mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Robust nonlinear control for nuclear reactors using sliding mode observer to estimate the xenon concentration

This paper presents findings on the sliding mode controller for a nuclear reactor. One of the important operations in nuclear power plants is load following. In this paper, a sliding mode control system, which is a robust nonlinear controller, is designed to control the pressurizedwater reactor power. The reactor core is simulated based on the point kinetics equations and six delayed neutron groups. Considering neutron absorber poisons and regarding the limitations of the xenon concentration measurement, a sliding mode observer is designed to estimate its value, and finally, a sliding mode control based on the sliding mode observer is presented to control the core power of reactor. The stability analysis is given by means Lyapunov approach; thus, the control system is guaranteed to be stable within a large range. The employed method is easy to implement in practical applications, and moreover, the sliding mode control exhibits the desired dynamic properties during the entire output-tracking process independent of perturbations. Simulation results are presented to demonstrate the effectiveness of the proposed observerbased controller in terms of performance, robustness and stability.
A Hybrid Method of Domain Lexicon Construction for Opinion Targets Extraction Using Syntax and Semantics

Opinion targets extraction of Chinese microblogs plays an important role in opinion mining. There has been a significant progress in this area recently, especially the method based on conditional random field (CRF). However, this method only takes lexicon-related features into consideration and does not excavate the implied syntactic and semantic knowledge. We propose a novel approach which incorporates domain lexicon with groups of syntactical and semantic features. The approach acquires domain lexicon through a novel way which explores syntactic and semantic information through Partof- Speech, dependency structure, phrase structure, semantic role and semantic similarity based on word embedding. And then we combine the domain lexicon with opinion targets extracted from CRF with groups of features for opinion targets extraction. Experimental results on COAE2014 dataset show the outperformance of the approach compared with other well-known methods on the task of opinion targets extraction.
A Modified Fuzzy C-Means Algorithm for Brain MR Image Segmentation and Bias Field Correction

In quantitative brain image analysis, accurate brain tissue segmentation from brain magnetic resonance image (MRI) is a critical step. It is considered to be the most important and difficult issue in the field of medical image processing. The quality of MR images is influenced by partial volume effect, noise, and intensity inhomogeneity, which render the segmentation task extremely challenging. We present a novel fuzzy c-means algorithm (RCLFCM) for segmentation and bias field correction of brain MR images. We employ a new gray-difference coefficient and design a new impact factor to measure the effect of neighbor pixels, so that the robustness of anti-noise can be enhanced. Moreover, we redefine the objective function of FCM (fuzzy c-means) by adding the bias field estimation model to overcome the intensity inhomogeneity in the image and segment the brain MR images simultaneously. We also construct a new spatial function by combining pixel gray value dissimilarity with its membership, and make full use of the space information between pixels to update the membership. Compared with other state-of-the-art approaches by using similarity accuracy on synthetic MR images with different levels of noise and intensity inhomogeneity, the proposed algorithm generates the results with high accuracy and robustness to noise.
B7 - H1的抗肿瘤免疫应答机制及其与上皮间质转化的关系

B7-H1是参与抗肿瘤免疫应答的一个重要的免疫卡控点(immune checkpoints)分子,它主要通过负性调控T细胞介导的抗肿瘤免疫应答,参与肿瘤的免疫抑制及逃逸。对于B7-H1对肿瘤细胞自身生物学行为的影响和作用机制尚未明确。本文将对B7-H1的抗肿瘤免疫应答机制及其与肿瘤细胞自身生物学行为的关系作一综述。
Co-templating Ionothermal Synthesis and Crystal Structure of a New Layered Aluminophosphate from a Protic Deep Eutectic Solvent

