左右滑动臂共取多工位级进模设计

基于左右滑动臂两件共取的级进模设计实例,详细阐述了级进模设计的思路,以及实现两件共取的方案。通过具体案例的介绍,对模具设计过程中的排样设计、冲裁设计、半冲设计、毛刺处理、及出料设计等工序进行了详细的说明和介绍,同时两个不同部件共取的方案可以缩减成本、提高经济效益。对于同类部件的设计及加工起到一定的参考及指导作用。

AM/AMPS/AMC_(14)S共聚物的合成

采用氧化 -还原引发体系 ,合成了丙烯酰胺 (AM) 2 -丙烯酰胺基 - 2 -甲基丙磺酸 (AMPS) 2 -丙烯酰胺基十四烷磺酸 (AMC14 S)三元共聚物。用红外光谱分析了聚合物的结构 ,初步评价了共聚物的溶液性能。结果表明 ,AM AMPS AMC14

非线性A_f-B_g型自由基交替共聚反应的凝胶网络结构参数

利用高分子反应统计理论 ,计算了非线性Af-Bg 型自由基交替共聚反应凝胶网络中的弹性有效链和悬吊链的链数及相应的链节数 .进而计算了弹性有效链的数量和质量分数、有效交联点数和弹性模量等网络结构参数 .

战略管理情境下的生态系统:一个动态过程整合模型

生态系统构建与管理是企业保持持续行业竞争优势的战略选择。现有研究对生态系统概念定义与特征阐释存在巨大争议:部分学者强调战略管理情境下的商业生态系统与创新生态系统概念相互独立;而另一部分学者认为两者不存在明显差异,并在研究中交替使用两个概念。基于关键文献评论方法,这一争议得到了调和。从静态角度看,商业生态系统区别于创新生态系统,前者强调系统成员价值共创过程,后者强调系统成员价值共取过程。但两者具有概念互补性:无论商业生态系统还是创新生态系统都可统一于系统生命周期和价值过程中。因此,从动态过程视角分析,战略管理情境下的生态系统着力于价值主张、价值共创、价值共享、价值分配以及价值共取;生态系统的价值过程在系统初创期、扩张期、成熟期以及衰落/复苏期具有不同的演化特征。未来相关研究可从历史演变角度,结合多学科视角,深化对生态系统概念演变规律的认识。

Substituent Effects on 13C NMR and 1H NMR Chemical Shifts of CH=N in Multi-substituted Benzylideneanilines

Fifty-three samples of multi-substituted benzylideneanilines XArCH=NArYs （abbreviated XBAYs） were synthesized and their NMR spectra were determined. An extensional study of substituent effects on the 1H NMR chemical shifts （δH（CH=N）） and 13C NMR chemical shifts （δc（CH=N）） of the CH=N bridging group from di-substituted to multi-substituted XBAYs was made based on a total of 182 samples of XBAYs, together with the NMR data of other 129 samples of di-substituted XBAYs quoted from literatures. The results show thatthe substituent specific cross-interaction effect parameter （△（∑σ）2） plays an important role in quantifying the δc（CH=N） values of XBAYs, but it is negligible for quantifying the δH （CH=N） values; the other substituent parameters also present different influences on the δc （CH=N） and （δH （CH=N）. On the whole, the contributions of X and Y to the δc （CH=N） of XBAYs are balanced, but the δH（CH=N） values of XBAYs mainly rely on the contributions of X.

Preparation and in Vitro Evaluation of Polylactic Acid (PLA) or Polylactic-co-Glycolic Acid (PLGA) Microcapsules Loaded with Estradiol

Aim PLA/PLGA was used as biodegradable and biocompatible carriers to achieve sustained release of estradiol (E 2). Methods Microcapsules (MC) were prepared by an emulsification solvent extraction method, and then the properties and in vitro drug release behavior of MC were examined. An analysis of variance (ANOVA) was used to test the statistical significance. Then, multiple comparisons were made with a T method between levels to examine the significance of difference further. For all the results a P value 】0 05 was considered statistically insignificant . Results Under the same conditions, the water adding speed and the particle size had significant effects ( P 【0 01) on the entrapment efficiency of MC; the water adding speed and the concentration of PLA in the oil phase had significant effects ( P 【0 01) on the diameter MC in medium. Release of E 2 from MC was influenced significantly ( P 【0 01) by the water adding speed and the type and molecule weight of the polymers. But the differences between levels of the variates were not all significant. Conclusion E 2 PLA/PLGA MC with various properties can be formed when the formulation and the technology were changed accordingly.

