mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Effect of soil management on soil erosion on sloping farmland during crop growth stages under a large-scale rainfall simulation experiment

Soil erosion on farmland is a critical environmental issue and the main source of sediment in the Yellow River, China. Thus, great efforts have been made to reduce runoff and soil loss by restoring vegetation on abandoned farmland. However, few studies have investigated runoff and soil loss from sloping farmland during crop growth season. The objective of this study was to investigate the effects of soil management on runoff and soil loss on sloping farmland during crop growth season. We tested different soybean growth stages (i.e., seedling stage (R1), initial blossoming stage (R2), full flowering stage (R3), pod bearing stage (R4), and initial filling stage (R5)) and soil management practice (one plot applied hoeing tillage (HT) before each rainfall event, whereas the other received no treatment (NH)) by applying simulated rainfall at an intensity of 80 mm/h. Results showed that runoff and soil loss both decreased and infiltration amount increased in successive soybean growth stages under both treatments. Compared with NH plot, there was less runoff and higher infiltration amount from HT plot. However, soil loss from HT plot was larger than that from NH plot in R1–R3, but lower in R4 and R5. In the early growth stages, hoeing tillage was effective for reducing runoff and enhancing rainfall infiltration. By contrast, hoeing tillage enhanced soil and water conservation during the late growth stages. The total soil loss from HT plot (509.0 g/m~2) was 11.1% higher than that from NH plot (457.9 g/m~2) in R1–R5. However, the infiltration amount from HT plot (313.9 mm) was 18.4% higher than that from NH plot (265.0 mm) and the total runoff volume from HT plot was 49.7% less than that from NH plot. These results indicated that crop vegetation can also act as a type of vegetation cover and play an important role on sloping farmland. Thus, adopting rational soil management in crop planting on sloping farmland can effectively reduce runoff and soil loss, as well as maximize rainwater infiltration during crop growth period.
Application and verification of simultaneous determination of cellulose δ~(13)C and δ~(18)O in Picea shrenkiana tree rings from northwestern China using the high-temperature pyrolysis method

Stable isotopes in tree-ring cellulose provide important data in ecological, archaeological, and paleoenvironmental researches, thereby, the demand for stable isotope analyses is increasing rapidly. Simultaneous measurement of cellulose δ~(13)C and δ~(18)O values from tree rings would reduce the cost of isotopic commodities and improve the analytical efficiency compared with conventional separate measurement. In this study, we compared the δ~(13)C and δ~(18)O values of tree-ring α-cellulose from Tianshan spruce (Picea schrenkiana) in an arid site in the drainage basin of the Urumqi River in Xinjiang of northwestern China based on separate and simultaneous measurements, using the combustion method (at 1050°C) and the high-temperature pyrolysis method (at 1350°C and 1400°C). We verified the results of simultaneous measurement using the outputs from separate measurement and found that both methods (separate and simultaneous) produced similar δ~(13)C values. The two-point calibrated method improved the results (range and variation) of δ~(13)C and δ~(18)O values. The mean values, standard deviations, and trends of the tree-ring δ~(13)C obtained by the combustion method were similar to those by the pyrolysis method followed by two-point calibration. The simultaneously measured δ~(18)O from the pyrolysis method at 1400°C had a nearly constant offset with that the pyrolysis method at 1350°C due to isotopic-dependence on the reaction temperature. However, they showed similar variations in the time series. The climate responses inferred from simultaneously and separately measured δ~(13)C and δ~(18)O did not differ between the two methods. The tree-ring δ~(13)C and δ~(18)O values were negatively correlated with standardized precipitation evapotranspiration index from May to August. In addition, the δ~(18)O was significantly correlated with temperature (positive), precipitation (negative), and relative humidity (negative) from May to August. The tree-ring δ~(13)C and δ~(18)O values determined simultaneously through the high-temperature pyrolysis method could produce acceptable and reliable stable isotope series. The simultaneous isotopic measurement can greatly reduce the cost and time requirement compared with the separate isotopic measurement. These results are consistent with the previous studies at humid sites, suggesting that the simultaneous determination of δ~(13)C and δ~(18)O in tree-ring α-cellulose can be used in wide regions.
Variable stars in M37

