Numerical Simulation of Asphaltene Precipitation and Deposition during Natural Gas and CO_(2) Injection

Asphaltene deposition is a significant problem during gas injection processes,as it can block the porous medium,the wellbore,and the involved facilities,significantly impacting reservoir productivity and ultimate oil recovery.Only a few studies have investigated the numerical modeling of this potential effect in porous media.This study focuses on asphaltene deposition due to natural gas and CO_(2) injection.Predictions of the effect of gas injection on asphaltene deposition behavior have been made using a 3D numerical simulation model.The results indicate that the injection of natural gas exacerbates asphaltene deposition,leading to a significant reduction in permeability near the injection well and throughout the reservoir.This reduction in permeability strongly affects the ability of gas toflow through the reservoir,resulting in an improvement of the displacement front.The displacement effi-ciency of the injection gas process increases by up to 1.40%when gas is injected at 5500 psi,compared to the scenario where the asphaltene model is not considered.CO_(2) injection leads to a miscible process with crude oil,extracting light and intermediate components,which intensifies asphaltene precipitation and increases the viscosity of the remaining crude oil,ultimately reducing the recovery rate.

一种基于等效平面磨损区的立铣刀底刃磨损评价方法

针对立铣刀底刃磨损值难以准确测量的问题,提出了一种基于等效平面磨损区的底刃磨损评价方法(称等效法)。面向四刃立铣刀,建立了磨损区边界点由二维向三维的映射模型,实现了磨损区的三维重构;应用几何变换,完成了底刃第一、二后刀面磨损区重构点的平面表示;在构建底刃等效平面磨损区的基础上,完成了对铣刀磨损的评价。在用硬质合金铣刀铣削淬硬钢件的实验中,选取了铣削时间为42 min的磨损区图像。结果表明:相比直接测量法,等效法获取的磨损区宽度增加了约8.0%-11.1%,面积增加了约6.9%-10.7%;底刃第二后刀面的磨损对评价影响明显。研究结果阐明了磨损区重构方法的可行性与准确性。

基于磨损区重构的圆柱立铣刀周刃磨损评价方法

针对周刃磨损值测量误差大的问题,提出了基于磨损区重构的铣刀周刃磨损的评价方法。从视频显微镜获取的磨损区图像出发,建立三维重构与曲面展开映射模型,实现周刃后刀面磨损区的三维重构以及螺旋面的近似平面展开;应用几何变换,实现第1、第2后刀面磨损区的平面表示及其共面表示,从而得到等效平面磨损区。通过对等效平面磨损区的分析,得到后刀面磨损宽度和磨损面积,进而对铣刀周刃磨损进行评价。在对四刃铣刀的磨损(切削时间为57 min)进行实证研究后发现用重构法得到的磨损宽度、面积相比于用直接法平均增加了0.16 mm和0.067 mm^(2),增率为17.0%和14.9%。研究结果表明了重构法的可行性和准确性。

Short-lived AIM2 Inflammasome Activation Relates to Chronic MCMV Infection in BALB/c Mice

Absent in melanoma 2(AIM2)inflammasome is a crucial link bridging the innate host defense and the subsequent adaptive immunity when activated by exogenous double stranded DNA(dsDNA).Through establishing models of disseminated murine cytomegalovirus(MCMV)infection in BALB/c and C57BL/6 mice,we evaluated dynamic expression of AIM2 inflammasome components and its relationship with pathological damage and viral replication,trying tofigure out whether AIM2 inflammasome is related to the chronic mechanism of MCMV.BALB/c and C57BL/6 mice were sacrificed on day 0,1,3,7,14 and 28 post infection.Expression levels of AIM2,pro-caspase-1,caspase-1 p20,pro-IL1β and mature IL1β in primary peritoneal macrophages(PMs)and spleens were detected by Western blotting.Contents of IL18 in the serum were detected by ELISA.Pathological examinations of livers were performed,and mRNA levels of MCMV glycoprotein B(gB)in salivary glands also assessed.Results showed that expression levels of AIM2 in PMs and spleens of C57BL/6 mice increased on day 3,even continued to day 28;caspase-1 p20 and mature IL1β increased on day 7,14 and 28;the persistently high expression of IL1β in the serum started on day 1,showing a double peak curve.As for BALB/c mice,expression of AIM2 in PMs increased on day 1 and day 7,while contents of AIM2 in spleens increased on day 1 and day 3;caspase-1 p20 and mature ILip merely increased 7 days fter infection.Thereafter,expression levels of AIM2,caspase-1 p20,mature IL1β and IL18 were limited;the duration of AIM2 inflammasome activation in BALB/c mice was much shorter than that in C57BL/6 mice.The severer pathological damage and more viral replications in BALB/c mice further proved the deficient antiviral immunity to MCMV.In conclusion,the activation of AIM2 inflammasome in BALB/c mice was short-lived,which is quite possibly related to the chronicity of MCMV infection.

