(5)multiple modes of rotary-percussive drilling,controlled by penetration speed and weight on bit(WOB).Experimental studies on the drilling characteristics in the lunar rock simulant-loaded state under different drill bit-percussive-vacuum environment configurations were conducted.The results show that the outgassing rate of the lunar soil simulant is greater than that of the lunar rock simulant and that a low-temperature environment contributes to a reduced vacuum of the lunar-based simulated environment.The rotary-percussive drilling method effectively shortens the sampling time.With increasing sampling depth,the temperature rise of the drilling tools tends to rapidly increase,followed by slow growth or steady fluctuations.The temperature rise energy accumulation of the drill bits under vacuum is more significant than that under atmospheric pressure,approximately 1.47 times higher.The real-time monitored drilling pressure,penetration speed and rotary torque during drilling serve as parameters for discriminating the drilling status.The results of this research can provide a scientific basis for returning samples from lunar rock in extreme lunar-based environments.

Characteristics of Rock Mechanics Response and Energy Evolution Regime of Deep Reservoirs in the Bozhong Sag,Bohai Bay Basin

Hydraulic fracturing is a mature and effectivemethod for deep oil and gas production,which provides a foundation for deep oil and gas production.One of the key aspects of implementing hydraulic fracturing technology lies in understanding mechanics response characteristics of rocks in deep reservoirs under complex stress conditions.In this work,based on outcrop core samples,high-stress triaxial compression tests were designed to simulate the rock mechanics behavior of deep reservoirs in Bozhong Sag.Additionally,this study analyzes the deformation and damage law for rock under different stress conditions.Wherein,with a particular focus on combining energy dissipation theory to further understand damage law for deep reservoirs.The experimental results show that regardless of stress conditions,the process of deformation/failure of deep-seated reservoirs goes through five stages:Fracture compaction,newfracture formation,stable fracture expansion,unstable fracture expansion,and post-peak residual deformation.Under different stress conditions,the energy change laws of specimens are similar.The energy dissipation process of rocks corresponds closely to the trend of deformation-failure curve,then displays distinctive stage characteristics.Wherein,in stage of rock fracture compaction,the input energy curve is approximately coincident with the elastic strain energy curve,while the dissipation energy curve remains near zero.With the increase of strain,the growth rate of elastic strain energy increases gradually,but with the deformation entering the crack propagation stage,the growth rate of elastic strain energy slows down and the dissipation energy increases gradually.Finally,in the post-peak stage,rock fracture releases a lot of energy,which leads to the sharp decline of elastic strain energy curve.In addition,the introduction of damage variable D quantifies the analysis of the extent of failure for rocks.During the process of increasing strain,rock damage exhibits nonlinear growth with increasing stress.

Sb-Cu alloy cathode with a novel lithiation mechanism of ternary intermetallic formation: Enabling high energy density and superior rate capability of liquid metal battery

Antimony(Sb) is an attractive cathode for liquid metal batteries(LMBs) because of its high theoretical voltage and low cost.The main obstacles associated with the Sb-based cathodes are unsatisfactory energy density and poor rate-capability.Herein,we propose a novel Sb_(64)Cu_(36)cathode that effectively tackles these issues.The Sb_(64)Cu_(36)(melting point:525℃) cathode presents a novel lithiation mechanism involving sequentially the generation of Li_(2)CuSb,the formation of Li_(3)Sb,and the conversion reaction of Li_(2)CuSb to Li_(3)Sb and Cu.The generated intermetallic compounds show a unique microstructure of the upper floated Li_(2)CuSb layer and the below cross-linked structure with interpenetrated Li_(2)CuSb and Li_(3)Sb phases.Compared with Li_(3)Sb,the lower Li migration energy barrier(0.188 eV) of Li_(2)CuSb significantly facilitates the lithium diffusion across the intermediate compounds and accelerates the reaction kinetics.Consequently,the Li‖Sb_(64)Cu_(36)cell delivers a more excellent electrochemical performance(energy density:353 W h kg^(-1)at 0.4 A cm^(-2);rate capability:0.59 V at 2.0 A cm^(-2)),and a much lower energy storage cost of only 38.45 $ kW h^(-1)than other previously reported Sb-based LMBs.This work provides a novel cathode design concept for the development of high-performance LMBs in applications for large-scale energy storage.

