白车身总成包边胶品技术标准及质量判定

焊装包边胶主要应用于车门、发动机罩、行李舱盖及顶盖天窗、后轮罩内外板等包边结构处的黏接,不仅起到取代焊点、消除凹坑及保证车身平滑美观的作用,还能够增强结构、密封车体并防止黏接部分锈蚀。重点介绍了焊装包边用胶的分类、性能及工艺特点。

车身气密性及白车身用胶技术标准

随着制造技术的发展,密封胶作为汽车生产中必须的一种辅助材料,应用越来越广。车身涂胶可以提升整车密封防水性能、提高NVH性能、实现减振降噪,同时在实现汽车轻量化、节能降耗等方面也发挥着重要作用。在汽车的生产过程中,涂胶工艺在焊装、涂装、总装车间都有应用,文章重点介绍了焊装车间用胶的分类、性能及工艺特点。

体积排阻色谱法在药物蛋白检测中的应用

探讨了单克隆抗体A、抗体融合蛋白B两种蛋白在不同的体积排阻色谱柱上的分离效果及流动相条件对体积排阻色谱柱分离抗体融合蛋白B的影响。结果表明,分析抗体融合蛋白B纯度和相对分子质量需要正确选择体积排阻色谱柱和合适的流动相条件。

Excellent Cracking Performance of Macroporous Amorphous Aluminosilicate Catalyst

Micrometer-scale macroporous aluminosilicate catalyst was prepared via the sol-gel process. Results of catalytic cracking of 1, 3, 5-triisopropylbenzene showed that the synthesized aluminosilicate catalyst exhibited much higher activity than traditional ZSM-5 zeolite under the same condition. It is worth mentioning that the polymer product selectivity of aluminosilicate was much lower than that of ZSM-5, which might be useful for implementing the catalytic cracking process. The unique structure of macroporous aluminosilicate with interconnected-macropores and continuous skeletons was believed to be responsible for its excellent catalytic activity and low polymer product selectivity. Detailed discussion on the reaction pathway was also conducted.

Changes of Pectin Quantity in Fresh and Frozen Apple Products

Recently more and more innovations enter the manufacture of food products and one of them is food hydrocolloids. Food colloids open a lot of different possibilities in dessert production, which are used to perform certain functions. Pectin is a traditional agent for jams and jellies, but its application extends to fruit products for the food industry. In food product technology pectin is added as gelling agent and stabilizer. The three apple varieties ＂Antonovka＂, ＂Baltais Dzidrais＂ and ＂Zarja Alatau＂ harvested in Latvia State Institute of Fruit Growing were used for the experiment. Photometric measurement was used to determine the composition of pectin. Pectin was isolated from the apple mass by leaching with ethanol, and from the residues by extracting with diluted sodium hydroxide solution. By adding carbasol and sulphuric acid to the extract, through different intermediate stages carroty condensation product formed, which was photometrically measured at 525 nm. Pectin, pH and soluble dry matter were determined in fresh and frozen apple mass from apples of three ripeness stages. On the basis of worked out functional analysis of colloids, it is possible to optimize regulation of heat processes for different ripeness stages of apples. It is established that ripeness stage influences pectin quantity in fruits, but there are no data about pectin quantity changes in frozen fruits. By fruit ripening under the impact of enzyme protopectinase, protopectin hydrolyzes and transforms into pectin, which flows from the intercellular spaces into protoplasm of cells. Therefore ripe as well as heat treated fruits are soft and loose. It is important to measure pectin in frozen apple mass, in order to determine its potential jellying power. For each kind of product appropriate conditions have to be chosen for freezing, as well as the condition of products before freezing has to be taken into consideration in order to reduce the harmful influence on their quality to the minimum. The results of the research indicate that pectin quantity in frozen apple mass has decreased substantially. This susceptibility of sugar containing products to temperature fluctuations possibly is due to their high concentration of unfrozen water and lower melting temperature. It is possible to calculate the mass fraction of ice depending on temperature and moisture content in product which is very important for prognosticating the product quality. The aim of the research is to compare changes of pectin quantity in fresh and frozen apple products depending on storage time. The research is related to application possibilities of the current colloids, which are used in food industry at present.