Protic deep eutectic mixtures are usually composed of organic amine hydrochloride salts and hydrogen bond donors in a specific molar ratio. Ionothermal synthesis of aluminophosphate as an example, herein, was reported for the first time from an urea-based protic eutectic mixture, consisting of diethylammonium chloride(DEACl) and 1,3-dimethyl urea(DMU). As a result, a new two dimensional aluminophosphate with 4.8-network,[CH_3NH_3]_2[(C_2H_5)_2NH_2]Al_3(PO_4)_4, has been successfully synthesized by co-templating the DEA and methylamine in situ generated from the decomposition of DMU in the absence of HF. Compared to alkyl quaternary ammonium salts with more alkyl-group connected with N atom, this kind of organic amine salts are more likely as the structure- directing agents to synthesize aluminophosphates in urea-based deep eutectic mixtures. It was also found that HF is crucial to the phase selectivity, a known compound with chain-like structure was obtained with the single methylamine as a structure-directing agent in the presence of HF. These materials were characterized by powder XRD, SEM, TG-DSC,~(13)C CP-MAS NMR and CHN analyses.
Effects of Strong Turbulence on the Spiral Plane Mode of Whittaker-Gaussian Beam through Terrene-Atmosphere

The analytic formulae of probability distribution of spiral plane modes for the Whittaker-Gaussian (WG) beams with orbital angular momentum (OAM) in strong turbulence regime are modeled based on the modified Rytov approximation. Numerical results show that the crosstalk range of OAM modes in the vicinity of signal mode increases with the increasing refractive-index construction parameter. However, effects of change of the width of the Gaussian envelope and the parameter Wo of WG beams on normalization energy weight of signal mode can be ignored. We find theoretically that signal spiral plane mode of WG beams at each OAM level approximatively has the same normalization energy weight, implying that the channels with WG (pseudo non-diffraction) beam have higher channel capacity than the channels with the Laguerre-Gaussian beam.
不同血压类型者冠状动脉血流储备的变化

目的观察隐蔽性高血压(MHT)、白大衣性高血压(WCHT)和持续性高血压(SHT)者冠状动脉血流储备(CFR)的变化及其影响因素。方法连续入选初诊未经治疗的MHT 92人(MHT组)、WCHT103人(WCHT组)和SHT患者128例(SHT组)为观察对象,另入选同期健康体检正常血压者80人为对照组(NT组)。采用经胸超声心动图检测CFR。比较各组间CFR的差异,并分析其可能的影响因素。结果SHT和WCHT组的诊室血压高于MHT和NT组(均P<0.05)。MHT和SHT组的24 h收缩压和舒张压、白天和夜间动态血压高于WCHT组和NT组(均P<0.05)。MHT组和SHT组的CFR低于NT组和WCHT组(MHT组:2.33±0.25比SHT组:2.30±0.37比WCHT组:2.86±0.38比NT组:2.92±0.42,均P<0.05)。Pearson相关分析显示,在所有受试者中,CFR与高敏C反应蛋白(hsCRP,r=-0.243)、诊室收缩压(r=-0.164)和舒张压(r=-0.193)、24 h动态舒张压(r=-0.457)和收缩压(r=-0.386)、白天动态收缩压(r=-0.455)和舒张压(r=-0.388)、夜间动态收缩压(r=-0.334)和舒张压(r=-0.265)和空腹血糖(r=-0.159)呈负相关(均P<0.05)。多因素线性回归分析结果显示,白天动态收缩压(β=-0.736)和夜间动态收缩压(β=-0.518)是CFR减少的影响因素(均P<0.05)。结论与WCHT和正常血压者比较,MHT和SHT患者的CFR明显降低,白天动态收缩压和夜间动态收缩压是CFR减少的影响因素。
编织样右冠状动脉1例