Left atrial diameter and atrial fibrillation,but not elevated NT-proBNP,predict the development of pulmonary hypertension in patients with HFpEF

Background The determinants of pulmonary hypertension(PH)due to heart failure with preserved ejection fraction(HFpEF)have been poorly investigated in patients with cardiovascular diseases(CVD).Methods From July 12017 to March 312019,a total of 149 consecutive HFp EF patients hospitalized with CVD were enrolled in this prospective cross-sectional study.A systolic pulmonary artery pressure(PASP)>35 mm Hg estimated by echocardiography was defined as PH-HFp EF.Logistic regression was performed to establish predictors of PH in HFpEF patients.Results Overall,the mean age of participants was 72±11 years,and 74(49.7%)patients were females.A total of 59(39.6%)patients were diagnosed with PH-HFpEF by echocardiography.The left atrial diameter(LAD)was related to the ratio of the transmitral flow velocities/mitral annulus tissue velocities in early diastole(E/E’)and the left ventricular diameter in systole(LVDs).N-Terminal pro B-type natriuretic peptide(NT-proBNP)was not found to be associated with LAD and impaired diastolic or systolic function of the left ventricle.Multivariable logistic regression showed that atrial fibrillation(AF)increased the risk of PH-HFpEF incidence 3.46-fold with a 95%confidence interval(CI)of 1.44–8.32,P=0.005.Meanwhile,LAD≥45 mm resulted in a 3.43-fold increased risk,95%CI:1.51–7.75,P=0.003.However,the significance levels of NT-proBNP,age and LVEF were underpowered in the regression model.Two variables,AF and LAD≥45 mm,predicted the PH-HFpEF incidence(C-statistic=0.773,95%CI:0.695–0.852,P<0.001).Conclusions Two parameters associated with electrical and anatomical remodelling of the left atrium were related to the incidence of PH in HFpEF patients with CVD.

Risks of incident heart failure with preserved ejection fraction in Chinese patients hospitalized for cardiovascular diseases

Background Endogenous aldehyde damages DNA and potentiates an ageing phenotype. The aldehyde dehydrogenase 2(ALDH2) rs671 polymorphism has a prevalence of 30%–50% in Asian populations. In this study, we aimed to analyze risk factors contributing to the development of heart failure with preserved ejection fraction(HFpEF) along with the genetic exposure in Chinese patients hospitalized with cardiovascular diseases(CVD). Methods From July 2017 to October 2018, a total of 770 consecutive Chinese patients with normal left ventricular ejection fractions(LVEF) and established CVD(hypertension, coronary heart diseases, or diabetes) were enrolled in this prospective cross-sectional study. HFpEF was defined by the presence of at least one of symptom(dyspnoea and fatigue) or sign(rales and ankle swelling) related to heart failure;N-terminal pro-B-Type natriuretic peptide(NT pro-BNP ≥ 280 pg/mL);LVEF ≥ 50%;and at least one criterion related to elevated ventricular filling pressure or diastolic dysfunction(left atrial diameter > 40 mm, E/E’ ≥ 13, E’/A’ < 1 or concurrent atrial fibrillation). Logistic regression was performed to yield adjusted odds ratios(ORs) for HFp EF incidence associated with traditional and/or genetic exposures. Results Finally, among 770 patients with CVD, 92(11.9%) patients were classified into the HFpEF group according to the diagnostic criteria. The mean age of the participants was 67 ± 12 years, and 278(36.1%) patients were females. A total of 303(39.4%) patients were ALDH2*2 variant carriers. In the univariate analysis, eight exposures were found to be associated with HFpEF: atrial fibrillation, ALDH2*2 variants, hypertension, age, anaemia, smoking, alcohol consumption and sex. Multivariable logistic regression showed that 4 ‘A’ variables(atrial fibrillation, ALDH2*2 variants, age and anaemia) were significantly associated with an increased risk of HFpEF. Atrial fibrillation was associated with a 3.8-fold increased HFpEF risk(95% CI: 2.21–6.61, P < 0.001), and the other three exposures associated with increased HFpEF risk were the ALDH2*2 variant(OR = 2.41, 95% CI: 1.49–3.87, P < 0.001), age(OR = 2.14, 95% CI: 1.27–3.60, P = 0.004), and anaemia(OR = 1.79, 95% CI: 1.05–3.03, P = 0.032). These four variables predicted HFpEF incidence in Chinese CVD patients(C-statistic = 0.745, 95% CI: 0.691–0.800, P < 0.001). Conclusions 4 A traits(atrial fibrillation, ALDH2*2 variants, age and anaemia) were associated with an increased risk of HFpEF in Chinese CVD patients. Our results provide potential clues to the aetiology, pathophysiology and therapeutic targets of HFpEF.