Gel Microbead Cultivation with a Subenrichment Procedure Can Yield Better Bacterial Cultivability from a Seawater Sample than Standard Plating Method

A gel microbead (GMD) cultivation method was employed to cultivate microorganisms from an amphioxus breeding zone in Qingdao, P. R. China. The culture results were compared with those by standard plating method. In the GMD-based method, the microcolony-forming GMDs were sorted by fluorescence-activated cell sorting (FACS). To further get pure cultures, a subsequent enrichment culture and a streaking purification procedure were conducted on marine R2A medium. Eighty bacterial strains isolated by the GMD-based method were randomly selected for sequencing. These isolates belonged to Alphaproteobacteria (33%), Gammaproteobacteria (44%), Bacteroidetes (11%), Actinobacteria (5%), Firmicutes (5%), Epsilonproteobacteria (1%), and Verrucomicrobia (1%), the last two groups being usually difficult to culture. The 16S rRNA gene sequences revealed a diverse community with 91.1%-100% of the bacterial rRNAs similarities. Thirteen strains were sharing 16S rRNA gene sequence which was less than 97% similar to any other rRNA genes currently deposited in TYP16S database. Seventy isolates derived from the standard plating method fell into 4 different taxonomic groups: Alphaproteobacteria (9%), Gammaproteobacteria (81%), Bacteroidetes (7%) and Firmicutes (3%) with a 16S rRNA gene sequence similarities between 95.8%-100%, in which only 3 strains were sharing 16S rRNA gene sequence of less than 97%. The results indicated that the GMD-based method with subenrichment culture yielded more taxonomic groups and more novel microbial strains, including members of previously rarely cultured groups, when compared with the standard plating method, and that this method markedly improved the bacterial cultivability.

Preparation and Characterization of Nimodipine-loaded Methoxy Poly(ethylene glycol)-poly(lactic acid) Diblock Copolymer Nanoparticles

Amphiphilic diblock copolymers, methoxy poly （ ethylene glycol）-poly（lactic acid） （MePEG-PLA）, were synthesized from monomers of DL-lactide and methoxy poly （ethylene glycol） by a ring opening bulk polymerizatiou in the presence of stannous octoate. Their chemical structure and physical properties were investigated using FTIR, NMR, GPC, and fluorescence spectroscopy. To estimate the feasibility as colloidal drug carrier, nimodipine （ND） was loaded into MePEG-PLA block copolymer nanoparticles by phaseseparation/dialysis method. The mean diameter and drug loading efficiency of ND-loaded MePEG-PLA copolymer nanoparticles depended ou PLA/MePEG block composition of the copolymer and drug/polymer feed ratio in preparatiou. NMR study confirmed that nimodipine was entrapped into the hydrophobic inner core of MePEG-PLA copolymer nanoparticles and hydrophilic PEG chains were located ou the surface of the drug-loaded polymer nanoparticles. In vitro release experiments exhibited the sustained release behavior of nimodipine from MePEG-PLA copolymer nanoparticles, without any burst effect.

Preparation of Composite Phase Change Material Based on Sol-Gel Method and Its Temperature-Adjustable Textile

In this study,the sol-gel method was introduced to prepare the composite phase change material (CPCM). The CPCM was added to fabric with coating techniques and the thermal activity of modified fabric was studied. In addition,the thermal property and the microstructure of CPCM were also discussed in detail by means of polarization microscope and differential scanning calorimeter,respectively. According to the analysis of main influencial factors of the property of CPCM,the optimal preparing technique was determined. It was proved that CPCM could exhibit a good thermal property while phase transformation process took place,and a better appearance of the fabric modified with CPCM could be obtained due to the fact that in a warm circumstance,the liquid-state phase change material could be firmly enwrapped and embedded in the three-dimensional network all the time during the phase transformation. Besides,the fabric treated with CPCM had a high phase-transition enthalpy and an appropriate phase-transition temperature. As a result,a desirable temperature-adjustable function appeared.

Swelling and Drug Release Characteristics of Poly （methacrylic acid-co-poloxamer） hydrogels

Poly (methacrylic acid-co-poloxamer) hydrogel networks were synthesized byfree-radical solution polymerization, and the dynamic swelling and in vitro release properties ofmodel drugs, dextromethorphan hydrobromide (DMP) and vitamin B_(12) (VB_(12)) were studied. Thesegels exhibited pH-dependant swelling and sustained drug release properties, and the water uptakerate and drug release rate in neutral or basic media were higher than that in acidic media. Theresults showed that the water uptake followed non-Fickian or zero order process in neutral or basicmedia, and the release of model drugs from hydrogels of appropriate composition was of zero orderkinetics over a period of several hours.

