施肥与蔬菜、西瓜病虫害抗性关系研究

在相同环境条件下,观察了施肥种类、数量、时期、方法对蔬菜、西瓜病虫害发生危害及其产量的影响。结果表明:花椰菜黑腐病、菜青虫,西瓜枯萎病的危害是随施氮量增加而严重,当施氮量吻合作物各个品种的耐肥能力时,病虫危害显著减轻,增产率明显提高。磷、钾肥用量增加,有助于花椰菜、西瓜增强抗逆性,菜青虫、黑腐病和枯萎病显著减轻。在作物营养生长期喷施浓度适当的稀土,花椰菜、芹菜、生菜、西瓜,才能达到减轻病虫害和提高产量的目的。

白粉病在小麦穗部的发生及穗叶抗性关系的研究

研究表明,随着小麦白粉病流行频率的提高,该病对小麦穗部的危害几乎与其对叶部的危害同等重要。供试的119个品种中,穗叶发病情况呈四种类型:I、穗叶均不发病;Ⅱ、穗病叶不病;Ⅲ、叶病穗不病;Ⅳ、穗叶均发病。以表现第Ⅳ类型的品种数最多,占95.8％。对表现第Ⅳ类型的品种穗叶病情资料所做的统计分析表明,穗部抗性与叶部抗性呈极显著的正相关(r=0.625)。

几个优良欧亚种葡萄品种(系)对黑痘病与霜霉病的抗性及关系

通过田间自然感病调查,利用配对数据处理,系统地研究了4 个欧亚种葡萄品种(系)对黑痘病与霜霉病的抗性及关系。结果表明,对于黑痘病,爱格丽为低感品种,88-02、88-03为中感品系,88-04为高感品系;对于霜霉病,爱格丽、88-02、88-04为高感品种(系),88-03为低感品系。且供试品种(系)对两种病害的抗性无显著相关。

Studies on the Synthesis, Anticonvulsant Activity, and the Structure-Activity Relationships of Phenyl Pyridazinones and their GABA Derivatives

In searching for effective anticonvulsant agents,fourteen 6-aryl-4.5-di- hydro-3(2H)pyridazinones.fifteen 6-aryl-3(2H)pyridazinones,and seventeen 3-GABA derivatives of 6-aryIpyridazines have been synthesized,and evaluated in mice for the ability to antagonize maximal electroshock seizure(MES).The ED_(50) values showed that 6-(2′,4′- dichlorophenyt)-3(2H)pyridazinone was the most potent anticonvulsant among these corn- pounds(ED_(50)=10.15 mg/kg).The structure-activity relationships of the aryl pyridazinones were studied.The result showed that:(1)the higher the value of the hydrophobic parameter л of the substituent on the phenyl ring.the more potent the anticonvulsant activity of the corn- pound.and(2)only the compounds with an electron withdrawing substituent on the phenyl ring exhibited appreciable anticonvulsant activity.

从耐氯菌谈未来供水管网水质安全保障技术发展趋势

供水管网中的耐氯菌存在广泛、适应性强。耐氯菌的控制是供水管网水质安全保障的核心问题之一。通过对供水管网中不同输送距离的耐氯菌生物种类多样性进行分析研究,同时基于实验室自制管道模拟装置,从管材、余氯浓度、菌落形态以及细菌种类等方面对分离出的耐氯菌进行研究。结果表明供水管网始端与中途耐氯菌的群落结构组成相差不大,但末梢处的耐氯菌群落结构组成存在较大差异。在抗生素的存在下,有些耐氯菌对抗生素具有耐药性,耐药性可以在不同的耐氯菌之间发生转移,导致原本非耐药的耐氯致病菌呈现出耐药性,最终导致耐氯致病菌对抗生素产生耐药性,对人类的健康具有潜在风险。最后,从耐氯菌对消毒剂和抗生素抗性关系的角度,分析与展望了未来供水管网水质安全保障技术发展趋势。

Research on the cutting force of a pick

Cutting tests were done using a test bed designed to measure pick cutting forces when cutting coal and rock.The test equipment has a drum with two starting helical vanes.Cutting forces on a pick were measured as a function of coal compressive strength,pick carbide tip diameter and the cutting depth per drum revolution.The results show that the cutting force is linearly related to the compressive strength.The relationship between the cutting force and both the carbide tip diameter and the cutting depth are exponential.Fluctuation in the cutting force does not increase with coal compressive strength but it has a linear relationship to tip diameter.A plot of cutting force fluctuations versus the cutting depth follows a sigmoidal curve.Based on the analysis of these test results a theoretical basis is supplied for design and effective use of shearer drums.

