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合理构建海岛综合能源系统对沿海能源清洁化转型意义重大，其优化调度更是实现海岛能源供需平衡的有效途径。为此，提出了一种考虑风光功率预测的海岛综合能源系统优化调度方法。首先，搭建包含氢能设备、海水源热泵、海水淡化装置、波浪能发电装置等新型能源转换设备的系统模型。其次，海上气候多变会导致新能源发电不稳定，故采用含环境变量重要性排序的一维卷积神经网络和双向长短时记忆神经网络（convolutional neural network-bi-directional long short-term memory，CNN-Bi-LSTM）联合模型对发电功率进行预测。然后，为维持海岛基本生存条件，以电-冷-淡水-氢平衡为约束，以改善系统运行经济性和可再生能源消纳率为目标函数，建立综合能源系统优化调度模型。对夏冬两个典型日进行仿真分析，结果表明所提出的预测模型具有较高的预测精度，所提优化调度方法可以实现海岛能源供需平衡，同时能够有效降低系统运行成本，提高可再生能源消纳率。

针对可见光通信系统传输性能问题，文章提出了一种无载波幅度相位（CAP）调制与数字脉冲间隔调制（DPIM）结合的混合调制方案。该方案分别利用两者频谱效率和功率效率较高的特点，发送端在脉冲间隔调制的脉冲时隙加载直流偏置光CAP（DCO-CAP）信号，实现混合调制信号的并行生成，接收端通过门限检测和最大似然检测完成混合调制信号的串行解调。推导了室内可见光高斯信道下混合调制方案的误码率（BER）及误帧率（FER）解析表达式。此外，从频谱效率和FER两方面对比分析了该混合调制方案与传统DPIM及DCO-CAP方案的性能优劣。数值仿真结果表明：当频谱效率相同时，混合调制方案较单一调制有更高的可靠性。

为了提高可见光通信系统的数据传输率,设计并实现了两种基于空间调制技术的可见光通信方案。发送端采用空移键控（SSK）分别与脉冲位置调制（PPM）和脉冲宽度调制（PWM）相结合,形成两种复合调制方式即空间脉冲位置调制（SPPM）和空间脉冲宽度调制（SPWM）来传输数据。复合调制充分利用了空间和信号二维资源,有效地提高了系统频带利用率。接收端采用电流反馈电路和电压放大电路来提高接收电平峰值的动态范围,利用C8051对光脉冲进行解调。基于单片机实现了4发1收的实验系统,测试结果验证了方案的有效性。

针对室内可见光通信网络技术在地铁车厢等特殊场景下的应用问题进行了研究。基于光attocell网络概念,构建了一种适用于地铁车厢的小单元覆盖矩形网络结构模型,并充分考虑了用户受相邻单元光接入节点（AP）干扰的情况。为了提高单元边缘区域频谱效率,将直接部分频率复用和软频率复用方案应用到模型中。推导了网络的信干噪比累积分布函数及单元频谱效率闭式表达式,通过频谱效率对比分析评估了不同复用方案的网络性能。结果表明,边缘区域频率复用因子为2的方案性能最佳,能够有效地缓解边缘区域用户受临近单元AP干扰的程度,提高边缘区域频谱效率。因此,在地铁车厢原有的照明设备下,采用直接部分频率复用（复用因子为2）的矩形网络结构可作为构建地铁可见光通信网络的推荐方案。

