轻烃芳构化工艺技术进展

本文将在对于国内外比较典型的轻烃芳构化工艺技术进行分析介绍的基础上．通过进行不同分子筛催化剂金属改性与反应条件对于催化剂芳烃构化性能的影响．以及轻烃芳构化反应机理的分析．实现对于轻烃芳构化工艺技术中沸石分子筛芳烃构化催化剂的改进发展与优化方向的分析论述。

Research on industrialization of eco-agriculture:theoretical framework and the case of Yunnan,China

The industrialization of eco-agriculture has applied modern science technology in accordance with ecological principles and has promoted agricultural production.As a subsystem of agricultural industrial clusters,the industrialization of eco-agriculture is the specific applications of cluster concept in the industrialization of eco-agriculture development.Industrialization of eco-agriculture cluster will achieve eco-agriculture and interact with industrial cluster which forms eco-agriculture integration and composite industry and ultimately realize the new benign circulation eco-agriculture model.According to the ecological engineering basic principles of recycling of the overall coordination,industrialization of eco-agriculture is focusing on the main systems operating coordination between the various subsystems and its various factors,and will maintain a reasonable ecological and economic structure to ensure the recycling of natural resources.Industrialization of eco-agriculture in Yunnan has adjusted the agricultural production structure to keep the stability of the gross grain production and economic development and has taken effective measures to vigorously improve land use and land productivity.Various ways of improving soil fertility has vigorously promoted other water-saving agricultural technologies.Ecological protection of rice no-tillage,cultivation of crop cultivation of the integrated control crop disease pests grass and agricultural production have taken the sustainable development.

Biomarker Records of Phytoplankton Productivity and Community Structure Changes in the Central Yellow Sea Mud Area During the Mid-Late Holocene

The Yellow Sea （YS） environmental and ecological changes during the Holocene are driven by the interactions between the Yellow Sea Warm Current （YSWC）, the East Asian Winter Monsoon （EAWM） and the Kuroshio Current （KC）. We report marine biomarker records of brassicasterol, dinosterol and C37 alkenones in core ZY1 and core ZY2 from the South Yellow Sea （SYS） to reconstruct the spatial/temporal variations and possible mechanisms of phytoplankton primary productivity and community structure changes during the Mid-late Holocene. The contents of the corresponding biomarkers in the two cores are similar, and they also reveal broadly similar temporal trends. From 6kyr to 3kyr, the biomarker contents in the two cores were relatively low with small oscillations, followed by a distinct increase at about 3 kyr indicating productivity increases caused by a stronger EAWM. The alkenone/brassicasterol ratio （A/B） is used as a community structure proxy, which also showed higher values in both cores since 3 kyr, indicating increased haptophyte contribution to total productivity. It is proposed that the YS community structure has been mainly influenced by the YSWC, with stronger YSWC influences causing an increase in haptophyte contribution since 3 kyr. Some differences of the biomarker records between ZY2 and ZYI suggest spatial variations in response to YSWC and KC forcing. When the KC was intensified during the periods of 6-4.2kyr and 1.7-0kyr, the YSWC extended eastward, exerting more influence on core ZY1. On the other hand, when the KC weakened during 4.2-1.7 kyr, the YSWC extended westward, exerting more influence on the ZY2.

Assessment of Climate Change Variability Impacts on Wheat and Barley Production in Palestine

The study aimed at addressing climate variability impacts on wheat and barley production in Palestine. A combination of literature survey and multiple semi-structured interviews with officials from the Palestinian governmental agriculture related agencies and active non-governmental organizations （NGOs） used for gathering information on wheat and barley production in Palestine. The gathered data along with information and subsequent results prevailed that the West Bank since the 1970s has experienced a significant decrease in winter rainfall. Across 15 sites, growing season rainfall （September to May） decreased by an average of 11% and the sum of rainfall in September and October decreased by 45%. Despite the large decline in rainfall, yields based on the actual weather data did not fall. These results were due to the rainfall changes mainly occurring in September and October, a period when rainfall often is less than crop demand. The study arrived at conclusion based on the study results that climate change variabilities have differential impacts on the yield growth of wheat and barley. However, both rainfed dependent crops are adversely affected by the current climate trends. The yields of barley and wheat are decreasing due to increased temperature and decreased precipitation.