Non-covalent associative structure of coal

The recent progress of non-covalent associative structure of coal, and the mechanisms of the CS2/NMP (1:1 by volume) mixed solvent and the additive addition enhancing the extraction yield of coals were reviewed, and the aggregation behavior of coal in solid and solution states were presented, and the aggregation behavior of coal in solid and solution states were introduced in this paper. Coal extraction and swelling in organic solvents at room temperature were the most useful methods to understand the associative structure of coal. CS2/NMP (1:1 by volume) is a unique solvent to give high extraction yields for some bituminous coals. Some additives can dissociate the stronger interactions among coal molecules and enhance the extraction yields of coal in the mixed solvent.

Multiple eutectic orientation relationships in undercooled Ni-38wt.%Si eutectic alloy

Eutectic orientation relationships(EORs) in an undercooled Ni-38 wt.%Si alloy were analyzed by electron backscatter diffraction. A total of seven EORs were identified, and three of them were found at the under-cooling degree ?T≈31 K. It is found that their orientations of the primary NiSi phase are same but the misorientation between the neighboring NiSi2 grains can be either 50° or 60°. The multiple EORs were ascribed to a possible change in the growth direction of the primary phase, the change of the primary phase from the NiSi phase to the NiSi2 phase, and the transition from coupled to uncoupled eutectic growth. The current work shows that epitaxial growth of the second eutectic phase on the primary eutectic phase can obey either a single EOR or multiple EORs, which is a unique phenomenon.

Design and Synthesis of 4,4'-Disubstituted-[2,2']-Bipyridines for Catalyzing CO/Styrene Copolymerization with Palladium(Ⅱ)

A series of 4,4＇-disubstituted-[2,2＇]-bipyridines, featuring electron withdrawing/donating functional groups such as amino, chloro, nitro, ethoxycarbonyl, carboxy, methyl, methoxy and hydroxymethyl, have been syn- thesized and employed in the copolymerization of carbon monoxide （CO） and styrene. The available bipyridine and its derivatives were coordinated with palladium （ II ） acetate for catalyzing the copolymerization of CO and styrene, and the concomitant polyketone was characterized by means of t3C NMR, FTIR, differential scanning calo- rimetry （DSC） and element analysis techniques concerning its structure and thermal performance. The effect of dif- ferent electron-donating and electron-withdrawing groups on catalyst performance and molecular weight of co- polymer was studied under certain experimental condition. It has been proved that the enhancement of electron donating and conjugative effects on bipyridine ligand will not only improve the catalytic activity of the composi- tion, but also increase the molecular weight of the as-prepared polyketone. The catalytic activity is the highest in hydroxymethyl substituted 2,2＇-bipyridine ligand（l 356 gSTCO/（gPd · h））, when the molecular weight and polydispersity index of the polyketone are Mn = 8 502, Mw = 1 3440 and Mw/Mn = 1.581, respectively.

Preparation of PLA or PLGA Microspheres with Estradiol the Effects of THF—adding on the Properties of MS

Aim Polylactic acid (PLA) or polylactide-co-glycolide (PLGA) was used asbiodegradable and biocom-patible carriers to achieve sustained release ofestradial-PLGA/PLA-Microspheres (E_2-PLGA/PLA-MS). THF was added in the organic phase to study itseffects on the properties of MS. Methods MS were formed by an emulsification-solvent extractionmethod with mixture of ethyl acetate (EtoAc) and tetrahydrofuran (THF) as the organic solvents, andthen the properties and in vitro drug release behavior were examined. Results The results indicatedthat the drug loading efficiency decreased when THF added, but when the ratio of EtoAc was more than50% , there was no obvious effect of THF ratio, but the particle size increased accordingly. Thecarriers' properties and the drug contents were the main factors influencing the in vitro drugrelease. Conclusions By controlling the technology and formulation, we can get sustained-release E_2biodegradable microsperes with proper particle size, drug content and low burst-release, althoughTHF with readily solubility in water was used in the organic phase.

Isolation and Identification of Nicotiflorin and Narcissin from the Aerial Parts of Peucedanum aucheri Boiss.

