中国南北方男性大学生在可接受冷环境区的生理适应性和主观感受

为了研究中国南北方男性大学生在可接受冷环境区生理适应的自主性调节反应和主观感受的差异,选取南北方受试者各16名,遴选生理指标包括皮肤温度、心率（HR）、心率变异性（HRV）、呼吸率、血容量（BVP）、肌电（EMG）,填写主观问卷。结果表明：南方受试者主观感受好于北方受试者;平均皮肤温度、EMG均值稍高于北方受试者;北方受试者心率值、LF/HF均值高于南方受试者;南北受试者从中性环境进入可接受冷环境区,南方受试者的主观感受指标差分均值和生理反应指标差分均值出现显著性差异的实验时间段明显少于或晚于北方受试者。结论：北方受试者对偏冷的环境更敏感,冷耐受力比南方受试者弱;冷习服弱,产生了较强的生理调节现象;南方受试者基础代谢和非战栗产热（代谢产热）稍高于北方受试者,产生较小的生理调节,有较好的冷环境忍耐力和较强的冷习服能力。     

三峡库区低水位运行期库尾支流筑坝对其水体CO2分压及排放的影响

为探究三峡库区低水位运行期间库尾支流河坝对其上下游水体CO₂分压、水气界面扩散通量的影响,于2019年8月对三峡库区库尾典型筑坝支流御临河进行采样研究。原位测定关键理化环境因子,采用顶空平衡法,结合亨利定律和薄边界层理论计算水体CO₂分压（p_CO2）及水气界面扩散通量（Flux（CO₂））。结果表明,库区低水位运行期御临河水体表层p_CO2为54.55~336.73 Pa,均值为206.68 Pa,Flux（CO₂）为1.65~67.84 mmol/（m²·d）,均值为39.01 mmol/（m²·d）,表现为大气CO₂排放源排放水平显著高于三峡库区中下游支流。御临河受其下游筑坝影响,河坝上游较近河段表现为湖泊型水体（流速v<0.05 m/s）,上游较远河段和下游表现为过渡型水体（v=0.05~0.2 m/s）。湖泊型水体p_CO2和Flux（CO₂）显著低于过渡型水体,且p_CO2随水深增加迅速增大。相关性分析及多元逐步回归分析表明,库区低水位运行期御临河p_CO2及Flux（CO₂）受水温、pH、DO、Chl-a等理化环境指标影响显著,Chl-a是影响p_CO2的最主要因素,p_CO2是影响Flux（CO₂）的最主要因素。     

中国便利店的照明能耗预测模型与主观评价

便利店销售额在传统零售业中增幅最高,照明在所调研样本总室内能耗中占比为43%。基于全国257家便利店的数据,探讨便利店的照明特征。采用多重线性回归方法建立照明能耗预测模型,采用因子分析方法探讨客观参数与主观评价的联系。研究表明,对便利店,考虑照明节能时需同步关注其主观评价的变化;进行照明设计时需因地制宜;照明能耗预测模型为ln y=0.479 ln x₁+ 0.248ln x₂-0.217（y为照明功率密度,x₁为单位面积照明造价,x₂为典型货架位置水平照度平均值）;顾客对照明充足度的“敏感性”比照明均匀度高;提高照度平均值有助于提高主观评价。     

间歇与连续供冷模式对可培养细菌浓度的影响

空气中的细菌,尤其是病原菌和益生菌,对人体呼吸系统、皮肤系统等均造成有利/不利影响,其分布特征随温度和相对湿度变化。设置房间空调器间歇运行和连续运行两类供冷模式,探究不同供冷模式下可培养总细菌、病原菌（金黄色葡萄球菌）、益生菌（乳酸杆菌）的时空分布差异和环境因素的关联。结果表明：时间尺度上,总细菌平均浓度在间歇运行下（（1 195±511）CFU/m3）是连续供冷模式下（（483±199）CFU/m3）的2.5倍;金黄色葡萄球菌平均浓度在间歇供冷模式下（（544±299）CFU/m3）是连续供冷模式下（（136±7）CFU/m3）的4倍;益生菌在连续和间歇供冷模式下差异较小,分别为（77±40）CFU/m3和（73±24）CFU/m3。总细菌和金黄色葡萄球菌浓度在间歇供冷模式下浓度波动较大;连续供冷模式下波动较小。空间尺度上,总细菌与金黄色葡萄球菌浓度随着距空调横向和垂向距离的增大而增大;随着距空调纵向距离的增大而减小。间歇供冷模式下,儿童呼吸区（z=0.5 m）细菌暴露风险高于成人呼吸区（z=1.5 m）。总细菌和金黄色葡萄球菌浓度均与温度呈显著正相关（p<0.001）,而与相对湿度关联较小。相比于连续供冷,间歇供冷模式下室内总细菌及病原菌浓度均较高,夏季时适当延长空调开启时间,可显著降低室内可培养细菌浓度,减少细菌感染风险。     

