发酵乳杆菌HCS08-005耐逆性及对体外细胞免疫调节作用的研究

目的 研究发酵乳杆菌(Lactobacillus fermentum) HCS08-005耐逆性及对体外细胞的免疫调节作用。方法 考察发酵乳杆菌HCS08-005的耐酸耐胆盐能力，并应用发酵乳杆菌HCS08-005细胞裂解物，处理小鼠单核巨噬细胞RAW264.7和小鼠脾脏细胞，用酶联免疫吸附测定试剂盒检测各类炎症因子包括肿瘤坏死因子-α (tumor necrosis factor-α，TNF-α)、白细胞介素-2 (inter-leukin-2，IL-2)、白细胞介素-12 (inter-leukin-12，IL-12)、γ干扰素(interferon-γ，IFN-γ)的表达水平。结果 显示发酵乳杆菌HCS08-005有较好的耐逆性，能够耐受酸和胆盐环境到达肠道发挥作用。不同浓度的发酵乳杆菌HCS08-005细胞裂解物对小鼠脾脏细胞和巨噬细胞分泌炎症因子均有极显著影响(P<0.01)，在质量浓度为100 μg/g时，IL-2分泌量为421.49 pg/g，TNF-α分泌量为161.23 pg/g，IFN-γ分泌量为846.14 pg/g，IL-12分泌量为12.88 pg/g，因子水平极显著提高(P<0.01)。结论 在体外细胞试验中，发酵乳杆菌HCS08-005有较好的耐逆性，对体外细胞有免疫调节作用。     

Type-II AsP/Sc2CO2 van der Waals heterostructure: an excellent photocatalyst for overall water splitting

In this work, we explore the application potential of AsP/M₂CO₂ (M = Sc, Zr) van der Waals heterostructures in photocatalytic water splitting through the first-principles calculations. The calculated results show that AsP/Zr₂CO₂ heterostructure possesses an unfavorable type-Ⅰ band alignment, whereas AsP/Sc₂CO₂ exhibits a desirable type-Ⅱ band alignment, which is beneficial for separating the photogenerated electron-hole pairs. Also, the band edge positions of AsP/Sc₂CO₂ heterostructure stride the redox potential of water, ensuring favorable reaction kinetics. Besides, the strong optical absorption of AsP/Sc₂CO₂ heterostructure in both visible and ultraviolet regions (especially up to 10⁻⁶ cm⁻¹ at about 250 nm) makes it possible to utilize solar energy effectively. Meanwhile, AsP/Sc₂CO₂ heterostructure has an exciton binding energy as low as 0.09 eV, which quantitatively illustrates the high separation efficiency of photogenerated charge carrier. Thus, the type-Ⅱ band alignment, suitable band edge position, strong light absorption, and low exciton binding energy together indicate that AsP/Sc₂CO₂ heterostructure is a potential photocatalytic material. In addition, the obvious redshift phenomenon in the optical spectrum of AsP/Sc₂CO₂ heterostructure shows that biaxial strain can improve its light capture capability. Also, the interconversion between type-Ⅱ and type-Ⅰ can be achieved by applying different strains. All these findings suggest that the novel AsP/Sc₂CO₂ heterostructure has significant application prospects in next-generation photovoltaic and photocatalytic devices.     

一种酰胺类沥青乳化剂的制备及性能研究

首先通过脂肪酸与酸酐反应，得到多元羧酸中间体，再将其与改性多乙烯多胺经过一系列反应合成一种酰胺类沥青乳化剂，采用傅里叶红外光谱对乳化剂结构进行表征。实验室对比测试了自制乳化剂与进口乳化剂的表面活性及其所制乳化沥青的性能。结果表明：两种乳化剂制备乳化沥青的各项性能指标均可满足微表处施工技术要求，且自制乳化剂具有较高的固含量和较好的储存稳定性，乳化沥青8 min即可破乳，用于微表处养护可快速开放交通；自制乳化剂价格仅为进口乳化剂的76.4%左右，应用前景良好。     

