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Helix-sense-selective radical polymerization of bulky styrenic monomers: chiral induction and liquid crystallinity

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Science China Chemistry 2014年第7期57卷 982-994页

作者： ZHAO ZhiYuan bai jianwei ZHANG Jie LIU AnHua WAN XinHua Beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular Engineering Peking University Polymer Materials Research Center College of Materials Science and Chemical Engineering Harbin Engineering University Key Laboratory of High Performance Ceramic Fibers of Ministry of Education College of Materials Xiamen University

Eight chiral vinylterphenyl monomers,(+)-2,5-bis{4′-[(S)-1″-methylpropyloxy]phenyl}styrene(Ia),(+)-2,5-bis{4′-[(S)-2″-methylbutyloxy]phenyl}styrene(Ib),(+)-2,5-bis{4′-[(S)-3″-methylpentyloxy]phenyl}styrene(Ic),(+)-2,5-bis{4′-[(S)-4″-methylhexyloxy]phenyl}styrene(Id),(?)-2,5-bis{4′-[(R)-1″-methylpropyloxy]phenyl}styrene(Ie),(+)-2-{4′-[(S)-1″-methylpropyloxy]phenyl}-5-{4′-[(R)-1″-methylpropyloxy]phenyl}styrene(IIa),(?)-2-{4′-[(R)-1″-methylpropyloxy]phenyl}-5-{4′-[(S)-1″-methylpropyloxy]phenyl}styrene(IIb),and(+)-2-{4′-[(S)-2′′-methylbutyloxy]phenyl}-5-{4′-[(S)-1″-methylpropyloxy]phenyl}styrene(III),were synthesized and radically polymerized.These molecules were designed to further understand long-range chirality transfer in radical polymerization and to possibly tune the chiroptical properties of the polymers by varying the spatial configuration,position,and various combination of the stereogenic centers at the ends of p-terphenyl pendants.The resultant polymers adopted helical conformations with a predominant screw sense.When the stereogenic centers ran away from the terphenyl group as in Ib?d,the corresponding polymers changed the direction of optical rotation in an alternative way and showed no obvious stereomutation upon annealing in tetrahydrofuran.The two stereogenic centers of IIa,IIb,and III acted concertedly in chiral induction,whereas those of Ia and Ie played a counteractive role.The five polymers derived from Ia,Ie,IIa,IIb,and III underwent stereomutation when annealed in tetrahydrofuran.The polymers PIa?e had good thermal stability and high glass transition temperatures(Tgs).They generated liquid crystalline phases at above Tgs that could be kept upon cooling,with the exception of PIe.This result was consistent with the extended helical structures.

关键词：自由基聚合反应苯乙烯单体手性诱导螺旋构象玻璃化转变温度结晶液体联苯基

Sulfur vacancies-doped Sb_(2)S_(3) nanorods as high-efficient electrocatalysts for dinitrogen fixation under ambient conditions

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Green Energy & Environment 2022年第4期7卷 755-762页

作者： Xuyan Wang jianwei bai Yantao Wang Xiaoying Lu Zehua Zou Junfeng Huang Cailing Xu State Key Laboratory of Applied Organic Chemistry Laboratory of Special Function Materials and Structure Design of the Ministry of EducationCollege of Chemistry and Chemical EngineeringLanzhou UniversityNo.222 Tianshui South RoadLanzhou730000China Lanzhou No.11 Middle School No.523 Pingliang RoadLanzhou730000China

Tuning surface electron transfer process by sulfur(S)-vacancies engineering is an efficient strategy to develop high-efficient catalysts for electroreduction N_(2) reaction(NRR). Herein, the distinct Sb_(2)S_(3) nanorods with S-vacancies(Sv-Sb_(2)S_(3)) have been synthesized by a simple twostep method including hydrothermal and hydrogenation in H_(2)/Ar atmosphere, which shows improved performance for NRR with the NH_(3) yield rate of 10.85 μg h^(-1) mgcat^(-1) at-0.4 V vs. RHE, the faradaic efficiency(FE) of 3.75% at -0.3 V vs. RHE and excellent stability for 24 h, largely outperforming bulk Sb_(2)S_(3). X-ray photoelectron spectroscopy(XPS) and density function theory(DFT) calculations demonstrate that the abundant S-vacancies can create an electron-deficient environment and modulate the electron delocalization in Sv-Sb_(2)S_(3), which can not only facilitate the N_(2) molecule adsorption, but also activate the N≡N, resulting in the enhanced performance for NRR.