Maternal Murine Cytomegalovirus Infection during Pregnancy Up-regulates the Gene Expression of Toll-like Receptor 2 and 4 in Placenta

Increasing evidence has revealed that maternal cytomegalovirus （CMV） infection may be associated with neurodevelopmental disorders in offspring. Potential relevance between the placental inflammation and CMV-related autism has been reported by clinical observation. Meanwhile, abnormal expression of Toll-like receptor 2 （TLR2） and TLR4 in placenta of patients with chorioamnionitis was observed in multiple studies. IL-6 and IL- 10 are two important maternal inflammatory mediators involved in neurodevelopmental disorders. To investigate whether murine CMV （MCMV） infection causes alterations in placental IL-6/10 and TLR2/4 levels, we analyzed the dynamic changes in gene expression of TLR2/4 and IL-6/10 in placentas following acute MCMV infection. Mouse model of acute MCMV infection during pregnancy was created, and pre-pregnant MCMV infected, lipopolysaccharide （LPS）-treated and uninfected mice were used as controls. At E13.5, E 14.5 and E 18.5, placentas and fetal brains were harvested and mRNA expression levels of placental TLR2/4 and IL-6/10 were analyzed. The results showed that after acute MCMV infection, the expression levels of placental TLR2/4 and IL-6 were elevated at E13.5, accompanied by obvious placental inflammation and reduction of placenta and fetal brain weights. However, LPS 50 ktg/kg could decrease the IL-6 expression at E13.5 and E14.5. This suggests that acute MCMV infection during pregnancy could up-regulate the gene expression of TLR2/4 in placental trophoblasts and activate them to produce more pro- inflammatory cytokine IL-6. High dose of LPS stimulation （50 gg/kg） during pregnancy can lead to down-regulation of IL-6 levels in the late stage. Imbalance of IL-6 expression in placenta might be associated with the neurodevelopmental disorders in progeny.

Topical tear stimulation-a new insight for dry eye therapy

Dry eye disease is the most prevalent ocular surface disease in eye clinics.The deficiency of tears is regarded as one of the main pathogenic factors for this disease.Due to the fact that the components of tears are still far beyond our knowledge,the restoration of physiological tears remains the optimum choice for dry eye patients.However,the traditional way to stimulate tear production by systemic administration of muscarinic agonists usually encounters severe side effects.Recently,Nakamachi and colleagues reported that PACAP,a native neurotransmitter present in tear fluid,could stimulate main lacrimal gland secretion and relieve dry eye-like symptoms in PACAP knockout mice.The finding of PACAP and its underlying mechanisms suggest a new modality for dry eye treatment via targeted topical tear stimulations.

High‐altitude tunnel‐catenary gap impulse discharge characteristics and breakdown voltage correction

Air gap impulse discharge characteristics of railway tunnel‐catenary at high‐altitude are of great significance to the electrical insulation design.The existing altitude correction methods for non‐uniform air gaps are not applicable to tunnel‐catenary.To investigate the impulse discharge characteristics of the tunnel‐catenary,a typical structural model was built in an artificial climate chamber.Different altitudes were simulated by adjusting the atmospheric pressure.The 50%breakdown voltages of the 300–700 mm tunnel‐catenary gap were tested at 243–4000 m.The test found that the altitude/atmospheric pressure and gap length have an evident effect on the 50%impulse breakdown voltage,and the influence of humidity is relatively small.The polarity effect was analysed by streamer theory.The{d,P,h}parameter method was employed to obtain the fitting formulas for the impulse breakdown voltage.A high‐altitude correction method for the tunnel‐catenary breakdown voltage based on 1 km altitude was proposed.Field natural tests were conducted to verify the accuracy of the proposed method.The results show that the breakdown voltage obtained by the correction method has an average error of 3.66%in the results of the field tests,indicating that the method has engineering application prospects.