Research on the Supply-Side Reform Promotes Economic Growth Model in Xi’an

Xi’an is situated at west China, the industrial structure the restriction function which grows to the economy is not balanced more obvious, uni？ es the Xi’an actual situation, speeds up the supplies side constitutive property reform, the promotion industrial structure optimized promotion appears especially importantly. Firstly, this paper analyzes the present situation and development trend of supply-side reform at home and abroad. Based on the situation of Xi’an, the author analyzes ？ ve production-side reforms, such as “de-production,” “de-stocking,” “deleveraging”, “cost reduction” The author puts forward the main problems of Xi’an’s supply-side reform to promote economic growth. Finally, it puts forward the path choice of supply-side reform to promote economic growth in Xi’an. Adhere to reform and expand and demand side, supply side in xian accurate docking, supply and demand in xi ‘an supply side reform should constantly improve production quality, give full play to the market on the supply side of the reform main body role and foster the subject of the new.

An Empirical Research of Producer Services＇ Cluster Development To Regional Industrial Structure Optimization And Upgrading --Based on the Research of 16 central cities＇ Panel Data in Yangtze River Delta

Based on the 16 central cities＇ Panel Data in Yangtze River Delta, location quotient index is used in this paper to measure and analyze the current cluster situation of producer services in Yangtze River Delta, fixed effects model of Panel Data model is also used in this paper, and the industrial structure is taken as the dependent variable, while the core explanatory variables is the degree of producer services＇ cluster development, which is calculated by location quotient, moreover, three control variables introduced in this paper and they are technology advantage, education level and R＆D spending, and the mentioned above is to empirically study the impacts of producer services＇ cluster development to the regional industrial structure. As a result, producer services＇ cluster development has a significant positive role in promoting the regional industrial structure optimization and upgrading, though the extent is not yet a big push and is still to be further strengthened. In this paper, it has provided a strong evidence that under China＇ s new normal economy, producer services is badly needed to promote regional industrial structure, and finally it makes specific suggestions based on the current cluster situation of producer services in Yangtze River Delta.

Eco-transformation of steel industry in China: from the perspective of industrial ecology and circular economy

Recently the behavior of human has resulted in the deterioration of global ecological environment, and global warming and environmental pollution have caused the occurrence of extreme events frequently If we repeat the reckless environmental overkill, civilization will enter a victous circle of decline and lose even the strength and vitality to live in harmony with the environment. At Present, China is in a speciat period of rapid economic develop- ment. Some enterprises focus on short-term profits and don＇t formulate long-term strategies. For example, with the rapid expansion of the steel industry, some serious problems have emerged. Based on principles of industrial ecology and the concept of circular economy, to develop a new development model, taking a new road to industrialization is very necessary. Re-examining the current steel enterprises, this＇ paper proposes the new methods of the integration of material, energy integration, water system integration and sharing of information and facilities. Through ecologi- calization of technology, system, and industrial structure and product structure adjustment, the eco-transformation of the modern steel industry will be gradually achieved in China

Optimizing forestry industrial structure based on the framework of rationalization,advancement and ecologicalization

Under the target of the sustainable development,optimization of forestry industrial structure contains rationalization and advancement of forestry industrial structure in the traditional sense,as well as ecologicalization of forestry industrial structure.The connotation of optimization of forestry industrial structure is analyzed at first,and then the paper chooses the typical evaluation indexes from the three sides of rationalization,advancement and ecologicalization to evaluate the current situation of the regional forestry industrial structure.With the aid of the theory of fuzzy mathematics and information entropy,the paper establishes a fuzzy evaluation model which is based on information entropy for optimization of forestry industrial structure,and the evaluation model is applied in the study for the current situation of forestry industrial structure from 2000 to 2006 in Hubei province.The results show that the grade of forestry industrial structure is bad basically during the research,of which the overall level of forestry industrial structure of Hubei province is poor,the degree of utilizing forest resource is lower,and ecological environment in the forest region has been damaged to some extent.On this basis,the author presents the countermeasure to promote the optimization of forestry industrial structure.

The Roles of Plant Secondary Metabolites from Cowpea Floral Structures in Resistance to the Flower Bud Thrips

