bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling spatial distributions of moisture and quality during drying of granular baker's yeast
Authors: Yüzgeç Uğur , Türker Mustafa , Becerikli Yasar 
Published: July 2008

AbstractA distributed parameter model was developed to predict the drying behaviour of granular baker's yeast by setting up material and heat balances at the particle level. Temperature and moisture gradients were calculated for cylindrical and spherical granules. The performance of the model with two granule sizes was compared with experimental measurements. The model was initially used for non‐shrinking granules but later modified to take shrinkage into account. The reduction in granule size during the course of drying was estimated and good correspondence with experimental measurements was obtained. In addition to temperature and moisture gradients, the product quality was predicted during drying and compared to experimental results. The accuracy of the model was better than the lumped parameter model.
An Efficient Synthesis of 1,5‐Benzodiazepine Derivatives by Lanthanide Trichloride‐catalyzed Condensation of o‐Phenylenediamine with α,β‐Unsaturated Ketone under Mild Conditions
Authors: FENG Shan‐E , XU Fan , SHEN Qi 
Published: July 2008

AbstractThe condensation of o‐phenylenediamine with various α,β‐unsaturated ketones was efficiently catalyzed by lanthanide trichloride and a variety of 1,5‐benzodiazepines were synthesized in moderate to high yields under mild conditions. The reactions catalyzed by ytterbium trichloride were investigated emphatically.
Electrochemical Reduction of 2‐Nitroanisole in Ionic Liquid BMIm‐BF4: Synthesis of 2‐Anisidine
Authors: LIU Ying‐Zi , LIN Mei‐Yu , XIAO Li‐Ping , ZHANG Kai , LU Jia‐Xing 
Published: July 2008

AbstractA new electrochemical synthesis of 2‐anisidine from 2‐nitroanisole has been developed in room‐temperature ionic liquid (RTIL), which was carried out under mild and safe conditions, where the volatile, toxic solvents, catalysts, as well as any additional supporting electrolyte were avoided. The maximal yield of 2‐anisidine reached 51.3% on Cu‐graphite couple electrodes under potentiostatic electrolysis at −1.0 V (vs. SCE) until 6 F·mol−1 of charge was passed at 50 °C, which offers a new and clean route to synthesis of 2‐anisidine. The reduction behavior of 2‐nitroanisole was studied in RTIL by cycle voltammertry. The RTIL could be recycled.
n‐Butane Monomolecular Cracking on Acidic Zeolites: A Density Functional Study
Authors: DING Bing‐Jing , HUANG Shi‐Ping , WANG Wen‐Chuan 
Published: July 2008

AbstractDensity functional theory was used to study monomolecular cracking reaction of n‐butane on acidic zeolite. Geometry optimizations of the local structures of the species reacting with the zeolite were carried out by using the 5T cluster model at the B3LYP/6‐311+G(3df,2p)//B3LYP/6‐31G(d) level. In this work, the deprotonation modes of two different order C atoms in n‐butane cracking on H‐ZSM‐5 were explored in detail by the density functional theory. The calculated activation barriers at the B3LYP/6‐311+G(3df,2p)//B3LYP/6‐31G(d) level are 238 kJ/mol for the primary CC cracking, 217 kJ/mol for the secondary CC cracking, 296 kJ/mol for the primary dehydrogenation, and 242 kJ/mol for the secondary dehydrogenation, respectively. The difference of the activation barrier is 54 kJ/mol for the deprotonation reactions of two different order C atoms in n‐butane. For the dehydrogenation reaction, the results indicate that the reaction is expected to be preferred at the secondary C atom. Additionally, the relation between the acidity and structure of the cluster shows that the acidity effect of the zeolite can be simulated by modifying the peripheral bonds of the cluster for the 5T cluster. Finally, the zeolite acidity effects on the reaction barriers were investigated by changing the cluster terminal SiH bond length.
Calculation of Heat of Formation for Tensile Cyclic Molecules in Condensed Phase Using Electrostatic Potential and QSPR Schemes
Authors: SHI Liang‐Wei , ZHOU Jun‐Hong , ZHANG Tao , KANG Qiang , CHEN Min‐Bo 
Published: July 2008