讨论编织样冠状动脉于1988年被Sane等首次描述,其将CAG中出现的多条管道形成随后再结合的现象形容为"8"字模式,并取名为编织样冠状动脉,其发生率低,鲜见报道。编织样冠状动脉是一种罕见的冠状动脉结构异常,形成原因目前尚不明确,一般不会引起临床症状,辅助检查结果正常,无死亡病例报道。编织样冠状动脉多在对急性心肌梗死、心绞痛患者进行CAG时被偶然发现,多见于右冠状动脉。本例也为偶然发现,右状冠动脉血流为TIMI-Ⅲ级。负荷试验中提示的心肌缺血部位与左前降支闭塞处相对应,干预闭塞段后患者症状缓解。一般认为导致患者胸痛的原因是冠状动脉狭窄或闭塞,与编织样冠状动脉无关,有学者对编织样冠状动脉进行3~5年的随访,期间未发生心血管不良事件,认为编织样冠状动脉为良性畸形。编织样冠状动脉这种异常改变,往往会被误认为自发或医源性冠状动脉夹层形成、冠状动脉内血栓形成或慢性闭塞后侧支形成,因此需进行鉴别。编织样冠状动脉不需给予特殊处理,应避免进行不必要的冠状动脉介入治疗,造成医源性的冠状动脉损伤。
Influence of the characteristics of fault gouge on the stability of a borehole wall

How to find more effective way to stabilize the borehole wall in the fault gouge section is the key technical challenge to control the stability of the borehole wall in the Wenchuan fault gouge section during the process of core drilling. Here we try to describe the characters of deep fault gouge in fracture zones from the undisturbed fault gouge samples which are obtained during the core drilling. The X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF) and Scanning Electron Microscope (SEM) provided the detailed information of the fault gouge's microscopic characteristics on the density, moisture content, expansibility, dispersity, permeability, tensile strength and other main physical-mechanical properties. Based on these systematic experimental studies above and analysis of the fault gouge instability mechanism, a new technical procedure to stabilize the borehole wall is proposed - a low water and a low loss low permeability drilling fluid system that consists of 4% clay + 0.5% CMC-HV + 2% S-1 + 3% sulfonated asphalt + 1% SMC + 0.5% X-1 + 0.5% T type lubricant + barite for core drilling in fault gouge sections.
Driving force and changing trends of vegetation phenology in the Loess Plateau of China from 2000 to 2010

Changes in vegetation phenology are key indicators of the response of ecosystems to climate change. Therefore, knowledge of growing seasons is essential to predict ecosystem changes, especially for regions with a fragile ecosystem such as the Loess Plateau. In this study, based on the normalized difference vegetation index (NDVI) data, we estimated and analyzed the vegetation phenology in the Loess Plateau from 2000 to 2010 for the beginning, length, and end of the growing season, measuring changes in trends and their relationship to climatic factors. The results show that for 54.84% of the vegetation, the trend was an advancement of the beginning of the growing season (BGS), while for 67.64% the trend was a delay in the end of the growing season (EGS). The length of the growing season (LGS) was extended for 66.28% of the vegetation in the plateau. While the temperature is important for the vegetation to begin the growing season in this region, warmer climate may lead to drought and can become a limiting factor for vegetation growth. We found that increased precipitation benefits the advancement of the BGS in this area. Areas with a delayed EGS indicated that the appropriate temperature and rainfall in autumn or winter enhanced photosynthesis and extended the growth process. A positive correlation with precipitation was found for 76.53% of the areas with an extended LGS, indicating that precipitation is one of the key factors in changes in the vegetation phenology in this water-limited region. Precipitation plays an important role in determining the phenological activities of the vegetation in arid and semiarid areas, such as the Loess Plateau. The extended growing season will significantly influence both the vegetation productivity and the carbon fixation capacity in this region.
Calculation of Nozzle Ablation During Arcing Period in an SF6 Auto-Expansion Circuit Breaker

The nozzle ablation process is described as two phases of heat and ablation in the interruption for an SF6 circuit breaker in this paper. Their mathematical models are established with the Fourier heat conduction di?erential equation respectively. The masses of nozzle ablation with di?erent arc durations and arc currents are calculated through the model of the nozzle ablation combined with an MHD (magneto-hydrodynamic) arc model. The time of the temperature rise on the inner surface of the nozzle under a given energy flux and of reaching the pyrolysis temperature under di?erent energy fluxes is respectively analyzed. The relations between the mass of nozzle ablation and breaking current and arc duration are obtained. The result shows that the absorbing energy process before the nozzle ablation can be neglected under the condition of the energy flux entering into nozzle q>10~9 W/m~2 . The ablation is the severest during the high-current phase and the ablation mass increases rapidly with the breaking current and with arc duration respectively.
厚朴治疗血管性痴呆的研究进展