分析对比了圆角多边形孔蜂窝梁孔间腹板屈曲承载力的不同计算理论,包括楔体理论模型、英国钢结构协会计算手册理论模型、LAWSON理论模型及斜压柱模型等。采用不同理论对蜂窝梁孔间腹板的屈曲承载力进行了计算,并与试验结果进行了对比。结果表明,应用于六边形孔的楔体理论计算值过于保守,与试验值偏差均超过50%;应用于圆形孔的英国钢结构协会计算手册理论模型及LAWSON理论模型计算值也过于保守,偏差范围在58%70%之间;斜压柱理论相比其它方法,计算结果较为准确,偏差范围在7.6%39%之间。并采用验证的有限元方法分析了不同孔距、孔高及腹板厚度的蜂窝梁孔间腹板的屈曲承载力。应用斜压柱理论模型计算孔间腹板剪力承载力,与有限元参数分析结果对比表明,斜压柱模型按规范BS 5950-1:2000计算的理论值过于保守,理论值与有限元结果比值范围在0.1850.384之间;按规范EN 1993-1-1计算的理论值评价孔距较小(S/d0=1.4)蜂窝梁的剪力承载力时偏于安全,理论值与有限元结果比值范围在0.8780.972之间,当孔距较大(S/d0>1.4)时,理论结果偏于不安全,理论值与有限元结果比值范围在1.0541.818之间,需要进一步修正。

由于室内环境的特殊性,传统定位技术在室内的应用受到诸多限制。针对室内定位问题,提出了一种基于智能手机的可见光室内定位方案。该方案利用室内LED（发光二极管）照明光源作为定位信标,通过智能手机内置摄像头的卷帘快门工作方式,接收LED照明光源发出的可见光调制信号,结合手机应用软件内的图像处理算法提取信标信息,从而实现智能手机可见光定位功能。实验结果验证了该方案的可行性及有效性。

针对可见光链路发射源发光二极管调制带宽有限的问题,提出了一种基于DCO（直流偏置）CAP（无载波幅度相位调制）的可见光通信系统设计方案（DCO-CAP）。该方案采用正交滤波器组进行基带脉冲成形来传输时域实信号,并利用直流偏置实现信号单极化。基于希尔伯特变换原理,给出两种正交滤波器组冲激响应形式,推导了DCO-CAP系统误码率的闭式表达式并分析了系统误码性能。仿真结果表明,不同滤波器组的抗限幅噪声性能相异,抗信道噪声性能一致。直流偏置取值存在最优解,能够使系统可靠性达到最佳。

通过有限元方法研究火灾下无防火保护蜂窝钢梁孔间腹板屈曲性能及屈曲温度。首先采用有限元传热分析,获得标准火灾下无防火保护蜂窝梁不同受火时刻的三维有限元温度分析结果,然后采用有限元受力分析确定三维有限元温度分析结果下蜂窝梁孔间腹板的受力性能和屈曲温度。传热分布结果表明,开孔后增加了孔洞周边厚度方向上腹板与空气间的热量交换,使得腹板升温速率明显大于翼缘。火灾下结构受力分析结果表明,由于钢材的力学性能随温度升高而降低,而且中心腹板升温速率快使蜂窝梁更易发生孔间腹板屈曲破坏。蜂窝梁的屈曲温度随孔间距及腹板厚度的增大而增大。通过对采用三维有限元温度分布与均匀温度分布的蜂窝梁进行对比分析,结果表明,由于不均匀温度分布使得沿腹板高度产生附加热应力,从而使得孔间腹板屈曲变形增大。

针对强度调制/直接检测可见光通信系统,提出了一种新的O-OFDM（光正交频分复用）技术方案,即HP-OFDM（哈特莱极性光正交频分复用）。该方法利用快速哈特莱变换产生OFDM信号,并通过坐标变换在极坐标系中实现OFDM信号单极化。硬件实现方面相较于常用的Cooley-Tukey FFT（快速傅里叶变换）可有效节约运算时间和存储空间,便于硬件实现,并且极坐标系单极化处理较好地解决了系统PAPR（峰均功率比）问题。仿真结果显示,HP-OFDM系统在达到ACO-OFDM（非对称限幅光正交频分复用）系统频谱利用率的同时,其误码性能和PAPR均得到改善。

蜂窝梁因腹板开洞,导致孔间腹板承受复杂的剪力、轴力和弯矩的共同作用,可能发生强度破坏和稳定破坏等多种破坏模式。孔间腹板破坏模式对蜂窝梁受力性能有着显著影响,孔间腹板屈曲承载力计算是蜂窝梁抗剪设计的主要内容。对国内外现有蜂窝梁孔间腹板屈曲问题的研究成果进行了综述,内容包括相关试验研究、理论方法及有限元分析等,分析了相关方法的适用范围及其存在的问题,指出了进一步研究方向。

