Study on energy release characteristics of reactive material casings under explosive loading

Reactive Materials(RMs),a new material with structural and energy release characteristics under shockinduced chemical reactions,are promising in extensive applications in national defense and military fields.They can increase the lethality of warheads due to their dual functionality.This paper focuses on the energy release characteristics of RM casings prepared by alloy melting and casting process under explosive loading.Explosion experiments of RM and conventional 2A12 aluminum alloy casings were conducted in free field to capture the explosive fireballs,temperature distribution,peak overpressure of the air shock wave and the fracture morphology of fragments of reactive material(RM)warhead casings by using high-speed camera,infrared thermal imager temperature and peak overpressure testing and scanning electron microscope.Results showed that an increase of both the fireball temperature and air shock wave were observed in all RM casings compared to conventional 2A12 aluminum ally casings.The RM casings can improve the peak overpressure of the air shock wave under explosion loading,though the results are different with different charge ratios.According to the energy release characteristics of the RM,increasing the thickness of RM casings will increase the peak overpressure of the near-field air shock wave,while reducing the thickness will increase the peak overpressure of the far-field air shock wave.

Amino functionalized chiral mesoporous silica nanoparticles for improved loading and release of poorly water-soluble drug

In the present paper, chiral mesoporous silica nano-cocoon(A-CMSN) functionalized with amino group was synthesized, and its loading and release of indomethacin(IMC), a poorly soluble drug, was studied. Due to the use of chiral anionic surfactants as a template, ACMSN possessed 2D hexagonal nano-cocoon morphology with curled channels on its surface, which was quite different from another 2D hexagonal mesoporous silica nanoparticles(MCM-41) with straightway channels. After being loaded into the two silica carriers by hydrogen bond, crystalline IMC converted to amorphous form, leading to the improved drug dissolution. And IMC loading capacity of A-CMSN was higher than MCM-41 because curled loading process originating from curvature chiral channels can hold more drug molecules. Compared with IMC, IMC loaded A-CMSN presented obviously fast release throughout the in vitro release experiment, while IMC loaded MCM-41 released faster than IMC at the initial 5 h then showed controlled slow release afterwards, which was closely related to the mesoporous silica nanoparticles and different channel mesostructures of these two carriers. A-CMSN possessed nano-cocoon morphology with curled 2D hexagonal channel and its channel length was shorter than MCM-41, therefore IMC molecules can easily get rid of the constraint of A-CMSN then to be surrounded by dissolution medium.

钢筋混凝土环境中负载型阻锈剂的研究进展

阻锈剂技术是抑制混凝土中钢筋锈蚀的重要途径,但传统阻锈剂的应用仍然面临功能单一、与混凝土的兼容性不佳、环保性和有效性难以兼顾等问题。将阻锈剂装载入载体中,以载体负载阻锈剂(Carrier-loaded corrosion inhibitor,CLCI)的形式将阻锈剂“间接”掺入混凝土,能够在避免阻锈剂原有缺陷的基础上,发挥载体的特有功能。本文围绕CLCI的离子固化、缓释效应、智能响应、pH自免疫系统、载体吸附效应等功能机制,结合CLCI对水泥基材料性能的影响,系统综述了CLCI的研究进展。最后,对其在混凝土中的研究和应用进行了展望,并提出了需要解决的问题,以期为CLCI在混凝土工程中的应用提供更多可能性。

含松香的聚氨酯载药微球的制备及性能

采用预聚—扩链—中和法合成松香基聚氨酯(RPU),以其为载体,以5-氟尿嘧啶(5-Fu)为模型药物,通过悬浮聚合法制备了负载5-Fu的松香基聚氨酯微球(5-Fu/RPUMs)。采用单因素实验优化了药物负载条件,通过红外光谱、X射线光电子能谱、扫描电子显微镜、能谱分析等对载药微球进行表征,研究了载药微球的体外释放性能及药物释放动力学模型。结果表明:成功制备了5-Fu/RPUMs微球,平均粒径为35.0μm,表面光滑圆整且有孔。药物最佳负载条件为:ρ_(5-Fu)=120 mg/mL,致孔剂种类为正丁醇/甲苯,此条件下RPU对5-Fu的包封率达63.35%,载药量达7.60%。5-Fu/RPUMs在不同pH下表现出不同的缓释性能,具有pH敏感性;在pH=6.8的PBS缓冲溶液中,264 h后的累积释放率为65.80%,具有长效的缓释作用。

