Effect of heat treatment on lignification of postharvest bamboo shoots (Phyllostachys praecox f. prevernalis.)

In order to evaluate the effects of heat treatment on the quality of postharvest bamboo shoots, the firmness, disease incidence, respiration and ethylene production, ACC synthase (ACS) and ACC oxidase (ACO) activities, lignin and cellulose contents, and the activities of phenylalanine ammonia-lyase (PAL), cinnamyl alcohol dehydrogenase (CAD) and peroxidase (POD) were examined during storage at 20 °C after heat treatment at 45 °C for 5 h. Heat treatment inhibited disease incidence and respiration, retarded ethylene production, and decreased ACS and ACO activities in bamboo shoots. Furthermore, heat treatment significantly delayed the rise in the activities of PAL, CAD and POD, which were associated with the inhibition of the synthesis of lignin and the delayed tissue lignification. These findings suggest that heat treatment could be a potential tool to delay lignification and decrease disease incidence in bamboo shoots during storage at 20 °C.     

The Protective Function and Modification of Secondary Metabolite Accumulation in Response to Light Stress in Dracocephalum forrestii Shoots

The aim of this work was to determine the effect of stress conditions caused by different light sources, i.e., blue LED (λ = 430 nm), red LED (λ = 670 nm), blue and red LED (70%:30%) and white LED (430–670 nm) on the growth and morphology of cultivated in vitro Dracocephalum forrestii shoot culture. It also examines the effects on bioactive phenolic compound production and photosynthetic pigment content, as well as on antioxidant enzyme activity (CAT, SOD, POD) and antioxidant properties. The most beneficial proliferation effect was observed under white LEDs (7.1 ± 2.1 shoots per explant). The white and blue lights stimulated the highest fresh weight gain, while red light induced the highest dry weight gain. The total phenolic acid content ranged from 13.824 ± 1.181 to 20.018 ± 801 mg g DW⁻¹ depending on light conditions. The highest content of rosmarinic acid was found in the control shoots (cultivated under fluorescent lamps), followed by culture grown under red light. All LED treatments, especially red and blue, increased salvianolic acid B content, and blue increased apigenin p-coumarylrhamnoside biosynthesis. The greatest ferric reduction activity was observed in shoots cultivated under red light, followed by blue; this is associated with the presence of the highest total phenol content, especially phenolic acids. Similarly, the highest DPPH radical scavenging potential was observed under red light followed by blue. This study proves that LEDs have emerged as significant support for directed in vitro propagation, taking advantage of specific stress responses on various light spectra. This study also showed how stress induced by different LED light spectra increases in Dracocephalum forrestii the synthesis of pharmacologically-active compounds. Hence, light stress may turn out to be a simpler alternative to metabolic engineering for improving the production of secondary metabolites of therapeutic value.     

井中激发地表接收的近地表结构调查方法

横波静校正是影响多波地震勘探效果的重要因素。地震微测井技术是获得近地表结构直接而有效的手段,但由于存在震源和初至识别等问题,在多波勘探中的应用受到一定限制。为此,基于炸药震源产生横波的物理机理,提出了井中串状震源激发、地表三分量检波器多道接收的近地表结构调查方法,提出了基于地面纵向排列多道记录能量和时间信息,通过初至叠加扫描获得纵、横波近地表速度的方法。将该方法应用于四川广安地区的横波资料静校正处理,获得了理想的效果,成像质量得到了提高。     

Integrating the Roles for Cytokinin and Auxin in De Novo Shoot Organogenesis: From Hormone Uptake to Signaling Outputs

De novo shoot organogenesis (DNSO) is a procedure commonly used for the in vitro regeneration of shoots from a variety of plant tissues. Shoot regeneration occurs on nutrient media supplemented with the plant hormones cytokinin (CK) and auxin, which play essential roles in this process, and genes involved in their signaling cascades act as master regulators of the different phases of shoot regeneration. In the last 20 years, the genetic regulation of DNSO has been characterized in detail. However, as of today, the CK and auxin signaling events associated with shoot regeneration are often interpreted as a consequence of these hormones simply being present in the regeneration media, whereas the roles for their prior uptake and transport into the cultivated plant tissues are generally overlooked. Additionally, sucrose, commonly added to the regeneration media as a carbon source, plays a signaling role and has been recently shown to interact with CK and auxin and to affect the efficiency of shoot regeneration. In this review, we provide an integrative interpretation of the roles for CK and auxin in the process of DNSO, adding emphasis on their uptake from the regeneration media and their interaction with sucrose present in the media to their complex signaling outputs that mediate shoot regeneration.     

乳酸菌发酵竹笋脯的研制

以竹笋为主要原料,经乳酸菌发酵制成乳酸发酵竹笋脯。产品色泽自然、风味独特、营养保健,是老少皆宜的现代方便食品。     

一种视频叠加芯片及其在摄像监视系统中的应用

介绍了上大众芯微电子有限公司推出的专用字符叠加芯片SDOlC0l的性能特点及其在摄像监视系统中的应用，给出了固定字符叠加和可变字符叠加部分的硬件电路设计，采用纯硬件电路实现，无须使用单片机，无须软件编程。     

A mathematical model of plant growth with particular reference to winter wheat

The mathematical analysis presented in this paper of plant growth is based on the assumption that the influence of deficiencies in the major root nutrients of water, N, P and K is to reduce the fraction of the plant mass devoted to photosynthesis by increasing the root fraction, thereby diminishing the rate of growth of the total plant.A reciprocal phenomenon occurs with deficiency of light. Using literature data on the influence of environmental conditions on plant growth and in particular on the root/shoot ratio, the relevant rate expressions are derived in a simple form and appear to be generally similar for a wide range of plants during their vegetative phase of growth.     

Effect of aluminium in the presence of phosphate and lime on growth and chemical composition of ryegrass and lucerne

The proposition that difficulty in establishing pasture in an allophanic soil was caused by aluminium toxicity was examined in a pot trial using ryegrass and lucerne as test plants. Ionic aluminium was added to the soil in the presence and absence of both phosphate and limestone, and its effects on yield and chemical composition of the plants, and on nodulation of lucerne roots, were recorded. Aluminium accumulated in the roots of the plants, in amounts similar to those found for calcium, without depressing yield very much; in fact the small depression which occurred seemed less associated with aluminium than with an accompanying increase in soil acidity. Since ions of aluminium are very toxic where they penetrate living cells, it seems that these plants have an in-built resistance whereby the element is immobilized outside the cell, probably in cell walls and as insoluble phosphates and hydroxides.     

重型子弹药气囊抛撒过程仿真研究

利用LS-DYNA有限元软件对用气囊抛撒重型子弹药的过程进行了数值模拟.分别计算了不同加载载荷时间历程和不同壳体承力面条件下的影响结果.获取了子弹药壳体最大主应力及内部装药所受的最大压力值.对其影响规律进行了分析.该研究结果对子母弹气囊抛撒子弹系统设计具有实际参考价值.     

防空武器系统射击方案研究

利用排队论思想对同类防空导弹武器系统的几种射击方案进行了分析计算，讨论了各种射击方案的正确使用条件。