高倍数水驱砂岩中原油黏度、岩心润湿性时变规律核磁共振实验

根据模拟原油黏度与横向弛豫时间谱几何平均值的变化关系,建立了模拟原油黏度预测模型,并结合高倍数水驱核磁共振(NMR)实验实现了孔隙介质中模拟原油黏度的时变规律定量表征;基于核磁共振弛豫理论推导出新的NMR润湿性指数计算公式,结合砂岩岩心高倍数水驱实验,定量表征了水驱过程岩石润湿性的时变规律。研究表明:岩心中剩余油黏度与过水倍数正相关,过水倍数较低时剩余油黏度升高速度较快,过水倍数较高时剩余油黏度升高速度趋缓。剩余油黏度的变化与储层非均质性相关,储层均质性越强,剩余油中重质组分含量越高,黏度越高。注水后储层润湿性将发生改变,亲油储层向亲水储层转变,亲水储层则亲水性更强,且改变程度随过水倍数增加而增强。原油黏度的时变性与润湿性的时变性具有很高的关联性,原油的黏度变化不可忽略,考虑模拟原油黏度变化时计算得到NMR润湿性指数与测试Amott(自吸法)润湿性指数更具有一致性,更加符合储层润湿性时变规律。

基于局部归一化互信息联合约束的三维头颈部CT/MR配准方法

针对头颈部图像的复杂解剖结构和不同模态图像的差异,提出一种改进的多模态配准方法。该方法采用局部归一化互信息作为相似性测度,以捕捉局部图像区域的相似性,并减少不同区域间的强度差异对配准结果的影响。此外,为解决MR图像易受到噪声和伪影的影响产生畸变的问题,引入F范数约束配准过程,抑制不必要的畸变。实验结果表明,所提方法在降低均方误差、提高配准精度和鲁棒性方面均有所提高。

硬岩引水隧洞掘进爆破参数研究

为探究不同岩性时引水隧洞爆破合理的延迟时间和最小抵抗线,以瓯江引水工程三标段隧洞爆破工程为背景,依据理论公式分析了隧洞爆破的合理延时;通过ANSYS数值模拟软件建立不同最小抵抗线的计算模型,对不同工况下岩体内有效应力、裂纹扩展情况进行对比分析。结果表明,对于花岗岩和凝灰岩,随着最小抵抗线增大,对应的延时也增大,有效应力作用呈衰减态势,裂纹扩展逐渐分散;根据优化结果以3m的炮孔深度为例,花岗岩和凝灰岩下掏槽孔与辅助孔、崩落孔间、崩落孔与周边孔的延时分别取80ms,50ms,30ms和90ms,50ms,40ms,最小抵抗线为600mm~650mm,经现场试验表明爆落岩石块度均匀、易于装运,断面轮廓成型规整,炮孔利用率达到91%,光爆效果良好、与研究结果吻合。

明清古籍及诗画中的茶花及其园林应用分析

茶花作为中国的十大传统名花和世界著名花卉,在中国有着近两千年的栽培和应用历史,其在中国的古籍、诗词与绘画中留下了诸多的科学和艺术记忆。在前人对唐宋诗画中茶花及其园林应用初探的基础上,进一步梳理明清时期古籍及诗画中茶花的发展脉络,为更好地探索茶花未来的创新性应用及发展方向提供借鉴。从搜集检索到的明清时期描写茶花的古籍、275诗首词曲赋以及部分绘画作品来看,明清时期的茶花品种多达百余种,在很大程度上丰富了园林应用的植物素材;在园林具体应用方面,茶花在私家园林及寺庙园林中应用频次更高、形式更为丰富,并出现了茶花专类园的雏形;在配植植物方面,茶花与梅花、水仙、竹子的配植依然盛行,并逐渐发展出茶花与玉兰、牡丹、柏树等植物的配置模式。

Ultrasound-guided paravertebral nerve block anesthesia for percutaneous endoscopic laser unroofing treatment of symptomatic simple renal cysts—An innovative ambulatory surgery mode