再生粗骨料取代率对碎卵石混凝土抗压性能影响研究

设计制作了再生粗骨料取代率r=0%、30%、50%、70%、100%的碎卵石混凝土立方体及棱柱体试件,在不同龄期下对其进行抗压试验。研究了五种再生粗骨料取代率下,不同龄期的混凝土立方体抗压强度以及棱柱体抗压强度的变化趋势。结果表明：在龄期为3 d和7 d情况下,r=30%时混凝土的抗压强度较r=0%时无显著变化;当r>30%时,混凝土的抗压强度随r的增加呈下降趋势,且下降幅度较明显。在龄期为14 d和28 d情况下,各组试件的抗压强度随着r的增加而降低。提出了考虑再生粗骨料取代率r的情况下,混凝土立方体抗压强度与棱柱体抗压强度相关关系计算模型f_c=（-0.190 3r²+0.148r+0.722 7）f_cu。     

非线性Mohr-Coulomb破坏准则下边坡可靠度上限

传统边坡可靠度分析往往在岩土参数服从线性Mohr-Coulomb（简称线性M-C）破坏准则的假设条件下进行,并且常常采用极限平衡法或有限元法计算安全系数。然而,岩土介质破坏准则具有一定的非线性。为能更加实际地描述岩土破坏机理和得到严格精确的解,基于非线性Mohr-Coulomb（简称非线性M-C）破坏准则,结合极限分析上限法和蒙特卡洛法,进行边坡可靠度上限分析。当非线性参数m=1时,与等效的线性M-C破坏准则进行对比计算,验证了方法的可行性。同时,将初始粘聚力、内摩擦角arctan（c₀/σ_t）和非线性参数作为随机变量且服从截断正态分布,进行了参数变异性和敏感性影响分析。研究表明：非线性M-C破坏准则下,边坡可靠度随初始粘聚力、内摩擦角arctan（c₀/σ_t）和非线性参数变异性的增大而减小;边坡可靠度随初始粘聚力和内摩擦角arctan（c₀/σ_t）的增大而增大,随非线性参数的增大而减小。     

近30年色林错湖面变化特征及其对气候变化的响应

为了探讨气候变化对高原湖色林错湖面面积变化的影响,基于1988—2020年Landsat卫星遥感影像资料,用最大似然法提取色林错水体信息,采用线性回归及M-K检验法分析色林错湖面面积及其流域内温度、降水和积雪深度等气候因子变化特征,并用皮尔逊相关分析法探讨了湖面面积与气象因子之间的相关性.结果表明:近30年色林错湖面面积增加了650.70 km²,增长速率为203.34 km²／(10 a).色林错湖面扩张存在着明显的空间差异,湖面向南、向北扩展比较明显;色林错流域年平均气温及降水量呈显著上升趋势(p<0.05),而积雪深度呈显著下降的趋势(p<0.05),其中增温速率为0.50℃／(10 a),降水量增加速率为17.32 mm／(10 a),积雪深度递减率为0.65 cm／(10 a);色林错湖面面积的变化与该流域气温的升高以及冷季积雪深度的降低具有极显著相关性(p<0.001),气温升高使得色林错上游的冰雪融水增加是色林错湖面面积增大的主要原因.     

底部加强双钢板混凝土组合剪力墙抗震性能研究

为研究底部加强双钢板混凝土组合剪力墙的抗震性能，以型钢数量（m=2、4、6）、型钢尺寸（I）、型钢强度（Q235、Q345）（f_p）、钢板强度（Q235、Q345）（f_s）、轴压比（n=0.4、0.5、0.7）为主要参数。设计了9片双钢板混凝土组合剪力墙，利用ABAQUS软件建立其有限元模型，并对类似双钢板混凝土组合剪力墙开展验证分析，将仿真结果与试验结果进行对比分析，验证结果的合理性。基于验证结果，开展了9片双钢板混凝土组合剪力墙的参数分析，研究不同参数对底部加强双钢板混凝土组合剪力墙抗震性能影响规律。研究结果表明，底部加强试件在承载能力、延性、塑性变性能力、刚度退化和耗能能力方面均有所提升。轴压比为0.4和0.5时，延性接近；轴压比为0.7时，延性下降；轴压比为0.5时，随着型钢数量的增加，承载能力逐渐提高；提高钢板和型钢强度，延性、初始刚度和耗能能力均有较大提升，抗震性能较优。     

