发用防晒成分芦荟甙的提取

芦荟甙不仅具有防晒功效,而且还具有润泽、软化头发,防止断发、护发止痒的功效.设计正交实验,用乙醇水溶液回流溶出芦荟甙,用减压蒸馏的方法得到产品,并找出最佳反应条件.用溴水和红外光谱定性分析,证明了所得产品为芦荟甙.将芦荟甙加入洗发香波中,使用效果良好.实验方法操作简单、可行性高,为芦荟的提取研究提供数据.     

Effect of chromium aging on the structural and thermal properties of chromium polyacrylate

The effects of aging time of Cr(III) solutions on the structural, thermal, magnetic, and morphological properties of chromium polyacrylate complexes were studied. Chromium retention was found to increase with longer aging periods. IR spectra revealed the formation of polychelate structures with noticeable changes on aging. The interaction of multivalent, polynuclear Cr(III) species with the polymer backbone resulted in a decrease in thermal stability for the complexes prepared from olated chromium solutions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 490–493, 2005     

腐植酸与普洱茶茶色素

对云南普洱茶特有品质与化学组成(多酚类、儿茶素、黄酮类、茶黄素、茶红素、茶褐素)的关系进行简要地阐述。茶色素被证实是一类具有多种生理活性的物质。依据腐植酸的形成及化学性质、结构特征,提出了普洱茶中茶色素与腐植酸,尤其是茶褐素和黄腐酸,在化学性质方面(结构和官能团)存在一定的相似性。由此提出了腐植酸(黄腐酸)在生理活性及治疗功能方面与茶色素应具有相似性。为腐植酸(黄腐酸)在医药方面的应用研究提出了新思路。     

关于有机-无机复混肥国家标准

介绍有机无机复混肥料国家标准的范围、技术要求和试验方法。     

高分子和盐对3-十二烷氧基-2-羟丙基三甲基溴化铵泡沫性能的影响

测定了3-十二烷氧基-2-羟丙基三甲基溴化铵(C12TAB)在PVP、PEG和溴化钠存在下的泡沫性能。结果表明：含量相同时，C12TAB／NaBr混合体系的起泡性能高于C12TAB／高分子体系，而稳泡性能低于后者。含量相同的C12TAB／高分子体系，PVP对C12TAB的影响好于PEG。     

Harnessing the Melting Peculiarities of Ultra‐High Molecular Weight Polyethylene Fibers for the Processing of Compacted Fiber Composites

Summary: Compacted fiber composites offer unique properties due to their lack of an extraneous matrix. The conditions of processing ultra‐high molecular weight polyethylene (UHMWPE) fibers were simulated in a heated pressure cell. In situ X‐ray diffraction measurements were used to follow the relevant transitions and the changes in the degree of crystallinity during melting and crystallization. The results strongly support the suggestion that the hexagonal crystal phase, in which the chain conformation is extremely mobile on the segmental level, constitutes the physical basis of compaction technologies for processing UHMWPE fibers into a single‐polymer composite. This report suggests that using a pseudo‐phase diagram outlining the occurrence of different phases during slow heating and the degree of crystallinity can provide valuable insight into the technological parameters relevant for optimal processing conditions.

Degree of crystallinity as a function of pressure and temperature in a region relevant to compaction processes.     

乙醇生产集成工艺流程的环境与经济性评价分析(英文)

乙醇是一种非常重要的可再生燃料,在本文中,从环境影响和经济效益的角度对不同的原料玉米、纤维素和乙烯生产制乙醇的工艺过程进行了评估,并利用AspenPlus模拟软件中的严格物料和能量平衡模块对典型的生产工艺进行了设计、模拟和优化。基于模拟的结果,提出了定量的环境影响方法一绿色度理论,并通过综合对比文献中报道的数据和模拟数据表明,纤维素制乙醇具有更强的环境影响优势,但在经济效益方面仍需要进一步改进。     

熔铸-原位反应法生成α-Al2O3晶须的形貌及结晶方向

利用熔铸－原位反应法制备TiC/Al复合材料时，发现Ti-C-Al反应块表面存在大量的Al2O3晶须，晶须的形貌包括长而直的板状和串珠状，取决于反应进行时铝熔体的温度，当铝熔体温度低于900℃时，形成板状晶须，而当铝熔体温度高于900℃时，形成串珠状的晶须，其原因是由于较高的铝熔体温度加剧了TiC原位反应的放热，热起伏的结果致使部分α－Al2O3晶须异常长大，X射线衍射和透射电镜分析确认晶须为α－Al2O3，其形貌以直板状为主，电子衍射花样斑点显示其结晶方向为[0002]。     

Microstructure and thermal cycling behavior of thermal barrier coating on near-α titanium alloy

Two kinds of thermal barrier coatings (TBCs), consisting of NiCoCrAlY bond coats (BCs) deposited by electron beam-physical vapor deposition (EB-PVD) and high velocity oxy-fuel (HVOF) thermal spraying, respectively, and top 8 wt%Y₂O₃–ZrO₂ (8YSZ) ceramic layers deposited by EB-PVD were prepared on near-α titanium alloys. The field emission scanning electronic microscopy and microhardness indentation are used to study the microstructure and microhardness. Different failure features including cracking patterns and the delamination degree of these two TBCs are discussed according to the thermal cycling tests in the atmosphere. It is found that the morphology of the two BCs deposited by different methods (EB-PVD and HVOF) determines the microstructure and microhardness of their corresponding top 8YSZ layers. The BC prepared by EB-PVD is dense and homogeneous, which leads to a dense and hard 8YSZ with clustered slim columnar grains. The BC prepared by HVOF, however, is porous and inhomogeneous in microstructure and, as a result, the top ceramic layer is loose with low microhardness and clustered coarse columnar grains.     

基于一次投影子空间追踪的压缩感知信号重构

为了降低信号重构算法的复杂度,实现对稀疏度未知信号的重构,提出了一种基于一次投影子空间追踪(OPSP)的信号重构方法。首先根据约束等距性质确定信号稀疏度的上下界,并将最接近上下界中值的整数作为稀疏度的估计值;然后在子空间追踪(SP)算法的框架下,去掉了迭代中观测向量在支撑集上的投影过程,降低了算法的复杂度。为了更准确地衡量算法的重构性能,提出用完整信号的重构概率作为衡量算法重构性能的指标。与传统的SP算法相比,所提算法可以重构稀疏度未知的信号,且重构时间短,重构概率高。仿真结果验证了该算法的有效性。