Coordinated Mining Procedures of Open Pit Mines Based on River Management

This paper primarily concerns the effective coordination of the procedures and methods employed in open pit mining operations under the background of river management.The central objective of this study is to identify a viable approach for ensuring rational and efficient development of open pit mineral resources while simultaneously protecting and restoring the ecological environment of the river.This approach should facilitate the realization of a harmonious symbiosis between mining and river management.The intricate mutual influence relationship between river management and open pit mining is first analyzed in depth,which provides a solid foundation for the subsequent coordination strategy development.In light of the aforementioned considerations,a set of coordination procedures for open pit mining based on river management conditions is proposed.These procedures emphasize the integration of river protection into the overall layout of mining at the planning stage.The implementation of scientific mining schemes,accompanied by rigorous control of the scope and depth of mining operations,has proven to be an effective means of reducing the impact of mining activities on river environments.This approach has also facilitated the achievement of a balance and coordination between mining and river management.

Construction of molecule-selective mixed matrix membranes with confined mass transfer structure

Extraordinary mass transfer phenomenon is usually found when the small molecules pass through a confined structure, whose effective size is commensurate with the mean free path of the molecules. Small changes in the confined mass transfer structure(including size, morphology and properties) will lead to significant fluctuations of the mass transfer coefficient. The mass transfer of the penetrant molecules in the dense membranes for pervaporation, gas separation and so on, is located in the scope of confined mass transfer. Incorporating nanofillers into polymer matrix to construct mixed matrix membranes(MMMs) is an effective approach to tune the confined mass transfer structure and enhance the performance of the widely used polymeric membranes. This review focuses on the construction and manipulation of the confined structure in the polymeric membranes via incorporating one-dimensional(1D), two-dimensional(2D) and three-dimensional(3D) fillers.The comparison of the MMMs for pervaporation is summarized, and the research prospective of the MMMs is provided.

Aqueous Two-Phase Interfacial Assembly of COF Membranes for Water Desalination

Aqueous two-phase system features with ultralow interfacial tension and thick interfacial region,affording unique confined space for membrane assembly.Here,for the first time,an aqueous two-phase interfacial assembly method is proposed to fabricate covalent organic framework(COF)membranes.The aqueous solution containing polyethylene glycol and dextran undergoes segregated phase separation into two water-rich phases.By respectively distributing aldehyde and amine monomers into two aqueous phases,a series of COF membranes are fabricated at water-water interface.The resultant membranes exhibit high NaCl rejection of 93.0-93.6% and water permeance reaching 1.7-3.7 L m^(−2) h^(−1) bar^(−1),superior to most water desalination membranes.Interestingly,the interfacial tension is found to have pronounced effect on membrane structures.The appropriate interfacial tension range(0.1-1.0 mN m^(−1))leads to the tight and intact COF membranes.Furthermore,the method is extended to the fabrication of other COF and metal-organic polymer membranes.This work is the first exploitation of fabricating membranes in all-aqueous system,confering a green and generic method for advanced membrane manufacturing.

Airline Disruption Management:A Review of Models and Solution Methods

The normal operation of aircraft and flights can be affected by various unpredictable factors,such as severe weather,airport closure,and corrective maintenance,leading to disruption of the planned schedule.When a disruption occurs,the airline operation control center performs various operations to reassign resources(e.g.,flights,aircraft,and crews)and redistribute passengers to restore the schedule while minimizing costs.We introduce different sources of disruption and corresponding operations.Then,basic models and recently proposed extensions for aircraft recovery,crew recovery,and integrated recovery are reviewed,with the aim of providing models and methods for different disruption scenarios in the practical implementation of airlines.In addition,we provide suggestions for future research directions in these topics.

Visible-light all-fiber vortex lasers based on mode selective couplers

We demonstrate visible-light all-fiber vortex lasers by incorporating the home-made mode selective couplers (MSCs). The MSC at green or red wavebands is fabricated by specially designing and fusing a single-mode fiber (SMF) and a few-mode fiber (FMF). The MSCs inserted into visible fiber cavities act as power splitters and mode converters from the LP01 to LP11 mode at green and red wavelengths, respectively. The red-light all-fiber vortex laser is formed by a 10-cm Pr3+/Yb3+:ZBLAN fiber, a fiber Bragg grating, a fiber end-facet mirror and the MSC at 635 nm, which generates vortex beams with OAM±1 at 634.4 nm and an output power of 13 mW. The green-light all-fiber vortex laser consists of a 12-cm Ho3+:ZBLAN fiber, two fiber pigtail mirrors, and the MSC at 550 nm, which generates vortex beams with OAM±1 at 548.9 nm and an output power of 3 mW.

