一种简单实用的橡胶条刮种机构的研制

分析了目前应用较多的几种刮种器的不足之处;通过对种子吸附在吸种孔上的受力分析,找出了影响刮种可靠性的因素(刮种装置的刚度);在此基础上设计了一种结构简单、性能良好的橡胶条式刮种器;在气吸式精量播种机高速作业(作业速度达到4～5km·h-1)的情况下,橡胶条刮种器能够将重播率控制在10%以内,而且对空穴率也能够控制在2%以下。

Control of Wheat Stripe Rust and Ensuring High Yield of Crops under Planting of Wheat Variety Mixtures

Wheat stripe rust has become the most dangerous disease which threaten safe yield of wheat in Sichuan Province. It is meaningful to provide technique support for integrated disease control by exploring the effective control measures of wheat stripe rust. Wheat stripe rust dynamic developments of all-planting and mixed-planting have been systematically investigated in this study by taking different mixed-planting combinations among 6 wheat varieties with different resistance levels. The results of this experiment show that the mixed-plantings of 4 and 6 wheat varieties can delay the occurance of wheat stripe rust,slow the speed of disease and decline the damage of disease as well as stabilize yield of wheats.

三尖杉的育苗技术

针对三尖杉种子休眠期长、发芽率极低(仅10%) 的问题，经近10年的试验研究，初步掌握了三尖杉种子的采收加工和播种育苗技术。以此 为基础，从采收及种子处理、种子层积催芽、播种育苗、育苗期的管护措施等方面，详细介 绍了三尖杉的育苗技术。

Optimization of the Conditions for Using Sewage to Cultivate Navicula tenera

[ Objective] This study was to improve the biomass of Navicula tenera, and thus to provide reference for achieving the industrial production of Navicula tenera. [Method] The feasibility of using sewage to cultivate Navicula tenera was preliminarily investigated based on the consideration of regional characteristics; and a series of culture conditions including the nutrient source of nitrogen（N）, phosphorus（P）, iron（Fe）, silicon（ Si ） and the salinity in medium for culturing Navicula tenera, were optimized by single factor test and orthogonal design.[Result] The optimized conditions for cultivating Navicula tenera using sewage are as follows： the water from Xiaoerlou Artificial Lake of Nanjing University of Technology as basic solvent; 360 mg/L urea; 150 mg/L N2HPO4 · 12H2O; 50 mg/L ferric citrate; 2 000 mg/L Na2SiO3 · 9H2O; 2.0 mol/L salinity. Navicula tenera was strongly adaptive to sewage and could well uptake the nutrient sources in the sewage. Under the optimized conditions, the culture cost decreased, and meanwhile the biomass of Navicula tenera reached 4. 766 g/L which is 3.57 multiples over original medium and 1.9 multiples over optimized medium No. 1.[ Conclusion] This study laid a foundation for the combination of culturing Navicula tenera in large scale and sewage treatment.

Study on High-yield Potential for Maize Varieties in Mountain Area of Yunnan-Guizhou Plateau

By field experiments with Uniform Design, the effects of planting density and nitrogen rate on three varieties （Yunrui No.8, Yunrui No.6 and Yunrui No.88） grain yield under different ecological conditions were studied in Yunnan Province. The results showed that the grain yields were different among the five experiment locations, when increasing of planting density, it did not affected the plant height, ear height and ear factor, with the planting density increased, stem diameter, leaf width, ear length, number of grains per row and 1 000-grain weight decreased sig- nificantly, but the grain yield of the third varieties increased. High planting density had a negative impact on ear traits, but the grain yield increased by high-density compensate for the adverse effects.Control space and time of fertilizer application can reach the highest yield under less Nitrogen fertilizer Yunrui 88 had the charec- teristics of wide range of adaptability and the density-tolerance, high-yielding poten- tial, which was favorable in planting on large areas.

Screening of Rice Stripe Virus(RSV)-resistant Germplasm from Landraces of Rice(Oryza sativa L.)

[Objective] The aim of this study was to screen rice strip virus （RSV）-resistant landraces. [Method] The resistance of 119 rice landraces to rice stripe virus was identified in field spontaneously infected with smal plant-hopper. [Result] There were 55 landraces resistant to rice strip disease in 56 indica rice landraces, but on-ly two resistant to rice strip disease in 63 japonica rice landraces. [Conclusion] The results revealed that there were abundant rice landscapes resistant to RSV in Chi-na, and these varieties can be used to develop more genes resistant to RSV.

