环境温度对斜拉桥动力特性的影响分析

基于东海大桥主航道斜拉桥健康监测系统测得的一年的环境温度和结构响应的数据分析了环境温度对结构动力特性的影响。首先基于环境温度的监测数据对环境温度的分布特点进行了分析,环境温度沿桥梁纵向具有很强的一致性,沿箱梁截面具有明显的温度梯度。接着分析环境温度对结构动力特性的影响机理,并通过实际监测数据进行了验证,其结果表明理论分析与实际监测数据具有很好的一致性。最后基于ARX模型对于环境温度对结构动力特性影响的惯性效应进行了分析,表明环境温度的影响具有明显的时间滞后效应,同时基于多点温度能够等效表示环境温度的惯性效应。     

基于监测数据的桥梁结构可靠性评估

桥梁结构健康监测系统能有效监测影响桥梁结构的各种作用及其在结构上产生的效应,可为准确评估桥梁结构的各种性能提供信息.影响桥梁结构性能的因素具有随机性,基于概率的方法是处理随机性的有效工具.研究了结构健康监测与可靠性评估相结合的桥梁结构性能评估方法.分析了纵向应变监测信号的特点,提出一种新的监测信息处理方法.结合工程实例,验证了该方法的可行性,并对可靠性评估结果进行分析.     

施工企业防范经营风险初探

施工企业经营风险是指企业在经营中对未来经营环境中的不确定因素与多变性无法全部或精确预测所造成预计支出与收益偏离实际的风险。企业经营风险是在经营过程中产生的,因此,经营风险贯穿于企业生产经营的全过程。     

同时存在导体和电介质的边界时电像法问题研究

讨论了导体与电介质同时存在情况下的电像法问题,指出了文献[1-2]中关于这一问题所出现的一些错误,并给出了正确的解答.     

Blockage of the NLRP3 inflammasome by MCC950 improves anti-tumor immune responses in head and neck squamous cell carcinoma

The NLRP3 inflammasome is a critical innate immune pathway responsible for producing active interleukin (IL)-1β, which is associated with tumor development and immunity. However, the mechanisms regulating the inflammatory microenvironment, tumorigenesis and tumor immunity are unclear. Herein, we show that the NLRP3 inflammasome was over-expressed in human HNSCC tissues and that the IL-1β concentration was increased in the peripheral blood of HNSCC patients. Additionally, elevated NLRP3 inflammasome levels were detected in tumor tissues of Tgfbr1/Pten 2cKO HNSCC mice, and elevated IL-1β levels were detected in the peripheral blood serum, spleen, draining lymph nodes and tumor tissues. Blocking NLRP3 inflammasome activation using MCC950 remarkably reduced IL-1β production in an HNSCC mouse model and reduced the numbers of myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs) and tumor-associated macrophages (TAMs). Moreover, inhibiting NLRP3 inflammasome activation increased the numbers of CD4⁺ and CD8⁺ T cells in HNSCC mice. Notably, the numbers of exhausted PD-1⁺ and Tim3⁺ T cells were significantly reduced. A human HNSCC tissue microarray showed that NLRP3 inflammasome expression was correlated with the expression of CD8 and CD4, the Treg marker Foxp3, the MDSC markers CD11b and CD33, and the TAM markers CD68 and CD163, PD-1 and Tim3. Overall, our results demonstrate that the NLRP3 inflammasome/IL-1β pathway promotes tumorigenesis in HNSCC and inactivation of this pathway delays tumor growth, accompanied by decreased immunosuppressive cell accumulation and an increased number of effector T cells. Thus, inhibition of the tumor microenvironment through the NLRP3 inflammasome/IL-1β pathway may provide a novel approach for HNSCC therapy.     