Acute headache in general neurology of China: Cause changes and predictors of short-term outcome

Background: Although patients with acute headache frequently present in emergency department, the causes and predictors of short-term outcome in patients with acute headache in general neurology have not been adequately investigated. Methods: We prospectively reviewed the medical records of 130 hospitalized acute headache pa-tients in general neurology of China. Their initial CT scan was assessed, as was their lumbar puncture (LP) examination if performed. Results: The main cause of acute headache was acute secondary headache (80.8%), which was mainly attributable to acute cerebrovascular events (72.4%) followed by intracranial infection (19.0%). Among the 10.8% of patients who died during hospitalization most (85.7%) had subarachnoid hemorrhage (SAH). Significant predictors of survival were severe headache versus thunderclap headache, meningismus, de-layed loss of consciousness, and hypertension (all p < 0.05). Multiple logistic regression analyses showed significant differences in severe headache or thunderclap headache (OR, 0.255;95%CI, 0.066 - 0.990;p = 0.048) and delayed loss of consciousness (OR, 0.060;95%CI, 0.016 - 0.224, p = 0.000) between patients who died and those who survived. Conclusions: The main underlying cause of hospitalized acute headache was acute cerebrovascular events. Severe headache and delayed loss of consciousness are predictors for poor outcome of acute headache.

热活化延迟荧光蓝光小分子取代基效应的研究进展

近年来,作为第三代有机发光二极管(organic light-emitting diodes,OLED)发光材料的热活化延迟荧光(thermally activated delayed fluorescence,TADF)材料受到了学术界和产业界的广泛关注.TADF分子由于其单线态与三线态之间的能级差较小,三线态激子可以被环境热活化而通过反系间窜越上转换至单线态,理论上可实现100%的激子利用率,从而使得OLED器件外量子效率显著提高.TADF材料被认为是突破高效稳定有机电致蓝光发射瓶颈的潜在解决方案.一般,TADF分子为含有电子给体(donor,D)和电子受体(acceptor,A)的纯有机推拉电子体系.通过改变给体单元和受体单元的结构、数量和取代基及其位置可以有效调节TADF分子的单线态-三线态能级差、前线轨道分布、聚集态结构、电致发光颜色及其性能.同时取代基在调控给、受体单元的推拉电子能力及TADF材料的分子构型、聚集态结构和稳定性等物化特性方面扮演着非常重要的角色.本综述分别对D-A型和多重共振型TADF蓝光分子的取代基效应进行了综述,以期为高效稳定的蓝光TADF分子的设计合成提供有效借鉴.

Towards visible-wavelength passively mode-locked lasers in all-fibre format

Mode-locked fibre lasers(MLFLs)are fundamental building blocks of many photonic systems used in industrial,scientific and biomedical applications.To date,1–2μm MLFLs have been well developed;however,passively modelocked fibre lasers in the visible region(380–760 nm)have never been reported.Here,we address this challenge by demonstrating an all-fibre visible-wavelength passively mode-locked picosecond laser at 635 nm.The 635 nm mode-locked laser with an all-fibre figure-eight cavity uses a Pr/Yb codoped ZBLAN fibre as the visible gain medium and a nonlinear amplifying loop mirror as the mode-locking element.First,we theoretically predict and analyse the formation and evolution of 635 nm mode-locked pulses in the dissipative soliton resonance(DSR)regime by solving the Ginzburg-Landau equation.Then,we experimentally demonstrate the stable generation of 635 nm DSR mode-locked pulses with a pulse duration as short as~96 ps,a radio-frequency signal-to-noise ratio of 67 dB and a narrow spectral bandwidth of <0.1 nm.The experimental results are in excellent agreement with our numerical simulations.In addition,we also observe 635 nm noise-like pulse operation with a wide(>1 nm)and modulated optical spectrum.This work represents an important step towards miniaturized ultrafast fibre lasers in the visible spectral region.

Metallaaromatics Containing Main-group Heteroatoms

Metallaaromatics are metallacycles that are derived from the formal replacement of a carbon atom in the framework of organic aromatics with a metal fragment. As an important subclass of metallaaromatics, metallaaromatics that contain main-group heteroatoms have attracted considera- ble attention. In the past ten years, we have developed several new methods to construct metallaaromatics as well as those containing main-group het- eroatoms, such as metallapyridine, metallapyridinium, metallapyridyne, metallafuran, metallabenzothiazole, metallabenzoxazole, metallabenzthiophene, aza-metallapentalene and some novel tricyclic/tetracyclic metallaaromatics. In addition, interesting reactions such as the first hetero-Diels Aider reaction between 1-metalla-1,3-dienes and nitriles, the first intramolecular nucleophilic aromatic substitution （SNAr） reaction of metallabenzene, and the first iodine-mediated electrophilic cyclizations of a metallabenzene complex were demonstrated. In this account, recent and novel approaches for their synthesis and property analyses are summarized. The structural diversity and unique properties of metallaaromatics containing main-group heteroatoms will strongly inspire further investigation of these species and provide a wide range of potential applications.