AbstractPDDG/PM3 method was evaluated as a suitable semiempirical calculation for heat of formation of tensile cyclic organic molecules in gas phase and used in subsequent researches. In order to compute the heat of formation of these compounds in condensed phase, electrostatic potential scheme was performed to obtain the area of the Bader surface at B3LYP/6‐311G∗︁∗︁ level. The root mean square (rms) of the calculated condensed phase heat of formation for 58 molecules from corresponding experimental values is 4.81 kcal/mol. Six QSPR schemes for predicting solid phase heat of formation of 38 model molecules with physically meaningful descriptors from genetic algorithm selection were established. These selected descriptors were recalculated by DFT B3LYP/6‐311G∗︁∗︁ and MP2/6‐311G∗︁∗︁ methods, which could then give similar and better results. The QSPR schemes adopted back‐propagation neutral network (BPNN) and support vector machine (SVM) as analysis tools. It was suggested that selection of descriptors with strong physical significance in QSPR calculation should be important.
Theoretical Study on the Photochemical Ring Opening Process of 2H‐pyran
Authors: LÜ Ling‐Ling , YAN Er‐Di , WANG Xiao‐Fang , WANG Yong‐Cheng , DAI Guo‐Liang 
Published: July 2008

AbstractA theoretical study of the reaction path for the photo‐ring‐open mechanism for a model system 2H‐pyran has been carried out using a CASSCF method. To monitor the electronic rearrangements along the minimum energy pathway (MEP), the electronic structures were analyzed using valence bond (VB) theory and natural bond orbital (NBO) analysis. Calculated results show that the S0‐Min, the absorption of the initial excitation, promotes the system to the S1 excited state with a (π‐π∗︁) character. From the S1‐Min, a low‐barrier path leads to an S1/S0 conical intersection. The energy of the S1/S0 crossing is located 0.63 eV below the S1‐Min. Thus, the initial movement of the nuclei will lead the system through the S1/S0 crossing to the ground state of the S0‐Prod in a very efficient nonadiabatic path along the MEP.
Topological Research on Standard Absolute Entropies, S⊖298, for Binary Inorganic Compounds
Authors: MU Lai‐Long , HE Hong‐Mei , FENG Chang‐Jun 
Published: July 2008

Abstract For predicting the standard entropy of a binary inorganic compound, two novel connectivity indexes mQ, mG and their converse indexes mQ', mG' based on adjacency matrix of molecular graphs and ionic parameters gi, qi were proposed. The qi and gi are defined as qi=(1.1+Zi1.1)/(1.7+ni), gi=(1.4+Zi)/(0.9+ri+ri−1), where Zi, ni, ri are the charge numbers, the outer electronic shell primary quantum numbers, and the radii of ionic i respectively. The good Quantitative Structure‐Property Relationship (QSPR) models for the standard entropies of binary inorganic compound can be constructed from 0Q, 0Q', 1G, and 1G', by using a multivariate linear regression (MLR) method and an artificial neural network (NN) method. The correlation coefficient r, the standard error s, and the average absolute deviation of the MLR model and the NN model are 0.9905, 8.29 J·K−1·mol−1 and 6.48 J·K−1·mol−1, and 0.9960, 5.37 J·K−1·mol−1 and 3.90 J·K−1·mol−1, respectively, for 371 binary inorganic compounds (training set). The cross‐validation by using the leave‐one‐out method demonstrates that the MLR model is highly reliable from the point of view of statistics. The correlation coefficients, standard deviations and average absolute deviations of predicted values of the standard entropies of other 185 binary inorganic compounds (test set) are 0.9897, 8.64 J·K−1· mol−1 and 6.84 J·K−1·mol−1, and 0.9957, 5.63 J·K−1·mol−1 and 4.18 J·K−1·mol−1 for the MLR model and the NN model, respectively. The results show that the current method is more effective than literature methods for estimating the standard entropy of a binary inorganic compound. Both MLR and NN methods can provide acceptable models for the prediction of the standard entropies of binary inorganic compounds. The NN model for the standard entropies appears to be more reliable than the MLR model.
Synthesis, Characteristics and Standard Molar Enthalpies of Formation of MZn2HPO4PO4 (M=Na+, K+)
Authors: YUAN Ai‐Qun , WU Jian , HUANG Zai‐Yin , WU Kun , SONG Bao‐Ling , LIAO Sen , TONG Zhang‐Fa 
Published: July 2008

