The puffing habits of smokers are unique to each person,vary withhis emotional state,and have a strong effect on the amount of smoke produced. The amount of smoke produced per cigarette is highly dependenton the number of puffs taken and the volume of the...[继续阅读]

    The advent of molecular techniques has recently provided novelstrategies for control of plant virus disease which make use of“pathogenderived resistance”. Pathogen-derived structural or non-structural genesequences expressed in the host plant in excess am...[继续阅读]

    The different types of tobacco differ in where and how they aregrown,how they are prepared for use in cigarettes,and what characteristics they impart to the smoke. Since tobacco is a natural product,it issubject to wide variations in properties within a g...[继续阅读]

    Particle removalTwo physical parameters must be considered in particle removal.Pressure drop,sometimes referred to as resistance to draw,is theamount of suction that must be used by the smoker to pull smoke throughthe filter. The filter′s resistance to dr...[继续阅读]

    Tobacco has been on the forefront of plants modified by genetic engineering,being the first plant used to express an engineered foreign gene.These first transformations of tobacco involved the use of Agrobacteriumtumefaciens as a vector. Since that time,s...[继续阅读]

    Plant part culture is generally known as organ culture. It is the firstsystem used with considerable success in culturing excised plant parts.Newly developed techniques may use either vegetative or reproductive organs.Culture from vegetative organs includ...[继续阅读]

    Only at adequate fertilizer levels,particularly N,can leaf tobaccobe produced for good quality and usability. A comparison of fertilizerrates on several critical leaf components was made of four plant positionsof flue-cured tobacco. The result shows,under...[继续阅读]

    SyntheticsThe first introduction of a wholly non-tobacco supplement as a component of a tobacco blend occurred in West Germany in late 1974 with themarketing of two brands containing 20%～25% tobacco supplement. Inearly 1975,a tobacco supplement was also i...[继续阅读]

    CasingThe solutions used contain mainly sugar and a humectant,both dissolved in water. The sugar helps overcome bitterness in the smoke andmakes it smoother. The humectant,usually glycerine or a higher glycol,serves to keep the tobacco moist and less sens...[继续阅读]

    Intraspecific hybridization is a cross between plants within the samespecies regardless of the genetic differences among the parents or the resulting level of heterozygosity of the hybrid. According to Burk and Chaplin,the self-pollination of an intraspec...[继续阅读]