关键词： Electrocatalyst N_(2)electroreduction reaction Vacancies Defect engineering

郑州市冬春季相对湿度和PM_(2.5)的关系

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河南科技 2024年第1期51卷 109-115页

作者：张雯白建伟张宁韦贞鸽李俊杰郑州市生态环境局河南郑州450007 郑州市生态环境监测和安全中心河南郑州450007 河南省郑州生态环境监测中心河南郑州450007

【目的】探究郑州市2019—2023年冬春季(11月至次年4月)PM_(2.5)浓度与相对湿度的关系,为开展城市PM_(2.5)监测和道路洒水作业提出建议。【方法】基于PM_(2.5)浓度及湿度、风速、降水、气温等气象观测数据,在STATA软件中建立多元逻辑回... 详细信息

【目的】探究郑州市2019—2023年冬春季(11月至次年4月)PM_(2.5)浓度与相对湿度的关系,为开展城市PM_(2.5)监测和道路洒水作业提出建议。【方法】基于PM_(2.5)浓度及湿度、风速、降水、气温等气象观测数据,在STATA软件中建立多元逻辑回归模型,设定参照组,分析PM_(2.5)随相对湿度的变化趋势。【结果】2019—2023年冬春季郑州市PM_(2.5)均值由72.41μg/m^(3)降为61.42μg/m^(3),降幅为15.2%。在相对湿度低于80%时,随着相对湿度增大,PM_(2.5)出现在较高浓度区间的概率也增大,且该结果具有统计显著性。【结论】空气中的水分会促进PM_(2.5)前体物生成二次颗粒物,并导致细颗粒物吸水进而增加重量,但相对湿度过高时可能由于降雨冲刷而导致PM_(2.5)浓度下降。建议在进行PM_(2.5)监测时充分剔除湿度对测量值的影响,在道路洒水作业前也要全面考虑气象条件及大气污染状况。

关键词：郑州相对湿度(RH) PM_(2.5) 监测

Assessing forest sustainability trajectory with temporal changes in timber output and ecological reserve: the case of China

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Journal of Forestry Research 2018年第1期29卷 171-176页

作者： jianwei bai Yang Zhao Longyu Shi Fengri Li School of Forestry Northeast Forestry University Department of Forest Resources State Forestry Administration Key Lab of Urban Environment and Health Institute of Urban Environment Chinese Academy of Sciences

We classified forest resources into four modes：high timber output and high ecological reserve（Mode T-E）; high timber output and low ecological reserve（Mode T-e）; low timber output and low ecological reserve（Mode t-e）; and low timber output and high ecological reserve（Mode t-E）. Ecological reserve is stand volume per unit area of natural forests and total area of natural forests;timber output is defined as total area of timber forests and unit area of timber production. We used this classification system to examine forest development in China between1950 and 2013. Data were acquired mainly from forest inventory statistics published by China’s Forestry Administration between the 1970 s and 2013. I Information from the 1950 s was acquired from relevant literature. Our analysis suggests that China’s forest resources transitioned from Mode t-E to Mode T-e during the period between the early 1950 s and late 1970 s, resulting in the destruction of both ecological vigor and timber resources. During the following 20 years, strategies were implemented to improve the ecological reserve and increase timber supply,resulting in a decline in the rate of forest degradation. Over the past decade, China’s forest resources have reached Mode T-E as a result of improvements in both the ecological reserve and the timber supply. Currently, the total area of timber forests is relatively low, representing the limiting factor for improvement in overall forest functionality. Nevertheless, along with increased efforts to protect natural forests and develop fast-growing forest plantations, it is hopeful that China’s forest resources will achieve a sustainable state. The four-mode TOER（timber output, ecological reserve） method introduced in this paper is a simple but an effective approach for characterizing the overall quality and quantity of forest resources. The data used for this type of evaluation are typically easy to obtain and reliable. This methodology has potential to be applied to forests in various regions and countries.

关键词： Ecological vigor Forest assessment Natural forests Sustainable forestry Timber

Coal-based activated carbon prepared by H2O activation process for supercapacitors using response surface optimization method

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Frontiers of Chemical Science and Engineering 2024年第6期18卷 31-40页

作者： Shanxin Xiong Fengyan Lv Chenxu Wang Nana Yang Yukun Zhang Qingyong Duan Shuaishuai bai Xiaoqin Wang Zhen Li jianwei Xu College of Chemistry and Chemical Engineering Xi’an University of Science and TechnologyXi’an 710054China Key Laboratory of Coal Resources Exploration and Comprehensive Utilization Ministry of Land and ResourcesXi’an 710021China Institute of Sustainability for Chemicals Energy and EnvironmentJurong Island 627833Singapore