AbstractMZn2HPO4PO4 (M=Na+, K+) double salts were synthesized by a solid‐state reaction at low temperature and a hydrothermal method, respectively, and characterized by XRD, FT‐IR, TG and SEM. Thermochemical study was performed by an isoperibol solution calorimeter. According to Hess's law, a new thermochemical cycle was designed. The results show that the obtained products are layered compounds with an isostructure of triclinic system. The decomposition temperatures are 415 and 430 °C by TG, respectively. With the dissolution enthalpies and other standard chemical data, the standard molar formation enthalpies of the MZn2HPO4PO4 (M=Na+, K+) were worked out as follows: =fH⊖m[NaZn2HPO4PO4, s] =(−3042.38±0.31) kJ·mol−1 and =fH⊖m[KZn2HPO4PO4, s] =(−3093.46±0.27) kJ·mol−1.
Thermodynamic Studies of Electrostatic Self‐assembly of Poly Diallyldimethylammonium Chloride on Proton Exchange Membrane
Authors: LIU Peng , LI Xi , PAN Mu 
Published: July 2008

AbstractThe electrostatic self‐assembly of polymer on proton exchange membrane was studied by calorimetric technique. The titration of poly diallyldimethylammonium chloride (PDDA) into Nafion membrane was designed and performed to determine the thermodynamic parameters. The enthalpy change ΔrH⊖mand binding constantKin the process of self‐assembly were obtained from data analysis with the help of Origin. According to the calculated thermodynamic parameters, the electrostatic self‐assembly of PDDA on the proton exchange membrane is an "enthalpy‐driven" reaction. The released heat indicates decrease of energy, which is helpful for the occurrence of the self‐assembly process, and the degree of disorder is reduced, which went against the adsorption process. As to every ion bond, the value of ΔrH⊖mof DDA is beyond PDDA because a small molecule can bind itself to the membrane without steric hindrance.
Characterization, Crystal Structure and Initial DNA Binding Mechanism Research of Multi‐nuclear Homometallic Complexes of 4,5‐Diazafluoren‐9‐one with Copper(II) and Cobalt(II)
Authors: ZHANG Rong‐Lan , ZHAO Jian‐She , XI Xiao‐Li , YANG Pin , SHI Qi‐Zhen 
Published: July 2008

AbstractTwo new multi‐nuclear homometallic complexes, [Cu2(OAc)4(H2O)2]·2dafo (1) and [(µ2‐O)2‐Co3(dafo)6]‐(ClO3)2·H2O (2) (dafo=4,5‐diazafluoren‐9‐one), were synthesized. The two complexes have been fully characterized by elemental analysis, IR, absorption spectra, emission spectra, and single‐crystal X‐ray diffraction analysis. The initial DNA binding mechanisms of the two complexes have been investigated by absorption spectra, emission spectra and cyclic voltammograms. Both complexes show similar perturbations on addition of calf thymus DNA in the UV region, their luminescence intensities in aqueous buffer are all enhanced in the presence of increasing amounts of DNA, and their electrochemical behavior is both completely different in the absence and presence of DNA. The results of the three methods indicate that the spectral characters and the electrochemical behavior of the two complexes are very similar to those of the known metallointercalators. So it can be concluded that the action mode of the two complexes with DNA is mainly intercalative.
From 1D Polymeric Chain to Two‐fold Parallel Interpenetration of (4,4) Net: Synthesis and Characterization of Two New Copper(II) Complexes Derived from Highly Polydentate Aminopolycarboxylate Ligand
Authors: WU Ya‐Pan , WANG Yao‐Yu , WANG Cui‐Juan , LI Dong‐Sheng , GUO Chun‐Yan , WEN Gui‐Lin , SHI Qi‐Zhen 
Published: July 2008

Abstract Two new copper(II) polymers, {[Cu2(egta)(bpe)(H2O)2]·H2O}n (1) and {[Cu2(egta)(bipy)(H2O)2]·5H2O}n(2), [H4egta=3,12‐bis(carboxymethyl)‐6,9‐dioxa‐3,12‐diazatetradecanedioic acid, bpe=1,2‐bis(4‐pyridyl)ethane, bipy4,4′‐bipyridyl] have been synthesized and structurally characterized by single‐crystal X‐ray diffraction, elemental analysis, IR spectra and TG analysis. The structure determination reveals that both 1 and 2 crystallize in a monoclinic system, space group P21/c. Complex 1 exhibits a two‐fold parallel interpenetration of (4,4) net framework consisting of 1D zigzag chains interlocked together through hydrogen bonding interaction. However, the meso‐helix chains of 2 are packed to form 2D supramolecular structures. Interestingly, in 2, the host frameworks encapsulate a unique pentamer water cluster and are further connected into 1D tapes by water‐water hydrogen bonding interaction. Magnetic measurements reveal that there is a weak ferromagnetic interaction between the adjacent Cu(II) ions in 1.
Synthesis, Crystal Structure and Characterization of Two Rare Earth Substituted Keggin‐Type Germanotungstates
Authors: WANG Jing‐Ping , YAN Qing‐Xia , DU Xiao‐Di , NIU Jing‐Yang 
Published: July 2008