【目的】探讨七氟烷和异氟烷预处理对大鼠肝脏缺血再灌注损伤(I/R)的保护作用及机制。【方法】96只SD大鼠随机分为假手术对照组(Sham)、肝脏缺血再灌注组(IR)、七氟烷预处理(Sev)和异氟烷预处理组(Iso),于肝脏缺血30min,再灌注30min、120min测各组大鼠血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)、乳酸脱氢酶(LDH)的含量以及肝脏组织中谷胱甘肽(GSH)、丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性。【结果】肝脏缺血再灌注后IR、Sev和Iso组血清ALT、AST和LDH含量均显著升高,肝组织SOD和GSH显著降低,而MDA明显升高,和Sham组相比有显著差异(P

【目的】探讨肝癌射频术中应用氟比洛芬是否可以减少静脉麻醉导致的呼吸抑制的发生。【方法】选择射频治疗肝癌患者60例，随机分为K组和N组，每组各30例，其中K组术前15min静脉注射氟比洛芬50mg，N组术前15min静脉注射生理盐水5mL，两组均以异丙酚复合瑞芬太尼微量泵维持麻醉。使记录术前、手术开始时、手术开始后5min及患者术后苏醒时的平均动脉压、心率、脉搏氧饱和度及呼吸频率，监测动脉血二氧化碳分压；记录患者苏醒时间；记录出现术中体动、呼吸暂停的例数。【结果】瑞芬太尼用量K组[（0．22±0．03）mg]显著少于N组[（0.51±0．07）mg，P〈0．01]。术中体动K组（2例）少于N组（7例），呼吸暂停N组（12例）显著大于K组（2例）。【结论】氟比洛芬可以减少肝癌射频术中瑞芬太尼的用量，降低呼吸抑制等副作用的发生率。

[目的]了解监狱警察睡眠和应对方式的关系。[方法]用匹兹堡睡眠质量指数（PSQI）和应对方式问卷（CSQ）对广东省监狱管理局的2093名监狱警察的睡眠和应对方式进行了调查。[结果]监狱警察PSQI均分为7.10±3.68,40.71%的监狱警察有睡眠问题。最常用的应对方式是解决问题（0.65±0.16）和求助（0.53±0.23）。不同性别、年龄和工作性质者的睡眠障碍和应对方式是有差异的。多元回归分析发现,PSQI分与自责和合理化的得分成正相关,与解决问题和求助的得分成负相关。[结论]对监狱警察的应对方式的干预可能有助于改善其睡眠质量。

【目的】观察急性超容性血液稀释(AHHD) 与控制性降压(CH)联合应用对脊柱手术病人血流动力学、 氧供、氧耗及动脉血乳酸浓度的影响。【方法】20 例拟行脊柱手术病人, 麻醉诱导后25 min 内输入60 g/L 的羟乙 基淀粉( 贺斯200/0.5, HES) 15 mL/kg。手术开始时用硝酸甘油+艾司洛尔进行控制性降压, 维持平均动脉压 (MAP) ( 60±5)mmHg。主要手术操作完成后停止降压。术中连续监测心率(HR) 、血压(BP) 、中心静脉压(CVP) 、心 输出量(CO) 。分别于诱导后动静脉置管完成时( 基础值, T0) 、手术开始即刻(AHHD 后, T1)、手术开始后60 min ( T2) 和停止降压后30 min( T3) 同时取动、静脉血进行血气分析及检测动脉血乳酸(LA)。据氧动力学值计算氧供 (DO2) , 氧耗(VO2) , 氧摄取率( ERO2) 。取同期20 例仅行术中CH, 未行AHHD 的脊柱手术患者作对照组, 对比两 组术中输血量及手术前后Hct、Hb 变化。【结果】试验组CVP、CO 在T1 、T2、T3 各时点均明显高于T0 值( P< 0.05 或P < 0.01) ,但仍在正常值范围内。在T1- 3 时点试验组Hct、Hb 明显降低( P < 0.01) 。DO2 在T1 时点明显升高( P < 0.05) , 在T2 时点明显降低( P < 0.05) 。ERO2 在T2 时点明显高于T0 值( P < 0.05) 。试验组VO2 和LA 在各时点 差异无统计学意义( P >0.05) 。与对照组比较, 试验组输异体血比率明显减少(P =0.001) , 而手术前后Hct、Hb 无 明显差异。术后随访两组病人均无并发症发生。【结论】AHHD 与CH 联合可安全用于骨科脊柱手术, 并明显减少 术中异体血用量。