Mapping of a Major Stripe Rust Resistance Gene in Chinese Native Wheat Variety Chike Using Microsatellite Markers

Chike （accession number Su1900）, a Chinese native wheat （Triticum aestivum L.） variety, is resistant to the currently prevailing physiological races of Puccinia striiformis Westend. f. sp. tritici in China. Genetic analysis indicated that resistance to the physiological race CY32 of the pathogen in the variety was controlled by one dominant gene. In this study, BSA （bulked segregant analysis） methods and SSRs （simple sequence repeats） marker polymorphic analysis are used to map the gene. The resistant and susceptible DNA bulks were prepared from the segregating F2 population of the cross between Taichung 29, a susceptible variety as maternal parent, and Chike as paternal parent. Over 400 SSR primers were screened, and five SSR markers Xwmc44, Xgwm259, Xwmc367, Xcfa2292, and Xbarc80 on the chromosome arm 1BL were found to be polymorphic between the resistant and the susceptible DNA bulks as well as their parents. Genetic linkage was tested on segregating F2 population with 200 plants, including 140 resistant and 60 susceptible plants. All the five SSR markers were linked to the stripe rust resistance gene in Chike. The genetic distances for the markers Xwmc44, Xgwm259, Xwmc367, Xcfa2292, and Xbarc80 to the target gene were 8.3 cM, 9.1 cM, 17.2 cM, 20.6 cM, and 31.6 cM, respectively. Analysis using 21 nulli-tetrasomic Chinese Spring lines further confirmed that all the five markers were located on chromosome lB. On the basis of the above results, it is reasonable to assume that the major stripe rust resistance gene YrChk in Chike was located on the chromosome arm 1BL, and its comparison with the other stripe rust resistance genes located on 1B suggested that YrChk may be a novel gene that provides the resistance against stripe rust in Chike. Exploration and utilization of resources of disease resistance genes in native wheat varieties will be helpful both to diversify the resistance genes and to amend the situation of resistance gene simplification in the commercial wheat cultivars in China.

Effect of Different Preservation Conditions on Mycelia Growth of Morcllhea conica

[Objective] This study aimed to investigate the effect of different short-term preservation conditions on mycelial growth of Morchella conica, and search for opti- mum preservation conditions. [Method] M. conica strains in tubes were preserved at two temperature treatments 10 ℃/5 ℃ （day/night） and 15℃/10 ℃（day/night） in scat- tered light or dark for 30 or 60 d. The strain preserved at 4 ℃ dark for 90 d was the control （CK）. So, a total of nine treatments were prepared in this study. [Result] Mycelial growth of M. conica preserved at 10 ℃/5 ℃ was better than that at 15 ℃/10 ℃ and control. The colony color and aerial hyphae of strains preserved in scattered light was also better than that in dark. Additionally, the preservation time showed no distinct effect on mycelial growth at 10 ℃/5 ℃. So the time could be lengthened. But the maximal preservation time was 60 d at 15 ℃/10 ℃. Therefore, preserved under the appropriate conditions of 10 ℃/5 ℃, scattered light for 30 d, the strain had the neat colony edge, moderate aerial mycelia, dense mycelia, lower sectoral variation, uniform mycelial growth rate and high dry weight of mycelia.

Soil Phosphorus Dynamics as Influenced by Land Use Changes in Humid Tropical, Southwest China

Land use changes can greatly influence soil phosphorus (P) dynamics, especially when converting native forests to agricultural land. Soils in Xishuangbanna, which is one of southwest China s tropical areas that maintain fragments of primary forests, were studied to a) evaluate the effect of two common land use changes, conversion of forests to agricultural land or rubber tree plantation, on the dynamics of available P and total P in bulk soils as well as total P in particle size fractions; b) assess the rel…

Microstructure of partially remelted billet of AM60 alloy prepared with self-inoculation method