固体蓄热装置放热特性的实验研究

储能系统是能源利用与转化的重要组成部分，在新能源消纳方面起着重要的作用，可有效实现电网的"削峰填谷"。为此，设计了3种不同保温层厚度和3种不同长高比（L/H）的蓄热体，采用实验方法研究了保温层厚度和蓄热体结构参数对固体蓄热装置放热特性的影响。结果表明：蓄热体与环境的温差是影响蓄热装置放热速率的主要因素；不同L/H的蓄热体放热速率明显不同，L/H=0.500时的放热速率最小，L/H=0.300时的次之，L/H=0.885时的最大。     

大气CO2浓度缓增对冬小麦土壤呼吸的影响

为研究大气CO₂浓度缓增对冬小麦（Triticum aestivum）土壤呼吸的影响，基于开顶式气室组成的CO₂浓度自动调控平台，在2017—2019年开展了两季冬小麦CO₂浓度缓增试验.每季试验在背景大气CO₂浓度基础上（CK，对照），均设置了CO₂浓度缓增处理（C₈₀和C₁₂₀，即从2016年起逐年增加40 μmol·mol^-1，至2017—2018年和2018—2019年冬小麦生长季CO₂浓度分别为CK+80 μmol·mol^-1和CK+120 μmol·mol^-1）.采用静态暗箱-气相色谱法测定土壤呼吸速率.结果表明：CO₂浓度缓增没有显著改变土壤呼吸的季节变化规律，但是会显著影响冬小麦旺盛生长期的土壤呼吸速率.在2018—2019年冬小麦抽穗-扬花期，C₁₂₀处理使土壤呼吸速率显著增加50.2％（P=0.008），且使得生长季土壤碳排放显著增加25.9％（P=0.044），而在2017—2018年冬小麦生长季，与CK相比，C₈₀处理对土壤呼吸没有显著影响.土壤呼吸与土壤温度呈指数正相关，与CK相比，CO₂浓度缓增降低了土壤呼吸对温度的敏感性.研究表明，CO₂浓度缓增120 μmol·mol^-1增加了冬小麦生长季土壤碳排放.     

服装热舒适性能的心理学评价

为了对服装的热舒适性能形成一种客观的心理学评价体系,基于热舒适感产生的生理与心理学基础,选取主观感觉评分、皮肤电阻、呼吸加重感、心跳加速感和腋温等指标作为测试指标进行实验,并通过spss软件对数据进行相关分析,对与微气候温度显著相关的指标进行进一步的曲线回归分析,得到回归方程式,最终确定了评价服装热舒适性能的八项指标。通过测量各指标值可以对微气候环境的温度进行估计,从而形成对服装热舒适性能的较客观的心理学评价。     

Effect of Lead Contents on the Properties of PMSZT Piezoelectric Ceramics

The effects of Pb content on crystallographic phase, microstructure, electric-properties of PMSZT piezoelectric ceramics were studied. The crystallographic phase and microstructure of the ceramics were examined by using X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The experimental result shows that the samples consist of a mixture of tetragonal and rhombohedral phases in the range of lead contents x=0.95-1.06, grains grow up homogeneously and the minimum value of Curie temperature was obtained with x-=1.02. With Pb content x〈l.02 or x〉1.02, the Curie temperature moves towards a high temperature. A well-situated electric-properties of ET33/E0 （1660）, d33 （344pC/N）, Kp （0.684）, Qm （2350）,tan 3（0.0030） were obtained when lead content x=1.02.     

动态条件下植物性填充材料家居鞋与普通家居鞋穿着保暖性能的对比研究

选取6种家居鞋,对其穿着舒适性及植物性填充材料的按摩性能进行主观评价.结果表明,随着时间的推移,绒类家居鞋始终处于不热、不湿、不闷和不黏状态,此种家居鞋在寒冷的冬天基本不具备保暖功能;当加热温度达35℃时,植物性填充材质保暖鞋的主观热感稍好于电暖鞋和丝绵家居鞋,但整体热感不是很明显;植物性填充材料保暖鞋、丝绵家居鞋及电暖鞋的主观湿感、闷感和黏感差异不大,都比较舒适;植物性填充材料颗粒越大越接近圆形,其痛痒感越明显.     

服装生理学评价指标及其测试技术

本文从服装工效学应用角度,总结了体核温度、体表温度、平均身体温度、新陈代谢产热量、热平衡差、热损失、出汗量、心率和血压等服装生理学评价指标;描述了这些生理指标的测试、计算方法以及有关测试仪器.从而为全面研究服装的舒适性与功能提供了可靠的生理学评价手段.     