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The study aimed to investigate the effects of different levels of isoleucine in the diet on the testicular growth and development, antioxidant function, and reproductive hormone levels in weaned piglets. A total of 18 weaned piglets at the age of 28 days were randomly divided into three groups with six replicates per group and one piglet per replicate. The dietary isoleucine levels in all groups were 0.8%, 1.0%, and 1.2%, respectively. The trial period was 21 days. The results showed that compared with 0.8% isoleucine group (control group), testis size and weight in 1.0% isoleucine group were significantly increased (P<0.05), the cross-sectional area and circumferential length of convoluted seminiferous tubule in 1.0% and 1.2% isoleucine groups were significantly increased (P<0.05). The activity of glutathione peroxidase (GSH-Px) in testicular tissue of 1.0% isoleucine group was significantly increased (P<0.05), and the content of malondialdehyde (MDA) was significantly decreased (P<0.05). The 1.0% isoleucine group had significant regulation on the reproductive related indexes of hypothalamic-pituitary-testicular gonad axis. The results show that 1.0% isoleucine can alleviate oxidative stress caused by weanling of piglets, and affect the morphology and reproductive indexes of the testis of piglets by changing the level of reproductive hormone secretion in the gonadal axis of hypothalamic-pituitary-testicular tissue. [ABSTRACT FROM AUTHOR]

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Copyright of Plateau Meteorology is the property of Plateau Meteorology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to study the influence of heterogeneous field with permeability coefficient to the subsurface flow exchange, this study adopted a stochastic first-order analysis method to explore the cross-correlation between hyporheic exchange flux and permeability coefficient, as well as the spatial distribution of velocity variance. The results show that hyporheic exchange flux is positively correlated with permeability coefficient heterogeneity in every part of the streambeds with the high cross-correlation zone near the dunes surface. Ignoring the heterogeneity of the riverbed will lead to greater uncertainty of the flow velocity at the shallow position of the riverbed, in the field, the permeability coefficient of the shallow position of the riverbed should be monitored to reduce the uncertainty of the subsurface flow exchange. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Functional Materials / Gongneng Cailiao is the property of Chongqing Functional Materials Periodical Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Shanghai Jiaotong University (Medical Science) is the property of Journal of Shanghai Jiaotong University (Medical Science) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The extensive generation of coal dust during underground mining operations has resulted in adverse working conditions, significantly elevating the occurrence of safety accidents, and posing health risks to coal miners. This paper explores the synergistic enhancement and wetting behavior of a selected composite surfactant solution when combined with four distinct types and concentrations of inorganic salt solutions. Various experimental methods were employed to investigate the interactions and wetting characteristics. The findings demonstrate that a composite solution consisting of 0. 9 mol/L NQ2SO4 with a combination of SDBS and Triton X 100 at a ratio of 4 : 1 exhibits the most favorable synergistic effect. Furthermore, a quantitative evaluation of the wetting performance parameters of the coal was based on the results obtained. It was observed that the spreading coefficient correlates positively with Na2SO4 concentration, while both adhesion work and surface free energy show a negative correlation with Na2 SO4 concentration, which suggests that the introduction of inorganic salt anions restores the absorbability of kaolinite, increasing the number of hydrophilic sites on the coal surface and enhancing the adsorption density of anion nonionic composite surfactants. Consequently, the wetting performance of the solution is significantly improved. [ABSTRACT FROM AUTHOR]