The billets of AM60 alloy, prepared with self-inoculation method, were partially remelted into semisolid state. Effects of process parameters on remelting microstructure of semisolid billet were investigated. Experimental results show that the solid particles obtained with self-inoculation method are in smaller grain size and globular shape after partial remelting, compared with those prepared with other casting methods. In the optimized process conditions, the average size of solid particles of partially remelted billet is 65 μm, and the shape factor is 1.12. The process parameters, i.e. pouting temperature, addition amount of self-inoculants, and the slope angle of multi-stream mixing cooling chalmel have influence on the microstructure of partially remelted billet. The optimized temperature is from 680 ℃ to 700 ℃, addition amount of self-inoculants is between 5% and 7% （mass fraction）, slope angle of multi-stream mixing cooling channel is between 30° and 45°, with which the dendritic microstructure of as-cast billet can be avoided, and the size of solid particles ofremelted billet is reduced.

Micro-site Conditions of Epiphytic Orchids in a Human Impact Gradient in Kathmandu Valley, Nepal

We studied distribution and site conditions of epiphytic orchids in a gradient of human interference in Kathmandu valley, central Nepal. The aim was to understand the recent distribution pattern of epiphytic orchids, with respect to (i) the micro-site conditions and (ii) the type and intensity of land use. The occurrence of epiphytic orchids was recorded for a grid with 1.5 km cell size. The cells represent different types and intensities of human impact. Site factors such as bark rugosity, bark pH, diameter at breast height (dbh; 1.3 m) of host trees, exposure to wind and sunlight intensity were recorded. With regard to the species richness and abundance of epiphytic orchids, we compared different human impact categories from very strong human impact (settlement area) to very low human impact (national park). Remote sensing was used for a supervised classification of land cover. Ficus religiosa turned out to be the most important host species for orchids in urban areas, while Schima wallichii and Alnus nepalensis significantly host orchids in the other categories. Both species richness and abundance of epiphytic orchids were significantly higher under very low human impact (forest in national park) and also some remaining patches of primary forest than the other regions. Micro-climate is crucial for orchid populations. Host bark pH, bark rugosity, sunlight intensity and host exposure were significantly different for all human impact categories in order to harbour epiphytic orchid species. Habitats with a mixture of mature trees are suitable and essential for the conservation of viable populations of epiphytic orchids in settled areas. The study reveals that to improve the population size of orchids it is essential for future urban forestry to: (i) Protect old trees as carriers of existing epiphytic orchid diversity, (ii) protect medium old trees to ensure that they may become old trees, (iii) plant new host trees for the future, (iv) plant in groups instead of single isolate trees. Trees should especially be planted in areas where orchids still exist to provide more trees for orchid population enlargement (e.g. along riparian system). Native species should be favoured; the pool of such native host species is wide.

Diatom diet selectivity by early post-larval abalone Haliotis diversicolor supertexta under hatchery conditions

Benthic diatoms constitute the primary diet of abalone during their early stages of development. To evaluate the dietary preferences of early post-larval abalone, Haliotis diversicolor supertexta, we analyzed the gut contents of post-larvae that settled on diatom films. We compared the abundance and species diversity of diatom assemblages in the gut to those of the epiphytic diatom assemblages on the attachment films, and identified 40 benthic diatom species in the gut contents of post-larvae 12 to 24 d after settlement. The most abtmdant taxa in the gut contents were Navicula spp., Amphora copulate, and Amphora coffeaeformis. Navicula spp. accounted for 64.0% of the cell density. In the attachment films, we identified 110 diatom species belonging to 38 genera. Pennate diatoms were the dominant members including the species Amphiprora alata, Cocconeis placentula var. euglypta, Cylindrotheca closterium, Navicula sp. 2, and A. coffeaeformis. Nano-diatoms （〈20 pm in length） accounted for a considerable proportion of the total species number and cell density of the diatom assemblages in the gut contents and on the films. This suggests that nano-diatoms are important to the efficient production of abalone seed. The difference of the composition and abundance of diatoms between in the guts and on the biofilms suggests that early post-larval grazing was selective. An early post-larval abalone preferred nano-diatoms and the genera Navicula and Amphora during the month after settlement.