Abstract Two germanotungstates based on the dysprosium cations and monovacant Keggin anions [GeW11O39]8−, [(CH3)4N]1.5H3.5[Dy(H2O)2(GeW11O39)]·1.5H2O (1) and [Cu(Hen)(en)]2[Cu(H2O)3]0.5{[Cu(H2en)(Hen)]‐[Cu(H2O)3]0.5[Dy(GeW11O39)2]}·1.25H2O (2), have been synthesized and characterized by elemental analysis, inductively coupled plasma (ICP) analysis, IR spectroscopy, thermal analysis, and single‐crystal X‐ray diffraction. Crystal data for 1: monoclinic, space group C2/c with cell dimensions of a=2.8201(5) nm, b=2.2885(3) nm, c=2.4033(4) nm, β=123.875(2)°, V=12.878(4) nm3, Z=8, µ=21.239 mm−1; and for 2: monoclinic, space group P21/n with cell dimensions of a=2.12808(5) nm, b=1.63834(4) nm, c=3.18074(4) nm, β=93.760(2)°, V=11.0658(5) nm3, Z=4, µ=24.803 mm−1. The Dy3+/[GeW11O39]8− ratio of compound 1 is 1:1, and it displays an interesting one dimensional chainlike arrangement. And the Dy3+/[GeW11O39]8− ratio of compound 2 is 1:2 , and it shows a typical dimeric structure.
A Green Approach to the Synthesis of Biologically Important Indeno[2,1‐e]pyrazolo[5,4‐b]pyridines via Microwave‐assisted Multi‐component Reactions in Water
Authors: SHI Feng , ZHANG Yan , TU Shu‐Jiang , ZHOU Dian‐Xiang , LI Chun‐Mei , SHAO Qing‐Qing , CAO Long‐Ji 
Published: July 2008

AbstractA green approach to the synthesis of biologically important indeno[2,1‐e]pyrazolo[5,4‐b]pyridines was successfully realized via multi‐component reactions of aldehyde, 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5‐amine and 1,3‐indanedione in water under microwave irradiation without catalyst. This protocol has the prominent advantages of environmental‐friendliness, short reaction time, excellent yields, low cost, easy operation as well as broad scope of applicability.
Studies on the Thermodenaturation Behavior of Bacillus subtilisα‐Amylase on Chromatographic Media
Authors: BIAN Liu‐Jiao , WANG Xiao‐Hua , YANG Xiao‐Yan , LIU Li 
Published: July 2008

AbstractThe thermodenaturation behavior of Bacillus subtilis α‐amylase on some chromatographic media was studied by determining their adsorption parameters with frontal analysis. The experimental results show that on a RP‐C18 reversed‐phase medium, a Chelating Sepharose Fast‐Flow chelated by Zn2+ affinity medium and a WCX‐1 cation‐exchange medium, a stable conformation of α‐amylase molecule separately exists below or over 30 °C; while on a PEG‐400 hydrophobic medium and a modified PEG‐400 medium, a stable conformation of α‐amylase molecule separately exists below 40 and 30 °C, and when the experimental temperatures are separately over 40 and 30 °C, a drastically conformational change of α‐amylase molecules can continuously take place. And by combining the intrinsic fluorescence emission spectrum and thermal inactivation profile of α‐amylase in free solution and on the PEG‐400 and modified PEG‐400 hydrophobic media, it can be concluded that in liquid chromatographic procedure, chromatographic media can induce the conformational change of α‐amylase molecules and promote their thermodenaturation; and in hydrophobic interaction chromatography, the higher the hydrophobicity of chromatographic medium, the lower the conformational change temperature of α‐amylase molecules on the chromatographic medium.
Detection and Sequence Identification of Dinucleotides Produced from N‐Phosphoryl Alanine and Four Nucleosides by HPLC‐ESI‐MS/MS
Authors: GUO Yan‐Chun , CAO Shu‐Xia , LIAO Xin‐Cheng , ZHAO Yu‐Fen 
Published: July 2008