求解增量二分图优化问题的动态规划驱动的局部搜索算法

增量二分图优化问题(dynamic bipartite drawing problem,DBDP)是一个具有NP难度的组合优化问题,该问题在实际生产生活中有着广泛的应用.本文提出了一种新的动态规划驱动的局部搜索(DP-LS)算法来求解该问题.不同于文献中求解该问题和该类问题的所有启发式算法的邻域搜索方式(即每次邻域操作只对一个或两个节点进行插入或交换动作),本文提出的动态规划驱动的局部搜索算法能从邻域结构中挑选出并执行多个独立的邻域动作,大大提高了邻域搜索的效率.DP-LS算法从一个随机初始解出发,迭代地利用基于动态规划的局部搜索算法来寻找局部最优解,同时结合扰动机制跳出局部极值陷阱实现全局搜索.本文提出的增量评估方法能够快速评估基于插入和交换的邻域动作,可以大大提高算法的搜索效率.本文针对1120个公共算例进行了计算实验并同文献中已有算法(包括通用求解器Gurobi)进行对比,表明了所提出的动态规划驱动的局部搜索算法在解的优度和计算效率两方面的有效性.此外,通过对比实验表明了DP-LS算法中动态规划机制的有效性(提升近十倍的搜索效率).值得注意的是,本文提出的基于动态规划的局部搜索算法不仅能够用于求解DBDP问题,也能作为一种通用的启发式算法来求解其他组合优化问题,尤其是排序类优化问题.

Drug resistance and pathogenic spectrum of patients coinfected with nontuberculous mycobacteria and human-immunodeficiency virus in Chengdu, China

Background:Human-immunodeficiency virus (HIV) infection is increasing worldwide and nontuberculous mycobacteria (NTM) is an established microbiologic cause of pulmonary disease,lymphadenitis,and disseminated disease in cases of advanced immune suppression.Data on patients coinfected with HIV and NTM are limited.Thus,this study aimed to analyze the clinical characteristics,drug resistance,and pathogen spectrum of patients coinfected with both HIV and NTM in the Chengdu area of China.Methods:Data of 59 patients coinfected with both HIV and NTM collected from the Public Health Clinical Center of Chengdu,between January 2014 and December 2018,were analyzed.NTM drug sensitivity testing was performed using the microporous plate ratio method.Data were analyzed using SPSS 19.0,and the change in drug resistance rate was analyzed using the chi-square (x2) test.Results:Seven species/complex of NTM were identified from patients coinfected with HIV and NTM in this study,with Mycobacterium avium-intracellulare complex (52.5%) and M.kansasii (27.1%) as the predominant species.Male patients were more affected 50/59 (84.7%);the mean age of the 59 cases was 45 years.The clinical characteristics mainly included anemia (86.4%),cough and expectoration (79.7%).The baseline CD4 count was <50 cells/μL (84.7%).Patients were mainly in advanced acquired immunodeficiency syndrome (AIDS) stage.Chest imaging mainly showed patchy shadows (42.4%) and nodules (32.2%),with various degrees of AIDS-defining diseases.The drug resistance of NTM was severe,and the rate of isoniazid resistance (100.0%) was the highest,followed by rifampicin (94.9%),streptomycin (94.9%),ofloxacin (93.2%),and others.Ethambutol (52.5%) and clarithromycin (33.9%) were relatively low.No significant difference was found in the drug resistance rate of NTM strain against nine antituberculosis drugs in 5 years (P > 0.05).Condusions:The immune level of patients coinfected with HIV and NTM is low in advanced AIDS stage;more male are affected in patients who are mainly infected with MAC and M.kansasii and with serious drug resistance,The drug resistance rate of ethambutol and clarithromycin is relatively low.

Performance of rolling piston type rotary compressor using fullerenes(C70)and NiFe204 nanocomposites as lubricants additives

A novel way for a compressor to improve its coefficient of performance was proposed in this paper.Fullerenes(C70)and NiFe2O4 nanocomposites were modified by span 80 and dispersed in refrigeration oil by solid grinding(SG).Besides,the tribological properties of the nanocomposites were investigated using a four ball friction tester.The results show that when the mass concentration of fullerenes nanocomposite is higher than 60 ppm and the concentration of nano-oil is 2 g/L,the friction coefficient decreases from 0.13 to 0.06 which means the wear is reduced.The coefficient of performance of the compressor under the air conditioning test condition can be raised by 1.23%.

Dark matter and LHC phenomenology of a scale-invariant scotogenic model

We study the phenomenology of a model that addresses the neutrino mass, dark matter, and generation of the electroweak scale in a single framework. Electroweak symmetry breaking is realized via the Coleman-Weinberg mechanism in a classically scale invariant theory, while the neutrino mass is generated radiatively through interactions with dark matter in a typically scotogenic manner. The model introduces a scalar triplet and singlet and a vector-like fermion doublet that carry an odd parity of Z2, and an even parity scalar singlet that helps preserve classical scale invariance. We sample over the parameter space by taking into account various experimental constraints from the dark matter relic density and direct detection, direct scalar searches, neutrino mass, and charged lepton flavor violating decays. We then examine by detailed simulations possible signatures at the LHC to find some benchmark points of the free parameters. We find that the future high-luminosity LHC will have a significant potential in detecting new physics signals in the dilepton channel.