Peucedanum aucheri Boiss. （Apiaceae） is a herbaceous wild plant native to Iran and is used in Iranian folk medicine as a diuretic and for the treatment of kidney disorders. Phytochemical investigation of different extracts prepared from the aerial part of P. aucheri Boiss. resulted to the isolation of two main flavonol glycosides from methanolic extract. Using comprehensive spectroscopic methods, including 1D and 2D nuclear magnetic resonance （NMR） spectroscopy and mass spectroscopy, chemical structure of isolated compounds were determined as kaempfrol-3-o-rutinoside （nicotiflorin） and isorhamnetin-3-o-rutinoside （narcissin）. Although narcissin has previously been isolated from P. ruthenicum, to the best of our knowledge, isolation of nicotiflorin from Peucedanum genus is reported for the first time.

A new ketosteroid from red alga Acanthophora spicifera

A new ketosteroid, along with six known steroids, was isolated from the ethanolic extracts of red alga Acanthophora spicifera （Vahl.） Boergesen. The structures, identified using chemical and spectroscopic methods including 2D NMR, were： （1） 22-hydroxy-5α-eholest-3,6-dione, （2） 6-hydroxycholest-4-ene-3-one, （3） cholest-4-ene-3,6-dione, （4） cholest-5-ene-3β-ol, （5） 5u-cholestane-3,6-dione, （6） β-Sitosterol and （7） Saringosterol. The MTT method was used to test the cytotoxicity of the compounds against the human cancer cell lines, HCT-8, Bel-7402, BGC-823, A549 and HELA. Compounds 1, 2, 3 and 5 showed moderate cytotoxic activity against human cancer cell lines.

嵌段液晶高分子的合成进展

综述了近几年嵌段液晶共聚物在合成方面取得的新进展，主要包括活性聚合、液晶（或非液晶）低聚物与非液晶（或液晶）聚合物的单体反应、液晶低聚物与非液晶低聚物直接反应和先制备非液晶嵌段共聚物再于侧链引入液晶基元四个方面。同时还简要地介绍了嵌段液晶共聚物的结构、性能以及今后的发展趋势。

高粘结性共聚酰亚胺

采用非酮胺体系研究成高粘结性共聚酰亚胺。确定了适用体系为 OB′B,获得最佳粘结性的条件是原料中 B 占二元酐的60—75mol.-%,共聚酰胺酸的分子量5—7万和热亚胺化温度250℃。对共聚物再共混、溶剂和被粘物对粘结性的影响以及粘结性提高的主要原因也作了讨论。

Automatic Extraction of Contextual Co-occurrence Chain and Its Relationship with Textual Cohesion

Semantic lexical chains have been regarded as important in textural cohesion, although traditionally, the classification of these chains has been limited to repetition, synonymy, hyponymy, and collocates. The cases of automatic extraction of lexical chains have found that the contextual synonyms can not be recognized, nor extracted automatically. This study took the data-based technology to extract the contextually co-occurring lexical chains through thematic lexical items. It found that these contextually co-occurring lexical chains can include the semantic lexical chains and contextual synonyms. It also found that, in extraction of collocates of the co-occurring lexical items, these collocates form secondary lexical chains, which contribute to textual cohesion. The vertical lexical chains made of contextually cooccurring lexical items and the horizontal chains made of collocational lexical items work together in making the text into a coherent whole.

Construction of folate-conjugated epirubicin liposomes for enhancing the cellular uptake and the co-localization with nuclei of invasive breast cancer cells

Drug resistance of anthracycline in the invasive cancer is associated with the lowered cellular drug uptake and diminished co-localization of drug with nuclei. In the present study, we aimed to construct the folate-conjugated epirubicin liposomes by incorporating a synthesized folate-lipid derivative; and to assess the effects on cellular drug uptake, co-localization of drug with nuclei and efficacy in treatment of invasive breast cancer cells. The studies were performed on invasive human breast cancer cells. The folate-PEG2ooo-DSPE conjugate was synthesized, and the constructed folate-conjugated epirubicin liposomes were approximately 1 O0 nm in size. The in vitro studies demonstrated that the folate-conjugated epirubicin liposomes had the strongest cellular drug uptake and co-localization with nuclei of the invasive breast cancer cells. Besides, the liposomes displayed the most significant efficacy in killing the invasive cancer cells, in preventing their invasive potential, and in penetrating ability into breast cancer spheroid as well. In conclusion, the constructed folate-conjugated epirubicin liposomes were able to enhance the efficacy in treatment of invasive breast cancer by improving the cellular drug uptake and increasing the co-localization with nuclei, hence offering a new strategy for potentially eradicating the invasive breast cancer cells.