Development of a void ratio-moisture ratio-net stress framework for the prediction of the volumetric behavior of unsaturated granular materials

Despite extensive research on the behavior of unsaturated fine-grained materials, there is still a lack of understanding of the volumetric behavior of unsaturated granular materials. In this research, a model has been developed to predict the fundamental volumetric behavior of unsaturated granular materials through loading and wetting state paths. In this regard, a loading-wetting surface was developed in a space of void ratio-moisture ratio-net stress. A distinctive feature of the proposed model is the relative simplicity in obtaining the model parameters using conventional geotechnical testing equipment. Two types of recycled granular materials, commonly applied in unbound pavements were used, namely, recycled crushed brick (CB) and excavation waste rock (WR). The uniqueness of the developed surface was evaluated by employing a number of loading and wetting state paths. The results indicate that the developed surface is unique in its loading state paths; however, it only shows uniqueness in its wetting state paths for stress levels greater than 2000 kPa. The proposed model seeks to introduce the application of the unsaturated soil mechanics theory, for predicting the behavior of granular materials in the field, by providing a practical and cost-effective methodology.     

羧基含氟聚合物纳米纤维膜的制备及对铜(II)的吸附性能

以甲基丙烯酸十二氟庚酯(DFHMA)和甲基丙烯酸(MAA)为单体,通过溶液聚合法制备出共聚物DFHMA-co-MAA,将DFHMA-co-MAA与聚偏氟乙烯(PVDF)按一定质量共混,采用静电纺丝方法,制备出羧基含氟聚合物(PVDF-DM)纳米纤维膜,用以吸附溶液中Cu(II)。讨论了PVDF和DFHMA-co-MAA的质量配比对纤维微观形貌和对Cu(II)吸附性能的影响,得出当PVDF与DFHMA-co-MAA的质量比为1∶2时,纤维的微观直径较均一且吸附性能最佳,故实验采用该质量配比制备PVDF-DM。使用红外光谱对PVDF-DM进行表征,显示出PVDF-DM纤维膜中含有—OH和C＝O等活性吸附基团。以PVDF-DM纳米纤维膜为吸附剂,探讨了吸附剂用量、吸附pH值和吸附时间对Cu(II)吸附性能的影响,并研究了吸附过程的动力学模型。结果表明,室温下,当吸附剂用量为0.03g,pH=5时,吸附60min达到吸附平衡,吸附率和吸附量分别为94.37%和62.91mg/g,PVDF-DM纳米纤维膜对Cu(II)的吸附过程同时满足拟一级动力学和拟二级动力学模型,说明该吸附过程包含了化学吸附和物理吸附。PVDF-DM纳米纤维膜循环使用5次后,吸附能力仅降低16.23%,说明PVDF-DM纳米纤维膜具有很好的再生使用能力。     

Social impact assessment of investment activities in the China–Pakistan economic corridor

In order to analyze potential social risks, and achieve smooth implementation of investment activities in the China–Pakistan economic corridor (CPEC), we attempt to establish social impact and risk indicators. Both the impacts on the projects and the impacts of the projects are used to develop risk indicators in accordance with the literature review, reality and international standard principles. Using an analytic hierarchy process (AHP) and average value to analyze questionnaires of both Chinese and Pakistani respondents, we identify the importance of various risk indicators. The primary social risks of the western high mountain region include tribal obstacles and religious extremism. The social risks to the southeast coastal plains include preserving the historical and cultural heritage of the area and international protection of national parks. The social risks in north Kashmir include disputes, extremist threats, religious and cultural differences, and the protection of natural reserves. The social risks of the Xinjiang region primarily involve social issues faced by ethnic minorities and environmental pressures.     

