Chloride migration in concrete with superabsorbent polymers

Superabsorbent polymers (SAP) can be used as a means for internal curing of concrete. In the present study, the development of transport properties of concrete with SAP is investigated. The chloride migration coefficient according to NT BUILD 492 is used as a measure of this. Twenty concrete mixtures are tested 7, 14, and 28 days after casting. The development of degree of hydration is followed for 20 corresponding paste mixtures.Both when SAP is added with extra water to compensate the SAP water absorption in fresh concrete and without extra water, the internal curing water held by SAP may contribute to increase the degree of hydration. No matter if SAP is added with or without extra water, it appears that the so-called gel space ratio can be used as a key parameter to link age and mixture proportions (water-to-cement ratio and SAP dosage) to the resulting chloride migration coefficient; the higher the volume of gel solid relative to the space available for it, the lower the chloride migration coefficient, because the pore system becomes more tortuous and the porosity becomes less.     

复频电导技术在隧洞超前探水中的应用

围岩富水带是隧道超前预报最关注的问题，目前，多使用电磁方法来预报围岩的含水性，但受到场地条件限制，面临掌子面条件、金属机具干扰、三维波场定位等诸多困难，特别是掌子面前方100 m范围内围岩的含水性预报，在国内外都是一个新的高难课题。在研究了岩体电导率与电容率复频特性的基础上，结合巴基斯坦NJ-TBM引水隧洞工程，开发了复频电导探水(CFC)技术。该技术基于电磁波反射与相干原理，选用100 kHz～10 MHz频率范围，采用电偶极子发射与阵列接收方式和偏移成像技术，突破了隧道内场地条件的限制。依据1/4相干波长确定含水体的位置，相干能量确定含水量的大小。在巴基斯坦NJ-TBM隧洞超前探水的应用，证明了该方法的可行性与有效性。      

Iterative improvement of parameter estimation for model migration by means of sequential experiments

Determining an optimal design for estimation of parameters of a class of complex models expected to be built at a minimum cost is a growing trend in science and engineering. We adopt a scale-bias adjustment migration strategy for integrating base and new models based on similar nature underlying processes. Further, we propose a Bayesian sequential algorithm for obtaining the statistically most informative data about the migrated model for use in parameter estimation. The benefits of the proposed strategy over traditional approaches presented in recent reported work are demonstrated using Monte Carlo simulations.     

电磁搅拌对大圆坯结晶器冶金行为影响的探讨

 为了探究结晶器电磁搅拌(M EMS)对大圆坯结晶器内综合冶金行为的影响。以大断面圆坯连铸结晶器冶金行为为研究对象，基于电磁热流体与凝固传输理论建立三维耦合数值模型。揭示大圆坯连铸常用五孔水口浇注条件下结晶器内电磁场、流场、传热与凝固等综合冶金行为，提出电磁搅拌对结晶器冶金性能影响的多参量评价方法。以中碳铬钼齿轮钢650 mm大圆坯连铸为例，指出结晶器电磁搅拌存在最佳搅拌电流，可获得相对较好的综合冶金效果。具体表现为弯月面保持一定的切向速度和过热度，有利于保护渣的熔化和夹杂物的上浮去除；液面波动幅度在控制范围内，可避免卷渣、改善表面质量；结晶器内钢液过热得到有效耗散，有利于等轴晶形核改善铸坯内部质量；侧孔出流钢液速度得到有效控制，可抑制注流对初凝坯壳的冲刷，提高了初生坯壳生长的均匀性。此外，电磁搅拌产生的水平旋流强度也可得到有效控制，有利于避免常见的皮下白亮带现象。     

吸收烟气中低浓度CO2的操作条件分析

Mg(OH)2浆液是一种具备低再生能耗潜力的CO2吸收剂，为了推进其在CO2捕集领域的应用而展开研究。在填料塔中，使用真实烟气研究了各种操作条件下Mg(OH)2浆液对CO2的捕集效率。研究发现,填料种类、气体名义停留时间、液气比均对CO2捕集效率有影响。结果表明，增加气体名义停留时间无法有效改善液相传质，而提高液气比能够有效改善液相传质；在试验条件下，拉西环、鲍尔环和IMTP的总体积传质系数分别为8.5×10-7～5.0×10-6、1.8×10-6～4.0×10-6和1.9×10-7～2.9×10-6 mol/(m3·s·Pa)。     

煤矿科室工作信息管理系统设计

为了提高了煤矿工作者的工作效率和矿井安全程度，设计了煤矿科室工作信息管理系统，分析了系统的关键技术，主要为J2EE技术和B/S和C/S的体系结构；根据现场调研，对系统需求进行了分析，然后设计了系统总体架构和系统功能模块。煤矿科室工作信息管理系统的应用，减少了人力资源的浪费，确保了信息的保存和查询的安全性。     

Optimizing PSMA Radioligand Therapy for Patients with Metastatic Castration-Resistant Prostate Cancer. A Systematic Review and Meta-Analysis

The aim of the review was to evaluate patient and treatment characteristics for patients with metastatic castration-resistant prostate cancer (mCRPC) treated with PSMA radioligand therapy (PRLT) associated with above-average outcome. The systematic review and meta-analysis followed recommendations by the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA). We searched for publications in PubMed, Embase, and ClinicalTrials.gov up to 31 September 2020. Thirty-six publications and four duplicates reported 2346 patients. Nearly two-thirds of the patients had bone metastases. Median overall survival (OS) was 16 months. Asymptomatic patients and patients with only lymph node metastases lived longer than symptomatic patients and patients with more extensive metastases. Patients treated with an intensified schedule of ¹⁷⁷Lu PRLT lived longer than those treated with a conventional schedule. Half of the patients obtained a PSA decline ≥ 50% and these patients lived longer than those with less PSA decline. Approximately 10% of the patients developed hematologic toxicity with anemia grade 3 as the most severe adverse effect. Characteristics for patients, cancer, restaging, and PRLT predict above average overall survival following treatment with PRLT.     

Revealing Electrical-Poling-Induced Polarization Potential in Hybrid Perovskite Photodetectors

Despite recent rapid advances in metal halide perovskites for use in optoelectronics, the fundamental understanding of the electrical-poling-induced ion migration, accounting for many unusual attributes and thus performance in perovskite-based devices, remain comparatively elusive. Herein, the electrical-poling-promoted polarization potential is reported for rendering hybrid organic–inorganic perovskite photodetectors with high photocurrent and fast response time, displaying a tenfold enhancement in the photocurrent and a twofold decrease in the response time after an external electric field poling. First, a robust meniscus-assisted solution-printing strategy is employed to facilitate the oriented perovskite crystals over a large area. Subsequently, the electrical poling invokes the ion migration within perovskite crystals, thus inducing a polarization potential, as substantiated by the surface potential change assessed by Kelvin probe force microscopy. Such electrical-poling-induced polarization potential is responsible for the markedly enhanced photocurrent and largely shortened response time. This work presents new insights into the electrical-poling-triggered ion migration and, in turn, polarization potential as well as into the implication of the latter for optoelectronic devices with greater performance. As such, the utilization of ion-migration-produced polarization potential may represent an important endeavor toward a wide range of high-performance perovskite-based photodetectors, solar cells, transistors, scintillators, etc.