Determination of chlorogenic acid in traditional Chinese prescription Shuanghuanglian capsule using quantitative nuclear magnetic resonance spectroscopy in combination with solid phase extraction

The determination method of chlorogenic acid in traditional Chinese prescription Shuanghuanglian capsule was established by using quantitative nuclear magnetic resonance spectroscopy(q NMR) in combination with solid phase extraction(SPE). As the capsule’s main active component, chlorogenic acid comes from the extraction of Chinese herb medicine Flos Lonicerae. The chlorogenic acid in capsule was ultrasonically extracted at room temperature using pure water as solvent. The extracting solution was enriched and cleaned using HC-C18 SPE cartridge. The effect of ultrasonic extraction, sample pretreatment conditions via SPE and q NMR experimental conditions were investigated. The q NMR experiment conditions were selected using deuterated DMSO as solvent, calibrated 1,4-phthalaldehyde as internal standard, and P1(pulse width) = 14.4 μs, d1(pulse delay time) = 1 s, NS(number of scan) = 512. The 1 H NMR peaks of δ 6.138–6.182(H-8’, d, 1 H) of chlorogenic acid was chosen as the quantitative peaks. Method validation was performed, including precision(the intra-day RSD = 1.2% and the inter-day RSD = 1.5%), linearity(correlation coefficient r>0.9999), LOD(0.0017 mg/g) and LOQ(0.079 mg/g). The recovery of the SPE-q NMR was within the range of 100.2%–103.2%. The result showed that the method was stable, accurate and reliabile. Determined by the method, the chlorogenic acid in a real Shuanghuanglian capsule was within the range of 9.68–10.35 mg/g.

A novel and concise synthetic access to chiral 2-substituted-4-piperidone

A novel and concise synthetic access to enantiopure chiral 2-aryl/alkyl substituted 4-piperidone has been demonstrated.This new route features two key steps:the highly diastereoselective conjugate addition of homochiral lithium amides to trans-β-substituted-α,β-unsaturated methyl esters guaranteed the enantiopurity at 2 position(de>19:1)and the intramolecular attacking of carbanions to methyl esters led to the formation of the piperidone ring.A wide range of substrates,including chiral2-aryl and 2-alkyl-4-piperidones,were successfully synthesized with modest to high yield.Moreover,some non-chiral3-substituted-4-piperidones were also synthesized with enhanced ring-formation yield,implicating the versatility of this method in construction of various piperidine rings.

Classification of EEG-based single-trial motor imagery tasks using a B-CSP method for BCI

Classifying single-trial electroencephalogram(EEG)based motor imagery(MI)tasks is extensively used to control brain-computer interface(BCI)applications,as a communication bridge between humans and computers.However,the low signal-to-noise ratio and individual differences of EEG can affect the classification results negatively.In this paper,we propose an improved common spatial pattern(B-CSP)method to extract features for alleviating these adverse effects.First,for different subjects,the method of Bhattacharyya distance is used to select the optimal frequency band of each electrode including strong event-related desynchronization(ERD)and event-related synchronization(ERS)patterns;then the signals of the optimal frequency band are decomposed into spatial patterns,and the features that can describe the maximum differences of two classes of MI are extracted from the EEG data.The proposed method is applied to the public data set and experimental data set to extract features which are input into a back propagation neural network(BPNN)classifier to classify single-trial MI EEG.Another two conventional feature extraction methods,original common spatial pattern(CSP)and autoregressive(AR),are used for comparison.An improved classification performance for both data sets(public data set:91.25%±1.77%for left hand vs.foot and84.50%±5.42%for left hand vs.right hand;experimental data set:90.43%±4.26%for left hand vs.foot)verifies the advantages of the B-CSP method over conventional methods.The results demonstrate that our proposed B-CSP method can classify EEG-based MI tasks effectively,and this study provides practical and theoretical approaches to BCI applications.