老年性痴呆是导致个人、社会经济负担增加的主要原因之一,是危及老年人生活质量及寿命的最常见疾患之一,其中最常见的是阿尔茨海默病(AD)、路易体痴呆、血管性痴呆(VD)。VD又被称为"可逆性痴呆",是一种慢性进行性疾病,有治愈的可能性。因此,中医药治疗VD的研究迫在眉睫,具有重要意义。
唐山市老年人基层卫生服务现状

目的了解唐山市城乡基层卫生服务机构为老年人的卫生服务现状。方法选取唐山市所辖5区、4县、1个县级市、1个开发区共11个行政区域的城市社区卫生服务(CHS)机构和乡镇卫生院为研究对象,应用卫生部颁发的《全国社区卫生服务示范区评估标准》进行评估。结果唐山市共有95家城市CHS机构和122家乡镇卫生院。96.3%建立了老年人的健康档案,老年便利就诊服务开展率57.1%,慢性病管理开展率99.1%,长期卧床病人卫生服务开展率36.4%,健康教育开展率91.7%。城乡之间除老年人的健康档案外,其他项目均存在差异,城市开展服务好于农村(P<0.05)。机构的运行和老年卫生服务的全面开展存在着资金支持不足、高素质卫生技术人员配备不足、医保运行不顺畅等问题。结论目前唐山市针对老年人卫生及照护服务的开展尚不能满足城乡老年人不断增长的需求,农村老年卫生及照护服务开展率低,呼吁政府及卫生部门给予重视和大力支持发展城乡基层老年卫生及照护服务。
贝伐单抗联合FOLFOX化疗在老年结直肠癌患者中的安全性和有效性

目的探讨贝伐单抗联合FOLFOX化疗在老年结直肠癌患者中的安全性和有效性。方法选择Ⅳ期结直肠癌患者198例,根据患者的年龄和贝伐单抗使用情况,将患者分为中青年贝伐单抗组(78例)、老年贝伐单抗组(59例)和老年对照组(61例)。主要观察指标为无进展生存期和2年死亡率;次要观察指标是健康相关的生存质量和严重并发症。结果与老年对照组相比,中青年贝伐单抗组和老年贝伐单抗组患者无进展生存期显著延长(P=0.006);2年死亡率显著降低(15.38%和20.34% vs.34.43%,P=0.015);健康相关的生存质量显著增高(73.14±14.25和72.98±12.04 vs.66.52±13.86,P=0.008)。三组患者临床并发症均无显著差异(P>0.05)。结论贝伐单抗在老年结直肠癌患者中是安全有效的,显著改善了患者的无进展生存期、2年死亡率和健康相关的生存质量。
血清尿酸水平对老年急性心衰患者病情变化的临床预测价值

目的探讨血清尿酸(UA)对老年急性心力衰竭患者病情变化的临床预测价值。方法选取老年急性心力衰竭患者323例。入院后1 h内取静脉血行UA、N末端B型脑利钠肽前体(NT-pro BNP)、生化、血常规等检测,根据UA水平分组,比较各组患者就诊5 d及30 d后随访的死亡率,探讨UA对于老年急性心力衰竭患者死亡的预测价值。结果(1)应用单因素方差分析比较各组患者就诊5 d及30 d死亡率,发现患者5 d、30 d死亡率在低UA组与正常UA组间无显著差异,而正常UA与高UA组间有显著差异(9.4% vs 19%,P=0.018;21.3% vs 35%,P=0.010)。(2)应用ROC曲线分析UA的评估价值:①UA对于患者就诊5 d、30 d死亡率的AUROC分别为0.662和0.588,具有轻度的预测价值;②UA联合NT-Pro BNP对于急性心力衰竭预后具有更好的预测价值:UA联合NT-pro BNP对患者就诊5 d、30 d死亡率的AUROC分别升至0.701和0.702。结论虽然UA对急性心力衰竭的预后仅有轻度预测价值,但其预测价值与NT-pro BNP相当;将UA联合NT-pro BNP进行检测,可以进一步提高NT-pro BNP对急性心力衰竭患者死亡的预测价值。
老年高血压合并糖尿病患者血压血糖水平与脂肪肝患病的相关性