Independent Prognostic Value of High-sensitivity C-reactive Protein in Patients with Coronary Artery Ectasia

Background：Despite its severity,coronary artery ectasia （CAE） is still poorly understood.High-sensitivity C-reactive protein （hs-CRP） has been recognized as a prognostic factor in some cardiovascular diseases but not assessed in CAE.The aim of this observational study was to investigate the prognostic value of hs-CRP in CAE.Methods：Our analysis evaluated the effect of the baseline hs-CRP on cardiovascular events （CVs） （cardiac death and nonfetal myocardial infarction） in consecutively enrolled stable CAE patients.We used the Cox proportional hazards regression models to examine the association between baseline hs-CRP level and follow-up CVs in CAE.The net reclassification improvement and integrated discrimination improvement （IDI） of hs-CRP were also assessed.Results：We obtained the follow-up results of 540 patients over a median follow-up period of 36 （37.41 ± 15.88） months.The multivariable Cox analysis showed that the hs-CRP was a significant predictor of adverse outcomes in CAE （hazard ratio [HR]：2.99,95% confidence interval [CI]：1.31-6.81,P =0.0091）.In Kaplan-Meier analysis,the group with hs-CRP 〉3 mg/L had a lower cumulative 66-month event-free survival rate （log-rank test for trend,P =0.0235） and a higher risk ofCVs （HR =2.66,95% CI：1.22-5.77,P =0.0140） than the group with hs-CRP ≤3 mg/L.Hs-CRP added predictive information beyond that given by the baseline model comprising the classical risk factors （P value for IDI =0.0330）.Conclusions：A higher level of hs-CRP was independently associated with cardiac death and nonfatal myocardial infarction in CAE patients.The hs-CRP level may therefore provide prognostic information for the risk stratification of CAE patients.

Metallacycle Expansion and Annulation:Access to Tetrazolo-Fused Osmacycles by Reaction of Cyclic Osmium Carbyne with Sodium Azide

The reaction of a cyclic osmacarbyne complex with sodium azide led to the formation of a ring expansion-annulation product,a unique tetrazole annulated polycyclic metallacycle.The reaction proceeds by insertion of a nitrogen atom into the metal carbon triple bond and the second azide participating in the[2+3]cycloaddition.The successful isolation and characterization of metalla-azirine complex and metallapyridinium derivative strongly validated the mechanism for the formation of the title complex.The work demonstrates a new strategy to enrich the varieties of aza-metallacyclic species.

通货膨胀预期、非对称性贬值与利润跨期转移——基于账税差异的实证检验

通货膨胀会将财富从债权人向债务人转移,因而对企业资产与负债具有非对称性影响。所得税作为一种现实债务,在通货膨胀条件下推迟支付会降低企业实际缴税成本。文章选择2003—2014年非金融类上市公司为研究样本,分别使用基于央行储户调查报告中的预期指数模型、随机游走模型与简单菲利普斯曲线模型估算预期通货膨胀率,实证检验通货膨胀预期是否导致企业通过利润跨期转移而推迟缴税。研究发现:当预期通货膨胀率越高时,企业利润跨期转移程度越大,且在名义税率越高、税收征管力度越宽松、盈利能力越强的公司中,面临通货膨胀预期条件下进行利润跨期转移的动机越显著。进一步研究发现:企业在预期通货膨胀率较高时,主要通过将未来成本费用转移至当期来实现利润跨期转移;上述研究结论不仅在排除税制改革因素的影响后依然稳健,而且还发现在通货膨胀预期条件下,所得税税率上升会显著抑制利润推迟行为,所得税税率下降会进一步加剧利润推迟行为。以上研究不仅揭示了通货膨胀预期影响微观企业会计行为的具体作用机理,而且为企业使用会计工具对冲通货膨胀、进而为公司创造价值提供经验证据。

Design,synthesis and antimycobacterial activity of novel nitrobenzamide derivatives

We report herein the design and synthesis of a series of novel nitrobenzamide derivatives. Results reveal that many of them display considerable in vitro antitubercular activity. Four N-benzyl or N- (pyridine-2-yl)methyl 3,5-dinitrobenzamides A6, All, Cl and C4 have not only the same excellent MIC values of<0.016 μg/mL against both drug-sensitive MTB strain H37 Rv and two drug-resistant clinical isolates as PBTZ169 and the lead 1, but also acceptable safety indices (SI > 1500), opening a new direction for further development.

Who Drives Environmental Governance of Enterprise:Official Tenure Evaluation or Five-Year Plan Target Assessment?

Based on the non-financial listed enterprises data from 2000 to 2014,this paper calculates the level of environmental governances of enterprises with environmental investment,and empirically analyzes the impact of provincial official tenure and Five-Year Plan target assessment on the environmental governance of enterprises.The results show that the enterprise environmental investment presents a significant periodic trend in the Five-Year Plan,while the trend is not significant in official’s tenure.The further test suggests that with the clear requirement of“environmental performance”incorporated into the performance evaluation system of local government officials,it has become significant in the periodic trend in the impact of officials’tenure on environmental investment.In contrast,the trend has become less prominent in the Five-Year Plan,which indicates that there is a substitute relation between the two evaluation systems.The mechanism test also finds that both environmental subsidies and pollution abatement expenditures present a significantly periodic trend in the Five-Year Plan.And official’s tenure plays a regulatory role in the Five-Year Plan periodic trend in the environmental governance of enterprise,showing that it is more significant when the time about officials’tenure evaluation is earlier than Five-Year Plan target assessment.The above results indicate that it is beneficial to improve local environment governance from the perspective of top institutional design by both strengthening the environmental evaluation.