近乎失传的工艺——虬角简介

虬角是将海象牙"茜绿"成翡翠色的一种工艺,始于清代,民国以后失传。由于密度大、手感和质感上佳、工艺保密而备受人们的推崇并带有"神秘感"。

北欧海盗神秘消失

1000多年前,“北欧海盗”维京人在没有海图、没有罗盘的情况下,仅凭自身的勇气和对未知世界的向往,投身于浩淼的波涛中,横渡大西洋,抵达美洲新大陆,比哥伦布发现新大陆要早500年。然而,就是这些集探险家、拓荒人和殖民者寸一身的好汉。

2008年十大考古发现

木乃伊、沉船、人的粪便化石、最古老的油画……2008年考古学家一刻也没停,他们从地底下、山洞中、海底里为我们找到了以下发现.……

Assessment of Sediment and Pollutants in Buyo Lake, Ivory Coast, Using SWAT （Soil and Water Assessment Tool） Model

The changes in land use in the last 30 years in the territory of agro-forest watershed of Lake Buyo resulted in significant sediment into the lake. Sediments are a preferred means of transportation for certain pollutants, like phosphorus in excess. By mapping the source areas of erosion, the authors can determine the risk areas and help to prioritize interventions in the territory. This mapping is done using the SWAT （soil and water assessment tool） model. Several types of data, including topography, land use, soil and climate data are needed to run the model. In this paper, all different steps are presented, from the designing of HRU （hydrological response units）, basic units to run the SWAT model until the simulations. The establishment of HRU has three main stages： space discretization, land use and soil data integration and HRU distribution： （1） space discretization which consist in extracting the limits and the water network of the watershed from the DEM （digital elevation model） and in subdividing them into sub-basins; （2） land use and soil data integration： it consists in digitizing the physical maps of land use and of soils under Mapinfo 7.5 and in keeping them in ＂shape＂ format; （3） HRU distribution： it leads to subdivide the sub-watersheds in small units that combine a single soil type and one type of land use. It appears from this study to obtain 23 sub-watersheds and 71 HRU. Once the HRU designed, it is necessary to integrate climate data, data on physico-chemical characteristics of soils and agricultural practices, before starting the simulations. This will allow the model to assess the risk of sedimentation and eutrophication of the lake using the MUSLE （modified universal soil loss equation） and phosphorus cycle.

The Impact of Colonial Rule on the Gyaman State

The balkanisation of the African continent by the European powers in the nineteenth century caused the territorial division of people with the same ancestry into two or more states under different European governments. During the partition, the European powers did not take into consideration the cultural and historical boundaries of the people of Africa. In West Africa for example, the partition made some Nzema people to be found in La Cote d＇Ivoire and in Ghana. Some Dagarti are also found in Burkina Faso and while others remained in Ghana. Ewes today can be found in the three countries of Ghana, Togo and Benin. The same applies to the Bono in Gyaman. Some of the Gyaman people can be found in the Ivory Coast with others in Ghana. This article discusses Gyaman under the British and French colonial rule. It focuses on the responses of Gyaman authorities to colonialism and details out British and French colonial policies and their impact on the Gyaman people.

Sprinkler Irrigation and Soil Tillage Practices in Sugarcane Plantations as Influenced by Soil Texture and Water Storage in Northern Ivory Coast

Soil survey investigations were carried out in Ferk6 1 as well as Ferk6 2 sugar mills of northern Ivory Coast to determine soil texture and water storage capacity for sprinkler irrigation and tillage management. A 5-year term observation experiment on reduced tillage compared with conventional tillage was also conducted in Ferk6 1 over an irrigated cane crop of 28 ha for yield optimization purpose. Soil sampling was achieved after harvest or prior to re-plantation at five different spots along two transects over 30 cm depth in every farmland which covers about 30-40 ha with 432 m long cane rows as to get an average soil sample of 1.5-2 kg. Soil physical properties like texture and water retention curves were determined locally in the sugar company＇s soil laboratory. It came out that the majority of soils investigated was coarse-textured for about 64% in Ferk6 1 and 85% in Ferk6 2, with a lower to medium water storage capacity （70-89 mm） over 60 cm depth which corresponds to a readily available moisture less than 60 mm. Except for the sugarcane plant crop, no significant difference in cane yields resulting from tillage practices was observed over four consecutive cropping seasons. The yield decline from plant cane to first ratoon was very high under conventional tillage （-16 t/ha） compared with the reduced tillage （＋3 t/ha）. Even higher cane yield was obtained on the second ratoon （89 t/ha） compared with the conventional tillage （83 t/ha）.

Late Season Sugarcane as Affected by Deficit Irrigation at the Yield Formation Stage in Northern Ivory Coast

A field trial was carried out in Ferk6 2 Sugar mill located in northern Ivory Coast, in order to study sugarcane growth and yield response to deficit irrigation imposed over the yield formation stage. The crop used was a first ratoon Co 957, a non flowering late season sugarcane variety. The experiment was completely randomized following a one-factor design with 4 water deficit treatments in 3 replicates. It came out that the optimum water deficit treatment reached 20%, i.e., 80% of crop water requirements were satisfied through irrigation. That treatment gave 7.9 kg cane/m3 or 0.98 kg sugar/m3 as irrigation water use efficiency. Relatively low crop growth rates （0.2-0.4 cm/day） as well as low cane yields （24.5-78.4 t/ha） were obtained as a result of an intensive and persistent dry season occurred over the yield formation stage. In line of prevailing climatic conditions, cane juice quality measured was particularly high on Co 957 which used to be a moderately performing variety in Ferk6 2 sugar mill.

Response of soil mite abundance and diversity to a monospecific timber Tectona grandis plantation in Ivory Coast

This study aims to assess the impact of monospecific Tectona grandis forest plantation on the soil mite abundance and diversity. To achieve these objectives, two sites situated in Ivory Coast were investigated. The first, a primary forest was characterized by a very weak human activities whereas the second, a teak plantation was characterized by a high disturbance performed during the planting. After extracting, sorted and description, 116 mite species were described in the two sites. Mite densities were lower in teak plantation and also higher in the litter and decreased to the depth in both sites. Species richness re- corded in teak plantation （52 species） was significantly lower compared to primary forest （98 species）. The same trend was ob- served for Oribatida but not for Gamasida. The lower Oribatida （5 vs. 17） and higher Oribatida （24 vs. 41） were recorded respec- tively in teak plantation and primary forest. Mite Shannon index and evenness were significantly different between sites. High Jaccard index values and the appearance of exclusive species in both habitats showed that the sites are very distinct. Total number of species recorded corresponded to 58%-63% of the total number of species estimated by ACE and Chao 1＆2 estimators, indi- cating that the sampling effort was not sufficient. Mite abundance and diversity varied depending on the characteristics of habi- tats. Chemical element （Corn, Ctot, Ntot, and SOM） values were lower in teak plantation （disturbed habitat） and significantly dif- ferent to primary forest in the topsoil. Apart from litter height, soil depth, pH and C/N ratio, others variables were strongly corre- lated to mite abundance and diversity [Current Zoology 59 （5）： 633-643, 2013].