番茄挥发物组分分析及其对番茄灰霉病菌的熏蒸抑菌作用

为了明确番茄不同部位的挥发物组分和番茄挥发物主要组分对番茄灰霉病菌的熏蒸抑菌作用。本试验采用HS-SPME-GC-MS法分析鉴定番茄花、果、叶的挥发物组分,并测定了主要共有组分桧烯和异松油烯对番茄灰霉病菌的熏蒸抑制作用。结果显示,番茄花、果、叶的共有组分为桧烯、异松油烯、α-水芹烯和α-蒎烯。桧烯在番茄花、果实、叶中含量分别为67.302%、57.761%和65.956%;异松油烯在番茄花、果实、叶中含量分别为10.570%、14.486%和10.836%。熏蒸抑菌试验发现,桧烯对番茄灰霉病菌抑制作用不明显,异松油烯对番茄灰霉病菌有较好的熏蒸抑制作用,EC₅₀为70.61μL·L^-1,EC₉₀为223.58μL·L^-1。松油烯处理后的番茄灰霉菌菌丝崩溃断裂,细胞结构受损明显。本试验为开发新型天然杀菌剂提供了依据。     

电视转播车音频系统中故障成因及克服办法浅谈

本文通过在数字转播车应用实践中,对转播车音频系统容易出现的故障问题,结合实际分析了具体形成的原因以及相应的克服办法.     

准确操控摄像机 努力提高电视节目技术质量

立足实际应用,对于通过对摄像机的准确调整,来提高电视节目技术质量的重要性以及相关具体的操作方法,谈了作者在实践中得到的几点理解与体会.     

Electrical impedance spectroscopy (EIS) in the urinary bladder: the effect of inflammation and edema on identification of malignancy

Previous studies have shown that tetrapolar electrical impedance spectroscopy measurements can identify cervical interstitial neoplasia with the same sensitivity and specificity as cervical smears. In the urinary bladder, the same technique yields significant differences (p < 0.05 at seven frequencies between 9.6 and 614 kHz) between normal and malignant urothelium, but is unable to classify individual measurements. Detailed histological examination demonstrates that inflammation and edema--both of which are common in abnormal urothelium--alter the impedance spectrum significantly in opposing directions. Consideration of morphological changes in abnormal urothelium suggests alternative measurement strategies.     

Observation of D+(s)K- and evidence for D+(s)pi- final states in neutral B decays

We report the first observation of a B meson decay that is not accessible by a direct spectator process. The channel B(0)-->D(+)(s)K- is found in a sample of 85 x 10(6) BB; events, collected with the Belle detector at KEKB, with a branching fraction B(B(0)-->D(+)(s)K-)=(4.6(+1.2)(-1.1)+/-1.3) x 10(-5). We also obtain evidence for the B0-->D(+)(s)pi(-) decay with branching fraction B(B0-->D(+)(s)pi(-))=(2.4(+1.0)(-0.8)+/-0.7) x 10(-5). This value may be used to extract a model-dependent value of |V(ub)|.     

Cryopreservation of protonemata of Ditrichum cornubicum (paton) comparing the effectiveness of four cryoprotectant pretreatments

If an ex situ programme for the conservation of rare and threatened bryophytes is to succeed, a method of long-term, basal storage is required. The aim of this study was to determine the effectiveness of sucrose, ABA and sucrose/ABA combined, as cryoprotectant pretreatments, for the long-term storage of protonemata of the endangered Cornish path moss, Ditrichum cornubicum. This work is a prelude to the in vitro conservation of rare and endangered UK bryophytes. The addition of sucrose and/or ABA in the pre-culture medium, reduced protonemal growth rate. However, pretreatment afforded a high level of protection against tissue damage during dehydration and freezing, with 100 % regeneration of pretreated plants after thawing, compared to 53 % regeneration of controls. Sucrose combined with ABA in the pre-culture medium gave the most effective cryoprotection, with protonemata having fewer necrotic tissues and rapid recovery of growth.     

High resolution spectrophotometry for identification of chlorine dioxide in concentrated chlorine solutions

Electrolyzed salt brine generators hold great promise for water disinfection in small communities and remote locations. Electrolysis cell liquors have been reported to contain chlorine, chlorine dioxide and ozone. High resolution spectrophotometry was used to observe the presence (or absence) of a unique spectral absorbance pattern present in solutions containing 1-2 mg/l chlorine dioxide.     

Toeplitz预条件子的统一构造与性能分析

１．引言考虑线性方程组ＴＮｘ＝ｂ（１．１）其中ＴＮ＝（ｔｉ,ｊ）是ＮｘＮ对称正定（ＳＰＤ）Ｔｏｅｐｌｉｔｚ矩阵,即ｔｉ,ｊ＝ｔ｜ｉ－ｊ｜（ｉ,ｊ＝０,１,...,Ｎ－１）且ＴＮ的所有特征值均为正数,并表为ＴＮ：＝Ｔ（ｔ。,ｔｉ,...,ｔＮ－１）．如果我们用预条件子共轭梯度法（ＰＣＧ）求解方程组（１．１）,最关健的任务是构造出高效的预条件子．而预条件子最自然的选择似乎其逆矩阵易求且构成矩阵ＴＮ的某种最优逼近．由于循环矩阵ＣＮ的逆矩阵ＣＲ'仍为循环矩阵,因此ＣＮ和ＣＨ'与向量的乘积可通ｉｓ速Ｆｏｕｒｉｅｒ…     

索尼超高速CMOS传感器颠覆传统数码相机概念

2006年2月8日,索尼在“ISSCC2006”上发布的CMOS传感器给数码相机开发者带来了巨大冲击。该公司此次主要发布了2款产品:一款是640万像素、最高帧速率达60f/s的样品A,另一款是276万像素、最高帧速率达180f/s的样品B。据日本某摄像元件厂商的技术人员介绍,这些产品的像素数据输出速率快得超出想象,令数码相机开发者感到相当震惊。索尼此次发布的C M O S传感器的输出速率是现有300万～600万像素家用CCD相机的20倍～60倍。与4K数字电影相比,样品A的输出速率为其1.5倍,样品B的输出速率为其2倍(见图1)。该技术人员还表示:“我们曾经以为C…