The CCD photometric observations of open star cluster M37 (NGC 2099) were carried out up to a limiting magnitude of V ∼ 20 in both B and V filters to search for variable stars using a 2k×4k CCD and the 1.3m telescope at the Vainu Bapu Observatory, Kavalur. A total of 314 stars were in the first observing run, out of which 60 were identified as variables. Eight out of the identified 60 variables are classified as W UMa binary stars. For model fitting, we used PHOEBE based on the W-D code to estimate the physical parameters of these newly detected W UMa binaries that theoretically best match the observed light curves.
Risk-based evaluation on geological environment carrying capacity of mountain city - A case study in Suide County, Shaanxi Province, China

With the rapid development and expansion of the cities in China, the carrying capacity of resource and environment has become a huge concern for local governments. From the perspective of geological environment, geological disasters are the main restraining factor of the development in mountain cities. This study was conducted in Suide County of Shaanxi Province with a risk-based approach as followed: a hazard analysis on geological disasters based on a slope geological survey at a scale of 1:10,000; a consequence analysis based on unmanned aerial vehicle (UAV) aerial survey data; integrating the results of hazard analysis and consequence analysis, a risk zonation and analysis of geological disasters in urban areas were completed considering urban planning, land use planning and the safety of infrastructure and major engineering. Subsequently, taking the acceptable levels of human life and property risks incurred by landslides as the criteria of the evaluation of geological environment carrying capacity, a comprehensive assessment of current and future urban carrying capacity was conducted based on the results of the risk analyses. Accordingly, the prior development zone, the restricted development zone and the prohibited zone were delineated, with corresponding suggestions for future urban development. The technological and methodological system used in the study can be applied to geological environment carrying capacity evaluation of other important mountain cities, which can provide scientific basis for the optimization of land and space.
Snow cover influences the thermal regime of active layer in Urumqi River Source, Tianshan Mountains, China

Snow cover is characterized by the high albedo, low thermal conductivity, and notable heat transition during phase changes. Thus, snow cover significantly affects the ground thermal regime. A comparison of the snow cover in high latitudes or high-altitude snowy mountain regions indicates that the eastern Tianshan Mountains (China) show a characteristically thin snow cover (snow depth below 15 cm) with remarkable temporal variability. Based on snow depth, heat flux, and ground temperature from 2014 to 2015 in the Urumqi River source, the spatialtemporal characteristics of snow cover and snow cover influences on the thermal conditions of active layer in the permafrost area were analyzed. During the autumn (Sept. - Oct.), thin and discontinuous snow cover can noticeably accelerate the exothermic process of the ground, producing a cooling effect on the shallow soil. During the winter (Nov. - Mar.), it is inferred that the effective thermal insulation starts with snow depth exceeding 10 cm during early winter. However, the snow depth in this area is generally below 15 cm, and the resulting snow-induced thermal insulation during the winter is very limited. Due to common heavy snowfalls in the spring (Apr. to May), the monthly mean snow thickness in April reached to 15 cm and remained until mid-May. Snow cover during the spring significantly retarded the ground warming. Broadly, snow cover in the study area exerts a cooling effect on the active layer and plays a positive role in the development and preservation of permafrost.
Trace Metals Analysis Along the Fildes Peninsula Coastline Using Two Red Algae, Rhodymenia antarctica and Iridaea cordata, as Monitors

Two red algae, Rhodymenia antarctica and Iridaea cordata (Rhodophyta), were employed to investigate the pollution situation along Fildes Peninsula coastline, King George Island. Ten sites from east and west coastlines were investigated, and the concentrations of Cu, Pb, Zn, Cd, Cr, As and Hg were determined. The metal pollution index (MPI) was used to evaluate the overall pollution level represented by the investigated sites and for interregional comparisons. The two algae exhibited different preference to special trace metal. R. antarctica could accumulate more Cd (0.63 mg kg~(–1)) and Hg (0.026 mg kg~(–1)) than I. cordata (Cd 0.34 mg kg~(–1), Hg 0.019 mg kg~(–1)). I. cordata could accumulate more As (15.53 mg kg~(–1)) than R. antarctica (10.11 mg kg~(–1)). There was no significant difference in accumulating Cu, Pb, Zn and Cr between the two algae. R. antarctica could be used to monitor Cd and Hg. I. cordata would be more appropriate for monitoring As. MPI monitored by the two algae were from 1.02 to 2.26 (R. antarctica), and 1.03 to 1.25 (I. cordata), respectively. Pollution situation of Fildes Peninsula was becoming serious, especially of the east coastline. The objective of this research was to gather the baseline information for trace metals investigation in Antarctic.
Assessing the spatiotemporal distributions of evapotranspiration in the Three Gorges Reservoir Region of China using remote sensing data