Floral structures of six cowpea （Vigna unguiculata） cultivars were analysed for secondary plant metabolites （polyphenols, terpenoids and flavonoids） to study their relationships with resistance to Megalurothrips sjostedti （Trybom）. Polyphenols varied significantly （P 〈 0.001） among the floral structures of the cultivars at the same growth stage. Significant negative correlations were obtained between polyphenols and damage indices （r = -0.57）, mean adult counts （r = -0.56） and mean larval counts （r = -0.64） of resistant cowpea cultivars especially in the late season, indicating that polyphenols play a significant role in cowpea resistance to M. sjostedti. High levels of polyphenols obtained from Sanzibanili and Sewe cultivars, coupled with highly significant correlations between the polyphenols and thrips population on resistant cultivars, and their damage indices, suggests that these polyphenols could be inhibitors or deterrents in this case. Terpenoid extracts （10 mg/mL） of IT90K-277-2, Sewe, Sanzibanili, TVu 1509 and KV - 404-8-1 racemes; KV ~ 404-8-I and TVu 1509 floral buds; IT90K-277-2, Sewe and Sanzibanili flowers caused significant （P 〈 0.001） larval mortalities, since mortality ranged between 56.7%-96.7%. Hence terpenoid extracts from floral structures of the cultivars are biologically active and confers antibiotic resistance to M. sjostedti larvae; this compound could be promising candidates for genetic transformation of cowpea cultivars.

Theoretical analysis of the use of modem human resource on employment predicament of college students

The problem is what plagued our society since the last decade as far as human resource allocation concerned. HR theory explains the phenomenon of Graduates Employment Dilemma and found a way to solve this problem, from theory and solution perspective. Maslow＇ s hierarchy of needs has some effect on students＇ employment. University Students should accelerate the transformation of the concept of employment, to accelerate the pace of structural adjustment, the implementation of the industrialization of education; Guide and encourage students to find a job by using two-factor theory; Make sure college students can stay in a dominant position in the intellectual property of human resource, in order to avoid structural unemployment, so as to make the most use of the students as valuable and effective human resources.

Reindustrialization or Postindustrial Development： Innovation Policy Debate in Ukraine

Usual recommendations concerning the principles of effective economic policy that were given by international experts, closely connected with the ＂Washington consensus＂ approach, for the transitive countries, especially to Ukraine, do not contain requirements of the active innovation technological policy, stressing importance the measures which provide efficiency of the existing production structure. This article discusses and criticizes such attitude as the strategic methodological platform. The theoretical backgrounds of the presented analysis lay in the Schumpeterian innovation theory of economic development and the Neo-Schumpeterian approaches concerning decisive value of structural and technological change for economic growth. It gives arguments for standpoint that a follow-up economic development can be successful if a country will be able to have expansion of new modem sectors and more innovative structure of production, as investments in the process of innovation must guarantee a permanent structural reform of the national economy on a new technological basis. One of the main means of realization should be the diversification of the organizational forms of the national economy, ensuring the cooperation of small, medium and large companies within the innovation ＂science-technology-production＂ cycle. Conclusion that in transitive countries and in Ukraine the contemporary innovation policy should provide effective mechanisms of investing into large-scale structural changes for the benefit of the sectors of the fifth and sixth technological paradigm.

Does the Digital Economy Optimize Tourism Industry Structure?Effects and Mechanisms Based on Quantile Regression and Threshold Modeling

A comprehensive evaluation index system is constructed,and the entropy weight TOPSIS method isused to measure the optimization level of the digital economy and tourism industry structure of 30 provinces inChina from 2012 to 2021.Moreover,models such as quantile regression and panel threshold are used to explorethe influence of the digital economy(DIG)on the optimization of the tourism industry structure(TIS)as well as itstransmission mechanism.The study reveals that DIG significantly promotes TIS,which remains valid after endogeneity and robustness tests;the impact of DIG on TIS exhibited a“U-shape”effect that first decreases and thenincreases,and its highest significance is at the 90%quartile level.Threshold model tests revealed a nonlinearthreshold effect with DIG and tourism total factor productivity(TTFP)as a single threshold and tourism technological progress index(TECH)as a double threshold,and the second threshold has the largest effect of 0.163.Mechanism analysis found that the mediating impact of the DIG on the TIS was mediated by increasing the TTFP,and the TECH accounted for the highest proportion of 12.15%.Regional analysis revealed that the role of DIG onthe TIS is Central>East>West>Northeast,and the empowering effect is more significant in the high digital economylevel area and the high tourism industry structure optimization area.