目的探讨血压及血糖水平与原发性高血压合并糖尿病患者脂肪肝患病的关系。方法将同时患有糖尿病和原发性高血压860例年龄>60岁的患者,按照其收缩压及糖化血红蛋白(HbA1c)水平进行分组,将患者根据收缩压分组:血压严格控制组(血压<130 mmHg),血压一般控制组(血压130~139 mmHg),血压未控制组(血压≥140 mmHg);根据其HbA1c水平分为血糖严格控制组(HbA1c<6.5%),血糖一般控制组(HbA1c=6.5%~7.5%),血糖未控制组(HbA1c≥7.5%)。同时对每位患者进行超声检查,记录脂肪肝的发病情况。结果多因素线性回归分析显示,年龄(X_1,β=0.027,P=0.010)、体重指数(BMI)(X_2,β=0.048,P=0.000)、收缩压(X_3,β=0.018,P=0.008)、HbA1c(X_4,β=0.002,P=0.004)、总胆固醇(X_5,β=0.284,P=0.007)、甘油三酯(X_6,β=0.465,P=0.000)、低密度脂蛋白胆固醇(X_7,β=0.373,P=0.000)均与脂肪肝(Y)呈正相关,为脂肪肝形成的危险因素。结论血压、血糖水平是脂肪肝患病的危险因素之一,而血脂紊乱也在其中起着很重要的作用。
慢性阻塞性肺疾病合并2型糖尿病的临床特征及治疗策略

目的探讨慢性阻塞性肺疾病(COPD)合并2型糖尿病(T2DM)患者的临床特征及治疗策略。方法收集2012年2月至2014年2月入住呼吸内科的COPD急性加重患者130例,合并T2DM患者(试验组)和单纯COPD患者(对照组)各65例,对两组的急性加重频率、外周血血红蛋白、肺部影像学、肺功能、血气分析、病原体分布特点、抗生素使用时间、总住院时间进行比较分析。结果与对照组比较,试验组急性加重住院次数频繁、抗生素使用时间、总住院时间延长,混合菌感染及真菌感染比例高,第1秒用力肺活量占用力肺活量的百分比(FEV1%)、动脉血氧分压(PaO_2)低(P<0.05);试验组贫血的比例明显高于对照组,而一口气弥散功能则明显低于对照组(P<0.001)。结论COPD合并T2DM患者更易急性加重而频繁住院,更易出现贫血,通气功能和弥散功能差,病情严重而复杂,平均抗生素使用时间和平均住院时间延长。综合治疗是提高COPD合并T2DM患者疗效、延缓病情发展的关键。
雷沙吉兰对乳胞素诱导帕金森病大鼠神经的保护作用及机制

目的观察雷沙吉兰对乳胞素诱导帕金森病(PD)大鼠神经的保护作用及机制。方法SD大鼠分为空白对照组、模型组、雷沙吉兰预治疗组和治疗组,通过立体定向注射乳胞素至模型大鼠左侧黑质部位诱导模型,进行行为学、组织病理学检测,PCR检测目的蛋白表达变化。结果模型大鼠在阿朴吗啡的诱导下,向右旋转;与空白对照组相比,其余各组大鼠脑组织切片中酪氨酸羟化酶(TH)阳性细胞数显著减少,但预治疗组和治疗组中TH阳性细胞较多; PCR定量显示Lamp2A与热休克蛋白(HSP)70在治疗组与空白组间存在差异(P<0.05),而治疗组间无差异。结论雷沙吉兰可以抵抗乳胞素所致的神经损害,改善动物行为学及组织病理学表现,具有神经保护作用,其机制可能与促进Lamp2A及HSP 70表达,减少TH阳性细胞丢失相关。
中国西南干旱河谷的植物多样性: 区系和群落结构的空间分异与成因