Wideband linear-to-circular polarization conversion realized by a transmissive anisotropic metasurface

We propose a metasurface which consists of three conductive layers separated by two dielectric layers. Each conductive layer consists of a square array of square loop apertures, however, a pair of corners of each square metal patch surrounded by the square loop apertures have been truncated, so it becomes an orthotropic structure with a pair of mutually perpendicular symmetric axes u and v. The simulated results show that the metasurface can be used as a wideband transmission-type polarization converter to realize linear-to-circular polarization conversion in the frequency range from12.21 GHz to 18.39 GHz, which is corresponding to a 40.4% fractional bandwidth. Moreover, its transmission coefficients at x-and y-polarized incidences are completely equal. We have analyzed the cause of the polarization conversion, and derived several formulas which can be used to calculate the magnitudes of cross-and co-polarization transmission coefficients at y-polarized incidence, together with the phase difference between them, based on the two independent transmission coefficients at u-and v-polarized incidences. Finally, one experiment was carried out, and the experiment and simulated results are in good agreement with each other.

Coal Seam Permeability Improvement and CBM Production Enhancement by Enlarged Borehole: Mechanism and Application

The permeability is a key factor to determine the efficiency of coalbed methane(CBM)production.The borehole enlargement technology using hydraulic and mechanical measures to cut coal is an effective method to increase the coal seam permeability and improve the efficiency of gas drainage.Reasonable design of the layout of boreholes is the prerequisite for efficient and economical gas drainage.In this paper,based on the strain-softening model,the stress and permeability model of the coal seam around the enlarged borehole was built,and based on the dual-medium model,the gas migration model in the coal seam was established.Then the borehole enlargement gas drainage engineering of E9/10 coal seam in Pingdingshan No.8 coal mine was simulated by using COMSOL Multiphysics software.The distribution of stress and permeability in the coal seam around a borehole was analyzed,and the reasonable borehole radius of 0.25 m and reasonable borehole spacing of 6 m were determined.Finally,in Pingdingshan No.8 coal mine,field application was carried out in E9/10 coal seam-21070 working face from the high-level gas drainage roadway.The results show that the actual average coal slag discharge rate is 77.82%,which achieved borehole enlargement.The natural gas flow rate from an enlarged borehole is 2.3–7.3 times that of a normal borehole,and the influence range of enlarged boreholes is more than 6 m.The average gas drainage concentration of a group of enlarged boreholes is about 42%,and the average gas drainage amount is about 0.53 m3/min.After two months of gas extraction,the outburst risk in this area was eliminated,which provides a guarantee for safe coal mining.