The scalable production of high grade activated carbon from abundant coal for supercapacitors application is an efficient way to achieve high value-added utilization of coal sources.However,this technology is challenging due to lack of comprehensive understanding on the mechanism of activation process and effect of external factors.In this paper,the effect of activating temperature and time on the specific capacitance of coal-based activated carbon prepared by H2O steam activation was studied using the response surface method.Under optimal conditions,coal-based activated carbon exhibits the largest specific capacitance of 194.35 F·g^(−1),thanks to the appropriate pore/surface structure and defect degree.Density functional theory calculations explain in detail the mechanism of contraction of aromatic rings and overflow of H2 and CO during the activation.Meanwhile,oxygen-containing functional groups are introduced,contributing to the pseudocapacitance property of coal-based activated carbon.This mechanism of reactions between aromatic carbon and H2O vapor provides understanding on the role of water during coal processing at the molecular level,offering great potential to regulate product distribution and predict rate of pore generation.This insight would contribute to the advancement of other coal processing technology such as gasification.

关键词： response surface optimization coal-based activated carbon supercapacitor activating mechanism

Screening for metastasis-related genes in mouse melanoma cells through sequential tail vein injection

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Biophysics Reports 2024年第1期10卷 15-21页

作者： Qinggang Hao Rui Dong Weiyu bai Dong Chang Xinyi Yao Yingru Zhang Huangying Xu Huiyan Li Xiang Kui Feng Wang Yan Wang Chengqin Wang Yujie Lei Yan Chen Junling Shen Lei Sang Yan bai jianwei Sun Center for Life Sciences Yunnan Key Laboratory of Cell Metabolism and Diseases State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan School of Life Sciences Yunnan University Key Laboratory of Tumor Immunological Prevention and Treatment of Yunnan Province Yan'an Hospital Affiliated to Kunming Medical University Shandong Provincial Key Laboratory of Animal Resistance Biology Collaborative Innovation Center of Cell Biology in Universities of Shandong Center for Cell Structure and Function Institute of Biomedical Science College of Life Sciences Shandong Normal University Department of Pathology The Second Affiliated Hospital of Kunming Medical University State Key Laboratory of Bioactive Molecules and Druggability Assessment Institute of Genomic Medicine College of Pharmacy Jinan University Department of Pathology School of Basic Medicine Qingdao University Department of Thoracic Surgery Yunnan Cancer Hospital & The Third Affiliated Hospital of Kunming Medical University & Yunnan Cancer Center

Tumor metastasis, responsible for approximately 90% of cancer-associated mortality, remains poorly understood. Here in this study, we employed a melanoma lung metastasis model to screen for metastasis-related genes. By sequential tail vein injection of mouse melanoma B16F10 cells and the subsequently derived cells from lung metastasis into BALB/c mice, we successfully obtained highly metastatic B16F15 cells after five rounds of in vivo screening. RNA-sequencing analysis of B16F15 and B16F10 cells revealed a number of differentially expressed genes, some of these genes have previously been associated with tumor metastasis while others are novel discoveries. The identification of these metastasis-related genes not only improves our understanding of the metastasis mechanisms, but also provides potential diagnostic biomarkers and therapeutic targets for metastatic melanoma.

关键词： Melanoma Lung metastasis model Gene screening Tail vein injection

Thermal Optimization of High-power Vertical Cavity Surface Emitting Laser Arrays

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Phase Ib study of anti-EGFR antibody(SCT200) in combination with anti-PD-1 antibody(SCT-I10A) for patients with RAS/BRAF wild-type metastatic colorectal cancer

Faguang Xuebao/Chinese Journal of Luminescence 2024年第6期45卷 970-977页

作者： Xia, Yuqi Mu, Jingfei Zhou, Yinli Zhang, Xing Zhang, jianwei Chen, Chao Yuan, Gaohui Zhang, Zhuo Liu, Tianjiao bai, Haopeng Xu, Yuehui Sun, Jingjing Ning, Yongqiang Wang, Lijun State Key Laboratory of Luminescence and Applications Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences Changchun 130033 China University of Chinese Academy of Sciences Beijing 100049 China

n this study，we designed a new parameter，the temperature impact factor，which considers the spacing between vertical-cavity surface-emitting laser（VCSEL）array units，size of the oxidation aperture，number of units，and the input current，and can be used to characterize the degree of thermal crosstalk in the array. Based on this，we designed an optimization layout algorithm for the VCSEL array and established a thermal-electric coupling model to verify the benefits of the optimized layout on temperature characteristics. Compared with the conventional layout，the temperature rise was reduced by 5%. In addition，under the condition of fixed current density and luminous area，reduction of the oxidation aperture and increasing the number of units can effectively improve the temperature characteristics of the VCSEL array. The average temperature of the 10 μm oxidation aperture was 30 K lower than that of the 30 μm oxidation aperture. The research results show that the impact of thermal crosstalk in the VCSEL array is effectively reduced and provide guidance for the design of the VCSEL array. © 2024 Editorial Office of Chinese Optics. All rights reserved.