Changes in China’s Grain Production Pattern and the Effects of Urbanization and Dietary Structure

Grain production patterns are the basis of a nation’s food security.Since China’s reform and opening-up began in 1978,China’s urbanization process,driven by rapid social and economic development,has accelerated steadily.During this time,the dietary structure of urban and rural Chinese has also changed significantly.Accordingly,grain production patterns have undergone major changes.First,traditional grain production patterns in the north and the south have changed,and the food production center has shifted toward the north.In 1980,the grain yield of southern provinces accounted for 60%of China’s total,while that of northern provinces accounted for 40%.In 2015,the grain yield of southern provinces accounted for 56%of the total,while that of northern provinces accounted for 44%.Second,grain production by regions of the country is“shrinking in the east but expanding in the central regions,”meaning that grain production in eastern coastal provinces has decreased significantly,while that in the central region has expanded.The proportions of the nation’s total grain production from the eastern,central and western regions were 38%,36%and 26%,respectively,in 1980.These had changed to 27%,46%,and 27%,respectively,in 2015.Third,the spatial centralization of grain production has increased.The total grain yield of 13 major grain-producing provinces and regions in the country accounted for 69.27%of nation’s total in 1980,and it had reached 76.18%in 2015,showing that the impact of major grain-producing areas on national food security has increased.The influence of rapid urbanization on grain production areas shows remarkable regional differences.As the level of urbanization has increased,build-up land occupies a large number of high-quality farmland,especially in east coastal provinces and thus the grain planting area decreased obviously.The effect of dietary structure changes on grain production patterns was evident in two ways.On the one hand,as dietary diversity has increased,total grain consumption has decreased.The reduction in the proportion of planting area for grain crops to total crop planting area dropped from 82%in 1980 to 68%in 2015,making this change in total grain consumption evident.On the other hand,the ratio of grain for human consumption declined as the ratio of grain consumed by animals increased.The reduction in the proportion of rice and wheat grown and an increase in the proportion of feed grain production(mostly maize)from 20%in the 1980s to 36%in 2015 makes this change in grain production and consumption evident.In the future,with the establishment of national functional areas for grain production,the spatial pattern of grain production will return,while the demand for feed grains will continue to increase but with the space for expansion limited.

Microstructures and mechanical properties of SiBCNAl ceramics produced by mechanical alloying and subsequent hot pressing

Amorphous SiBCNAl powders were prepared via a mechanical alloying (MA) technique using crystalline silicon (Si), hexagonal boron nitride (h-BN), graphite (C), and aluminum (Al) as starting materials. SiBCNAl powders were consolidated by a hot pressing (HP) technique at 1800 °C under a pressure of 30 MPa in argon and nitrogen. The sintering atmosphere had a great influence on the microstructures and mechanical properties of the ceramics. The two ceramics had different phase compositions and fracture surface morphologies. For the ceramics sintered in argon, flexural strength, fracture toughness, elastic modulus and Vickers hardness were 421.90 MPa, 3.40 MPa·m1/2, 174.10 GPa, and 12.74 GPa, respectively. For the ceramics sintered in nitrogen, the mechanical properties increased, except for the Vickers hardness, and the values of the above properties were 526.80 MPa, 5.25 MPa·m1/2, 222.10 GPa, and 11.63 GPa, respectively.

Recent advances in heterogeneous catalytic conversion of glucose to 5-hydroxymethylfurfural via green routes

With concerns of diminishing fossil fuel reserves and environmental deterioration, great efforts have been made to explore novel approaches of efficiently utilizing bio-renewable feedstocks to produce chemicals and fuels. 5-Hydroxymethylfurfural(HMF),generated from dehydration of six-carbon ketose, is regarded as a primary and versatile renewable building block to realize the goal of production of these high valued products from renewable biomass resources transformation. In this review, we summarize the recent advances via green routes in the heterogeneous reaction system for the catalytic production of HMF from glucose conversion, and emphasize reaction pathways of these reaction approaches based on the fundamental mechanistic chemistry as well as highlight the challenges(such as separation and purification of products, reusing and regeneration of catalyst, recycling solvent) in this field.

Study on China＇s Economic Vulnerability to Energy Import Using Decomposition Method

Vulnerability means the degree to which that a system is susceptible to suffer damage. This paper focuses on the economic vulnerability to risk of energy import by employing ratio of net energy import to GDP as indicator, and decomposes the vulnerability change into effects of energy import, structure and intensity in order to find out key factors that influence economic security to energy import. Decomposition analysis on China indicates that effect of rising energy import takes more than 90 percent of total vulnerability change during the last 10 years, along with insignificant effect of structural change and intensity decline. International analysis on cross- section data of net energy importers also presents the positive relationship between external energy dependence and economic vulnerability. However, results of America show that long-term effect of energy intensity is much larger than China from 1954 to 2007, which is 70.8% of its total vulnerability change. Experience from developed countries confirms the necessary and validity of improving energy efficiency on depressing economic vulnerability to energy import, which provides lessons for the energy development of China.