Environmental Control of Triplet Emission in Donor–Bridge–Acceptor Organometallics

Carbene‐metal‐amides (CMAs) are a promising family of donor–bridge–acceptor molecular charge‐transfer (CT) emitters for organic light‐emitting diodes. A universal approach is demonstrated to tune the energy of their CT emission. A blueshift of up to 210 meV is achievable in solid state via dilution in a polar host matrix. The origin of this shift has two components: constraint of thermally‐activated triplet diffusion, and electrostatic interactions between guest and polar host. This allows the emission of mid‐green CMA archetypes to be tuned to sky blue without chemical modifications. Monte‐Carlo simulations based on a Marcus‐type transfer integral successfully reproduce the concentration‐ and temperature‐dependent triplet diffusion process, revealing a substantial shift in the ensemble density of states in polar hosts. In gold‐bridged CMAs, this shift does not lead to a significant change in luminescence lifetime, thermal activation energy, reorganization energy, or intersystem crossing rate. These discoveries offer new insight into coupling between the singlet and triplet manifolds in CMA materials, revealing a dominant interaction between states of CT character. The same approach is employed using materials which have been chemically modified to alter the energy of their CT state directly, shifting the emission of sky‐blue chromophores into the practical blue range.     

含氟无皂乳液P(CTFE-IBVE-SUA)的合成及性能研究

通过无皂乳液聚合法制备得到聚(三氟氯乙烯-乙烯基异丁基醚-十一烯酸钠)[P(CTFE-IBVE-SUA)]含氟乳液。考察了单体配比对聚合反应的影响,研究了SUA用量对乳液及聚合物性能的影响,并对聚合物的结构及乳胶粒的形貌进行了测定。结果表明:含氟无皂乳液P(CTFE-IBVE-SUA)的稳定性好、粒径分布均匀;改变单体配比中IBVE和CTFE的比例可以得到不同结构的含氟聚合物乳液;SUA用量对乳液的稳定性、乳胶粒的粒径大小及粒径分布、聚合物膜与水的接触角都有很大的影响;制得的乳液具有明显的核壳结构。     

新型冠状病毒疫情对我国电力行业的影响分析

全球经验表明,疫情会对经济社会产生负面影响。此次中国武汉市新型冠状病毒疫情爆发的时间节点、波及的领域范围,以及为应对疫情釆取的相关部署安排,既考验着电力行业保障电力安全可靠供应的能力,也会直接或间接通过电力供求形势变化影响电力企业的生产运行。结合疫情因素和近年来中国经济运行中电力供求变化特点,本文认为疫情将会降低工业和商业用电负荷,医疗机构新增用电和居民生活用电将会显著增长,但鉴于工商业用电比重较高的事实,全社会用电量同期同比增速将明显放缓。考虑到近年来用电增速放缓的经验事实,此次疫情或将放大电力行业积聚的矛盾和困难,因此为发挥市场在电力资源配置中的决定性作用而加快推进电力体制改革和全国统一电力市场建设愈发重要与迫切。     

Protective effect of nanosilica on irradiated dates against saw toothed grain beetle,Oryzaephilus surinamensis (Coleoptera: Silvanidae) adults

The insecticidal activity of nanosilica particles (NSPs) [20 ± 4 nm] was determined using the saw-toothed grain beetle, Oryzaephilus surinamensis (L) adults as the experimental insect. When the unsexed adults were exposed to different doses of nanosilica (0.2, 0.4, 0.6, 0.8 and 1.0 mg/Petri dish) for different periods (1, 2 and 3 days), it was found that NSPs had more insecticidal activity against O. surinamensis. Moreover, it was found that as the exposure time and dose increased, the mortality percentages of the adults increased. When the adult fed on irradiated dates which treated with different doses of nanosilica (0.5, 1,2 and 4 mg/1date) the mortality was higher than in nanosilica alone. The LD₅₀ of the bioassay tests showed that the calculated LD₅₀ values of each treatment were 0.468, 1.201 and 0.572 mg/1date. The adult of O. surinamensis (untreated, treated with LD₅₀ of nanosilica and fed on unirradiated or irradiated dates) examined by a scanning electron microscope. The examination showed the same malformations in all treatments which caused abrasion and damage on the outer surface. Nanosilica can be effectively replacing chemical insecticides to protect stored products.