Introduction of Pinus radiata for afforestation:a review with reference to Aba, China

Pinus radiata D. Don, native to a Californian coastal environment, has been introduced to many parts of the world as an exotic species for afforestation. It is now a major plantation species in the Southern Hemisphere. In 1990, it was introduced to the heavily degraded, dry Min river valley area in Aba prefecture of Sichuan Province, P. R. China. Survival and growth of young trees planted at several sites appear to be reasonable. This review is to serve as an introduction to the large body of literature on P. radiata for forest scientists in China. It covers the following aspects: P. radiata in its native environment and in ex situ plantations, provenance and genetic variations, environmental limitations and climate niche, diseases and pests, lessons from unsuccessful introductions, and the use of P. radiata for ecological restoration. The early growth of P. radiata planted in the dry river valley area is briefly described. Potential problems associated with the introduction of P. radiata in Aba and future research needs are also identified.

Lead-phase and red-stripe color morphs of red-backed salamanders Plethodon cinereus differ in hematological stress indices:A consequence of differential predation pressure?

Throughout the animal kingdom there are species that have two or more phenotypic forms or ‘morphs＇, and many of these are amphibians. In North America, the red-backed salamander Plethodon cinereus can have either a red dorsal stripe or no dorsal stripe （lead-phase form）, and evidence to date indicates the lead-phase form incurs a greater number of attacks from predators. In a recent collection of 51 P cinereus, blood smears of both color morphs （35 red-stripe, 16 lead-phase） were examined to obtain numbers of circulating leukocytes （via light microscopy）, which can be used to indirectly estimate levels of stress hormones in vertebrates via a ‘hematological stress index＇, which is the ratio between the number of two leukocyte types （neutrophils and lymphocytes）. Our results showed that lead-phase salamanders tended to have greater numbers of circulating neutrophils and lower numbers of circulating lymphocytes than red-stripe morphs, leading to higher average neutrophil-lymphocyte ratios in lead-phase individuals. Since the salamanders were held （refrigerated） for 7 days before sampling, we cannot be certain if this effect is a stress reaction to the captivity or the normal level for this morph. However comparison with two sets of related salamanders that were captured and sampled immediately indicates the red-stripe salamanders were either not stressed from the captivity at all, or their white blood cell distributions had returned to normal after 7 days of captivity. Taken together, our results indicate that lead-phase forms of P. cinereus have higher stress levels than the red-stripe forms, which may be a consequence of their higher exposure to, and/or attacks from, predators. They may also indicate that the lead-phase form is less-suited to captivity than the red-stripe form of this species.

The Control Effect of Prevention and Control Technology Combination against Southern Rice Black-Streaked Dwarf Disease

Objective] This study aimed to explore a better prevention and control technology combination against southern rice black-streaked dwarf disease. [Method] The control effects of seed dressing, antiviral agents and fly net along with 25%pymetrozine against southern rice black streaked dwarf disease were determined. [Result] When the seeds were dressed with 60% imidacloprid （FS, 2 g a.i./kg）, and the rice seedlings were sprayed once with 25% pymetrozine （WP, 360 g/hm2） 10 d before the transplanting and sprayed twice with 30% Dufulin （WP, 800×） at three-leaf stage and 7 d after the transplanting respectively, the control efficiency reached 88.05%. When fly net and pesticides were applied simultaneously, the fly net was lifted and 25% pymetrozine （WP） was spayed once on the rice seedlings at six-leaf stage and the seedlings were hardened for 3 d and sprayed once with 25%pymetrozine （WP） 10 d after the transplanting, the control efficiency reached 80.50%. [Conclusion] Seed dressing or applying antiviral agents alone can not better control diseases. The southern rice black-streaked dwarf disease can be better con-trol ed by seed dressing, along with spraying of planthopper-kil ing agents at two-leaf stage, 3 d before the transplanting and 7 d after the transplanting, respectively. If condition al ow, fly net can be instal ed to achieve better control effect.