Evapotranspiration (ET) is a critical component of the global hydrological cycle, and it has a large impact on water resource management as it affects the availability of freshwater resources. It is important to understand the hydrological cycle for the water resources planning and management. This study used Moderate Resolution Imaging Spectroradiometer (MODIS) satellite derived ET, and potential evapotranspiration (PET) and Tropical Rainfall Measuring Mission (TRMM) satellite derived precipitation datasets to assess the spatial and temporal distributions of ET, PET, and precipitation during the study period at Three Gorges Reservoir (TGR) region. Based on the topographic variations and land-use/land-cover distributions, the study region which includes five counties of Hubei Province and nineteen counties of Chongqing Municipality was divided into four study zones. The ET and precipitation data were evaluated using in situ observations. The ET, PET, and precipitation data were compared to analyze the spatial and long-term (2001-2016) temporal distributions of average annual ET, PET, and precipitation, and to understand the relationships between them in the study region. The results showed that each selected zone had highest ET at the counties with the Yangtze River passing through whereas lowest at the counties which were located away from the river. Results also showed increasing trends in ET and PET from south-west to north-east in the study region. Analysis showed TGR had a significant impact on spatial and temporal distributions of ET and PET in the study region. Therefore, this study helps to understand the impact of TGR on spatial and temporal distributions of ET and PET during and after the construction.
The evolution of tea spatial agglomeration in China: An analysis based on different geographical scales

The spatial agglomeration of agricultural production is conducive to reducing planting costs, increasing production efficiency and improving product quality. It is an important way to promote the transformation and upgrad of tea industry and realize the modernization of China’s tea industry. This study used Gini coefficient and spatial autocorrelation analysis to explore the characteristics of tea spatial agglomeration in China from three geographical scales: regional level, provincial level and prefecture level from the year 2005 to 2015. The results indicated that there was a significant scale effect on the tea spatial agglomeration. The agglomeration degree increased from the regional level, provincial level to prefecture level. The types of spatial agglomeration evolution of the three scales were Ushaped, continuous diffusion, and continuous agglomeration. The spatial autocorrelation of tea production could only be found at the prefecture level. Meanwhile, at the prefecture scale, we could not only reveal the pattern changes at the regional and provincial levels, but also identify tea production agglomeration regions. Compared with the large scale, the small scale could reveal the characteristics of tea spatial agglomeration in more details. Factors such as natural resource endowments, cost factor, technological advancement, agglomeration economy, and agricultural policy influenced the evolution of tea spatial agglomeration from different geographical scales. Finally, from the perspectives of spatial transfer of tea production, promoting spatial agglomeration, building tea production bases, and breaking administrative boundaries, we proposed several policy suggestions for optimizing the spatial layout of tea production.
克莱恩-莱文综合征一例

本例主要需与下列疾病相鉴别:(1)发作性睡病:二者发病年龄相近,均以嗜睡为主要表现.本例患者人院后嗜睡时间较短,PSG潜伏期为0,故容易与发作性睡病混淆. 但本例无以下发作性睡病的典型表现:无明显间歇期的嗜睡,并伴发猝倒、睡眠瘫痪和睡眠幻觉.且人院后5次MSLT结果平均人睡潜伏期为15.7 min,5次均未出现REM期,不支持发作性睡病的诊断.入院时PSG提示潜伏期0考虑为器械准备时间过长患者接线后巳人睡所致,临床意义小.(2)双相情感障碍:这是本例的鉴别难点.
工程机械技术营销市场的安全管理探究--评《工程机械技术服务与营销》

近年来,我国的铁路公路建设、工农业基础建设和市政工程建设步入了快速发展阶段,尤其是工程机械设备增长趋势明显,工程机械设备的操作人员队伍也日益壮大。同时工程机械企业的销售模式也产生了新的变化,各类企业日益重视销售模式的效率、成本以及对销售风险的控制。因此,高校教学应当紧跟时代步伐,帮助学生掌握相应的市场动态和营销安全策略,为今后服务于社会打下坚实的基础。
肾混合性上皮和间质肿瘤3例临床病理分析