Copyright of West China Journal of Stomatology is the property of Sichuan University, West China College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Previous studies have shown that the nuclear factor E2-related factor 2/heme oxygenase 1 signaling pathway is crucial for the development of osteoarthritis, and metformin has a certain protective effect on chondrocytes. OBJECTIVE: To investigate the protective effect and mechanism of metformin on chondrocyte injury induced by lipopolysaccharide. METHODS: Sprague-Dawley rat chondrocytes were isolated, cultured, and identified in vitro. Passage 3 chondrocytes were selected and treated with different concentrations of lipopolysaccharide (0, 10, 50, 100, 500, 1 000, and 5 000 μg/L) and metformin (0, 50, 100, 500, 1 000, 5 000, and 10 000 μmol/L) for 24 hours. Cell viability was then detected by cell counting kit-8 method, and the optimal mass concentrations of lipopolysaccharide and metformin were screened. According to different treatment factors, the chondrocytes were divided into blank group, lipopolysaccharide (5 000 μg/L) induced group, and 5 000 μg/L lipopolysaccharide +1 000 μmol/L group. Cell apoptosis was detected by flow cytometry. Oxidative stress was detected by reactive oxygen species, malondialdehyde, and superoxide dismutase kits. The mRNA and protein expressions of interleukin-1β, cyclooxygenase 2, type II collagen, nuclear factor E2- related factor 2, and heme oxygenase were detected by RT-PCR and western blot, respectively. RESULTS AND CONCLUSION: Lipopolysaccharide reduced the activity of chondrocytes and induced apoptosis of chondrocytes, while metformin increased the activity of chondrocytes and decreased the apoptosis rate. The levels of reactive oxygen species and malondialdehyde were increased and the activity of superoxide dismutase was decreased in lipopolysaccharide-induced chondrocytes, while treatment with metformin decreased the levels of reactive oxygen species and malondialdehyde and increased the activity of superoxide dismutase in lipopolysaccharide-induced chondrocytes. Lipopolysaccharide increased the expressions of interleukin-1β and cyclooxygenase-2 in chondrocytes, and decreased the expressions of type II collagen, nuclear factor E2-related factor 2, and heme oxygenase 1 in chondrocytes. After metformin intervention, the expressions of interleukin-1β and cyclooxygenase-2 were decreased, and the expression of type II collagen, nuclear factor E2-related factor 2, and heme oxygenase 1 were increased. To conclude, metformin can inhibit lipopolysaccharide-induced chondrocyte injury, possibly through the activation of nuclear factor E2-related factor 2/heme oxygenase 1 signaling pathway [ABSTRACT FROM AUTHOR]

As oil and gas wells are drilled deeper and deeper, higher formation pressures need to be balanced with high density drilling fluids, and this leads to another problems: the treatment of more and more high density waste muds. Waste muds are generally treated with chemical flocculants and problems such as high treatment cost, poor universality and potential secondary pollution are the norm. In a study an electric field was applied to treat a high density waste mud. Based on the results of a singlefactor experiment, the effects of three factors, i.e., current intensity, time of gel breaking and the distance between two electrodes, as well as the interaction of the three factors on the Zeta potential and particle size distribution of the drilling fluid were studied using response surface methodology (RSM). It was found that an optimum gel breaking can be obtained when the electric current intensity = 8 A, the time of gel breaking = 10 min, and the distance between two electrodes = 3 cm. After gel breaking, the Zeta potential of the drilling fluid was increased by 38.29%, reaching −26.2 mV, and the particle size distribution factor D90 reached 562.5 μm, indicating that the gel stability of the waste drilling fluid was broken, and this provided a powerful support to the subsequent recovery of the useful mud components as well as the treatment of the waste portion of the waste drilling fluid. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)