基于响应能量和无响应时间的冲击危险性动态评价技术

煤岩冲击危险性评价的研究在煤矿安全生产领域引起广泛关注,已有多种静态评价方法指导现场防冲工作。一方面,对于冲击地压的致灾机理和影响因素目前尚未完全掌握;另一方面,伴随着开采活动,煤岩冲击危险性是动态变化的,因此静态评价方法不足以解决井下煤岩冲击危险性评价的问题。而基于现场监测的冲击危险性动态评价技术对于井下安全生产活动具有更强的参考性。依据统计损伤力学原理,对煤岩受载条件下的能量演化行为进行分析,发现累积能量释放速率对时间的响应具有临界敏感性,即在煤岩临近灾变时,累积能量释放速率会激增。此外,依据统计学原理,复杂系统处于正常状态(无危险性)的行为应该占据较大概率,非正常状态(有危险性) 的行为应该占据较小概率,故某一时刻系统行为偏离正常状态的程度实际上反映了其自身所处危险状态的变化。基于以上原理,初步建立了以响应能量异常系数和无响应时间异常系数为指标的冲击危险性动态评价的微震技术,对短期预警或临震预警展开尝试。最后在典型冲击地压矿井已有微震数据基础上,进行了现场验证。研究结果表明,微震累积能量释放速率可直接反映煤岩所处冲击危险状态;缺震时间频次分布规律满足正偏态分布;在此基础上构建的两个异常系数指标相互结 合能够实现对现场冲击危险性的实时连续评价;基于统计学原理,随着开采活动的进行,对冲击危险性指标的阈值进行动态修正,保证动态评价结果更为灵敏、准确,这一思想可应用于其他动态评价技术中。     

Sequential Release of Paclitaxel and Imatinib from Core–Shell Microparticles Prepared by Coaxial Electrospray for Vaginal Therapy of Cervical Cancer

To optimize the anti-tumor efficacy of combination therapy with paclitaxel (PTX) and imatinib (IMN), we used coaxial electrospray to prepare sequential-release core–shell microparticles composed of a PTX-loaded sodium hyaluronate outer layer and an IMN-loaded PLGA core. The morphology, size distribution, drug loading, differential scanning calorimetry (DSC), Fourier transform infrared spectra (FTIR), in vitro release, PLGA degradation, cellular growth inhibition, in vivo vaginal retention, anti-tumor efficacy, and local irritation in a murine orthotopic cervicovaginal tumor model after vaginal administration were characterized. The results show that such core–shell microparticles were of spherical appearance, with an average size of 14.65 μm and a significant drug-loading ratio (2.36% for PTX, 19.5% for IMN, w/w), which might benefit cytotoxicity against cervical-cancer-related TC-1 cells. The DSC curves indicate changes in the phase state of PTX and IMN after encapsulation in microparticles. The FTIR spectra show that drug and excipients are compatible with each other. The release profiles show sequential characteristics in that PTX was almost completely released in 1 h and IMN was continuously released for 7 days. These core–shell microparticles showed synergistic inhibition in the growth of TC-1 cells. Such microparticles exhibited prolonged intravaginal residence, a >90% tumor inhibitory rate, and minimal mucosal irritation after intravaginal administration. All results suggest that such microparticles potentially provide a non-invasive local chemotherapeutic delivery system for the treatment of cervical cancer by the sequential release of PTX and IMN.     

两种材料的性质对双材料界面裂纹能量释放率及应力强度因子的影响

在实际工程中,结构往往是由多种材料构成,而裂纹经常在两种材料的界面上扩展.针对双材料界面裂纹,建立相应的计算模型.用能量释放率来描述裂纹的扩展情况,并根据界面裂纹能量释放率解析计算方法对不同的材料性质、外荷载、构件厚度,以及裂纹两侧不同的材料宽度对裂纹扩展时的能量释放率和应力强度因子进行仿真分析,得到了能量释放率和两种材料的弹性模量、外荷载及构件厚度之间的关系变化的曲线,以及裂纹两侧不同的材料宽度和应力强度因子之间的关系.并对界面裂纹和单一材料裂纹的情况进行分析、比较.     

西藏某铜铅锌选矿废水处理及回用探析

出于对拉萨河水体保护要求,对西藏某铜铅锌矿选矿废水进行处理并全部回用,实现废水的零排放。排放废水中主要含有重金属离子和部分有机污染物,采用"混凝沉淀—ClO2氧化—曝气—吸附—调pH值—回用"处理工艺,可有效去除废水中的重金属离子及有机污染物,满足废水回用生产的要求,实现废水的零排放目标。     