Influence of Aloe Gel Enrichment on the Physicochemical, Textural and Sensory Characteristics of Dahi

Aloe gel, derived from Aloe vera plant is well known for its nutraceutical potential, It is available commercially as a juice with poor sensory quality. The therapeutic benefits of Aloe gel could be extended to food products concomitantly improving its acceptability. Dahi/curd is an Asian fermented dairy product that enjoys tremendous mass appeal. The objective of the present study was to formulate dahi enriched with Aloe gel （AG） as a functional ingredient and to study its effect on the quality of dahi. Plain dahi was prepared by addition of 2.5% skimmed milk powder （SMP） and suitable starter to milk. For the preparation of AG enriched dahi, SMP was replaced by AG at different levels （0.1-0.25%）. The products were evaluated for moisture, pH, titrable acidity （TA）, whey syneresis （WS）, total solid content （TS）, water holding capacity （WHC）, total yield （TY）, whiteness index （WI）, and viscosity. Microbial analysis and sensory evaluation were also carried out. Enrichment of dahi with AG was found to improve its quality characteristics by causing a significant reduction in WS and an increase in TA, TS, WHC, TY, WI and viscosity. AG dahi recorded good sensory acceptability. Storage study also indicated AG dahi to perform better in terms of the various parameters studied. The present investigation suggests the feasibility of adding Aloe gel powder as a functional ingredient to dahi to enhance product quality as well as its nutritional and therapeutic potency. It could be commercially exploited as a novel product.

Study and Evaluation of Aluminum Capsules to Irradiation of Gaseous Samples in Nuclear Reactor

Gas irradiation in research nuclear reactors is an important way to produce radionuclides. Although some nuclear reactors centers offer this type of service, there are few publications about capsules to irradiation of gaseous samples. This paper describes a method to fabricate and evaluate aluminum capsules to irradiate gaseous samples in nuclear reactor. A semi-circular slotted die from a hydraulic presshead was modified to seal aluminum tubes. The aluminum capsules were subjected to leak detection tests, which demonstrated the accordance with standard ISO 9978.

Gelling Behavior of Plant Proteins and Polysaccharides in Food Systems

Biological macromolecules, such as proteins and polysaccharides, are widely used in food systems because their interactions impart a desirable texture to food products. Plant proteins interact with food components via protein-protein and protein-polysaccharide associations, and the formation of a matrix, which can entrap other food components such as water, lipids and flavors. These networks provide structural integrity to food products and can serve as important functional ingredients in processed foods. Intermolecular interactions of typical polysaccharides result either in simple associations or in the form of a double or triple helix. The linear double helical segments may then interact to form a super junction and a three-dimensional gel network. The formation of these structural networks takes place during processing and involves the transformation from a liquid or viscous sol into a solid material with elastic properties. Interests in the behavior of mixed gels center on the prospects of enhanced flexibility in their mechanical and structural properties compared to those of pure gels. Findings on molecular interactions between plant proteins （e.g., soy, canola and pea proteins） and polysaccharides （e.g., guar gum, carrageenan, and pectin） allow for the modification of physical and textural characteristics of mixed biopolymers to meet desired functional property.

Optical Density and Antimicrobial Characteristics of Georgian Propolis

Apiotherapy has been applied by Georgian people since time immemorial. Treatment with bee products in Georgia has been described in popular writings. Among bee products, honey and propolis are of most particular interest. Propolis is characterized by antimicrobial, antiviral, antioxidant, anticarcinogenic and analgesic properties. We have studied relationship between optical density and antimicrobial properties. Almost all samples of Georgian propolis are characterized by high optical density and antimicrobial activity. Studies have discovered that optical density was high in the samples of spring season. The maximal absorption values have been observed at a wavelength of 290-310 nm that is characteristic of flavonoids. Also, the sample with a relatively low optical density （Baghdati district） has exhibited antimicrobial activity that is conditioned not by polyphenols, but flavonoids.