目的探讨肾混合性上皮和间质肿瘤( mixed epithelial and stromal tumor of the kidney,MESTK)的临床病理学特征、免疫表型、鉴别诊断及预后。方法回顾性分析3例MESTK临床病理特征并复习相关文献。结果3例均为女性,年龄39 ~ 43岁。肿瘤与周围肾组织分界清楚或形成推挤式边界。镜下见肿瘤组织均由不同比例的上皮和间质两种成分构成:上皮成分呈密集成簇的微囊/小腺管状、粗大乳头状或甲状腺滤泡样结构排列,较大囊腔被覆扁平或靴钉样细胞;间质成分为少细胞的胶原纤维或富于细胞的梭形纤维间质,局部间质疏松水肿、慢性炎细胞浸润或夹杂数目不等的脂肪细胞,可见富细胞性卵巢样间质围绕在囊性结构周围及成簇厚壁血管。免疫表型:上皮成分表达PAX-8,间质成分表达vimentin、SMA、ER、PR; Ki-67增殖指数均< 1%。结论MESTK是一种罕见的肾脏原发性良性肿瘤,手术切除后预后良好,确诊主要依靠病理学形态及免疫表型,需与肾脏其他伴有囊性结构或兼具上皮和间质结构的良恶性肿瘤相鉴别。
耳鼻喉科新护士准入岗位胜任力考核评价指标的构建

目的构建耳鼻喉科新护士准入岗位胜任力考核评价指标,为新护士规范化培训的效果评价提供参考。方法课题组初拟耳鼻喉科新护士准入岗位胜任力考核评价指标体系,采用德尔菲法对33名专家进行2轮函询。结果2轮函询专家的积极系数分别为100%和84.8%,2轮专家权威系数分别为0.82、0.88,一、二、三级指标的协调系数为0.29、0.26和0.22(均P<0.05),最后形成了7个一级指标,25个二级指标,6个三级指标的考核评价体系。结论构建的耳鼻喉科新护士准入岗位胜任力考核评价指标具有科学性、可操作性,可作为评价新护士培训效果、修订培训计划的参考工具。
六步手指操改善经桡动脉介入术后患者肢体症状的效果评价

目的探讨六步手指操对经桡动脉行经皮冠状动脉介入(PCI)术后患者肢体症状改善的效果。方法将经桡动脉行PCI术的101例患者随机分为对照组(50例)和观察组(51例),对照组采用常规护理方案,观察组采用六步手指操进行康复锻炼,比较两组术后术侧肢体疼痛、肿胀程度和出血情况。结果观察组术后4h和24h术侧肢体疼痛程度和肿胀程度显著轻于对照组(均P< 0.01);两组术后出血情况无明显差异。结论六步手指操可有效改善经桡动脉行PCI术后患者患侧肢体疼痛和肿胀情况,可有效提升术后患者舒适度。
人乳库质量控制与安全管理研究现状

介绍国内外人乳库的质量控制与安全管理现状,分析现存的安全隐患与质量问题,针对我国人乳库安全管理的现状与不足提出建议和对策,旨在为完善、健全我国人乳库管理工作提供参考。
精准护理的人本底蕴与实证应用探究

通过溯源精准护理的人本底蕴、比较精准护理与常规护理的异同、阐释精准护理的实证依据、分析精准护理的临床应用现状来彰显精准护理的承继开新,以期为患者提供最佳适配的个人化护理以实现精准护理。提示精准护理主要是奠基于个别化医疗,以个人化量身订制来强化患者的照护成效。精准护理的发展应紧跟时代潮流,护理学者需要更广泛的研究主题以鼓励创新的方法学来发展精准护理,并利用大数据来建立实证数据引导精准护理的临床应用。
乌拉地尔减少动脉化静脉皮瓣血流灌注量的作用

