按“用功量”计算投资 提高机修梯田质量标准

三川河流域开展重点治理以来,机械修筑梯田在我县得到了迅速的发展。截止1992年底,全县共新建机修梯田1266.8hm^2。在组织开展机修梯田中,我们对机修梯田投资管理进行了一些探索研究,不断改革完善,由以修筑面积投资到按土方量投资,1991年又改为按“用功量”计算投资,既考虑修平土方量,又考虑土方运移距离(用功量=梯田修平土方×平均运距),并根据梯田适宜宽度要求,规定单位“用功量”计费标准,较好地解决了机修梯田中的合理计费和田面过宽或过窄的问题。其主要实施办法是: (一)加强技术指导,严格质量标准。明确规定,新建机修梯田必须做到“四结合、三达到、两不小”,即新建机修梯田与土地开发利用相结合,与流域综合治理相结合,修地与埂坎利用相结合,与深耕结合;机修梯田集中连片面积必须达到6.67hm^2以上,一般地形田面宽度必须达到10m以上。

某型飞机起落架主减震系统吸收功量的计算与分析

飞机减震系统在各种状况下吸收功量的情况是设计、使用、维修等部门始终关注的重要问题之一。由于我国长期沿用前苏联强度规范,在某型飞机起落架使用与维修中存在着一些需要探讨和澄清的问题。本文通过对某型飞机主减震系统吸收功量的计算与分析认为,该机减震系统不存在长期以来一直认为的偏软问题,而是偏硬。在紧急情况下,认为飞机可以超载着陆,不必放油减重,减震系统吸收功量没有问题。

Scheme of Nitrogen Reasonable Fertilization in Mulberry Gardens of Sichuan Hilly Areas

Abstract In the research, five test groups were set, including urea at O, 120, 240, 360 and 480 kg/hm^2, respectively, and analysis was conducted on mulberry leaf yield and some characters of the quality in order to establish utility functions of ap-plied N in mulberry gardens with different production purposes and to provide schemes of rational N fertilization. The results indicated that yield of mulberry leaf and content and yield of active nutritional substances in the leaves would be reduced either by insufficient or excessive N quantity. In addition, 240 kg/hm^2 of applied N significantly improved active nutritional substances in leaf and 360 kg/hm^2 of applied N significantly improved yields of mulberry leaf and active nutritional sub-stances. Therefore, utility functions of applied N quantity with leaf yield, DNJ content and yield were established accordingly. The optimal N quantity in mulberry gardens for sericulture is recommended 360 kg/hm^2 and the optimal N quantities in mulberry gardens for increase of yield and content of DNJ are 299.56 and 294.72 kg/hm^2, respectively.

Design of similarity measure for discrete data and application to multi-dimension

Similarity measure design for discrete data group was proposed. Similarity measure design for continuous membership function was also carried out. Proposed similarity measures were designed based on fuzzy number and distance measure, and were proved. To calculate the degree of similarity of discrete data, relative degree between data and total distribution was obtained. Discrete data similarity measure was completed with combination of mentioned relative degrees. Power interconnected system with multi characteristics was considered to apply discrete similarity measure. Naturally, similarity measure was extended to multi-dimensional similarity measure case, and applied to bus clustering problem.

Resource Allocation for Two-Way Amplify and Forward OFDM Relay Networks

Physical-layer network coding(PNC) promises substantial theoretical gain to achieve the maximum system throughput in cooperative relay transmission. However, with the increasing global warming, how to reduce power consumption while satisfy system throughput requirement is becoming a vital issue. In this paper, we investigate energy-efficiency resource allocation(RA) based on PNC with amplify-and-forward(AF) protocol in orthogonal frequency division multiple(OFDM) bidirectional transmission. To minimize the overall transmit power consumption with required system throughput requirement, we consider joint subcarriers and power allocation and formulate the objective task into a constrained optimization problem where the best relay node is selected to minimize total transmit power. The closed form optimization power allocation solutions are acquired by analytical derivation. Based on derivation, we propose a novel optimal energy-efficient power allocation(OE-PA). Numerical results are given to evaluate the performance of the derived scheme as compared to other schemes and show that our scheme has signifi cant improvement to energy saving.

Impact of Mechanization on Lowland Rice Production in Nigeria

The study examined the impact of using power tiller as a means of mechanizing lowland rice production in Nigeria. The study was carried out in Bida area, Niger State, where the sawah rice production was disseminated by Watershed Initiative in Nigeria （WIN）. And in Ajase Ipo of Kwara State, some of the parameters assessed during the study included average speed of operation, average wheel slip/travel reduction, average draught of implement, and fuel consumption. The cost of operation and yield over five years of usage at Niger State and two years in Kwara State was determined and it was therefore concluded that the power tiller is the most appropriate field machinery for tillage operations such as puddling, leveling on lowland rice production in Nigeria.

SVM multiuser detection based on heuristic kernel

A support vector machine （SVM） based multiuser detection （MUD） scheme in code-division multi- ple-access （CDMA） system is proposed. In this scheme, the equivalent support vector （SV） is obtained through a kernel sparsity approximation algorithm, which avoids the conventional costly quadratic pro-gramming （QP） procedure in SVM. Besides, the coefficient of the SV is attained through the solution to a generalized eigenproblem. Simulation results show that the proposed scheme has almost the same bit er-ror rate （BER） as the standard SVM and is better than minimum mean square error （MMSE） scheme. Meanwhile, it has a low comoutation complexity.