中国西南干旱河谷基本分布在横断山区及其南延山系范围之内(张荣祖, 1992), 涉及怒江、澜沧江、元江、金沙江、南盘江、雅砻江、大渡河、岷江、白龙江(含支流白水江)等的上、中游干流及部分支流的下陷河谷段, 多呈南北或西北-东南走向, 海拔范围在500-2,500 m。这些生境相似的河段在地形上相对封闭, 且被高耸的山岭彼此阻隔, 相距数十至数百公里, 形成了横断山区特有的倒置生境孤岛群。西南干旱河谷生物多样性的研究意义在于它代表了中国热带和亚热带湿润季风气候控制的自然地理背景下具有隐域和残遗性质的半干旱-干旱植被和植物区系(吴征镒和王荷生, 1983), 这是青藏高原隆起、南亚-东亚季风加强所产生的诸多自然地理变迁结果之一(张新时, 1978; 郑度和杨勤业, 1985), 并与全球同纬度以干旱-半干旱气候主导的植被与植物区系背景相呼应(张荣祖, 1992; 金振洲, 2002; 吴征镒等, 2011)。
Pressure Regulation for Earth Pressure Balance Control on Shield Tunneling Machine by Using Adaptive Robust Control

Most current studies about shield tunneling machine focus on the construction safety and tunnel structure stability during the excavation. Behaviors of the machine itself are also studied, like some tracking control of the machine. Yet, few works concern about the hydraulic components, especially the pressure and flow rate regulation components. This research focuses on pressure control strategies by using proportional pressure relief valve, which is widely applied on typical shield tunneling machines. Modeling of a commercial pressure relief valve is done. The modeling centers on the main valve, because the dynamic performance is determined by the main valve. To validate such modeling, a frequency-experiment result of the pressure relief valve, whose bandwidth is about 3 Hz, is presented as comparison. The modeling and the frequency experimental result show that it is reasonable to regard the pressure relief valve as a second-order system with two low corner frequencies. PID control, dead band compensation control and adaptive robust control (ARC) are proposed and simulation results are presented. For the ARC, implements by using first order approximation and second order approximation are presented. The simulation results show that the second order approximation implement with ARC can track 4 Hz sine signal very well, and the two ARC simulation errors are within 0.2 MPa. Finally, experiment results of dead band compensation control and adaptive robust control are given. The results show that dead band compensation had about 30° phase lag and about 20% off of the amplitude attenuation. ARC is tracking with little phase lag and almost no amplitude attenuation. In this research, ARC has been tested on a pressure relief valve. It is able to improve the valve’s dynamic performances greatly, and it is capable of the pressure control of shield machine excavation.
智能电网信息安全防御体系与信息安全测试系统构建乌克兰和以色列国家电网遭受网络攻击事件的思考与启示

乌克兰和以色列国家电网遭受网络攻击事件分析智能电网是一种典型的信息物理融合系统,由传统电力基础架构与信息基础架构共同组成。智能电网的安全问题包括物理安全和信息安全两个方面。智能电网信息化及其物理系统与信息系统的深度融合为其引入了新的安全隐患,针对信息系统的网络攻击在破坏其功能的同时,也会传导至物理系统并威胁其安全运行。近几年来,通过网络攻击智能电网并进行破坏的事件时有发生。
直肠癌术后肠梗阻案

每天针刺2次,两种体位各一次,分上下午进行,并且周六、周日休息,为了避免过于频繁刺激,降低刺激量,同时也为了保护患者正气。患者腹部X线检查无液平面后,少量进食小米粥,引起呕吐,考虑为患者肠胃久未纳食,从而出现胃不受纳之现象。因生姜为"呕家圣药",故用生姜水煮粥,取得奇效。该患者因病情特殊,西医治疗手段不多,基本以中医基础理论为指导思想,运用针刺方法进行治疗。最终解决患者病痛,并且随访1年,胃肠功能始终正常,证明了中医针灸的实效性。
A Measure System of Zero Moment Point Using Wearable Inertial Sensors