Synthesis and electrochemical properties of polyradical cathode material for lithium second batteries

A stable polyradical, poly (2 ,2,6,6-tetramethylpiperidinyloxy methacrylate)(PTMA) , was synthesized, and its structure was determined by infrared, ultraviolet-visible, and ESR spectroscopy. Cyclic voltammograms of the PTMA polyradical electrodes were obtained by using a three-electrode cell at a scan rate of 5 mV/s within a potential range of 3. 2-4. 0 V. The results show that the shape of oxidation peak is very similar to that of reduction peak, and oxidation peak current is equal to the corresponding reduction peak current, which suggest that PTMA possesses an excellent reversibility. The difference of the anodic peak potential (Ea,p = 3. 66 V, vs Li/Li+) and ca-thodic peak potential(Ec,p = 3. 58 V, vs Li/Li+ ) is estimated at 80 mV, which is extremely less than that of the other organic positive materials in lithium second batteries such as organosulfide compounds, leading to a capability for high current capability in the charging and discharging process of the battery. The maximum discharge specif     

Effect of juglone on immunity response and oxidative stress in mice

To research juglone's immunology regulation, several perspectives including immunology regulation, lymphocyte proliferation, and cytokines were presented.The index of thymus and spleen, total supperoxide dismutase activity (T-SOD), serum malondialdehyde (MDA), content of nitrogen oxide (NO), the anti-superoxide anion ability, the suppressing hydroxy radical ability, contents of reduced glutathione (GSH) in thymus, total antioxidationability (T-AOC) and the level of mouse lysozyme (LZM) in plasma were measured. LPS-induced B thymocytes proliferation was measured by MTT assay.In the low-immunity model group, MDA and NO levels were decreased (p<0.001). Juglone improved lysozyme (LZM), GSH contents in thymus, T-AOC, T-SOD activity, the anti-superoxide anion ability (anti- O2-) (p<0.001).In the stimulation immunity model group, MDA and NO levels (p<0.05), anti- O2- and T-SOD activity (p<0.05) were up-regulated, whereas LZM, T-AOC contents were down-regulated.juglone has a significant effect, which promotes cell regeneration and function recovery, also may alleviate oxidative damage; juglone possesses a dual regulating effect on humoral immunity in mice.     

Hot deformation behavior of squeeze casting SiCp/2A50 matrix composites

The flow stress behaviors of squeeze casting SiCp/2A50 matrix composites were investigated by means of compression tests on a Gleeble 1500 therma1 mechanical simulator at isothermal constant strain rates ranging from of 0.001 to 1.0 with the testing temperature ranging from 350 to 500 ℃. The experiments showed that the relationship between stress and strain was obviously influenced by the strain rate and temperature. Dynamic recrystallization generally occurred at a higher temperature and a 1ower strain rate. A linear equation could be fitted between the Zener-Hollomon parameter Z and stress in the experiments. The mean value reciprocal of temperature at every true strain had a linear relation with natural logarithm of Z parameter, and the correlation coefficient, R=0.99, which was very significant by examination. The hot deformation activation energy of SiCp/2A50 matrix composites was 163.47 KJ/mol by calculation.     

Preparation of p-menthane hydroperoxide from p-menthane in presence of metalloporphyrins

The aerobic oxidation of p-menthane to p-menthane hydroperoxide (PMHP) in the presence of metalloporphyrins was investigated in an intermittent mode under an atmospheric pressure of air. Several important reaction parameters, such as the structure of metalloporphyrin, the air flow rate, and the temperature, were studied. The preliminary mechanism of the aerobic oxidation of p-menthane catalyzed by metalloporphyrins was also discussed. The results show that the reaction is greatly accelerated by the addition of metalloporphyrins at very low concentration, in terms of both the yield and formation rate of PMHP, and the high selectivity of PMHP is maintained during the reaction. Temperature of 120 ℃ and reaction time of around 5 h are the optimal conditions for the best result in the presence of 0.06 mmol/L monomanganeseporphyrins ((p-Cl)TPPMnCl). Furthermore, the yield of PMHP is increased remarkably when the reaction is carried out under programmed temperature compared with the constant temperature. When the reaction is catalyzed by 0.06 mmol/L((p-Cl)TPPMnCl) at the air flow rate of 600 mL/min and 120 ℃ for 4 h, and then the temperature is reduced to 110 ℃, for another 4 h, the yield of PMHP reaches 24.3%, which is higher than that of the reaction at a constant temperature of 120 ℃ or 110 ℃ for 8 h.     

Flow stress behavior of Cu13Zn alloy deformed at elevated temperature

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