Sub-100 fs watt-level Kerr-lens mode-locked Yb:CaYAlO4 laser with a gigahertz repetition rate

We report a 1.04 GHz high-power Kerr-lens mode-locked Yb:CaYAlO4 laser pumped by a single-mode fiber laser at 976 nm. Based on a bow-tie cavity, stable unidirectional mode-locked operation is obtained with an output coupler of 1.6%. The oscillator delivers pulses with an average power of 1.46 W and with the pulse duration of 99 fs, which, to the best of our knowledge, is the first gigahertz-level Kerr-lens mode-locked laser based on the Yb:CaYAlO4 gain medium. We believe that the watt-level solid-state femtosecond laser at GHz would be an excellent source for developing time-resolved broadband dual-comb spectroscopy

Effects of MVP regimen on operation and cancer tisswes of Lung Cancer patients

Background and objective Preoperative chemotherapy increases the difficulty and risk of patients爷operation. The aim of this study is to analyze the change of thoracic tissue, study the influence ofchemotherapy to operation, discuss the special aspects of surgical management and observe the pathological change of focus after chemotherapy. Methods 100 patients were chosen and randomly divided into two groups(operation first group, 50 cases; chemotherapy first group, 50 cases) . Some patient爷s pathological sections were observed to investigate focus morphological influence of preoperative chemotherapy and the clinical response rate were compared with pathological response rate. Results It was showed that preoperative chemotherapy conduced different degree thoracic tissue fibrosis. Data statistics demonstrated that there were no significance difference of the operation time, blood loss during operation and drainage volume in first day after operation between two groups. The preoperativechemotherapy increased the difficulty of operation because of tissue fibrosis and scarification, but the risk could be avoided by skillful operation. In first operation group, there were various pathological changes in tumor tissue and the pathological response rate was not completely accordance with the clinical response rate. The focus pathological response rate of two cycles chemotherapy was more higher than that of one cycle chemotherapy. Conclusion Chemotherapy increases the risks of operation. Surgeons carefulness and better skills during operation are the key points to avoid the hazards of surgery. Two preoperative chemotherapy cycles are more suitable for the patients

Accessing Tunable Afterglows from Highly Twisted Organic AIEgens via Effective Through-Space Conjugation

Nonaromatic, cross-conjugated, and highly twisted luminogens consisting of acylated succinimides demonstrate aggregation-induced emission (AIE) characteristics and tunable multicolor photoluminescence and afterglows in their single crystals. Effective through-space conjugation among different moieties bearing n/π electrons promote the SOC and ISC transitions and lead to diverse emissive clusters with concurrently rigidified conformations, thus allowing readily tunable emissions. Derived from it, the proof of concept application for advanced anti-counterfeiting is illustrated. These results should spur the rational design of novel nonaromatic AIEgens, and moreover advance the understanding of the origin of tunable multicolor afterglows

Research progress and prospect of gravity erosion in loess region

Gravity erosion is one of the most important types of soil erosion in the loess region, and it is the focus and difficulty of the current erosion research in the loess region. This paper systematically reviews the research progress of gravity erosion experimental observation methods, gravity erosion occurrence critical conditions, the relationship between gravity erosion and watershed water sediment, and gravity erosion process simulation and so on, It points out that the lack of monitoring capacity of gravity erosion process caused by the random, sudden and rapid characteristics of gravity erosion is the bottleneck of gravity erosion mechanism research, It is proposed that new techniques such as photogrammetry with strong anti-interference ability and high spatial-temporal resolution should be introduced to strengthen experimental observation; Integrating the long-term and short-term influencing factors of gravity erosion process, revealing the control mechanism of infiltration on the occurrence of gravity erosion, and clarifying the critical law of gravity erosion; Strengthen the study of critical conditions and redistribution mechanism based on process, and reveal the mechanism of gravity erosion material stabilization and sediment yield differentiation; The combination law of influencing factors in the process of gravity erosion and sediment yield is explored, the uncertainty mechanism of the process of erosion and sediment yield is analyzed, and the zoning method of gravity erosion prone areas is explored; A watershed water sediment coupling simulation model with the physical mechanism of gravity erosion is developed to deeply reveal the coupling relationship between gravity erosion and watershed water sediment process, and to provide reference for related research

Research progress and prospect of gravity erosion in loess region

Gravity erosion is one of the most important types of soil erosion in the loess region, and it is the focus and difficulty of the current erosion research in the loess region. This paper systematically reviews the research progress of gravity erosion experimental observation methods, gravity erosion occurrence critical conditions, the relationship between gravity erosion and watershed water sediment, and gravity erosion process simulation and so on, It points out that the lack of monitoring capacity of gravity erosion process caused by the random, sudden and rapid characteristics of gravity erosion is the bottleneck of gravity erosion mechanism research, It is proposed that new techniques such as photogrammetry with strong anti-interference ability and high spatial-temporal resolution should be introduced to strengthen experimental observation; Integrating the long-term and short-term influencing factors of gravity erosion process, revealing the control mechanism of infiltration on the occurrence of gravity erosion, and clarifying the critical law of gravity erosion; Strengthen the study of critical conditions and redistribution mechanism based on process, and reveal the mechanism of gravity erosion material stabilization and sediment yield differentiation; The combination law of influencing factors in the process of gravity erosion and sediment yield is explored, the uncertainty mechanism of the process of erosion and sediment yield is analyzed, and the zoning method of gravity erosion prone areas is explored; A watershed water sediment coupling simulation model with the physical mechanism of gravity erosion is developed to deeply reveal the coupling relationship between gravity erosion and watershed water sediment process, and to provide reference for related research

DNA Inspirited Rational Construction of Nonconventional Luminophores with Efficient and Color-Tunable Afterglow

Persistent room-temperature phosphorescence (p-RTP) from pure organics is attractive due to its fundamental importance and potential applications in molecular imaging, sensing, encryption, anticounterfeiting, etc.1-4 Recently, efforts have been also made in obtaining color-tunable p-RTP in aromatic phosphors5 and nonconjugated polymers6,7. The origin of color-tunable p-RTP and the rational design of such luminogens, particularly those with explicit structure and molecular packing, remain challenging. Noteworthily, nonconventional luminophores without significant conjugations generally possess excitation-dependent photoluminescence (PL) because of the coexistence of diverse clustered chromophores6,8, which strongly implicates the possibility to achieve color-tunable p-RTP from their molecular crystals assisted by effective intermolecular interactions. Here, inspirited by the highly stable double-helix structure and multiple hydrogen bonds in DNA, we reported a series of nonconventional luminophores based on hydantoin (HA), which demonstrate excitation-dependent PL and color-tunable p-RTP from sky-blue to yellowish-green, accompanying unprecedentedly high PL and p-RTP efficiencies of up to 87.5% and 21.8%, respectively. Meanwhile, the p-RTP emissions are resistant to vigorous mechanical grinding, with lifetimes of up to 1.74 s. Such robust, color-tunable and highly efficient p-RTP render the luminophores promising for varying applications. These findings provide mechanism insights into the origin of color-tunable p-RTP, and surely advance the exploitation of efficient nonconventional luminophores.</div