Objective:This study was designed to evaluate the feasibility,efficacy,and safety of percutaneous ureteroscopy laser unroofing as an ambulatory surgery for symptomatic simple renal cysts under multilevel paravertebral nerve block anesthesia.Methods:From December 2015 to September 2017,33 simple renal cyst patients who had surgical indications were enrolled.Under ultrasound guidance,the T10/T11,T11/T12,and T12/L1 paravertebral spaces were identified,and 7-10 mL 0.5%ropivacaine was injected at each segment.Then a puncture needle was placed inside the cyst cavity under ultrasonic monitoring.A guidewire was introduced followed by sequential dilation up to 28/30 Fr.The extra parenchymal portion of the cyst wall was dissociated and incised using a thulium laser,and a pathological examination was performed.Results:Sensory loss to pinprick from T8 to L1 and sensory loss to ice from T6 to L2 were observed in all patients.None of the patients complained of pain during surgery.No serious complications occurred perioperatively.After the surgery,all patients recovered their lower limb muscle strength quickly,got out of bed,resumed oral feeding,and left the hospital within 24 h of admission.The pathologic diagnosis of all cyst walls was a simple renal cyst.The mean follow-up was 35.8 months.At the end of follow-up,the cyst units were reduced in size by more than 50%compared to the preoperative size,and no patient experienced a recurrence.Conclusion:Multi-level paravertebral nerve block for percutaneous ureteroscopy laser unroofing as an ambulatory surgery mode is feasible,safe,and effective for the treatment of simple renal cysts in selected patients.

Extraction,chemical components,bioactive functions and adulteration identification of walnut oils:A review

Walnut oil is a functional wood oil known to researchers that may potentially be a large source of Chinese edible oils.There are various extraction methods for walnut oil,including traditional(pressing,solvent-and enzymeassisted extraction)and novel methods(microwave,ultrasound,supercritical CO_(2),subcritical and other extraction technologies).Walnut oil is rich in nutrients,including phytosterols,tocopherols,polyphenols,squalene and minerals.It provides many health benefits,such as antioxidant,antitumor,anti-inflammatory,antidiabetic and lipid metabolism-related functions.In addition,the authentication of walnut oil has received much research attention.The present review provides detailed research on walnut oil extraction,composition,health benefits and adulteration identification methods.The path toward further walnut oil improvement in the context of the market value of walnut oil is also discussed.

Analysis and Prediction Model Reinforced UHPC Shrinkage Property

This paper explores the shrinkage of reinforced UHPC under high-temperature steam curing and natural curing conditions.The results are compared with the existing shrinkage prediction models.The results show that the maximum shrinkage strain of reinforced UHPC after steam curing is 164μεand gradually becomes zero.As for natural curing,the maximum shrinkage strain is 173μεand the value stabilizes on the 10th day after pouring.This indicated that steam curing can significantly reduce shrinkage time.Compared with the plain UHPC tested in the previous literature,the structural reinforcement can significantly inhibit the UHPC shrinkage and greatly reduce the risk of cracking due to shrinkage.By comparing the results in this paper with the existing models for predicting the shrinkage strain development,it is found that the formula recommended in the French UHPC structural and technical specification is suitable for the shrinkage curve in the present paper.

磷酸盐完井液高温腐蚀特征及膜转化缓蚀方法

通过分析170℃下磷酸盐完井液对P110钢的腐蚀特征,揭示了磷酸盐完井液的高温腐蚀机理,提出膜转化缓蚀方法并优选高效成膜剂,采用扫描电子显微镜图像、X射线能谱及X射线衍射结果表征腐蚀试片表面沉淀膜的微观形貌、元素组成及物相组成,明确了膜转化缓蚀效果与机理。研究表明:磷酸盐完井液通过高温水蒸气及其水解产物腐蚀试片,生成铁系磷酸盐腐蚀产物膜。Zn^(2+)成膜剂通过改变腐蚀反应路径,在试片表面生成耐高温、厚度均匀、晶体堆积紧密的KZnPO_(4)沉淀膜,抑制试片腐蚀,缓蚀效率可达69.63%。Cu^(2+)成膜剂与Fe通过电化学反应在试片表面析出微量单质Cu,从而形成保护膜,抑制金属腐蚀,缓蚀效率可达96.64%,但耐磨性差。将0.05%Cu^(2+)成膜剂与0.25%Zn^(2+)成膜剂复配后,在试片表面形成KZnPO_(4)晶体与单质Cu复合保护膜,缓蚀效率可达93.03%,既保证了较高的缓蚀效率又生成耐温耐磨的沉淀膜。