爆轰加载下TATB基钝感炸药的冲击-卸载-再冲击实验装置设计与模拟

在一些特殊的工程应用和意外事故中,炸药内部可能会受到多次冲击压缩和卸载作用从而使其起爆性能发生变化,因此,需要一种可以模拟多次冲击和卸载的实验加载装置,用以研究炸药在复杂载荷下的起爆响应。基于爆轰加载原理,提出并设计了一种可以实现完全卸载的冲击-卸载-再冲击的爆轰加载实验装置,利用数值模拟对该装置进行了仿真设计和参数优化,并通过实验验证了数值模拟的准确性和装置设计的可行性。结果表明:利用所设计的爆轰加载装置驱动钨镁双层飞片撞击TATB基钝感炸药,通过调整装置中的间隙宽度,可以对炸药实现完全卸载的冲击-卸载-再冲击加载,为后续研究炸药在复杂载荷多次冲击下的起爆响应提供了一种新的实验技术。

高砷无烟煤低负荷燃烧过程中砷的释放特性及灰中砷形态分布规律

选取高砷无烟煤,采用管式炉研究了低负荷燃煤工况下砷的释放及灰中砷形态的变化规律。结果表明:800~900℃区间内,随着温度的升高煤中砷的释放速率出现明显峰值,灰中As^(3+)占比呈上升趋势;灰中弱吸附态砷在800~900℃区间逐步升高,在900℃时As^(3+)占比达到最大值;1000~1200℃区间内,灰中弱吸附态砷氧化分解,砷酸盐占比增加,促使As^(3+)向As^(5+)转变,As^(3+)占比逐渐降低;O_(2)体积分数的升高促进了灰中As^(3+)的氧化过程;此外,随着炉内煤粉停留时间的增加,煤中砷的释放速率与灰中As^(3+)占比呈现同步变化趋势。

原位覆盖对异龙湖底泥氮磷释放抑制效果的实验研究

底泥中埋藏的氮磷等营养物质二次释放作用是导致浅水湖泊富营养化难以根治的主要过程,因此,抑制底泥氮磷释放控制技术对于湖泊生态修复具有重要的现实意义.本研究以重度富营养高原浅水湖泊异龙湖为对象,通过开展为期36d的底泥覆盖抑制氮磷释放试验,对比了生石灰+石膏(2∶1)、生石灰+石膏+红壤(2∶1∶1)、三氯化铁改性高岭土(1∶4)、无覆盖4种覆盖处理对氮磷释放的抑制效果,以期筛选出有效削减异龙湖内源负荷的覆盖材料与最优方案.试验结果表明:与无覆盖组相比,3种材料覆盖都可抑制底泥磷的释放,加入生石灰处理组的水体pH大幅上升,会破坏湖泊自然生境,不宜用于湖泊底泥生态修复;三氯化铁改性高岭土覆盖处理的抑磷效果达75.9%,可作为抑磷释放覆盖材料.同时相比无覆盖组,只有三氯化铁改性高岭土覆盖能抑制氮的释放,抑氮效果达64.1%,而其它两组处理对氮释放的抑制效果均不明显.因此,从抑制氮磷释放效果及其生态环境效应角度综合考虑,三氯化铁改性高岭土是最佳的覆盖材料,可为高原浅水富营养化湖泊的氮磷内源控制提供工程修复技术参考.

