Prenatal diagnosis of congenital cystic adenomatoid malformation of the lung by fetal lung biopsy

A case of type III congenital cystic adenomatoid malformation of the lung was successfully diagnosed prenatally by fetal lung biopsy. We performed this procedure at 22 weeks of gestation, using a biopsy gun system under ultrasound guidance. The pregnancy was undisturbed by the procedure but as the condition was incompatible with life, an abortion was performed. The diagnosis was confirmed at post-mortem examination. Fetal lung biopsy appears to be a useful method for prenatal diagnosis of fetal lung disorders.     

三峡工程与长江中游沿江产业带建设

讨论了长江中游沿江产业带发展条件、限制因素和未来发展，指出三峡工程的建设将对长江中游产业的布局和经济发展带来深刻的变化；防洪作用促进中游两岸大型工业项目的兴建，调整现有沿江城镇的布局，使之结构趋于合理化；电力供应经解能源的紧张状态，改善航运条件，发挥长江黄金水道的综合效益。当然，由于坝下河道冲刷，对现有的码头带来一定的影响，由于冬季水位抬升引起两岸低湖田地下水位上升，加剧两岸土壤潜育化和沼泽化。     

2002年3-6月国内安全事故数据

统计了2002年3-6月国内发生的各种安全事故871起,包括矿业事故、交通事故、爆炸事故、火灾、毒物泄露和中毒及其他事故.统计表明,在这些事故中,矿业事故最多,占61. 8%,平均每天4.5起事故,其次是交通事故(16.3%)、爆炸事故(6.7%)、火灾(6.0%)、其他事故(5.6%)、毒物泄露和中毒(3.7%).871起事故共死亡2 197人,伤3 321人,死亡人数的百分比分别为矿业事故53.7%、交通事故28.0%、火灾6.1%、爆炸事故5.9%、其他事故5.1%、泄露中毒1.2%;受伤人数的百分比分别为泄露中毒37.4%、交通事故26.9%、爆炸事故14.2%、矿业事故11.8%、其他事故5.3%、火灾4.4%.     

COMPARISON OF STOCHASTIC AND DETERMINISTIC DYNAMIC PROGRAMMING FOR RESERVOIR OPERATING RULE GENERATION1

ABSTRACT: Two dynamic programming models — one deterministic and one stochastic — that may be used to generate reservoir operating rules are compared. The deterministic model (DPR) consists of an algorithm that cycles through three components: a dynamic program, a regression analysis, and a simulation. In this model, the correlation between the general operating rules, defined by the regression analysis and evaluated in the simulation, and the optimal deterministic operation defined by the dynamic program is increased through an iterative process. The stochastic dynamic program (SDP) describes streamflows with a discrete lag-one Markov process. To test the usefulness of both models in generating reservoir operating rules, real-time reservoir operation simulation models are constructed for three hydrologically different sites. The rules generated by DPR and SDP are then applied in the operation simulation model and their performance is evaluated. For the test cases, the DPR generated rules are more effective in the operation of medium to very large reservoirs and the SDP generated rules are more effective for the operation of small reservoirs.     

EFFECTS OF ADJACENT AGRICULTURAL ACTIVITIES AND WATERSHED CHARACTERISTICS ON STREAM MACROINVERTEBRATE COMMUNITIES1

Benthic macroinvertebrate communities in streams adjacent to cornfields, streams where cows had unrestricted access, and reference locations without agriculture were compared to examine the effects of local land use and land use/land cover in the watershed. At each local site, macroinvertebrates and a variety of habitat parameters were measured upstream, adjacent, downstream, and farther downstream of the local land use. A geographic information system (GIS) was used to calculate drainage basin area, land use/land cover percentages in each basin, and the distance from sample sites to the stream source. Three‐way analysis of covariance (ANCOVA) tests with date, site type, and sampling location as main effects were used to explore differences in macroinvertebrate metrics using median substrate size, percent hay/pasture area, and stream depth as covariates. The covariates significantly improved model fit and showed that multiple contributing factors influence community composition. Local impacts were greatest at sites where cows had access, probably because of sedimentation and embeddedness in the substrate. Differences between the upstream and the adjacent and downstream locations were not as great as expected, perhaps because upstream recolonization was reduced by agricultural impacts or because of differences in the intensity or proximity of agriculture to riparian areas in the watershed. The results underscore the importance of both local and watershed factors in controlling stream community composition.     

有意违章行为动因分析与控制对策探讨

对有意违章行为的含义进行了界定 ,并对有意违章行为产生的动因进行了详细分析 ,提出了有意违章行为的动因主要包含违章行为与遵章行为满足生理心理需要作用的差值ΔXW、违章行为会受到法规惩处的作用FW、违章行为可导致人身伤害的主观感觉的作用RW3个方面。同时对 3个方面的动因按弗鲁姆的激励理论进行了转化 ,给出了各自的含义说明。笔者按动因分析的结果 ,给出了控制有意违章行为的步骤和措施     

水雾荷电净化空气飘尘与细菌的研究

研究一种高压静电水雾场产生的荷电净化空气中飘尘与细菌的方法。实验结果表明:在静电电压15kV、通风量540m~3/h的工况下,实验装置的一次性除尘效率高于80%、除菌效率达到88%以上;实验装置可以连续运行,能耗低、出风无二次污染。     

黄河流域水资源价值的计算与分析

利用经济杠杆的调节作用促使水资源的高效利用，是缓和水资源供需矛盾的有效措施之一。本文以水资源价值理论为基础，从黄河全流域水资源优化配置角度出发，以利用水资源获得最大经济效益为目标，测算了黄河水资源的理论价值，为制定黄河水资源费的征收标准提供科学的理论依据。     

三峡库区几种林下苔藓的保水功能

通过对三峡库区三种森林类型(松栎混交林、栓皮栎纯林、马尾松纯林)林下苔藓储量调查分析及其持水特性试验，得到不同森林类型林下苔藓储量、最大持水量、吸水速率等水文特征参数。结果表明，马尾松纯林林下苔藓储量最大(12．93t／hm^2)，松栎混交林和栓皮栎纯林林下苔藓储量相同(9．47t／hm^2)。松栎混交林林下苔藓最大持水量为5．36mm，栓皮栎纯林为5．73mm，马尾松纯林为6．26mm。研究结果还表明，三峡库区林下苔藓持水量随时间变化过程与森林类型无关。在只有苔藓覆盖情况下，不同森林类型林内不产生水分下渗和地表径流时的最大降雨量和最大降雨雨强分别为：松栎混交林林地5．36mm，5．820mm／h；马尾松纯林林地6．26mm，7．420mm／h；栓皮栎纯林林地5．73mm，6．060mm／h。     

水资源条件约束下西北农村地区生态经济发展对策

西北地区生态脆弱，社会经济发展相对落后。农业在全区经济中占有重要的地位，所以农村地区可持续发展对于实现西北地区可持续发展具有重要意义。通过分析西北地区水资源现状及特点和本区农村社会、经济发展现状，认为西北地区水资源严重缺乏，干旱化趋势将长期存在；农业结构不合理，乡镇工业污染严重、城镇化进程缓慢是制约本区农村地区可持续发展的主要因素。在此基础上，提出了在水资源严重缺乏条件下西北农村地区实现生态经济可持续发展的具体对策：积极调整农业结构，大力发展节水农业和推进农业产业化；加强小城镇社区生态环境基础设施建设，实施城镇化发展战略和乡镇企业可持续发展；建设生态型的小城镇，建立农村地区新型生态能源结构，加强小流域综合治理是改善农村生态环境和实现农村地区生态经济可持续发展的有效途径。