浅埋大断面隧道矿山法施工方案比选

为保证大断面隧道施工期间的安全性和高效性,以实际工程为依托,利用ANSYS数值模拟软件,研究了某地铁隧道出入场线分别采用双中隔壁台阶法和中隔壁法(CD法)开挖的施工过程,分析隧道开挖过程中围岩的位移和衬砌结构的应力变化情况。研究结果表明:大跨度隧道在软岩中的开挖采用中隔墙法产生的位移和衬砌结构应力都在安全范围内。双中隔壁台阶法采用三台阶施工每个台阶均可使用机械施工提高了开挖效率,与中隔墙法相比产生的位移和衬砌结构应力更小,拱顶处竖向位移最大不超过16.2mm,开挖10m即DK45+868处衬砌结构的等效应力最大值不超过19.9MPa,因此控制位移变形能力和衬砌结构应力效果更好,可优先考虑双中隔壁台阶法。同时在实际工程中监测位移与模拟值差距在1mm以内,验证了模拟结果的可行性。

基于EMT的敏感场特性仿真研究

电磁层析成像(Electromagnetic Tomography,EMT)技术相较于传统的无损检测技术具有非侵入、非接触、无危害的特点,有着广阔的应用前景。对EMT技术中的正问题的研究旨在通过建立模型研究系统的参数变化对测量值的影响,对敏感场特性的研究直接关系到后续进行图像重建所提取的物场特征信息变化敏感程度,进而会直接影响成像质量。在之前的研究中对EMT的成像范围尚未有比较精确的规范,针对敏感场中激励频率与物场特性的变化,利用有限元仿真软件(COMSOL Multiphysics)对EMT系统的激励系统进行仿真分析,不同于传统的对互感值进行研究的方法,选择了更加直观的电压值,最终得出在不同激励频率与不同物场特性下的拟合曲线,获得了系统敏感场参数变化与测量值的关系,通过该研究确定了EMT系统的有效检测范围,提高了EMT系统检测的准确性,更有利于后续进行高质量的图像重建。

High-temperature corrosion of phosphate completion fluid and corrosion inhibition method by membrane transformation

By analyzing the corrosion of phosphate completion fluid on the P110 steel at 170 °C, the high-temperature corrosion mechanism of phosphate completion fluid was revealed, and a corrosion inhibition method by membrane transformation was proposed and an efficient membrane-forming agent was selected. Scanning electron microscope (SEM) images, X-ray energy spectrum and X-ray diffraction results were used to characterize the microscopic morphology, elemental composition and phase composition of the precipitation membrane on the surface of the test piece. The effect and mechanism of corrosion inhibition by membrane transformation were clarified. The phosphate completion fluid eroded the test piece by high-temperature water vapor and its hydrolyzed products to form a membrane of iron phosphate corrosion product. By changing the corrosion reaction path, the Zn2+ membrane-forming agent could generate KZnPO4 precipitation membrane with high temperature resistance, uniform thickness and tight crystal packing on the surface of the test piece, which could inhibit the corrosion of the test piece, with efficiency up to 69.63%. The Cu2+ membrane-forming agent electrochemically reacted with Fe to precipitate trace elemental Cu on the surface of the test piece, thus forming a protective membrane, which could inhibit metal corrosion, with efficiency up to 96.64%, but the wear resistance was poor. After combining 0.05% Cu2+ and 0.25% Zn2+, a composite protective membrane of KZnPO4 crystal and elemental Cu was formed on the surface of the test piece. The corrosion inhibition efficiency reached 93.03%, which ensured the high corrosion inhibition efficiency and generated a precipitation membrane resistant to temperature and wear.