An Energy Efficient Transmission Scheme for OFDM Systems in LTE

In orthogonal frequency division multiplexing(OFDM) systems,for given total transmit power,insertion of the noninformation bearing cyclic prefix(CP) will reduce the effective energy per information bit.Generally,the energy loss is proportional to the ratio of CP length to the symbol duration.If the CP is too long,the energy loss will be considerable high.In this paper,we propose an energy efficient transmission scheme for OFDM systems in Long Term Evolution(LTE) which is developed based on reduction of the CP energy.Simulation results show that the proposed method can save up to about10%of the total energy,while keeping almost the same bit-error-rate(BER) performance in some applications.

Application of Bidirectional Power Converters to Overcome Some Disadvantages of SVC Substation

When the authors research on the fact that some SVC （static var compensator） substations connected at some buses in power system, they realized that some main functions ensured to operate well. Those are： compensate reactive power following value U＊ according to the requirements of the Vietnamese power system dispath center, flit harmonic by passive filter... However, it still has some disadvantages of this substation that need to be overcome： use large number of main devices, generate harmonics by itself, cause a lot of active power losses. Thus, the authors have an idea to solve these problems by applying a bidirectional power converter with having difference circuit structure and PWM （pulse width modulation） controller with SVM （space vector modulation） pulse generated section, so compensative current which is created by inductance element can be reserved, adjust continuos and always has full sinusoidal form, not generating harmonic. The benefit of this new solution is to eliminate the three above fundamental disadvantages. This new model is built based on authors＇ research about BESS （battery energy storage system）. The research results have been verified by simulations in Matlab/Simulink software.

Effect of Removing the Lower Leaves on the Physiological Features and Aroma Constituents of Flue-Cured Tobacco

Yunyan 97 was selected as the raw material. The effects of removing different number （0, 2, 3 and 4） of lower leaves on root activity, chlorophyll content, physiological features and contents of neutral aroma constituents in the flue-cured tobacco were analyzed. The results showed that the removal of lower leaves could significantly increase the root activity, chlorophyll content, net photosynthetic rate （Pn） and transpiration rate （Tr）, and delay the photosynthetic functional decline. Such effects were the greatest in lower leaves, followed by middle leaves and upper leaves. Moreover, the degree of the effects increased with higher number of leaves removed. After She lower leaves were removed, the water use efficiency （WUE） of leaves in the first 10 d became higher with more leaves removed. In the later periods （24 d, 38 d）, WUE decreased with more leaves removed. For the middle and upper leaves, the removal of three leaves （T2） and two leaves （T1） resulted in the highest contents of aroma constituents, respectively. For the tobaccos cultured in soil with moderate fertility under the experimental conditions, the appropriate number of lower leaves removed should be 2-3.

Clinical study of optimizing acupoint combining in treatment of bronchial asthma with acupoint application

Objective:To observe the therapeutic efficacy of acupoint application at different groups of acupoints in treating bronchial asthma in remission stage.Methods:A total of 120 patients with bronchial asthma in remission stage were recruited and divided by the random number table method into acupoint application group 1,acupoint application group 2 and acupoint application group 3,with 40 cases in each group.In all the three groups,Tiantu(CV 22),Dazhui(GV 14)and Feishu(BL 13)were selected,with Dingchuan(EX-B 1)added in acupoint application group 1,Shenshu(BL 23)added in acupoint application group 2,and Gaohuang(BL 43)added in acupoint application group 3.Before intervention,one month and 3 months after intervention,clinical symptoms,peak expiratory flow(PEF)and forced expiratory volume in 1 second percentage of predicted value(FEV1%)of the three groups were observed,and their clinical efficacies were evaluated.Results:Comparing the therapeutic efficacy regarding traditional Chinese medicine symptoms and signs,after 1-month treatment,the total effective rate was 87.5%in acupoint application group 1,versus 62.5%in acupoint application group 2 and 55.0%in acupoint application group 3,and the between-group differences were statistically significant.After 3-month treatment,the total effective rate was 95.0%in acupoint application group 1,versus 70.0%in acupoint application group 2 and 65.0%in acupoint application group 3,and the between-group differences were statistically significant.After intervention,the three groups all showed significant improvements in pulmonary function with statistical significance;among the three groups,the improvement in acupoint application group 1 was more significant than that in the other two groups.Conclusion:Tiantu(CV 22),Dazhui(GV 14)and Feishu(BL 13)as basic prescription plus Dingchuan(EX-B 1)can improve symptoms of bronchial asthma in remission stage,and it works better in improving pulmonary function than the basic prescription plus Shenshu(BL 23)or Gaohuang(BL 43).

Influence of acupuncture on pulmonary function of patients with asthma： a review

Asthma is a common disease with recurrent onset which severely affects patients＇ quality of life. Acupuncture can improve pulmonary functions in asthma patients and thus treat this disorder. To summarize the status of acupuncture treatment for asthma, we have collected clinical literatures published in the recent 20 years and analyzed the influence of acupuncture on pulmonary functions in asthma patients from the aspects of frequently used points, needling techniques, manipulation and mechanisms to provide references for treating asthma with acupuncture.