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| 1 | Cold hardiness estimation of Pinus densiflora var. zhangwuensis based on changes in ionic leakage, chlorophyll fluorescence and other physiological activities under cold stress显示文摘Pinus densiflora var. zhangwuensis grows fast,and its drought and salinity resistance are better than Pinus sylvestris var. mongolica. We compared cold hardiness and mechanisms of cold hardiness between the two species, to provide a theoretical basis for promoting and applying P.densiflora var. zhangwuensis in cold regions. A cold stress experiment was carried out on 3-year-old plantlets of P.densiflora var. zhangwuensis and P. sylvestris var. mongolica after hardening at five temperature regimes, 5,-10,-20,-40, and-60℃, respectively. Some indices of needle samples for both species were measured, such as relative conductivity(REL), maximum photochemical efficiency(F_v/F_m), malondialdehyde(MDA), catalase(CAT), proline(Pro), soluble sugar(SS), and stomata density. REL and MDA values of both species after hardening had the same trend of increasing, but the trend was opposite in F_v/F_mvalue with increasing cold stress. Compared with P. sylvestris var. mongolica, the P. densiflora var. zhangwuensis had smaller increases in REL and MDA,and a smaller decline in F_v/F_mduring cold stress. Compared to the control, REL growth of P. densiflora var.zhangwuensis and P. sylvestris var. mongolica at-60℃ were 0.41 and 0.60, and MDA growth was 29.94 mol g^-1FW and 47.80 mol g^-1FW, and F_v/F_mdeclines were 0.08 and 0.27. Half-lethal temperatures(LT_50) calculated by logistic equation for P. densiflora var. zhangwuensis and P.sylvestris var. mongolica were-58.23 and-50.34℃,respectively. These data suggest that cold resistance of P.densiflora var. zhangwuensis is stronger than that of P.sylvestris var. mongolica. Cold-resistance mechanisms of the two species differed. In response to cold stress, P.sylvestris var. mongolica had strong osmotic adjustment ability because of higher Pro and SS content, while P.densiflora var. zhangwuensis had strong antioxidant ability due to stronger CAT activity. Stomata density and diameter of P. densiflora var. zhangwuensis were smaller, as were single leaf area and number of leaves per plant, both characteristics promoting survival in a cold environment.Greater shoot height and total biomass of seedlings of P.densiflora var. zhangwuensis might be another reason for its stronger cold tolerance. | Peng Meng Xuefeng Bai Hongdan Li Xiaodong Song Xueli Zhang | 2015 | Journal of Forestry Research2015，26，3： | 8 |
| 2 | Synergistic Effect of Carbon Nanotubes and Layered Double Hydroxides on the Mechanical Reinforcement of Nylon-6 Nanocomposites显示文摘Synergistic effect in network formation of nylon-6(PA6) nanocomposites containing one dimensional(1D) multi-walled carbon nanotubes(CNTs) and two dimensional(2D) layered double hydroxide(LDH) platelets on improving the mechanical properties has been studied. Mechanical tests show that, with incorporation of 1 wt% LDHs and 0.5 wt% CNTs, the tensile modulus, the yield strength as well as the hardness of the ternary composite are greatly improved by about 230%, 128% and 110% respectively, as compared with neat PA6. This is mainly attributed to the unique, strong interactions between the CNTs and the LDHs as well as the jammed network-like structure thus formed between the nanofillers, as confirmed by the morphological observations. As compared with the binary nanocomposites, a much enhanced solid-like behavior in the terminal region of the rheological curves can clearly be observed for the ternary system, which also indicates the formation of a percolating filler network. | 刘天西 Hongdan Peng Yue-E Miao Weng Weei Tjiu Lu Shen 韦春 | 2014 | Chinese Journal of Polymer Science2014，32，10： | 2 |
| 3 | Heterogeneous ultrathin films of poly(vinyl aleohol)/layered double hy- droxide and montmorillonite nanosheets via layer-by-layer assembly显示文摘 | Huang Shu Cen Xi Peng Hongdan | 2009 | J Phys Chem B2009，113，15： | 1 |
| 4 | Prepara tion and mechanical properties of exfoliated CoAl layered double hydroxide(LDH)/polyamide 6 nanocomposites by in situ poly merization显示文摘 | Peng Hongdan Tjiu Wuiwui Chauhari Shen Lu | 2009 | Composites Science and Technology2009，69，78： | 1 |
| 5 | Iron-Catalyzed Cross-Electrophile Coupling of Inert C-O Bonds with Alkyl Bromides显示文摘An example of iron-catalyzed cross-electrophile couplingof inert C-O bonds with alkyl bromides via aniron/B_(2)pin_(2) catalytic system has been developed.Aryl and heteroaryl carbamates can smoothly undergothis transformation under mild conditions, deliveringthe alkylated products with good efficiency.This protocol exhibits good functional group compatibilityand enables the late-stage functionalizationof biorelevant compounds, thus providingexcellent opportunities for applications in medicinalchemistry. Control experiments and computationalstudies reveal that a high spin Fe(I/II/III) catalyticmechanism might be involved in this reactionthrough single electron transfer to activate alkylbromides, oxidative addition of aryl carbamates, andreductive elimination to form Csp^(2)-Csp^(3) bonds. | Shuo Chen Zijian Wang Shasha Geng Hongdan Zhu Zhengli Liu Yun He Qian Peng Zhang Feng | 2023 | CCS Chemistry2023，5，7： | 0 |
| 6 | Identification and attribute analysis of key stakeholders who influence multidrug-resistant tuberculosis prevention and control in China显示文摘Background There could be various stakeholders who influencing multidrug-resistant tuberculosis(MDR-TB)policy development and implementation,yet their attributes and roles remain unclear in practice.This study aimed to identify key stakeholders in the process of policy-making for MDR-TB control and prevention and to analyse the attributes and relationships of the stakeholders,providing evidence for further policy research on MDR-TB control.Methods This study was conducted from October 2018 to March 2019 and applied the stakeholder analysis guidelines and domestic stakeholder analysis.An initial candidate stakeholder list was developed by policy scanning.Ten experts were invited to identify these candidate stakeholders.The major attribute of these stakeholders were analysed using the Michell scoring method.Based on these results,the intertwined relationships among groups of stakeholders were analysed and mapped through a systematic scan of the policy and literature on MDR-TB control,as well as information obtained from the interviews.Results A list of 21 types of candidate stakeholders was developed after a literature review and policy scanning,of which 11 received 100%approval.After expert evaluation and identification(the total expert authority was 0.80),19 categories of stakeholders were approved and included in the stakeholder analysis.We categorized all of the stakeholders into three groups:(i)definitive stakeholders who are mainly involved in administrative departments and the Provincial Center for Disease Control and Prevention(CDC);(ii)expectant stakeholders who are mainly involved with MDR-TB patients,clinical departments of TB hospitals at different levels,community health care facilities,prefectural CDC and charity organizations;and(iii)latent stakeholders who mainly involved family members and neighbours of MDR-TB patients and TB related products manufacturers.Government departments and higher-level CDCs have strong decision-making power in developing MDR-TB control policies whereas the recommendations from service providers and the concerns of patients should be considered.Conclusions The MDR-TB prevention system was a multistakeholder cooperation system that was mainly led by government stakeholders.Enhancing communications with front-line service providers and patients on their unmet needs and evidence-based suggestions would highly benefit policy-making of MDR-TB prevention and control. | Bin Chen Hongdan Bao Xinyi Chen Kui Liu Ying Peng Wei Wang Fei Wang Jianmin Jiang Biao Xu | 2021 | Infectious Diseases of Poverty2021，10，4： | 0 |
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