功能化纳米农药载药系统研究进展

纳米材料因其粒径小、尺寸易调节、种类丰富以及良好的移动性等优势,作为有效载体,在农药载药系统及农业病虫害防治方面受到了广泛关注。纳米材料与技术在提升农药生物利用度、溶解性和缓控释特性等方面展现出巨大的潜力。本文总结了利用纳米材料与技术开发具有功能化纳米农药载药系统的研究进展,系统综述了精准释放农药活性成分的智能响应型农药控释制剂、叶面亲和型、土壤用药型及农药双载体系等不同功能化纳米农药载药系统,概述了其在农药减量增效和精准施用方面的作用效果,并对功能化纳米农药载药系统的应用场景与产业化潜力进行了展望。

基于同轴微流控纺丝技术的CS/SA掺杂PVA复合载药纤维的制备及其释药性能

为延长药物的可控释放时间,提高累计释放率,将生物相容性良好的天然高分子材料壳聚糖(CS)和海藻酸钠(SA)分别与聚乙烯醇(PVA)溶液混合作为纺丝液,通过同轴微流控纺丝技术制备具有药物缓释性能的复合载药纤维。以氨苄西林钠(AS)为药物模型,比较研究了PVA/CS/AS(PCA)和PVA/SA/AS(PSA)两种复合载药纤维的药物缓释效果,并分析了两种天然高分子材料及其含量对载药纤维形貌结构、力学性能以及释药性能的影响。结果表明:PCA和PSA载药纤维均具有稳定的成型性和良好的形貌结构。PCA的断裂强度高于PSA复合纤维,而PSA的断裂伸长率远大于PCA复合纤维。此外,这两种纤维对药物均具有良好的缓释效果。其中,PCA复合纤维在短期内释药量大,当PVA与CS质量比为5∶1时,PCA复合纤维在180 min内药物的累计释放率最高为60%;而PSA复合纤维可以实现58 h的长时间药物释放,当PVA与SA质量比为64∶1时,PSA复合纤维药物累计释放率最高为94.1%,适合治疗慢性疾病,达到长期有效释药的目的。利用这两种载药复合纤维可设计适用于不同给药患者的药物缓释系统,展现出其在药物缓控释中的广阔应用前景。

药物缓释高分子材料的最新研究进展

药物释放体系的重要组成部分是药物载体材料,其作用是让药物以一定速度在一定时间内从载体材料中缓慢释放。本文主要综述近5年以来,药物缓释高分子载体在不同给药途径、不同制备工艺和不同靶向及智能型响应载药体系等研究方面的最新进展。通过梳理相关研究进展,为设计合成绿色友好、选择应用范围宽、毒副作用小、可控制、靶向释放和环境稳定性的理想药物释放体系打下坚实的基础,以期在医药、农业、食品等方面有更好的前景与发展。

Characterization and Performance of Magnesium Doped Bioactive Glass Nanoparticles

The bioactive glass and related biomaterials have become increasingly popular, and have also attracted the research interest of many researchers in recent years due its special performance and tissue engineering application. In this study, to create a material with a variety of properties Mg doped hollow bioactive glass (Mg-HBG) of 80SiO2-5P2O5-10CaO-5MgO system had been produced by using a sol-gel method. The porous structure nanoparticles were specifically made by employing the cetyltrimethylammonium bromide (CTAB) as a surfactant. Magnesium was selected as a doped material with HBG, because it is the most existing cations in the human body which helps for bone metabolism as well as it has antibacterial property. Based on different investigations resulted nanoparticle with the inclusion of the lower molar fractions magnesium has good tested result. For a drug model vancomycin hydrochloride (VAN) was used in this study and it has also good antibacterial activity effect. These findings help the possibility of using Mg-HBG nanoparticles to treat infectious bone abnormalities by demonstrating their compatibility with antibiotics, drug loading and release behavior.

日光温室主动蓄放热系统热过程模拟与参数优化研究

为进一步提高日光温室太阳能利用效率,降低加温成本,在当前日光温室主动式水循环蓄放热系统的基础上,构建了系统运行数学模型,利用该模型对系统参数(循环水流量与蓄热水箱体积)进行优化设计。研究结果表明:在兰州地区冬季日光温室生产条件下,当系统循环水流量为0.23 m^(3)·h^(-1),蓄热水箱体积为0.13 m^(3)时,系统性能最优,集、放热效率达到70.62%与98.38%,集/放热单元夜间平均热流密度达到237.84 W·m^(-2)。利用优化后参数,为兰州地区EPS装配式日光温室设计了一套太阳能主动蓄放热加温方案:集放/热单元(高2.05 m,宽1.105 m,厚3 cm)为50个,循环水泵流量为11.5 m^(3)·h^(-1),蓄热水箱体积为6.5 m^(3)。该方案可满足日光温室越冬生产,较优化前节约2个集/放热单元,8.5 m^(3)蓄水池体积,降低了加温成本。