目的初步探讨乌拉地尔减少动脉化静脉皮瓣血流灌注量的机制。方法2016年5月至2016年7月,选取20只体质量为(25.0±5.0)kg的雄性巴马小型猪,均在上腹部设计动脉化静脉皮瓣,根据乌拉地尔的用药方式随机分为局部用药组及肌注用药组。术后监测两组给药前后的皮瓣血流灌注量与血压,以及术后1周观察皮瓣的成活情况。结果用药前、用药后15 min、用药后30 min,局部用药组的皮瓣血流灌注量分别为(76.99±7.14)pu、(76.80±6.61)pu、(77.25±6.89)pu,收缩压分别为(109.90±7.02)mmHg、( 110.20± 6.49)mmHg、(110.40±7.01)mmHg,舒张压分别为(84.60±7.47)mmHg、(84.70±7.03)mmHg、(85.20±7.48)mmHg;肌注用药组的皮瓣血流灌注量分别为(77.33±5.68)pu、(57.42±5.11)pu、(44.32±4.72)pu,收缩压分别为(111.00±6.06)mmHg、(96.50±6.69)mmHg、(94.60±5.70)mmHg,舒张压分别为(87.90±9.15)mmHg、(75.70± 10.23)mmHg、(74.00±10.37)mmHg,局部用药组的皮瓣血流灌注量与血压在用药前、后差异均无统计学意义(P>0.05),而肌注用药组的皮瓣血流灌注量与血压在用药后有明显下降(P<0.05)。术后第7天,局部用药组皮瓣坏死2例,不同程度的部分坏死6例,成活2例;肌注用药组没有完全坏死的皮瓣,不同程度的部分坏死3例,成活7例。通过Fisher确切概率法检验,可认为肌注用药组皮瓣的存活质量比局部用药的要高(单侧,P< 0.05)。结论乌拉地尔肌注用药作用于全身,扩张了全身静脉系统,使全身的有效循环血量减少、血压降低的同时,也减少了动脉化静脉皮瓣的血流灌注量(前负荷),从而提高了动脉化静脉皮瓣的成活质量。
人体常用体表骨性标志在康复治疗中的应用研究

表面解剖学(surface anatomy)是研究人体深层结构与表面关系的科学,它借助于人体的表面形态特征,如骨性标志、肌性标志、皮纹标志和一些标志线来确定深部脏器和结构的体表定位、大小、范围和走向,为体格检查和技术操作、手术定位等提供比较强的应用性解剖知识,是解剖学知识走向实际应用的桥梁和纽带。人体体表标志在各类疾病的康复治疗中应用十分广泛,作为功能恢复的实践者和指导者的康复治疗师,在人体表面施加各类疗法是其工作的核心,掌握表面解剖才能更好地分析运动障碍的原因、探讨康复机制和指导运动治疗实践。但国内还没有专门研究表面解剖在康复治疗应用的内容。本文重点介绍表面解剖学中体表骨性标志在康复治疗中的应用。
基于Teager-Kaiser能量算子与自适应双阈值的上肢痉挛状态评定系统

目的:结合改良Ashworth量表(MAS)与表面肌电(sEMG)信号特性,设计基于Teager-Kaiser能量算子(TKEO)与自适应双阈值的上肢痉挛状态评定系统,解决临床痉挛状态评定主观性大的问题,提高痉挛状态评定的信度与效度。方法:提出一种牵张反射阈值(SRT)测试方法,设计了评定系统:利用TKEO处理肱二头肌sEMG,根据sEMG的TKEO信号幅值及变化率设定自适应双阈值判定牵张反射起始点(SRO),然后联合关节角度判定SRT,探索其与痉挛状态的关系。25名受试者参与了此试验。结果:自适应双阈值判定算法能够有效地识别SRO(识别率:96%)且SRT能够反映痉挛状态,与MAS评分显著相关,相关性满足(r=-0.904,P<0.01)与(r=-0.902,P<0.01),组内相关系数(ICC)显示重测信度为0.915,同时Bland- Altman分析显示95.65%点位于一致性界限(LoA)范围内。结论:该系统可为上肢痉挛状态评定提供一种客观定量的分析手段,并为后续实时监测痉挛状态提供理论基础。
不同时期膝骨关节炎的膝关节6自由度步态变化

膝骨关节炎(knee osteoarthritis,KOA)是骨科的一种常见疾病,尤其常见于老年人群。早期几乎所有的患者都会有疼痛症状,并且受生物力学的影响因素很大。针对膝骨关节炎的评价方法多种多样,主要为主观量表、影像学或者综合评价。其中,主观量表评价主观性太强,容易产生误差,而综合评价需要更多的评价方法来增加其客观性,因此,近年来能够客观反映患者下肢生物力学变化的步态分析逐渐成为研究热点。步态分析的方法多种多样。本文主要通过运动捕捉系统和计算机辅助系统得到膝关节活动的6种自由度的改变,从而客观的反映不同时期膝骨关节炎的步态变化。这6种膝关节自由度均为股骨相对胫骨的活动度。
2016-2017年烟台市水果中22种杀菌剂和植物生长调节剂残留情况