Structural features of substituted triazole-linked chalcone derivatives as antimalarial activities against D_(10) strains of Plasmodium falciparum: A QSAR approach

A quantitative structure–activity relationship(QSAR) was performed to analyze antimalarial activities against the D10 strains of Plasmodium falciparum of triazole-linked chalcone and dienone hybrid derivatives using partial least squares regression coupled with stepwise forward–backward variable selection method. QSAR analyses were performed on the available IC50 D10 strains of Plasmodium falciparum data based on theoretical molecular descriptors. The QSAR model developed gave good predictive correlation coefficient(r2) of 0.8994, significant cross validated correlation coefficient(q2) of 0.7689, r2 for external test set)(2predr of 0.8256, coefficient of correlation of predicted data set)(2sepred,r of 0.3276. The model shows that antimalarial activity is greatly affected by donor and electron-withdrawing substituents. The study implicates that chalcone and dienone rings should have strong donor and electron-withdrawing substituents as they increase the activity of chalcone. Results show that the predictive ability of the model is satisfactory, and it can be used for designing similar group of antimalarial compounds. The findings derived from this analysis along with other molecular modeling studies will be helpful in designing of the new potent antimalarial activity of clinical utility.

Quantitative structure-activity relationship of 2-alkyl-4-(biphenylylmethoxy) pyridine derivatives with AT1 receptor antagonistic activity

The quantitative structure-activity relationship(QSAR) of 2-alkyl-4-(biphenylylmethoxy) pyridine derivatives was studied.Three different alignment methods were used to get the models of the comparative molecular field analysis(CoMFA),the comparative molecular similarity indices analysis(CoMSIA),and the hologram quantitative structure?activity relationship(HQSAR).The statistical results from the established models show believable predictivity based on the cross-validated value(q2>0.5) and the non-validated value(r2>0.9),The analysis on contour maps of CoMFA and CoMSIA models suggests that hydrophobic and hydrogen-bond acceptor fields are important factors that affect the AT1 antagonistic activity of 2-alkyl-4-(biphenylylmethoxy) pyridine derivatives besides the steric and electrostatic fields,The structural modification information from different atom contributions in the HQSAR model is in agreement with that in the 3D-QSAR models.

Genetic Relationship Analysis of Ramie Accessions by RAPD Markers

Genetic relationship of 12 ramie varieties with different drought resistance was analysed by using RAPD.Twenty-five 10-mer random primers were used to amplify the total DMA of these varieties.The results showed that the amplified products of 12 ramie varieties could be obtained with 12 primers.The length of amplified products was 0.6-5.15 kb.Ninety bands were identified in total,of which 11 bands were common in all 12 varieties and 79 bands were polymorphic.The polymorphic bands were 87.78% of the total amplified bands.According to the result of cluster analysis,12 ramie varieties could be divided into two classes and three groups.It was found that high drought resistant varieties were clustered into different groups or subgroups in the same class,which shows near relationship among them.

Experimental study on similarity materials for soft rock of deep-buried tunnels

When every parameter is properly scaled down in accordance with some similarity coefficients, it is possible to study the physical-mechanical properties of rock mass with a scale model. To identify the key mechanisms of soft rock in deep buried tunnels, the proper sand, binder and ratio were selected. During the process, the model manufacture technology was introduced and typical tests were done and the results were presented. The physical and meehanieal properties effects caused by each composition were discussed. It is shown that the physical and mechanical properties of chosen ratio material such as uniaxial compressive strength tests, elasticity modulus, tensile strength, internal frictional angle, and Poisson＇s ratio meet with similarity relationship well. The physical and mechanical properties of deep soft rock are simulated successfully.

Design and synthesis of 1-substituted-β-carboline derivatives as potential anticancer agents

In the present study, we designed and synthesized a series of 1-substituted-β-carboline derivatives through modification of position-l, 2 and 9 of β-carboline nucleus in order to discover novel leading compounds with better antitumor activities and less toxicity. Their structures were confirmed by 1H NMR, 13C NMR, MS, IR and elemental analyses. All the target compounds were tested for cytotoxic activity against six cancer cell lines, including Bel-7402, HepG2, A549, A375, 786-0 and HT-29 by methyl thiazolyl tetrazolium （MTT） method. Studies of structure-activity relationships indicated that the effects of substituents in position- 1 on cytotoxic activities were in an order as follows： 2-thienyl 〉2-chlorophenyl 〉4-chlorophenyl 〉benzyl group.

Antagonistic effects of extracts from Artemisia rupetris L. and Leontopodium leontopodioides to CC chemokine receptor 2b(CCR2b)

The present study was designed to establish a suitable assay to explore CCR2 b receptor antagonists from the natural products of Artemisia rupetris and Leontopodium leontopodioides. An aequorin assay was developed as a cell-based assay suitable for 384-well microplate and used for screening CCR2 b receptor antagonists from natural products. Through establishing suitable conditions, the assay was shown to be suitable for screening of CCR2 b receptor antagonists. Seven compounds were identified in preliminary screening. Five of them showed evident dose-response relationship in secondary screening. The structure–activity relationship study suggested that 7-position hydroxyl group of flavonoids was necessary, a polar group should be introduced on the 3-position, and the substituents on 2-position benzene ring of flavonoids have little influence on the potentency of the inhibition activity on CCR2 b receptor. The ortho-position dihydroxyl structure in quinic acid compounds may be important. In conclusion, Compounds HR-1, 5, 7, and AR-20, 35 showed activity as antagonist of CCR2 b receptor, which shed lights on the development of novel drugs as CCR2 b receptor antagonists for preventing inflammation related diseases.