Effective field theory approach to lepton number violatingτdecays

We continue our endeavor to investigate lepton number violating(LNV)processes at low energies in the framework of effective field theory(EFT).In this work we study the LNV tau decaysτ^(+)→lP_(i)^(+)P_(J)^(+),where L=e.μand P_(i,j)^(+)denote the lowest-lying charged pseudoscalarsπ^(+),K^(+).We analyze the dominant contributions in a series of EFTs from high to low energy scales,namely the standard model EFT(SMEFT),the low-energy EFT(LEFT),and the chiral perturbation theory(χPT).The decay branching ratios are expressed in terms of the Wilson coefficients of dimension-five and-seven operators in SMEFT and the hadronic low-energy constants.These Wilson coefficients involve the first and second generations of quarks and all generations of leptons;thus,they cannot be explored in low-energy processes such as nuclear neutrinoless double beta decay or LNV kaon decays.Unfortunately,the current experimental upper bounds on the branching ratios are too weak to set useful constraints on these coefficients.Alternatively,if we assume the new physics scale is larger than 1 TeV,the branching ratios are well below the current experimental bounds.We also estimate the hadronic uncertainties incurred in applyingχPT toτdecays by computing one-loop chiral logarithms and attempt to improve the convergence of chiral perturbation by employing dispersion relations in the short-distance part of the decay amplitudes.

Toward High Performance Ambipolar Transport from Super-exchange Perspective:Theoretical Insights for IID-based Copolymers

High-performance ambipolar charge transport materials can reduce the manufacturing cost of OFET and OPV devices,and simplify circuit design and device structure.In order to obtain ambipolar donor-acceptor(D-A)polymer,many efforts have been made through different donor and acceptor combination,halogenation or heteroatom substitution.However,the influencing factor for charge transport polarity is still much complicated.Based on intra-chain super-exchange mechanism for D-A polymer,we found that the energy alignment of donor and acceptor moiety has large impact on charge transport polarity.When the HOMO-LUMO(H-L)gap of the acceptor moiety is narrow,its HOMO/LUMO energy level both lie between the HOMO and LUMO of the donor moiety(sandwich-type energy alignment),and the corresponding D-A copolymers will be more likely ambipolar transport.And thus,take a narrow H-L gap thiazoleisoindigo(TzIID)acceptor as an example,we demonstrated that a series of TzIID based copolymers combined with wide H-L gap donor moieties can reveal ambipolar transport.We further predict several high performance ambipolar D-A copolymers(TzIID-TT etc.)with balanced electron and hole transport,whose effective mass(m_(e)^(*)=0.146 and m_(h)^(*)=0.128)is one of the smallest effective masses among ambipolar materials.

Effect of compound Sophorae Flavescentis Jiechangrongcapsule on expression of NF-κB p65 and STAT6 in theintestinal mucosa of patients with ulcerative colitis

The effects of compound Sophorae Flavescen-tis Jiechangrong capsule(CSFJC)on the expression of nuclear factor-κB p65(NF-κB p65)and signal transducer and activator of transcription 6(STAT6)in the intestinal mucosa of patients with ulcerative colitis and the possible mechanism were investigated.Eighteen patients with ulcerative colitis were randomly divided into a traditional Chinese medicine(TCM)group(n=11)treated by CSFJC and a western medicine(WM)group(n=7)treated by Sulfasalazine tablets.The treatment duration lasted eight weeks.Before and after the treatment,the symptoms and the physical signs were observed,and the routine stool test,the colonoscopy,and pathological examination were performed in the two groups.The expression levels of NF-κB p65 and STAT6 were detected by using immuno-histochemistry.The results showed that the total effective rate of the curative effectiveness in TCM and WM groups was 100%and 71.4%,respectively,and the total effective rate of colonic mucosa lesion in TCM and WM groups was 90.9%and 71.4%,respectively,with the differences being significant(all P<0.05).The total effective rate of syndromes of damp-heat blocking according to the TCM in TCM and WM groups was 90.9%and 71.4%,respectively.After the treatment,the expression of NF-κB p65 and STAT6 in the two groups was decreased,and the decrease of NF-κB p65 and STAT6 expression in TCM group was more significant than in WM group(P<0.05).It was concluded that CSFJC can inhibit the activation and expression of NF-κB p65 and STAT6 in the intestinal mucosa of patients with ulcerative colitis,which is a possible mechanism for CSFJC treating ulcerative colitis.