基于贝叶斯离散优化的电力调度网络发令多任务优先级解耦方法

电网输电线路的负荷率和利用率的不断加重,为电力系统运行调度增加了难度。为了合理规划调度任务,保证电网运行安全,研究基于贝叶斯离散优化的电力调度网络发令多任务优先级解耦方法。建立电力调度模型,设定调度优化目标和约束条件;基于贝叶斯离散优化预测电力负荷,为任务优先级判定提供依据;通过分块解耦动态仿真电力系统,将复杂外部系统转换为简单等值系统;通过电力调度多任务优先级解耦,划分优先级,接收操作令,完成电力调度的解耦。经实验论证分析,所提模型得到的解耦前后的仿真曲线较为吻合,仿真结果可以真实准确地反映电力系统的动态行为,对过载线路有功功率的调节效果明显,越限问题得到了很大程度的改善。

基于大数据的公路桥梁检测技术及应用方法

在实际的公路桥梁设计与施工中,需要进行大量的检测作业,以确保整体工程质量和运营安全。因此,文章利用大数据对公路桥梁结构进行动力学检测,建立荷载试验模型,采用能量释放法对模型进行求解,以加固公路桥梁的刚性结构,并根据历史数据对模型进行调整,提高公路桥梁荷载的准确性。试验结果表明:利用大数据的公路桥梁检测技术使事故减少了23%,公路桥梁性能优良,满足设计与施工要求。

A novel nanogel delivery of poly-α,β-polyasparthydrazide by reverse microemulsion and its redox-responsive release of 5-Fluorouridine

To achieve GSH-responsive 5-Fluorouridine(5-FU) delivery, a novel family of nanogel drug carriers has been successfully prepared. The new class of PAHy-based nanogels was prepared by the crossing-link reaction of poly-α, β-polyasparthydrazide(PAHy) chains and 3,3′-dithiodipropionic acid(DTDPA) consisting of a redox-responsive chain network. This particle highlights recent efforts in introducing a disulfide bond to drug delivery nanogel by DTDPA,and the increased release properties of complex nanogels produced excellent glutathione(GSH)-sensitivity and significant anti-tumor therapeutic efficacy. The PAHy-based nanogels were characterized by Fourier transform infrared spectroscopy(FT-IR), dynamic light scattering(DLS)(nano-particle size ~200 nm), UV–vis spectrometry, X-ray diffraction(XRD) and differential scanning calorimetric(DSC). PAHy-based nanogels are promising controlledrelease carriers for the tumor-targeting delivery of the anticancer agent 5-Fluorouridine.

Effect of rhBMP-2 sustained-release nanocapsules on the ectopic osteogenesis process in Sprague-Dawley rats

Objective:To explore the effect of sustained-release recombinant human bone morphogenetic protein-2(rhBMP-2) on ectopic osteogenesis in the muscle pouches of rats through preparing rhBMP-2 sustained-release capsules by wrapping morphogenesis protein bones-2(BMP-2)using chitosan nanoparticles,and compositing collagen materials.Methods:Twenty four SpragueDawley rats were randomly divided into four groups with six rats in each group,that is Group A(control group),Group B(only treated with collagen),Group C(rhBMP-2+collagen treated group) and Group D(rhBMP-2/cs+collagen treated group).The composite materials for each group were implanted in the bilateral peroneal muscle pouches in rats.The peroneal muscles were only separated without implanting any materials in control group.Rats were sacrificed 2 weeks and 4 weeks post treatment and samples were cut off for general observation,Micro CT scans and histological observation.Results:General observation showed no new bone formation in Groups A and B mice,while new bones were formed in Groups C and D mice.Two weeks after treatment Micro CT scans showed that The bone volume fraction(BVF),trabecular thickness(Tb. Th),bone mineral density(BMD) in Group C mice were all higher than that in Group D(P<0.05). At the fourth week,the BVK,Tb.Th and BMD were significantly higher than that at the second week(P<0.01).Conclusions:The slow-release effect of rhBMP-2/cs sustained-release capsules can significantly promote ectopic osteogenesis.Its bone formation effect is better than that of rhBMP-2 burst-release group.