关键词： Oxidation

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Cancer Biology & Medicine 2024年第7期 636-650页

作者： Ming bai Yao Lu Chunmei Shi jianwei Yang Wei Li Xianli Yin Chenghui Huang Lin Shen Liangzhi Xie Yi Ba Department of GI Medical Oncology Tianjin Medical University Cancer Institute & Hospital National Clinical Research Center for Cancer Key Laboratory of Cancer Prevention and TherapyTianjin Tianjin's Clinical Research Center for Cancer Tianjin Key Laboratory of Digestive Cancer Fujian Medical University Union Hospital Fujian Provincial Cancer Hospital Cancer Center The First Hospital of Jilin University Department of Medical Oncology Gastroenterology and Urology Hunan Cancer Hospital Affiliated Cancer Hospital of Xiangya School of Medicine Central South University Department of Oncology The Third Xiangya Hospital Central South University Department of Gastrointestinal Oncology Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing) Peking University Cancer Hospital and Institute Beijing Engineering Research Center of Protein and Antibody Sinocelltech Ltd. Department of Cancer Center Peking Union Medical College Hospital Chinese Academy of Medical Sciences

Objective: This study evaluated the safety and efficacy of an anti-epidermal growth factor receptor(EGFR) antibody(SCT200) and an anti-programmed cell death 1(PD-1) antibody(SCT-I10A) as third-line or subsequent therapies in patients with rat sarcoma viral oncogene(RAS)/v-raf murine sarcoma viral oncogene homolog B(BRAF) wild-type(wt) metastatic colorectal cancer(mCRC).Methods: We conducted a multicenter, open-label, phase Ib clinical trial. Patients with histologically confirmed RAS/BRAF wt m CRC with more than two lines of treatment were enrolled and treated with SCT-I10A and SCT200. The primary endpoints were the objective response rate(ORR) and safety. The secondary endpoints included disease control rate(DCR), progression-free survival(PFS), and overall survival(OS).Results: Twenty-one patients were enrolled in the study through January 28, 2023. The ORR was 28.57% and the DCR was 85.71%(18/21). The median PFS and OS were 4.14 and 12.84 months, respectively. The treatment-related adverse events(TRAEs) were tolerable. Moreover, compared with the monotherapy cohort from our previous phase I study evaluating SCT200 for RAS/BRAF wt m CRC in a third-line setting, no significant improvements in PFS and OS were observed in the combination group.Conclusions: SCT200 combined with SCT-I10A demonstrated promising efficacy in previously treated RAS/BRAF wt m CRC patients with an acceptable safety profile. Further head-to-head studies with larger sample sizes are needed to validate whether the efficacy and safety of combined anti-EGFR and anti-PD-1 therapy are superior to anti-EGFR monotherapy in the third-line setting.(Registration No. NCT04229537).

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240 nm AlGaN-based deep ultraviolet micro-LEDs:size effect versus edge effect

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Journal of Semiconductors 2024年第1期45卷 55-62页

作者： Shunpeng Lu Jiangxiao bai Hongbo Li Ke Jiang jianwei Ben Shanli Zhang Zi-Hui Zhang Xiaojuan Sun Dabing Li State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Electronic Materials and Devices of Tianjin School of Electronics and Information EngineeringHebei University of TechnologyTianjin 300401China

240 nm AlGaN-based micro-LEDs with different sizes are designed and fabricated.Then,the external quantum efficiency(EQE)and light extraction efficiency(LEE)are systematically investigated by comparing size and edge effects.Here,it is revealed that the peak optical output power increases by 81.83%with the size shrinking from 50.0 to 25.0μm.Thereinto,the LEE increases by 26.21%and the LEE enhancement mainly comes from the sidewall light extraction.Most notably,transversemagnetic(TM)mode light intensifies faster as the size shrinks due to the tilted mesa side-wall and Al reflector design.However,when it turns to 12.5μm sized micro-LEDs,the output power is lower than 25.0μm sized ones.The underlying mechanism is that even though protected by SiO2 passivation,the edge effect which leads to current leakage and Shockley-Read-Hall(SRH)recombination deteriorates rapidly with the size further shrinking.Moreover,the ratio of the p-contact area to mesa area is much lower,which deteriorates the p-type current spreading at the mesa edge.These findings show a role of thumb for the design of high efficiency micro-LEDs with wavelength below 250 nm,which will pave the way for wide applications of deep ultraviolet(DUV)micro-LEDs.

关键词： AlGaN deep ultraviolet micro-LEDs light extraction efficiency size effect edge effect