Association of MBOAT7 rs641738 polymorphism with hepatocellular carcinoma susceptibility:A systematic review and meta-analysis

BACKGROUND The MBOAT7 rs641738 single-nucleotide polymorphism(SNP)has been proven to influence various liver diseases,but its association with hepatocellular carcinoma(HCC)susceptibility has been debated.To address this discrepancy,we conducted the current systematic review and meta-analysis.AIM To perform a systematic review and meta-analysis on association of MBOAT7 SNP and HCC susceptibility.METHODS We performed a systematic review in PubMed,Web of Science,Scopus,and EMBASE;applied specific inclusion and exclusion criteria;and extracted the data.Meta-analysis was conducted with the meta package in R.Sensitivity and subgroup analyses were also performed.This meta-analysis was registered in PROSPERO(CRD42023458046).RESULTS Eight studies were included in the systematic review,and 12 cohorts from 6 studies were included in the meta-analysis.Our meta-analysis revealed an association between the MBOAT7 SNP and HCC susceptibility in both the dominant[odds ratio(OR):1.14,95%confidence interval(95%CI):1.02-1.26,P=0.020]and recessive(OR:1.21,95%CI:1.05-1.39,P=0.008)models.Subgroup analysis revealed that stratification of the included patients by geographical origin showed a significant association in Asia(OR:1.20,95%CI:1.03-1.39).CONCLUSION This meta-analysis underscores the contribution of the MBOAT7 rs641738 SNP to hepatocarcinogenesis,especially in Asian populations,which warrants further investigation.

Quantitative tracing of bioprobes by simultaneously monitoring radiative and nonradiative relaxations

Bioprobe based on fluorescence is widely used in biological and medical research due to its high sensitivity and selectivity.Yet,its quantification in vivo is complicated and often compromised by the interaction between the fluorophore with the environmental factors,as well as the optical scattering and absorption by the tissue.A high florescence quantum yield and minimal interference by the environment are key requirements for designing an effective bioprobe,and the prerequisitions severely limit the available options.We propose that a comprehensive evaluation of potential bioprobe can be achieved by simultaneously measuring both radiative and nonradiative transitions,the two fundamental and complementary pathways for the energy de-excitation.This approach will not only improve the accuracy of the quantification by catching the information from a broader spectrum of the energy,but also provide additional information of the probe environment that often impacts the balance between the two forms of the energy transition.This work first analyzes the underlying mechanism of the hypothesis.The practical feasibility is then tested by means of simultaneous measurements of photoacoustic signal for the non-radiative and fluorescence for the radiative energy processes,respectively.It is demonstrated that the systematic evaluation of the probe energy de-excitation results in an improved quantitative tracing of a bioprobe in complex environment.

突发公共事件下的员工远程办公——进展与未来展望

突发公共事件极大地加快了企业远程办公的进度。为了进一步了解突发公共事件对企业远程办公的影响,本文梳理了2020年初至今远程办公的最新研究,并与之前的研究结果进行了对比、回顾、评述和展望。首先,从相关学科重要的中英文期刊中甄选出59篇主题相关文章,回顾并比较了突发公共事件发生前后的研究进展。其次,本文阐释了突发公共事件发生前后远程办公的内涵演变,并比较了对员工身心健康和工作表现影响结果的异同,进而基于组织行为的情境理论,构建了突发公共事件下的员工远程办公作用机制和影响效果框架图。最后,本文探讨了当前突发公共事件下远程办公的研究方向。

双交联型泡沫凝胶的制备及其暂堵压井防漏机理

针对低压储层修井防漏技术难题,研发了一种双交联型泡沫凝胶压井液,基本配方为:3%聚丙烯酰胺+2%起泡剂+1.5%交联剂A+0.1%交联剂B。显微镜观察表明,单一交联型及双交联型泡沫凝胶均具有明显双膜结构,但双交联型泡沫凝胶膜更厚实,气核最外层凝胶膜厚度最大为77.35μm,气核外层液膜总厚度最大为188.48μm,表现为较好抗压强度和稳定性,其稳定时间大于10d,远高于单一交联型体系。流变性与黏弹性测试表明,双交联型泡沫凝胶具有高弹低黏特征,利于泵送和后期返排解堵。暂堵压井模拟实验表明,对于渗透率在90~208mD的中高渗岩心,在2MPa正压差下60min内作用于岩心的压降值≤0.05MPa,滤失量几乎为零,该双交联型泡沫凝胶压井液具有一定抗压能力与低滤失特性,能有效暂堵储层,在低压油气井修井防漏领域具有较好应用前景。

