广东省农业生态环境问题与对策

随着社会经济和城市化的快速发展，以及人口的剧增，广东省的农业发展正面临一系列严重的生态环境问题。这些问题包括耕地资源日益缺乏，农业环境污染日益严重，土壤肥力退化和水土流失仍未遏止，地区性的洪旱灾害频繁，森林生态系统简单而脆弱，外来物种入侵猖獗，等等。文章对这些问题进行了讨论，并提出了若干治理对策。认为要使广东省农业可持续发展，必须合理开发利用农业自然资源，严格控制非农业用地与人口增长，加强农业环境污染的防治，加强土壤肥力退化和水土流失的综合治理，发展节水农业，改善林分结构和生态服务功能。此外，认为还应加强外来物种的安全防范工作和科学研究，防止外来物种对农业生态系统的组成、结构和功能的破坏。     

From economic prosperity to ecological sustainability──A theoretical and practical concern of sustainable development in China

Ｆｒｏｍｅｃｏｎｏｍｉｃｐｒｏｓｐｅｒｉｔｙｔｏｅｃｏｌｏｇｉｃａｌｓｕｓｔａｉｎａｂｉｌｉｔｙ──ＡｔｈｅｏｒｅｔｉｃａｌａｎｄｐｒａｃｔｉｃａｌｃｏｎｃｅｒｎｏｆｓｕｓｔａｉｎａｂｌｅｄｅｖｅｌｏｐｍｅｎｔｉｎＣｈｉｎａＷａｎｇＲｕｓｏｎｇ，Ｈｕ...     

Effects of simulated acid rain on saplings of Pinus massoniana and Cunninghamia lanceolata

The effects of simulated acid rain with pH values of 6.63 (control, 4.5, 3.0, and 2.0 on saplings of Pinus massoniana and Cunninghamia lanceolate, were studied. The results showed that the pH of C.lanceolate, leaf sap and soil decreased as the acidity of rainfall increased. The acid rain with very low pH had significant effects on the photosynthetic rates per plant, but not on that of the per unit weight of dry leaves. The respiration rates of the two species were stimulated. Root and leaf boimass, but not stem biomass, were also reduced tremendously during a seven months period.     

Roleofscienceandtechnologyinenvironmentally sound urbanization in China

１　ＢｒｉｅｆｉｎｇｕｒｂａｎｉｚａｔｉｏｎｐｒｏｃｅｓｓｉｎＣｈｉｎａ１．１　ＴｈｅｉｍｐｏｒｔａｎｃｅｏｆｕｒｂａｎｉｚａｔｉｏｎｔｏＣｈｉｎａ○ｓｍｏｄｅｒｎｉｚａｔｉｏｎｄｒｉｖｅＴｈｅｆｉｒｓｔａｎｄｆｏｒｅｍｏｓｔｂｅｎｅｆｉｔｏｆｕｒｂａｎｉｚａｔｉｏｎｉｎＣｈｉｎａｓｈｏｕｌｄｂｅａｔｔｒｉｂｕｔｅｄｔｏｔｈｅｅｃｏｎｏｍｉｃｇｒｏｗｔｈ，ｗｈｉｃｈｉｓｔｈｅｐｒｉｍａｒｙｃｏｎｃｅｒｎｏｆｎｏｔｏｎｌｙｔｈｅｇｏｖｅｒｎｍｅｎｔ，ｂｕｔｔｈｅｏｒｄｉｎａｒｙｐｅｏｐｌｅａｓｗｅ…     

Sulfur dioxide-hydrogen peroxide relationships and acidification of precipitation in Guiyang area-a case study

-The concentrations of gas phase SO2, O3 and chemical composition of sequential rainwater samples were measured on 6/11/88 to 6/28/88 at some sites of Guiyang area. S (IV) was present in great excess of H2O2 in rainwater samples collected at residential sites of the city corresponding to high level of gas phase SO2. Considerable H2O2 in rainwater samples was observed in background air at suburbs. The evidence that clean rainwater samples were collected at 20km away from the city in 6/18/88 precipitation event revealed that the major process of acidification of the rain in the high polluted areas was below-cloud scavenging of trace gases. From a simulation calculation it was found that the rate of oxidation of S(IV) by O3 and by Mn2+, Fe3+ catalytic in high pH rainwater is significant, but for low pH the major SO42- is produced by the reaction of S (IV) with H2O2.     

GH4169合金超塑性挤压工艺的研究

此文通过挤压比为9:1的GH4169合金超塑性挤压工艺的研究,对GH4169合金的精密成形方式做了一些探讨。在自制的玻璃基润滑剂HLB03的使用下,T=1000℃、平均挤压速度y=2mm/min、最大单位挤压力P_(max)=561.7MPa时,得到了满意的挤压效果。     

Comparison of some atmospheric chemical modeling schemes

ＣｏｍｐａｒｉｓｏｎｏｆｓｏｍｅａｔｍｏｓｐｈｅｒｉｃｃｈｅｍｉｃａｌｍｏｄｅｌｉｎｇｓｃｈｅｍｅｓＳｈｅｎＪｉ，ＺｈａｏＱｉａｎｘｕｅＲｅｓｅａｒｃｈＣｅｎｔｅｒｆｏｒＥｃｏＥｎｖｉｒｏｍｅｎｔａｌＳｃｉｅｎｃｅｓ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙ...     

Fractal properties of patch perimeters in a disturbed montane landscape, Beijing, China

１ＩｎｔｒｏｄｕｃｔｉｏｎＬａｎｄｓｃａｐｅｆｒａｇｍｅｎｔａｔｉｏｎａｎｄｉｔｓｉｍｐａｃｔｓｏｎｂｉｏｌｏｇｉｃａｌｄｉｖｅｒｓｉｔｙｈａｖｅｂｅｅｎｔｈｅｈｉｇｈｌｙｃｏｎｃｅｒｎｅｄｔｏｐｉｃｓｉｎｔｈｅｒｅｃｅｎｔｙｅａｒｓｂｉｏｌｏｇｉ...