具有梯级释药性能的核壳型双重载药微球

分别利用单轴和同轴静电喷雾法成功制备出以聚乳酸-羟基乙酸共聚物（PLGA）为内核基质、聚乙烯吡咯烷酮（PVP）为外壳基质的核壳型双重载药微球,其中,抗菌药物盐酸万古霉素（VA）被包封于微球外壳,促成骨药物地塞米松（DA）被负载于微球内核。对载药微球的形貌结构、物理性质和体外释药性能进行了表征和分析。结果表明,当电喷前体PVP浓度为80g/L时,单轴和同轴静电喷雾方法均可得到大小均一、球形良好的核壳型微球。X射线衍射（XRD）和差示扫描量热（DSC）结果表明,DA晶体被成功包封于核壳型微球后转变为无定形状态。基于PVP的水溶性和PLGA的缓慢降解特性,两种核壳型载药微球都实现了壳层VA快速释放、内核DA缓慢释放的梯级释药性能。本文制备得到的具有梯级释药性能的核壳型载药微球在药物控释、组织工程等领域有很好的应用前景。     

Characterising the release of flavour compounds from chewing gum through HS-SPME analysis and mathematical modelling

The headspace solid-phase microextraction (HS-SPME) technique combined with GC–MS was evaluated to study 33 selected flavour compounds released from chewing gum. The operating conditions of SPME were optimised, including different fibres (PDMS, DVB/CAR/PDMS, PA and PDMS/DVB), sample size, extraction time and temperature. The results indicated that while HS-SPME was a rapid and valuable technique, poor reproducibility occurred under all conditions. It was found that this deficiency could be alleviated by utilising mathematical modelling techniques, an approach which had not been previously used in the analysis of flavour compounds in chewing gum by HS-SPME. Compared to the instrumental analysis data themselves, the models provided more insights to the release behaviour of flavour compounds from chewing gum and the more reproducible kinetic rate constants might be used for comparing the release of different compounds or the same compound under different conditions.     

Matrix effects on flavour volatiles release in dark chocolates varying in particle size distribution and fat content using GC–mass spectrometry and GC–olfactometry

Influences of matrix particle size distribution (PSD) (18, 25, 35 and 50 μm) and fat content (25%, 30% and 35%) on flavour release of dark chocolate volatiles were quantified by static headspace gas chromatography using GC–MS. Sixty-eight (68) flavour compounds were identified, comprising alcohols, aldehydes, esters, ketones, furans, pyrans, pyrazines, pyridines, pyroles, phenols, pyrones and thiozoles. From GC–olfactometry, 2-methylpropanal, 2-methylbutanal and 3-methylbutanal had chocolate notes. With cocoa/roasted/nutty notes were trimethyl-, tetramethyl-, 2,3-dimethyl-, 2,5-dimethyl-, 3(or 2),5-dimethyl-2(or 3)-ethyl- and 3,5(or 6)-diethyl-2-methylpyrazine and furfuralpyrrole. Compounds with fruity/floral notes included 3,7-dimethyl-1,6-octadien-3-ol and 5-ethenyltetrahydro-R,R,5-trimethyl-cis-2-furanmethanol. Caramel-like, sweet and honey notes were conferred by 2-phenylethanol, phenylacetaldehyde, 2-phenylethylacetate, 2,3,5-trimethyl-6-ethylpyrazine, 2-carboxaldehyde-1H-pyrrole, furancarboxaldehyde, furfuryl alcohol and 2,5-dimethyl-4-hydroxy-3(2H)furanone. There were direct relationships of fat content with 3-methylbutanal and branched pyrazines but inverse ones with 2-phenylethanol, furfuryl alcohol, methylpyrazine, phenylacetaldehyde, 2, 3, 5-trimethyl-6-ethylpyrazine and 2-carboxaldehyde-1-H-pyrrole. Particle size influenced higher alcohol, aldehyde, ester, ketone and pyrazine concentrations at all fat contents. A multivariate product space suggested flavour effects of the interacting factors.     

FA100型多功能气流塔的开发和应用

为了解决清梳联流程中单轴流开棉机由于工艺风量、风压配置不合理,出现易堵车而造成停产的问题,介绍了专利产品——FA100型多功能气流塔开发的背景及其结构、特点。该设备通过两次释压,解决从抓棉到开棉、混棉间的气流不平衡问题,通过试验和实际使用,指出多功能气流塔能有效解决单轴流的堵车,保证清梳联的稳定运行;在除尘、重物分离和去铁杂等方面也有着较为理想的效果;能解决原各辅机在输棉管路中分散接入的缺点,简化了清梳联流程;能提高生条、成纱的质量。说明多功能气流塔在生产实际中有着较高的实用价值。     

小型断路器保护特性及其在低压配电系统中的应用

分析小型断路器的脱扣曲线特性及其在低压配电系统中的应用。指出了在有保护选择要求的场所,不能够选择两串联小型断路器进行配电保护,以及不宜选择小型断路器作为消防负荷的过载保护。该分析有助于小型断路器的正确使用。     

铜浇铸脱模剂的研究

现有脱模剂的配比与运用不能达到理想的脱模效果,时常出现白板率高、板面开裂、背筋、结渣结块等现象,对铜阳极板的质量和外观有很大影响。采用复合型脱模剂为主体材料,研究了高聚物添加剂聚乙烯醇和聚羧酸对脱模剂性能的影响,脱模剂的主要成分为:BaSO4 40%~70%、SiO2 25%~50%,Al2O3 2%~8%,CaO 1%~4%;聚羧酸与聚乙烯醇以微量加入。研制出的脱模剂能够改善脱模效果与板面质量。