急性重症脑梗死静脉溶栓患者预后影响因素的分析

目的观察新发的重症脑梗死患者溶栓前后动态脑电图的变化,为重症脑梗死患者的预后提供参考。方法选取2015年1月—2016年12月于乐山市人民医院就诊的符合重组组织型纤溶酶原激活剂静脉溶栓标准的98例重症脑梗死患者,监测患者动态脑电图溶栓前后脑电波的变化。详细记录患者的一般资料、溶栓前后脑电图及头颅影像学检查结果。用Excel建立数据库,应用单变量和Logistic回归分析判断重症脑梗死患者的预后。结果两组患者年龄、发病至就诊时间、脑电图检查及头颅影像学检查结果比较,差异有统计学意义(P<0.05);多因素Logistic回归分析显示,重症脑梗死患者年龄≥65岁[Ol^R=2.958(95%CI:1.347,6.495)]、发病至就诊时间>3.5 h[Ol^R=3.643(95%CI:0.563,5.267)]脑电图检查阳性[Ol^R=4.079(95%CI:1.588,10.477)]、头颅影像学检查阳性[Ol^R=3.021(95%CI:1.554,5.870)]是预后差的独立危险因素。结论入组前年龄>65岁、溶栓后脑电图波形异常及头颅影像学检查结果异常是重症脑梗死患者预后差的独立危险因素。将动态脑电图监测应用于重症脑梗死患者重组组织型纤溶酶原激活剂静脉溶栓,对于预测重症脑梗死患者的预后具有重大意义。

城市地下空间工程专业就业结构与实践教学优化

实践教学环节作为应用型本科专业培养的重要组成部分,其有效执行程度与毕业生初次就业后的工作适应性密切相关.以安徽理工大学城市地下空间工程专业为例,统计分析了往届毕业生的初次就业结构,结合实践教学中存在的问题,提出了实践教学的优化方案,为类似条件城市地下空间工程专业实践教学提供参考.

基于流线聚类人工智能方法的水驱油藏流场识别

以某碳酸盐岩油藏注水开发为例,提出针对流线模拟结果的流场识别方法。在流线模拟计算完成后,利用基于Ocean平台自行编写的插件将流线数据导出,并通过Python编程语言进行后续数据处理及聚类分析,直观反映不同开发阶段水驱油藏流场分布。采用密度峰值聚类算法作为流线聚类主要算法,以轮廓系数算法作为聚类评价算法,选取合理的聚类数,并对不同聚类算法结果进行对比。当聚类数相同时,密度峰值聚类算法比K-means、层次聚类、谱聚类算法对不同类型流线区分能力更强且轮廓系数较高,说明了算法的有效性。依据流线聚类结果可对流场进行量化处理,有效识别油藏中无效注水循环通道以及具有开发潜力的区域,同时可对同一注采井间流线进行细分,描述注采井间水相驱动能力大小分布,为注水优化、井网层系调整、深部调剖等方案决策提供依据。

多龄期钢框架结构地震损伤模型研究

基于ABAQUS非线性有限元分析,通过控制变量法分析得出影响多龄期钢框架地震损伤的主控因素为构件有效截面收缩与钢材极限强度退化。定义广义的锈蚀损伤,并探索锈蚀损伤与未锈蚀原型结构地震损伤的关系,最后建立基于未锈蚀原型结构地震损伤的多龄期结构地震损伤模型。

南阳市经济增长、能源消费与碳排放的关系研究及Tapio脱钩分析

以南阳市1994—2016年的GDP与能源消费数据为样本,通过碳排放系数法估算出每年的碳排放量,分析了南阳市能源消费与碳排放之间的关系状态,并采用Tapio脱钩分析法对碳排放与GDP的关系进行了研究.结果表明,南阳市能源消费与碳排放之间呈多元化表现状态;南阳市GDP与碳排放存在不稳定的脱钩关系,绝大多数处于弱脱钩状态或强弱交替脱钩状态,但尚未实现GDP增加而碳排放量降低的目标.因此,对南阳市能源政策的建议是通过加强低碳产业体系和低碳能源体系构建以进一步优化能源结构,通过建立减排长效机制进一步加强对工业和交通领域碳排放的控制,从而逐步实现南阳市GDP与碳排放的强脱钩关系.