Polymeric Hydrogel Nanocapsules: A Thermo and pH Dual-responsive Carrier for Sustained Drug Release

Hydrogel capsules show attractive prospects in drug delivery recently because of high drug loading and sustained release behavior. In this study we reported a simple and convenient route to fabricate poly(acrylic acid)-poly(N-isopropylacrylamide)(PAA-PNIPAm) hydrogel capsules by using hydroxypropylcellulose-poly(acrylic acid)(HPC-PAA) complexes as the templates. The capsules showed a high drug loading(～280% to the weight of capsules) for Doxorubicin hydrochloride. The release of drug from the capsules was responsive to the temperature and p H of the surroundings, showing a low-rate but sustained release behavior favorable for low-toxic and long-term therapy. Together with the convenient preparation, high drug loading, dual responsivity as well as the sustained release feature, it is implied that this polymeric hydrogel capsule might be a promising candidate for new drug carriers.

ON CRACK-TIP STRAIA ENERGY RELEASE RATE IN NON-PRINCIPAL DIRECTIONS OF ELASTICITY FOR SIMPLE LAYER PLATE OF COMPOSITE MATERIALS

In this paper, the fracture problem in non-principal directions of elasticity for a simple layer plate of linear-elastic orthotropic composite materials is studied. The formulae of transformation between characteristic roots, coefficients of elastic compliances in non-principal directions of elasticity and corresponding parameters in principal directions of elasticity are derived. Then, the computing formulae of strain energy release rate under skew-symmetric loading in terms of engineering parameters for principal directions of elasticity are obtained by substituting crack-tip stresses and displacements into the basic formula of the strain energy release rate.

Surface lurking and interfacial ion release strategy for fabricating a superhydrophobic coating with scaling inhibition

The design and manufacture of anti-scaling surface is a prospective way to prevent scaling in oil field.In this work,a novel superhydrophobic Cu^(2+)-loaded and DTPMPA-modified anodized copper oxide(S-Cu^(2+)/D-ACO)coating was fabricated by modification of 1H,1H,2H,2H-perfluorodecyltriethoxysilane.The valid storing of scale inhibitors at the coating surface and the interfacial release of Cu^(2+)ions contribute to enhancing the anti-scaling of the S-Cu^(2+)/D-ACO coating.The water contact angle of the S-Cu^(2+)/D-ACO coating is 163.03°and exhibits superhydrophobicity,which makes it difficult for CaCO_(3)to deposit at the surface of the coating.DTPMPA will steadily lurk into the inner space,and Cu^(2+)will be loaded at the interface in the form of the DTPMPA:Cu^(2+)chelate.During the deposition of CaCO_(3),the dynamic release of DTPMPA can be realized by transferring DTPMPA:Cu^(2+)to DTPMPA:Ca^(2+).Interestingly,the released Cu^(2+)hinders the active growth of CaCO_(3).After 48 h of scaling,the mass of CaCO_(3)scale at the S-Cu^(2+)/D-ACO coating surface is only 44.1%that of the anodized copper oxide coating.The excellent anti-scaling performance of the S-Cu^(2+)/D-ACO coating is determined by the synergistic effect of the DTPMPA lurking and dynamic release,as well as the Cu^(2+)inhibition at the interface of superhydrophobic coating and against CaCO_(3)deposition.This research provides a new exploration for designing and fabricating anti-scaling superhydrophobic surface for oil field development.

Preliminary study on Anti-inflammatory and Anti-tumor Effects of Gelatin-based on pH-responsive Drugloaded Nanoparticles

Gelatin as one kind of nano-drug carrier is a polysaccharide which can be absorbed after releasing all nano-drugs.Poly(ethylene glycol)as a polymer material that can modify nano-drugs is able to extend circulatory time of doxorubicin and aspirin,enhance stability and reduce toxicity.At precancerous,aspirin will be released slowly to resist inflammation.When tumor cell appears at a more advance stage,doxorubicin release from Gel to achieve anti-tumor effect.After all those steps,poly(ethylene glycol)could be expelled from body.In brief,the nano-drug that has doxorubicin and aspirin is able to prevent the growth of tumor cells and kill them when they appear more precisely.