AbstractThe products of the model reaction between N‐(O,O‐diisopropyl phosphoryl) alanine (DIPP‐Ala) and four nucleosides (adenosine, uridine, cytidine and guanosine) were studied by HPLC‐ESI‐MS/MS. The results showed that different mononucleotides and dinucleotides were produced. The sequences of dinucleotides formed from the DIPP‐Ala and four nucleosides were identified. The results revealed that the c‐ions from backbone fragmentation of the dinucleotides could be considered as the sequence‐diagnostic ions. It was firstly testified that the diagnostic c‐ions in positive and negative modes could be applied to identify the sequence of dinucleotide products formed in the reaction system.
Catalytic Synthesis Methods for Triazolopyrimidine Derivatives
Authors: CHENG Chun‐Sheng , GAI Yong‐Ming , WANG Xin‐Lei , PENG Jun 
Published: July 2008

AbstractA new method for catalyzed synthesis of triazolopyrimidine derivatives is reported. Alkylamine reaction with dialkyl cyanodithioiminocarbonate was catalyzed by quaternary ammonium salts at room temperature to yield 3‐alkylamine‐5‐amino‐1,2,4‐triazole in good quality and high yields. After imidization and reaction with an α,β‐unsaturated acid derivative, the reaction intermediate was hydrolyzed in the presence of a Lewis acid to obtain the target product. This novel catalytic method for triazolopyrimidine derivatives can be carried out under inexpensive and mild conditions, and is safe and environmentally friendly. 1H NMR results for all intermediates are reported.
Synthesis of β‐Amino Acids via Catalyst‐ and Solvent‐Free Aza‐Michael Reaction
Authors: ZOU Bo , JIANG Huan‐Feng 
Published: July 2008

AbstractA safe, environmentally friendly and cost‐effective method for the synthesis of β‐amino acid derivatives has been developed. Treatment of α,β‐unsaturated compounds with aliphatic amines furnishes β‐amino acid derivatives in good to excellent yields via a catalyst‐ and solvent‐free aza‐Michael addition.
Silica Nanotubes Prepared under Dilute Gelator Concentrations
Authors: CHEN Yuan‐Li , PEI Xian‐Feng , JIANG Yun , ZHOU Lei , ZHANG Juan , BI Li‐Feng , LI Hai‐Tao , YANG Yong‐Gang 
Published: July 2008

AbstractSingle‐handed helical silica nanotubes that can trap water and organic solvents were prepared by sol‐gel transcription under dilute gelator concentrations.
In(OTf)3‐mediated Facile Preparation of 2‐(3,4,5‐Trimethoxyphenyl)‐5‐[(5‐alkylthio‐1,3,4‐oxadiazol‐2‐yl)methylthio]‐1,3,4‐thiadiazole Derivatives in Aqueous Media
Authors: WU Qin , SONG Bao‐An , YANG Song , BHADURY Pinaki S. , HU De‐Yu , XUE Wei , JIN Lin‐Hong , CHEN Zhuo 
Published: July 2008

AbstractTen new 2‐(3,4,5‐trimethoxyphenyl)‐5‐[(5‐alkylthio‐1,3,4‐oxadiazol‐2‐yl)methylthio]‐1,3,4‐thiadiazole derivatives were synthesized from 2‐mercapto‐5‐(3,4,5‐trimethoxypheny1)‐1,3,4‐thiadiazole in four steps of thioetherification, hydrazidation, cyclization and thioetherification. The synthesis of the title compounds catalyzed by In(OTf)3 at 40 °C in aqueous media was easily achieved in high yields under environmentally benign conditions. Furthermore, In(OTf)3 can be recovered and reused without any notable loss of its catalytic activity.
A Novel Surfactant‐free Microemulsion System: N,N‐Dimethyl Formamide/Furaldehyde/H2O
Authors: NI Peng , HOU Wan‐Guo 
Published: July 2008