目的了解烟台市售水果中22种杀菌剂和植物生长调节剂残留水平及其可能带来的安全性风险。方法于2016-2017年采取随机抽样的方法采集居民消费量较大的14个品种563份样品。依据国家食品污染物和有害因素风险监测工作手册标准操作程序,对水果中16种杀菌剂和6种植物生长调节剂残留进行检测并评价其安全性。结果烟台市售水果22种农药残留检出率为40.1%(226/563),均未超出GB 2763-2016限量值。14种水果中检出农药残留,圣女果、草莓、葡萄的检出率较高,分别为95.7%(45/47)、84.9%(45/53)和83.3%(25/30)。共检出11种农药残留,多菌灵、嘧霉胺、烯酰吗啉检出率较高,分别为22.7%(128/563)、17.8%(100/563)和11.4%(64/563)。不同监测年度和不同季节样品检出率之间差异均无统计学意义。农贸市场样品检出率高于商场超市和水果专营店总检出率(P <0.05)。结论烟台市售水果存在杀菌剂和植物生长调节剂残留污染,含量水平处于安全范围。
常州市护理专业新生负性生活事件应激量与伤害发生关系

目的了解护理专业学生负性生活事件应激量和情绪特征等因素对伤害发生的影响,为预防青少年伤害的发生提供基础数据。方法采取前瞻性队列研究的方式,于2012年10月选取常州市某所卫生类高职院校护理专业428名新生[男性21人(4.9%),女性407人(95.1%)],采用青少年生活事件量表(ASLEC)、Beck焦虑量表(BAI)、Beck抑郁自评量表(BDI)、家庭功能指数量表(APGAR),通过问卷调查的形式取得基线资料,并在2015年5月进行随访。采用Logistic回归的方法建立统计模型并分析负性生活事件应激量与伤害发生的关系。结果伤害的发生率为21.03%。单因素分析显示伤害的发生与随访期焦虑状况有关(t = 2.244,P <0.05);多因素Logistic回归结果显示,基线期负性生活事件的受惩罚因子应激量每提高1分,伤害的发生风险增加6.8%(RR = 1.068,P <0.05);调整其它影响因素后下降至5.9%(aRR = 1.059,P <0.05),调整变量中随访期焦虑状况评分每提高1分,所对应的伤害发生风险增加4.3%(RR = 1.043,P <0.05)。结论入学时期的部分负性生活事件和离校实习前的焦虑状况,会增加护理专业学生伤害发生的风险。
重症急性胰腺炎合并十二指肠瘘一例

本例患者为SAP并发十二指肠瘘,病程长、病情复杂,降钙素原单独指导治疗的准确性有限,重视各项指标的联合评估并结合患者症状体征及影像学检查有助于外科医师判断病情严重程度、调整抗菌药物的使用及选择合理的治疗方式。
关节镜下穿骨缝线方式治疗肩袖损伤的早期临床疗效

肩袖损伤是常见的中老年疾病,对于存在症状且保守治疗无效的患者,手术方式大多采用带线锚钉的肩袖缝合术,而内固定耗材费用较高,增加了患者的经济负担。近年来对关节镜下穿骨缝线缝合技术的生物力学及临床研究结果表明,穿骨缝线方式缝合强度与带线锚钉方式相近,临床效果可靠,且具有占骨量少,增加肌腱与骨质的有效接触面积,减弱肌腱在内排缝合点滑动的幅度,降低术后固定物周围骨溶解几率,肩袖在缝合后获得更好的血供,利于翻修等诸多优势,并且费用较低,可能成为未来肩袖缝合技术发展的方向。2017年12月至2018年2月,中国中医科学院望京医院运动医学科对9例肩袖损伤患者采用关节镜下穿骨缝线技术治疗,并进行早期临床效果观察,以此作为开展穿骨缝线方式肩袖缝合手术临床研究的参考依据。
国产千赫兹皮秒激光器在卫星激光测距领域的新进展

千赫兹皮秒激光器是决定卫星激光测距(satellite laser ranging, SLR)精度的核心设备.中国科学院光电研究院樊仲维项目组攻克了高主从脉冲比、脉冲光谱控制、高效率倍频转换等关键技术,获得单脉冲能量2.2 mJ/脉冲宽度、25.4 ps/光束质量、M2因子小于1.1的532 nm绿光皮秒激光输出,主从脉冲比超过3000:1,达到国际同类产品最好水平.与中国科学院上海天文台合作,实现了地球同步轨道卫星(3.6万千米)亚厘米级测距精度:北斗卫星(Compass-I3)单次测距精度8.5 mm,是我国卫星激光测距领域迄今达到的最好水平.
黑碳光化学老化的新机制