Influence of Cropping Systems on Soil Properties in Semi-arid Conditions of Setif, Algeria

The effects of two culture systems, conventional and no-till combined the previous crop （lentil and wheat） on soil properties were studied in the experimental site of the station Technical Institute for Field Crops （ITGC） Setif （Algeria） during the crop year 2011/2012. The results indicate that the no-till system affects positively the variables of soil properties and the organic matter has a rate of 2.89% compared to 2.44% in conventional tillage. If the conventional system has an infiltration of moisture relatively higher than that observed for no-till throughout the cycle, the no-tillage is distinguished by a higher storage of moisture at the end of cycle wheat cultivation. The results also indicate that the density （1.44 g/cm）, permeability （22.79 cm/h） and soil compaction （12.51 kg/cm） in no-till were significantly higher compared to conventional tillage 1.35 g/cm, 14.13 cm/h, 7.40 kg/cm, respectively.

Effect of Leaf Removal on Grapes of Cabernet Sauvignon and Sangiovese Cultivated in Different Italian Environments

Leaf removal is a farming practice that can affect must and grape quality; it is closely related to the meteorological conditions of the year and the climate of the area. The present study aims to analyse the effects of different types of defoliation, all conducted at veraison and removing 5-6 basal leaves. The trial provided four tests： leaf removal only on the east side, only on the west side, total defoliation （both sides）, and a non-defoliated treatment （control test）. Two different cultivars, the Sangiovese and the Cabernet Sauvignon, were studied in five different Italian environments： Puegnago （BS）, Scansano （GR）, Bolgheri （LI）, Brisighella （RA）, and Montefalco （PG）. The trial was repeated four times, once per year for the successive years 2007, 2008, 2009, and 2010. The years differed mainly with regard to the total rainfall; because of the variability of the years, different results, both for the same cultivar and between the cultivars, were observed. The differences existing between these two varieties and among the different environments led to different reactions to defoliation, especially concerning the analytical parameters of musts and grapes.

Main Wild Medical Fungi and Their Functions in Eastern Forest Region of Zhongtiao Mountain in Shanxi Province

A total of 21 species of wild medical fungi have been currently found in Zhongtiao Mountain,including wild Ganoderma spp.,Bai Lingzhi,Ganoderma applanatum（Pers.） Pat.,Phellinus igniarius（L.ex Fr.） in mulberry tree,Phellinus pini,Fomitopsis rosea Karst,Pyropolyporus adamantinus,Fomes fomentarius,Ganoderma mastoporum Pat,Inonotus obliquus,Fuscoporia punctate,Ganoderma tsugae,Trametes versicolor,Trametes orientalis Imaz,Laetiporus sulphureus,Ganoderma capense（Lloyd） Teng,Hericium erinaceus,Lycoperdon bovista,Polyporus umbellatus Fries,Wolfiporia extensa and Cordyceps barnesii Thwaites.In this paper,the main functions of the major fungi species in eastern forest region of Zhongtiao Mountain in Shanxi Province were introduced.

Road Geometry Recovery Using On-board Camera in Various Conditions

A 3D road geometry reconstruction system using on-board camera for vehicle driver assistance is developed. Given calibration of the camera, 3D structure of the road in front of the vehicle is built via multiple vanishing points estimation and local parallelism of the road. The road will be modeled as a piecewise linear approximation of space curve. Vanishing points are estimated through line grouping and histogram method in the image. The system is not restricted to the roads which lie on 2D plane, but also is capable of recovering a full 3D geometry. The ambiguity of distance （scale） is resolved by usage of parallel line segnents an the road image.

Physiological Analysis for Universal Design of Public Seat Under Diverse Conditions

Public vehicle seats are used under diverse conditions, therefore, the design of these seats is desired to be universal design. In the past study, seat swing function used in public vehicle seats, and it was optimized from the mechanical aspect under diverse conditions. Seat swing function is the function to prevent hip-sliding force, which causes sitting uncomfortable feeling. Recent study clarified that the reduction of blood flow in the legs causes physiological dysfunction, which is one of the causes of Long Flight Thrombosis, and the social issue. Thus, in the design of seat swing function, it is necessary to consider not only mechanical aspects but also physiological aspects. For the universal design of seat swing function considering the physiological aspect （blood flow）, the influence of blood flow on seat swing function in diverse conditions was analyzed. The method of this study was measuring blood flow and body pressure distribution on seat cushion of seat swing function under diverse conditions. From the analysis, it was indicated that it was necessary to reduce the compressive force behind the knees of the user conditions; the short physique and the high weight physique in standard sitting posture, for the universal design of seat swing function to prevent reduction of blood flow in the legs.