弗氏盐法废水除氯产物资源化及二次利用进展

废水中高浓度氯离子不仅会腐蚀工业设备,还易污染水环境。目前,已报道了一系列去除废水中氯离子的技术,如膜分离或浓缩、蒸发结晶、化学沉淀、吸附、离子交换、电解、氧化和溶剂萃取等。化学沉淀法在设备投资和可操作性等方面具有较大的优势,其中,相对于基于银、铜或铋等除氯方法,弗氏盐沉淀除氯法因所用原料来源广、价格低而得到广泛研究。但弗氏盐沉淀除氯后会产生大量的化学污泥,这些污泥主要含有弗雷德盐(3CaO·Al_(2)O_(3)·CaCl_(2)·10H_(2)O)、加藤石[Ca_(3)Al_(2)(OH)_(12)]和氢氧化钙等,成分复杂,循环再生难。为使弗氏盐沉淀除氯法能够推广应用,对其除氯产物,特别是其中的弗雷德盐进行资源化再利用至关重要。本工作在介绍弗雷德盐成分结构特性的基础上,通过比较弗雷德盐不同制备方法,突出弗氏盐沉淀法(如超高石灰铝法和钙铝石法)既能去除氯离子又能得到弗雷德盐的优势。根据弗雷德盐含铝和钙成分和层状双金属氢氧化物结构特性,可进行有效的资源化利用,包括去除各类重金属阳离子(如Cu^(2+),Cd^(2+),Co^(2+),Zn^(2+),Pb^(2+))和含氧阴离子[如Sb(OH)_(6)^(-),AsO_(4)^(3-),SeO_(4)^(2-),CrO_(4)^(2-)],并制备聚合氯化铝混凝剂、作为污泥脱水调理剂等,这些用途都具有广阔的应用前景,为弗氏盐沉淀除氯法的进一步发展提供借鉴和探索方向。

TRIM21的抗病毒作用研究进展

TRIM(tripartite motif)家族因具有相似的N端结构又被称为RBCC家族,其成员在诸多与固有免疫相关的生物学过程中发挥重要作用.近年来的研究发现,TRIM家族参与宿主的胞内抗病毒作用,其中一些TRIM家族蛋白被认为是病毒的限制因子.最近,TRIM21作为E3泛素连接酶的抗病毒作用相继被报道,其可通过抗体依赖的细胞内抗病毒作用(antibody dependent intracellular neutralization,ADIN)及参与固有免疫通路发挥抗病毒作用,现就TRIM21的结构、表达分布、抗病毒作用及其机制的研究进展进行总结和综述.

TRIM21胞内免疫功能与治疗应用

三基序蛋白21(tripartite-motif protein 21,TRIM21)是一种存在于细胞胞质内的泛素连接酶,也是一类胞内抗体受体或者感应器,成为抵御病毒入侵的固有免疫防线。对于在细胞外已经逃逸了中和抗体作用,并被非中和抗体吸附而通过细胞膜侵入细胞内的病毒,TRIM21可以通过与病毒-抗体复合物中的抗体Fc段结合,发挥阻止病毒复制和诱导细胞免疫的抗病毒作用。TRIM21的降解病毒颗粒与激活免疫信号的双重效应功能,受自身的泛素化和磷酸化的严格调控。此外,TRIM21还能够与补体系统协同发挥作用。文章对TRIM21细胞内抗病毒和激活免疫功能的机制,病毒载体介导的基因治疗、抗体工程和TRIM-AWAY技术进行综述。

Low Shear Stress Regulating Autophagy Mediated by the p38 Mitogen Activated Protein Kinase and p53 Pathways in Human Umbilical Vein Endothelial Cells

To the Editor：Autophagy is reported to play a critical role in low shear stress （LSS）-induced endothelial cell injury and the formation of atherosclerotic plaques.[1] However,the corresponding mechanisms remain unclear.[2-8] This study was to investigate the changes and mechanism of LSS-induced autophagy in human umbilical vein endothelial cells （HUVECs）.HUVECs were treated with LSS of 5 dyn/cm2 for 0,5,15,30,and 60 min in a parallel plate flow chamber system.Light chain （LC） Ⅱ,LC3 Ⅰ,and p62,p38 mitogen-activated protein kinase （MAPK） and their protein of phosphorylation of p38 （p-p38） were detected with Western blot analysis.The protein levels of p-p53 （ser15） and their distribution were detected by immunofluorescence （IF）.