Parameters Effecting on Head Brown Rice Recovery and Energy Consumption of Rubber Roll and Stone Disk Dehusking

Application of improper methods on rice processing affects rice quality and head rice recovery. In Vietnam, paddy with different moisture contents （from 13% to 17%） is dehusked by both rubber roll and stone disk. Thus, objective of this research was to evaluate the technical and economic aspects of the two methods. Optimization was conducted with 20 experiments for input factors （moisture content） and output factors （head brown rice recovery, specific energy consumption）. Besides, other factors were also monitored, such as the gap between the two disks, speed of disk and roll, and pressure of rubber roll on paddy. Test results showed that the maximum value of head brown rice （77.4%） and the minimum value of specific energy consumption （0.66 kWh/ton） corresponding to moisture content of paddy of 13.7% for stone disk dehusker. At similar moisture content （13.7%）, head brown rice recovery and specific energy consumption were 77.2% and 1.04 kWh/ton for rubber roll dehusker, respectively. As the result, specific energy consumption of rubber roll dehusker was higher than that of stone disk dehusker, corresponding to the higher dehusking efficiency.

An Experimental and Numerical Study of Effect of Textured Surface by Arc Discharge on Strength of Adhesively Bonded Joints

Aluminum alloys are being increasingly applied in the automotive industry as a means to reduce mass. Their application to the vehicle structure is typically via a combination of either mechanical or fusion joining with adhesive bonding. Correspondingly, there has been a large effort in improving the adhesive bonding characteristics by changing the surface properties using different surface treatment techniques. One such method is the atmospheric arc discharge process which develops a specific surface roughness which can be leveraged to improve adhesive bonding. In this paper the effect of a textured surface by arc discharge on the failure mode and strength of adhesively bonded aluminum alloy sheets is investigated. A single-lap joint configuration is used for simulation and experimental analysis. A two-dimensional （2D） finite element method （FEM） involving the morphology of treated surfaces and using interfacial elements based on a cohesive zone model （CZM） are used to predict the joint strength which is an enabler for faster product development cycles. The influence of arc process parameters： the arc current and the torch scanning speed, on the surface morphology and joint strength are explored in this study. Specifically, the present study shows that the surface treatment of aluminum alloys by arc discharge can strongly enhance adhesive bond strength. Additionally, arc treatment not only increases the joint strength but also improves the quality of bond along the interface （transition toward cohesive failure mode）. The current FE simulation of adhesive joint using the elastic and elasto-plastic （non-linear） material properties for adherend and adhesive, respectively, and cohesive zone elements for interface shows an accurate prediction of the resulting joint strength. By inclusion of non-linear multi-scale geometry model via considering the surface topographical changes after surface treatment the FE joint strength prediction can be successfully implemented.

Radiation-pressure-driven mechanical oscillations in silica microdisk resonators on chip

We demonstrate radiation-pressure-driven mechanical oscillations from high optical quality factor silica microdisk resonators on chip. Mechanical quality factors of 3520 in air and 12540 in vacuum for the fundamental radial breathing modes are obtained from 73 μm-diarneter silica microdisks with mechanical frequencies of -51 MHz. The measured mechanical oscillation threshold powers for the input light are determined to be 62.5 μW in air and down to 26.6 μW in vacuum.

No-formaldehyde Wood-plastic Composite Plywood in China

As a new product invented by the Research Institute of Wood Industry, no-formaldehyde wood-plastic composite plywood is the harvest of the cross-study on wood-plastic composite and plywood industry, It has no formaldehyde emission, with an excellent environment-friendly performance and a good bonding quafity. This paper analyses the strongpoints and market of this wood-plastic composite plywood.

A review of nutriology of food hydrocolloids

Most current commercially important hydrocolloids could be considered as dietary fibers.A great deal of research has focused on the bio-function of hydrocolloid materials resulting from their chemical structure,including antioxidant properties,bacteriostatic capacity and cancer prevention.However,the colloidal properties of hydrocolloids in water-holding,high viscosity,gelling and indigestion,which are characterized by macromolecules,also contribute to the human health.Therefore,the nutritional value of hydrocolloids deriving from their colloid properties is defined as colloid nutriology.More specifically,hydrocolloids in this study refer to dietary fibers which are metabolically inert or fermented in the colon or large intestine.Based on this conception,this mini-review attempts to elaborate the nutritional value of hydrocolloids resulting from its colloidal properties.