黑碳是大气气溶胶的重要组成成分,在长距离输送过程中会与大气中的环境介质相互作用发生老化,使得自身的化学组成、结构、吸湿性、光学性质等发生显著改变[1,2].黑碳对可见光和红外光具有强烈吸收,近年来的研究发现这些吸收的太阳光还能够引发黑碳自身的光化学反应,促进黑碳的老化,从而影响其环境行为与效应[3],因此大气中黑碳的光化学老化受到高度关注[4].
Assessment of gas and dust explosion in coal mines by means of fuzzy fault tree analysis

During the past decade, coal dust and gas explosions have been the most two serious types of disasters in China, threatening the lives of miners and causing significant losses in terms of national property. In this paper, an evaluation model of coal dust and gas explosions was constructed based on a fuzzy fault tree by taking the Xingli Coal Mine as a research site to identify the risk factors of coal dust and gas explosions. Furthermore, the hazards associated with such explosions were evaluated for this particular coal mine. After completing an on-site investigation, the fuzzy probabilities of basic events were obtained through expert scoring, and these expert opinions were then aggregated as trapezoidal fuzzy numbers to calculate the degrees of importance of all basic events. Finally, these degrees of importance were sorted. According to the resulting order, the basic events with higher probabilities were determined to identify key hazards in the daily safety management of this particular coal mine. Moreover, effective measures for preventing gas and coal dust explosions were derived. The fuzzy fault tree analysis method is of high significance in the analysis of accidental coal mine explosions and provides theoretical guidance for improving the efficiency of coal mine safety management in a scientific and feasible manner.
Weakening effects of hydraulic fracture in hard roof under the influence of stress arch

For the problem of hydraulic fracture propagation when weakening the hard roof in fully mechanized top-coal caving stope of ultra-thick coal seam, based on the stress arch theory and the fracture mechanics, a two-dimensional model for hydraulic fracture of the roof in the stope was established to investigate the propagation laws of hydraulic fracture. The result shows that, after mining, the principal stress direction of overlaying rock deflects to form the stress arch, whose arrow height and arch thickness increase with the increase of the mining width and the side pressure coefficient. Within the influence range of stress arch, the hydraulic fracture in hard roof deflects towards the stope direction in the course of propagation and forms the ‘‘arch” fracture, which cuts off the roof below the fracture in a laminated way. The deflection angle of hydraulic fracture increases with the increase of the mining width, but decreases with the increase of the side pressure coefficient and the fractured horizon. This research can provide theoretical basis for the application of hydraulic fracturing method in the stope roof weakening.
Evaluation of the 20 L dust explosibility testing chamber and comparison to a modified 38 L vessel for underground coal

The phenomenon of combustible dust explosions is present within many industries. Tests for explosibility of dust clouds per ASTM E1226 use a 20 L explosive chamber that places the combustible dust directly below the dispersion nozzle which generates a thorough mixture for testing purposes. However, in the underground coal mining industry, there are a number of geologic, mining, and regulatory factors that change the deposition scheme of combustible coal dust. This causes the atmosphere of a coal mine to have a variable rock dust-coal dust mixture at the time of ignition. To investigate the impact of this variable atmosphere, a series of lean explosibility tests were conducted on a sample of Pittsburgh Pulverized coal dust. These explosibility tests were conducted in a 38 L chamber with a 5 kJ Sobbe igniter. The 38 L chamber generates a variable air-dust mixture prior to ignition. The test results indicate that the 38 L chamber experiences reduced explosive pressures, and lower explosibility index values when compared to the 20 L chamber.
Guest editorial-Special issue on dynamic failures in underground mines

Significant improvements in mining practices over the years have enabled the mining industry to improve sustainability through increased productivity, health and safety. Improvements in health and safety management strategies have assisted mines to mitigate the risks associated with a number of major hazards. However, despite these improvements, there are still hazards that require significant research to improve our knowledge and mitigate risks. Dynamic failure in underground mines, such as coal burst and rock burst, is a hazard that poses significant safety risk and has caused many fatalities and injuries in mines around the world.