透过CMIPPI-C-S2项目浅析灌溉项目中土方施工方法

该文通过一灌溉项目的执行,借助图片、图形,形象地论述了在土方施工过程中遇到的问题,以及如何有效地予以解决的方法。

Effects of Ultra-drying Treatment on Large Amounts of Four Kinds of Crop Seeds

This study was to understand the physiological changes of four kinds of crop seeds including baby corn, cowpea, radish and rape- seed, under the treatment of ultra-drying. Large amounts of seeds as experimental materials （ 10 kg for each material） were respectively dried to the suitable water content consistent with the ultra-dried seed criterion via heating at 50 ~C; then the physiological indices of these ultra-dried seeds such as water content, seed germination, dehydrogenase activity and SOD activity were measured. The results showed that except cowpea seeds, whose ultra-drying treatment should be controlled between two and four days, other three kinds of seeds were tolerant to high tem- perature and low water content. The ultra-dried seeds assumed similar or even higher activities than CKs, but showed no damage symptom. Our result proves that ultra-drying treatment via heating at 50 ℃ is safe and efficient to experimental seeds.

Maps of International Research Collaboration in Clean Energy

Clean energy is the most promising technology for sustainable growth. The development of clean energy requires a considerable amount of R ＆ D （research ＆ development） expenditure and various core technologies, and therefore, international research collaboration is necessary for prompt and efficient development. The study is aimed at establishing a knowledge base that can help to prepare international research collaboration policies for solving global challenges effectively. The authors demonstrate the research capacity and international research collaboration in solar cell and fuel cell technologies, using global research network diagrams gathered from 35,322 and 33,136 academic papers, respectively. The diagrams include the data of research competency and co-authorship. More than 6,000 institutions and 100 countries are involved in each field. Based on the diagrams, the technologies are compared and international collaboration is analyzed. A valley of research collaboration in Asia is identified for both technologies. Then, science and education policies that influence the structures are discussed.

A study of virtual land trade between China and ASEAN based on material flow analysis model

In this paper,based on the material flux analysis model（MFA） and its corresponding theories and algorithms of ＂virtual land＂ virtual land contents of five primary agricultural products are calculated and＂Virtual land trade＂hidden in those imported and exported products are also obtained through analyzing the primary agricultural product trade between China and ASEAN. In the process of calculationl following the thought of Changing agricultural products to ＂Virtual land trade＂land content, trade condition and spatiai distribution of agricultural products Were integratedly considered. indicate that China exported 73;057 km^2 of virtual land area to ASEAN by tea, vegetables; maize and grain, ASEAN exported： 57.332 km^2 to China by natural rubber from 2002 to 2005. It obvious; that china has lost 15,725 km^2 arable land through agricultural product trade, Additionally, in order to process： of calculation Virtual land trade, Thailand taker as an example to analyze its international trade of rice and Wheat from 1991 to 2005 and Calculate their ＂Virtual land trade＂ 2001 through 2005. According to and calculation, it is not difficult to conclude that ＂Virtual land trade＂ very important and could be used for China to guide agricultural export or import Structure and maintain Sustainable use of land resources.

Effect of the Nutritional Supplement VIUSlD Vet on the Productivity of Fattening Pigs in a Low-Input Farming System

The objective of the study was to evaluate the effect of the nutritional supplement VIUSID vet on the mortality and the productivity behaviour of fattening pigs in a low-input farming system. Two experiments were carried out at a pig farm in the municipality of Jatibonico, Sancti Spiritus province, Cuba. The farm has a low level of specialization, pigs are fed using local resources such as sugarcane （Saccharum officinarum） juice and locally produced concentrated feed. In both studies, the treatment consisted in administering together with the feed 2.0 g of VIUSID vet per Kg of feed. Results showed that in low-input rearing conditions, supplying VIUSID vet significantly reduced deaths （17.65%） in the pigs treated, favoured leukocyte and lymphocyte counts, and significantly improved weight gain （16.33%） and feed efficiency （14.41%）.

商代锡料来源初探

据文献记载,华北至少有39处古代锡矿,分布于河南、河北、山东、山西与陕西。因此,不能排除商代在华北获得锡料的可能性。此外,内蒙古与新疆产出许多锡矿,而邻近的阿尔泰山、叶尼塞河谷地以及七河地区,均有丰富的锡矿,其中部分矿区从安德罗诺沃文化以来即已被开采,因而还需考虑商代是否有锡料来自中亚地区。

Enabling practical electrocatalyst-assisted photoelectro- chemical water splitting with earth abundant materials

Sustainable development and continued prosperity of humanity hinge on the availability of renewable energy sources on a terawatts scale. In the long run, solar energy is the only source that can meet this daunting demand. Widespread utilization of solar energy faces challenges as a result of its diffusive （hence low energy density） and intermittent nature. How to effectively harvest, concentrate, store and redistribute solar energy constitutes a fundamental challenge that the scientific community needs to address. Photoelectrochemical （PEC） water splitting is a process that can directly convert solar energy into chemical energy and store it in chemical bonds, by producing hydrogen as a clean fuel source. It has received significant research attention lately. Here we provide a concise review of the key issues encountered in carrying out PEC water splitting. Our focus is on the balance of considerations such as stability, earth abundance, and efficiency. Particular attention is paid to the combination of photoelectrodes with electrocatalysts, especially on the interfaces between different components.