Micropillar-arrayed surfaces promote transforming growth factor beta 1 induced epithelial to mesenchymal transition by focal adhesion kinase-related signaling in A549 cells

To the Editor:Substrate rigidity and topography are two important biomechanical factors that can modulate the biological behavior of cancer cells such as epithelial to mesenchymal transition(EMT).Currently,although studies have begun to focus on how the mechanical microenvironment determines the fate of multiple cells,the mechanism of the mechanical microenvironment affecting EMT is still unclear.

广州市天河区结直肠癌筛查:基于粪便免疫化学检测和危险因素初步筛选出需要行结肠镜检查者

目的:探讨联合粪便免疫化学检测(FIT)和高危因素问卷调查(HRFQ)初筛出需行结肠镜检查者的结直肠癌(CRC)筛查方案应用于中国的可行性。方法:2015-2016年间,我们对中国广州市天河区45岁以上居民进行了一项CRC筛查项目。所有筛查对象均接受FIT检测和HRFQ调查,作为初筛。对于FIT阳性和/或HRFQ调查结果考虑存在高危风险的受检者,我们推荐其行进一步结肠镜检查。结果:共计10074名居民纳入CRC筛查项目,其中17.5%的受检者FIT阳性,19.4%经HRFQ调查被认为具有高危风险。经推荐,有773名受检者接受了进一步的结肠镜检查。该筛查方案对非腺瘤性息肉、低危腺瘤、高危腺瘤和CRC的总体阳性预测值分别为4.9%、11.4%、15.9%和1.6%。其中,FIT阳性结果对上述四种病变的阳性预测值分别为5.2%、15.9%、22.5%和2.5%,HRFQ阳性结果分别为4.1%、10.2%、14.3%和1.4%,FIT和HRFQ均为阳性结果的阳性预测值分别为4.5%、16.4%、23.7%和2.8%。结论:我们的两步法CRC筛查策略(FIT和HRFQ阳性者行进一步结肠镜检查)可有效发现早期CRC。鉴于对CRC和腺瘤较的高检出率和阳性预测值,该筛查方案可继续用于我们这项大规模CRC筛查项目的后续研究。

To Commemorate the 100^(th) Year Anniversary of Forensic Science Education in China: A Brief Review of the Lives and Achievements of Forensic Science Pioneers from Zhejiang Province

Looking back at modem China's 100-year history of forensic science education,we have found a number of forensic science pioneers from the Zhejiang Province who have made historic contributions to forensic science education.This paper briefly reviews the lives and achievements of these pioneers in chronological order.They include Song-Ming Xu,Ji-Zu Wang,Lv-Gao Chen,Jin-Chang Zhu,Ying-Han Xu,Mei-Yun Wu,Jia-Zhen Zhu,Guang-Zhao Huang,Zhan-Pei Zheng,and Shi-Xian Chen.History is only worth writing about if it teaches us about the future.This historical review sets examples for both current and future forensic pathologists to learn from the contributions of these pioneers.

Postpartum depression and major depressive disorder:the same or not?Evidence from resting-state functional MRI

Background Although postpartum depression(PPD)and non-peripartum major depressive disorder(MDD)occurring within and outside the postpartum period share many clinical characteristics,whether PPD and MDD are the same or not remains controversial.Methods The current study was devoted to identify the shared and different neural circuits between PPD and MDD by resting-state functionalmagnetic resonance imaging data from 77 participants(22 first-episodic drug-naleMDD,26 drug-nale PPD,and 29 healthy controls(HC)).Results Both the PPD andMDD groups exhibited higher fractional amplitude of low-frequency fluctuation(fALFF)in left temporal pole relative to the HC group;the MDD group showed specifically increased degree centrality in the right cerebellum while PPD showed specifically decreased fALFF in the left supplementary motor area and posterior middle temporal gyrus(pMTG_L),and specifically decreased functional connectivities between pMTG and precuneus and between left subgeneual anterior cingulate cortex(sgACC_L)and right sgACC.Moreover,sgACC and left thalamus showed abnormal regional homogeneity of functional activities between any pair of HC,MDD,and PPD.Conclusions These results provide initial evidence that PPD and MDD have common and distinct neural circuits,which may facilitate understanding the neurophysiological basis and precision treatment for PPD.