AbstractGenerally, a microemulsion consists of oil, water, surfactant and sometimes cosurfactant. Herein, for the first time to our knowledge, a novel surfactant‐free microemulsion (SFME), consisting of furaldehyde (oil phase), water and N,N‐dimethyl formamide (DMF) without the amphiphilic molecular structure of traditional surfactant is reported. The phase behavior of the ternary system was investigated, finding that a single‐phase microemulsion region and a two‐phase region were formed. The electrical conductivity measurement was employed to investigate the single‐phase microemulsion region. On the basis of the percolation theory, the single‐phase microemulsion region was identified to consist of three different microregions: furaldehyde‐in‐water (O/W), bicontinuous region and water‐in‐furaldehyde (W/O), which were further proved by freeze‐fracture transmission electron microscopy (FF‐TEM) observations. The diameter of the microemulsion spherical droplets is in the range of 40–70 nm.
A New Triterpenoid from the Fruits of Phellodendron chinensevar. glabriusculum Schneid
Authors: YAN Chen , WANG Ye , DU Hua , HAO Xiao‐Jiang 
Published: July 2008

AbstractA new triterpenoid 21α‐methylmelianol(21R,23R)epoxy‐24‐hydroxy‐21α‐methoxyl]triucalla‐7,25‐dien‐3‐one (1), was obtained from the fruit of Phellodendron chinense var. glabriusculum Schneid and elucidated by means of spectroscopic analysis. Niloticin and melianone type tirucallane triterpenoids were major constituents in the EtOAc fraction of crude extract of the the fruit of Phellodendron chinense var. glabriusculum Schneid.
Der Ionenbegriff – historischer Spätzünder und gegenwärtiger Außenseiter
Authors: Barke Hans‐Dieter , Pieper Christian 
Published: July 2008

AbstractDas Ion ist seit fast zwei Jahrhunderten ein schillernder Begriff für ein allgegenwärtiges Teilchen! Am Aufbau eines jeden Kochsalzkristalls oder Marmorkristalls sind ausschließlich Ionen beteiligt, in jedem Leitungswasser oder Mineralwasser sind bestimmte Ionenarten vorhanden: Etikette von Mineralwasserflaschen weisen es meist definitiv aus (Abb. 1). Trotz der Allgegenwärtigkeit der Ionen als kleinsten Teilchen der Materie gibt es Probleme mit dem Verständnis des Ionenbegriffs: mehr als die Hälfte der Jugendlichen aller Klassenstufen stellen sich beispielsweise unangemessen „NaCl‐Moleküle”︁ in Kochsalz oder „CaCl2‐Moleküle”︁ in Mineralwasser vor [1]. Die Ionen scheinen an der Seite von verstehbaren Atomen und Molekülen schwer vermittelbar zu sein: Sind sie exotische Außenseiter‐Teilchen?Der Aufsatz soll im ersten Teil ausweisen, wie schwierig die Ausschärfung des Ionenbegriffs historisch gewesen ist und dass sich diese Schwierigkeiten in der Lehre an den Universitäten widerspiegelten: lange noch lehrte man die „NaCl‐Moleküle”︁ ohne Hinweise auf das Ion – es erwies sich als historischer Spätzünder!
Chemie im Kontext in Holland
Authors: Apotheker Jan 
Published: July 2008

AbstractUnzufriedenheit mit dem Curriculum, Evaluationen von Schülern, die das Fach Chemie als langweilig und wenig ansprechend empfinden, sowie rückläufige Studentenzahlen waren für das Bildungsministerium der Niederlande Anlass für eine Analyse der angeführten Probleme. Als Resultat erschien ein Bericht [1], der eine Reihe möglicher Fakten, die dabei im Chemieunterricht eine Rolle spielen, zusammenstellte. Aufgrund dieses Berichts wurde durch das Bildungsministerium ein Lenkungsausschuss gegründet, der beauftragt wurde, den Chemieunterricht in den Niederlanden neu zu gestalten. Ein Ansatz, den der Lenkungsausschuss aufgriff [2], war der des kontextbasierten Lernens, der in Deutschland unter anderemdurch Chemie im Kontext vertreten wird. Daraufhin startete an der Universität Groningen eine Gruppe von Dozenten mit der Entwicklung einer ersten exemplarischen Unterrichtseinheit zum Thema Verbrennungen, die analog zu den Strukturen und Ideen von Chemie im Kontext gestaltet wurde. Das Thema Verbrennungen wurde ausgewählt, weil es gut in das Curriculum der 3. Klasse (entsprechend der 9. Klasse in Deutschland, vgl. Abb. 1) des niederländischen Bildungssystems passt. In der 3. Klasse Chemie behandelt man die Einführung in die Chemie durch verschiedene Reaktion wie z.B. Verbrennungen.