Mutations in myosin heavy chain 11 cause a syndrome associating thoracic aortic aneurysm/aortic dissection and patent ductus arteriosus

We have recently described two kindreds presenting thoracic aortic aneurysm and/or aortic dissection (TAAD) and patent ductus arteriosus (PDA) and mapped the disease locus to 16p12.2-p13.13 (ref. 3). We now demonstrate that the disease is caused by mutations in the MYH11 gene affecting the C-terminal coiled-coil region of the smooth muscle myosin heavy chain, a specific contractile protein of smooth muscle cells (SMC). All individuals bearing the heterozygous mutations, even if asymptomatic, showed marked aortic stiffness. Examination of pathological aortas showed large areas of medial degeneration with very low SMC content. Abnormal immunological recognition of SM-MHC and the colocalization of wild-type and mutant rod proteins in SMC, in conjunction with differences in their coimmunoprecipitation capacities, strongly suggest a dominant-negative effect. Human MYH11 gene mutations provide the first example of a direct change in a specific SMC protein leading to an inherited arterial disease.     

Game-theoretic approach to power and admission control in hierarchical wireless sensor networks

Power efficiency and link reliability are of great importance in hierarchical wireless sensor networks (HWSNs),especially at the key level,which consists of sensor nodes located only one hop away from the sink node called OHS.The power and admission control problem in HWSNs is comsidered to improve its power efficiency and link reliability.This problem is modeled as a non-cooperative game in which the active OHSs are considered as players.By applying a double-pricing scheme in the definition of OHSs’ utility function,a Nash Equilibrium solution with network properties is derived.Besides,a distributed algorithm is also proposed to show the dynamic processes to achieve Nash Equilibrium.Finally,the simulation results demonstrate the effectiveness of the proposed algorithm.     

一维双极粘滞量子流体力学模型解的存在性

研究了一类一维稳态双极半导体方程的粘滞量子流体力学模型.该模型包含关于粒子浓度和电流密度的连续方程以及电势Poisson方程的耦合方程组,其中含有三阶量子修正项和二阶粘滞项.该问题在有界区间(0,1)中讨论,并通过边界条件的假设将原方程组变形为常见的形式,得到原问题的等价问题.用截断方法将等价问题正则化,并得到正则化问题解的先验估计.利用Leray-Schauder不动点定理证明正则化问题解的存在性,最后通过L∞估计证明正则化问题的解即为原问题的解,从而证明了原双极粘滞量子流体力学模型存在稳态解.     

Lipids of sulfate-reducing bacteria and sulfur-oxidizing bacteria found in the Dongsheng uranium deposit

U-bearing sandstones from the Dongsheng deposit in Ordos Basin contain abundant C15-C18 fatty acids. The fatty acids may have been derived from modern and ancient organisms including organisms from the intervals of U mineralization. A certain amount of i15:0, a15:0, a17:0 fatty acids coexist with small amounts of i17:1ω7c and 10me16:0, characteristic biomarkers of Desulfovibrio and Desulfobacter sp., respectively. This indicates the existence of sulfate-reducing bacteria (SRB) in the sandstones. The presence of sulfur-oxidizing bacteria (SOB), such as Beggiatoa and Thioploca, is indicated by significant amounts of 16:1ω7c and 18:1ω7c fatty acids. The existence of the SRB in the deposit, as inferred from the fatty acids, is consistent with results from fossilized microorganisms and isotopic compositions of ore-stage pyrite. This suggests that the environment may have been favorable for the SRB to grow since ore formation (9.8-22 Ma). The bacteria may have degraded hydrocarbons directly, or indirectly utilized hydrocarbons degraded by oxic microbes in the deposits. This process may have produced 12C-rich calcite and prominent baseline humps of unresolved complex mixtures (UCM), and 25-demethylated hopanes and tricyclic terpanes. The existence of sulfur-oxidizing bacteria and sulfate-reducing bacteria in the deposit may have resulted in bacterial sulfate reduction to sulfide, re-oxidization of the sulfide to sulfate and subsequent reduction of the sulfate to sulfide. This assertion is supported by ore-stage pyrite with δ34S values as low as-39.2‰, and the lightest sulfate (about 11‰) measured during the Phanerozoic, a difference of more than 46‰.     

掘进机电气系统结构及故障判断

文章论述了掘进机电气系统所采用的控制方式以及保护方式,结合掘进机电气系统原理,提出电气系统故障点分布,进行分析,使维修人员能够快捷地判断和处理故障。