Keeping balance is the premise of human walking. ZMP(zero moment point) is a point where total torque achieves balance. It is an important evaluation parameter of balance ability in walking, since it can be used to better reflect the dynamic balance during walking. ZMP can be used in many applications, such as medical rehabilitation, disease diagnosis, treatment and etc. In this paper, wearable inertial sensors system based on MEMS is used to measure ZMP (zero moment point) during walking, which is cheap, convenient, and free from the restriction of lab. Our wearable ZMP measurement system consists of inertial measurement subsystem and PC real-time monitoring station. Inertial measurement subsystem includes 9-axis inertial sensing nodes, the body communication network and the central node. Inertial sensing nodes are mounted on different parts of the body to collect body posture information in real-time, and then the best estimation of current posture are obtained by Kalman filter. The data from sensors is aggregated to the central node through the CAN bus, and then ZMP is calculated. Finally, it can be showed in the PC monitoring station. Experiments prove the system can achieve real- time ZMP detection during walking.
Efficient perovskite solar cells based on novel three-dimensional TiO_2 network architectures

Mesoscopic lead halide perovskite solar cells typically use TiO_2 nanoparticle films as the scaffolds for electron-transport pathway and perovskite deposition. Here, we demonstrate that swelling-induced mesoporous block copolymers can be templates for producing threedimensional TiO_2 networks by combining the atomic layer deposition technique. Thickness adjustable TiO_2 network is an excellent alternative scaffold material for efficient perovskite solar cells. Our best performing cells using such a 270 nm thick template have achieved a high efficiency of 12.5 % with pristine poly-3-hexylthiophene as a hole transport material. The high performance is attributed to the direct transport pathway and high absorption of scaffolds, small leakage current and largely reduced recombination rate at interfaces. The results show that TiO_2 network architecture is a promising scaffold for mesoscopic perovskite solar cells.
Diffusion-correlated local photoluminescence kinetics in CH_3NH_3PbI_3 perovskite single-crystalline particles

Understanding the correlation between the lifetime, mobility and diffusion length of photoinduced charge carriers in organolead halide perovskite is essential to successful perovskite-based solar cells. In this paper, through mapping the local photoluminescence (PL) dynamics using laser/PL-scanned confocal imaging microscopy and simulating the carrier diffusion process in an individual CH_3NH_3PbI_3 single-crystalline particle, we report that the rapid diffusion of charge carriers can produce a fast local PL kinetics when the perovskite is partially excited. This result indicates that using PL kinetics to estimate the carrier lifetime in perovskite single crystals needs to exclude the effect of carrier diffusion.
Characteristics of the Two Active Stages of Lightning Activity in Two Hailstorms

Two hailstorms that occurred in Beijing and Tianjin, respectively, are investigated, based mainly on the total lightning data observed by the System d’Alerte Fondre par Interferometric Radioelecctrique (SAFIR3000), the cloud-to-ground (CG) lightning data of a CG lightning location system, and the echo data of a Doppler radar. Both hailstorms exhibited two lightning frequency peaks: the first was before the hailfall and the second was after the hailfall, with the second peak greater than the first. The dominant polarity of the CG lightning was positive in the stage around the first frequency peak, but changed to negative in the stage around the second frequency peak. The evolution of radar echoes and the height distribution of lightning radiation sources are explored, revealing that both hailstorms had stronger convection and the main positive charge occurred at mid levels during the stage around the first frequency peak. However, whilst the Beijing hailstorm experienced the enhancement of convection, with the main positive charge at upper levels around the second frequency peak, the Tianjin hailstorm generated its second frequency peak during the period when the convection kept weakening and the main positive charge dropped to mid–lower levels. Through evaluation of the radar parameters, we investigate the mechanisms responsible for the second stage of active lightning discharge. Furthermore, the lightning activity exhibited a close relationship with radar echo parameters and hailfall. Lightning jump signals were found before the hailfall and were associated with the change ratio of the 40-dBZ echo volume above the –15℃ level, which demonstrates the application value of lightning data in severe weather warning.